human
***task***
the task is to summarize an input biomedical literature in six sentences

***input***
the input is a biomedical literature

***output***
the output is the summary of an input biomedical literature in six sentences

***documentation***

***examples***

input: glucosinolates ( gss ) are sulfur - and nitrogen - containing secondary metabolites found in cruciferous plants . a central carbon is connected to a thioglucose , to a sulfate via a nitrogen atom , and to a side chain ( r ) ( figure 1 ) . the side chain determines whether the glucosinolate is defined as aliphatic ( straight - or branched - chain alkyl , alkenyl , and oxo - , hydroxyl forms ) , aromatic , or indole . many glucosinolates also contain one or two more sulfur atoms in the side chain to form another sulfur - containing unit , such as methyl - thio - ( s ) , methyl - sulfinyl - ( so ) , methyl - or benzyl - sulfonyl - ( so2 ) , mercapto - ( hs ) , glucosyl - disulfanyl ( s s ) , and cysteinyl - thio - [ hooc ch ( nh2 ) ch2s ] . the glucosinolates and their enzyme - hydrolyzed products ( thiocyanates , isothiocyanates , and nitriles ) have shown important human health benefits , especially with respect to cancer prevention . thus , many studies have been carried out on the isolation and structural elucidation of glucosinolates and their hydrolyzed products with respect to their biological activities and distribution in the plant kingdom . an electronic database of the structures , formulas , and accurate masses of 200 knownn and a further 180 predictedn gss has been established . desulfoglucosinolates , glucosinolate - related nitriles , and isothiocyanates ( figure 1 ) formed by the loss of so3 or other functional groups through the action of sulfatase and myrosinase have been isolated from plants . glucosinolates , widely distributed in many plants of the cruciferae family , have also been found in plants from other familiesn although at significantly reduced levels . the glucosinolate profiles of many foods derived from cruciferous plants have been studied qualitatively and quantitatively to establish their dietary intake and relationship to health outcomes in biological , epidemiological , and clinical studies . the fragmentation patterns of glucosinolates have been studied using multistage mass spectrometry ( ms ) , primarily in the negative ionization mode . high - performance liquid chromatography and ms with electrospray ionization ( hplc - esi / ms ) has been widely used to identify the intact glucosinolate components of plants . most glucosinolates have an ultraviolet ( uv ) absorbance maximum wavelength ( max ) between 219 and 228 nm . they can be quantified directly from the uv absorbance at 225 nm when they are well separated . however , in most cases , quantification has been based on absorbance of the desulfoglucosinolates following sulfatase hydrolysis . quantification is based on calibration with a single compound and predetermined relative response factors ( rrfs ) . rorippa indica ( linn . ) hiern . is a perennial plant of the cruciferae family that is widely distributed throughout the world . its fresh spear - shaped leaves and tender seedlings are used as a healthy food , and the whole plant is used as an animal feed in china . the dried whole plant material is used as a chinese traditional herb with purported diuretic , anti - inflammatory , antifever , and anticough properties and to help with blood circulation and rheumatoid arthritis . ronifore ( 9 - methylsulfonylnonyl nitrile ) and its related amide ( rorifamide ) were isolated as the anticough components of rorippa montana . fifteen isothiocyanates and desulfoglucosinolates were isolated from the roots of rorippa plants , and several flavonol glycosides , phenolic acids , and derivatives , and other organic compounds have been reported . this paper presents a comprehensive study of the glucosinolate and polyphenolic components of r. indica . phenolic compounds are widely distributed in plant - derived foods , whereas the glucosinolates are among the biologically active components of cruciferous plants . both types of compounds are known to have many potential benefits to human health . as a part of our project to systematically identify and quantify these compounds , both standardized hplc - pda - esi / ms and uhplc - pda - esi / hrms methods were developed to identify and quantify the phenolics using their molar relative response factors ( mrrfs ) for uv absorbance . in this study , the uhplc - pda - esi / hrms method was used to analyze the phenolic and glucosinolate profiles of r. indica and led to the identification of 33 glucosinolates , including 24 for the first time , and more than 40 flavonol glycosides . this study found that r. indica was a rich plant source for glucosinolates on the basis of its structural variety and total concentration of glucosinolates . glucocheirolin potassium salt [ 3 - ( methylsulfonyl ) propyl glucosinolate - k , mw = 439 + 39 da ] , rutin 3h2o ( mw = 610 + 54 da ) , quercetin , kaempferol , and isorhamnetin were obtained from chromadex , inc . formic acid , hydrochloric acid ( 37 % ) , hplc grade methanol , and acetonitrile were purchased from vwr international , inc . hplc grade water was prepared from distilled water using a milli - q system ( millipore lab . , the stock standard solution consisted of dried rutin ( 1.27 mg ) and glucocheriolin - k ( 1.43 mg ) in 10.0 ml of methanol / water ( 60:40 , v / v ) . the stock solution was prepared at three concentrations ( 1 , 1/2 , and 1/4 ) to provide a range of signals suitable for the quantification of the main glucosinolates and phenolics of this sample . each of the solutions ( 2 l ) was injected in triplicate , and the relative standard deviation ( rsd ) for each peak was 5.0 % . the three standards provided a linear calibration curve for estimating the concentration of the main compounds of the extract . the dried r. indica plant materials were purchased by the longjin pharmaceutical co. , ltd . , from local herb stores in chongqing , china . the plant materials were ground into powders and passed through 60 mesh sieves prior to extraction . the ground powder ( 200 mg ) was extracted with 5.0 ml of methanol / water ( 60:40 , v / v ) using an fs30 ultrasonic sonicator ( fisher scientific , pittsburgh , pa , usa ) for 60 min at room temperature . the slurry mixture was centrifuged at 2500 rpm for 15 min ( iec clinical centrifuge , damon / iec division , needham , ma , usa ) , and the supernatant ( 4.000 ml ) was filtered through a 17 mm ( 0.45 m ) pvdf syringe filter ( vwr scientific , seattle , wa , usa ) . two microliters of the extract was injected in triplicate into the hplc for analysis . the filtered extracts ( 0.50 ml ) were mixed with concentrated hcl ( 37 % , 0.1 ml ) and heated in a capped tube at 85 c for 2 h. then , 0.4 ml of methanol was added to the mixture , and the solution was sonicated for 10 min . the solution was refiltered prior to hplc injection . the uhplc - dad - esi / hrms - ms system used consisted of an ltq orbitrap xl mass spectrometer with an accela 1250 binary pump , a pal htc accela tmo autosampler , a diode array detector ( dad ) ( thermoscientific , san jose , ca , usa ) , and a g1316a column compartment ( agilent , palo alto , ca , usa ) . the separation was carried out on an uhplc column ( 200 mm 2.1 mm i.d . , hypersil gold aq rp - c18 , 1.9 m ) ( thermoscientific ) with an hplc / uhplc precolumn filter ( ultrashield analytical scientific instruments , richmond , ca , usa ) at a flow rate of 0.3 ml / min . the mobile phase consisted of a combination of a ( 0.1 % formic acid in water , v / v ) and b ( 0.1 % formic acid in acetonitrile , v / v ) . the linear gradient was from 4 to 20 % b ( v / v ) at 40 min , to 35 % b at 60 min , to 100 % b at 61 min , and held at 100 % b to 65 min . the pda recorded spectra from 200 to 700 nm , and peak intensities at 225 and 354 nm were used for the quantification of the main glucosinolates and flavonoids , respectively . the ms was operated in the negative ionization mode using the following conditions : sheath gas at 70 ( arbitrary units ) , auxiliary and sweep gas at 15 ( arbitrary units ) , spray voltage at 4.8 kv , capillary temperature at 300 c , capillary voltage at 15 v , and tube lens at 70 v. the scan range was from m / z 100 to 1500 with a resolution of 15000 , ftms agc target at 2e5 , ft - ms / ms agc target at 1e5 , isolation width of m / z 1.5 , and maximum ion injection time of 500 ms . high - accuracy ion mass values were determined for all primary ions ( i.e. , the deprotonated molecular ions ) . the most intense ion was selected for the data - dependent scan to provide msan additional separate data - dependent scan with high - energy collisional dissociation ( hcd ) at 75 % was also carried out for high - accuracy measurement of some of the ms ions with the resolution of 7500 . figure 1 lists the identification codes , putative identification , retention times ( recorded on the tic chromatogram ) , deprotonated molecule high - resolution mass , formula , error between the experimental and calculated values , and main and important fragments from ms , ms , and ms fragmentations for each peak . the tic and pda ( at 225 nm ) chromatograms are shown in figure 2 . thirty - three of the compounds were putatively identified , and nine compounds could not be identified . chromatograms ( a , tic ; b , pda at 354 nm ; and c , pda at 225 nm ) of rorippa indica ( only the main glucosinolates and flavonoids are labeled ) . the main glucosinolates of this plant consisted of methylsulfonyl straight alkyl chain compounds ( ch3s ( o ) 2 ( ch2 ) n ) ( figure 1 ) . the most concentrated glucosinolate ( gs - 1 ) had tic and uv peaks with retention times ( tr ) at 18.88 and 18.83 min ( figure 2 ) , uv max at 225 nm , and a [ m h ] of 522.1134 da for c17h32o11ns3 ( calcd 522.1129 da , with the error of 1.72 ppm ) for 9 - ( methylsulfonyl ) nonylglucosinolate ( gs - 1 ) . the assignment of this compound as 9 - ( methylsulfonyl ) nonyl glucosinolate ( gs - 1 ) was based on the fact that the hydrolyzed products , desulfoglucosinolate , isothiocynate , and nitrile ( rofifone ) , had been previously isolated from this plant . furthermore , the authors in china isolated the related nitrile from the same plant material and confirmed the structure by nuclear magnetic resonance . gs - 1 had major ms fragments at m / z 291 ( 100 % , [ c6h11o9s2 ] ) , 275 ( 28 % , [ c6h11o8s2 ] ) , and 259 ( 73 % , [ c6h11o9s ] ) , ions a , c , and b in figures 3 and 4a . ms had a major fragment at m / z 97 ( 100 % , [ hso4 ] ) , ion d in figure 4b . the compositions for ions a , c , and b were confirmed by the experimentally determined masses of 290.9842 ( error 2.7 ppm ) , 274.9890 ( error 3.9 ppm ) , and 259.0117 ( error 4.8 ppm , figure 3 ) , respectively , from the additional data - dependent scan with activation in hcd . ms ( a ) and ms ( b ) spectra of 9 - ( methylsulfonyl ) nonylglucosinolate ( gs - 1 ) . figure 3 illustrates the fragmentation pathway leading to the four product ions through the loss of rcn and rncs groups . some glucosinolates , such as 4 - methoxyglucobrassin , glucobrassicin , 3 - hydroxyglucoisatisin , glucoisatinsin , and sinalbin , were reported to present an ms fragment ( b , 291 da ) with a relative intensity of 661 % . these diagnostic ions fully supported the identification of this compound as a glucosinolate . two minor peaks ( gs - 2 and gs - 3 , tr = 10.39 and 21.00 min ) had the same high - resolution deprotonated molecular ion masses as gs - 1 and similar ms and ms fragments . three glucosinolates , gs4 , gs - 5 , and gs - 6 , are analogues of gs - 1 and identified as 7 - methylsulfonylheptyl - ( tr = 6.67 min , [ m h ] = 494.0823 da ) , 8 - ( methylsulfonyl ) octyl - ( tr = 12.24 min , [ m h ] = 508.0978 da ) , and 10 - methylsulfonyldecylglucosinolates ( tr = 27.25 min , [ m h ] = 536.1301 da ) , respectively . their retention times correlate with increasing mass , suggesting that the r groups are straight chains and the increasing number results in increased retention times as the polarity decreases . four other glucosinolates ( gs - 7gs - 10 ) containing methylsulfinyl ( ch3so ( ch2 ) n ) were detected . they were putatively identified as 8 - ( methylsulfinyl ) octyl - ( tr = 11.39 time , [ m h ] = 492.1031 da ) , 9 - ( methylsulfinyl ) nonyl - ( tr = 17.66 and 18.71 min , [ m h ] close to 506.1189 da , two isomers , gs - 8 and gs - 9 ) , and 10 - ( methylsulfinyl ) decyl glucosinolates ( tr = 25.28 min , [ m h ] = 520.1347 da ) , respectively . all of them showed the same diagnostic fragments , confirming them as glucosinolates , and their elution time increased with increasing numbers of ch2 units . gs - 11 ( tr = 11.85 min ) contained an indole function and was putatively identified as 4 - methoxyindol -3-ylmethylglucosinolate on the basis of its high - resolution mass value of 477.0635 da . eight of the above glucosinolates ( gs - 1 , gs - 4 , gs - 5 , gs - 6 , gs - 7 , gs - 8 , gs - 10 , and gs - 11 ) were previously reported , and gs - 7 , gs - 8 , and gs - 11 were found in rorippa plants . furthermore , the desulfoglucosinolates and / or isothiocyanates of the above glucosinolates ( except gs - 4 ) were previously isolated from the roots of this plant . the remaining 21 peaks were putatively identified as glucosinolates and will be discussed in detail . gs - 12 ( tr = 33.33 min , [ m h ] = 488.1622 da ) had a deprotonated molecular ion of c18h34o10ns2 ( error 0.49 ppm ) and showed the classic glucosinolate ms fragments at m / z 259 ( 100 % ) , 275 ( 44 % ) , and 291 ( 33 % ) . after subtraction of ion b ( m / z 259 , c6h11o9s ) or ion a ( m / z 291 , c6h11o9s2 ) from the deprotonated molecule ( figure 3 ) , the masses for r - ncs or r - cn were obtained . each showed a formula for r = ho ( ch2 ) 11 , that is , c11h23o , the same as that obtained directly from r = c18h34o10ns2 c7h11o9ns2 ( figure 3 ) . in this way , the structures for the glucosinolates can be figured out easily . this glucosinolate was not among the predicted 180 new glucosinolates in the electronic database of clarke because the number of ch2 groups ( n ) is 11 and 10 was the largest considered in the prediction set . the first group ( gs - 13gs - 16 ) contained four isomers ( tr = 5.41 , 6.47 , 7.74 , and 10.55 min , [ m h ] = 538.1081 da ) . they showed product ions of m / z 291 , 275 , 259 , and 97 and were identified as 9 - ( methylsulfonyl ) hydroxynonylglucosinolates . they had one more hydroxyl group than that of related 9 - ( methylsulfonyl ) nonylglucosinolate ( gs - 1 ) and its isomers ( gs - 2 and gs - 3 ) . the second group ( gs - 17 and gs - 18 ) consisted of two isomers ( tr = 10.97 and 13.34 min , [ m h ] = 552.1236 da ) . they showed the same diagnostic gs fragments and were putatively identified as 10 - methylsulfonylhydroxydecylglucosinolates and to be the hydroxyl derivatives of 10 - methylsulfonyldecylglucosinolate ( gs - 6 ) and its isomers . the r groups for the isomers can be determined in the same manner as described previously for gs - 12 . among them , gs - 13 and gs - 17 ( with suggested straight chains for the r group ) were among the predicted 180 new glucosinolates in the electronic database of clarke with code numbers 245 and 246 , respectively . four minor peaks ( gs - 19gs - 22 ) had different retention times ( tr = 17.68 , 16.08 , 16.84 , and 20.92 min ) but a similar mass ( [ m h ] = 684.1658684.1663 da ) corresponding to a formula of c23h42o16ns3 ( errors less than 2.0 ppm ) . gs - 19 had major ms fragments at m / z 522 ( 77 % , [ m h ] 162 , loss of glucosyl ) , 453 ( 100 % , 291 + 162 , ion ag , the g means the fragment contained a glucosyl , c6h10o5 , figure 3 ) , 437 ( 23 % , 275 + 162 , ion cg ) , 421 ( 94 % , 259 + 162 , ion bg , figure 3 ) , and 259 ( 14 % , ion b ) ( figures 4 and 5 and table 1 ) . the detection of ions a , b , and c plus a glucosyl is reasonable , and [ m h ] = 421.0670 ( error of 3.0 ppm ) for ion b confirmed its composition as c12h21o14s . thus , the data suggest that these compounds are the glucosides of 9 - ( methylsulfonyl ) nonyl glucosinolate ( the glucoside of gs - 1 ) . ms spectra of the glucosides ( a , gs - 19 ; and b , gs - 22 ) of 9 - ( methylsulfonyl ) nonylglucosinolate . gs - 20 , gs - 21 , and gs - 22 also showed the typical glucosinolate glucoside fragments at m / z 453 , 437 , and 421 ( figures 3 and 5 and table 1 ) . on the basis of both of the high - resolution mass values and the presence of the gluocosinolate glucoside characteristic fragments , they were identified as the glucosides of 9 - ( methylsulfonyl ) nonylglucosinolates ( the glucosides of gs - 1gs - 3 ) . because there was no hydroxyl function on the r group , this glucosyl was most likely connected to the thioglucoside and most likely at the 6 - position as that for a monoacylated glucosinolate . similarly , four other compounds ( gs - 23gs - 26 ) were recognized as the glucosides of glucosinolates on the basis of the fact that they presented the same diagnostic fragments at m / z 453 , 437 , and 421 . gs - 23 ( tr = 22.55 min , [ m h ] = 654.1554 da , c22h40o15ns3 , error less than 2 ppm ) was putatively identified as a glucoside of 9 - ( methylsulfinyl ) nonylglucosinolate ( the glucoside of gs - 8 ) . gs - 24gs - 26 ( tr = 23.37 , 24.29 , and 28.18 min , [ m h ] = 698.1915 da , c24h44o16ns3 , error 1.8 ppm ) were putatively identified as the glucosides of 10 - methylsulfonyldecylglucosinolates ( the glucosides of gs - 6 and its isomers ) . one pair of isomers , gs - 27 and gs - 28 ( tr = 16.43 and 18.58 min , [ m h ] = 668.1712 da , c23h42o15ns3 , error 1.5 ppm ) were putatively identified as glucosides of 9 - ( methylsulfinyl ) nonylglucosinolate ( the glucosides of gs - 5 or its isomer ) . gs - 29 ( tr = 22.79 min , [ m h ] = 682.1868 da , c23h44o15ns3 , error 1.5 ppm ) was thought to be the glucoside of 10 - ( methylsulfinyl ) decylglucosinolate ( the glucosides of gs - 10 or its isomer ) . the base ms fragments ( m / z 604 for gs - 27 and gs - 28 and m / z 618 for gs - 29 ) showed a loss of 64 da ( loss of ch3 so h ) , indicating that these glucosinolates contained a methylsulfinyl ( ch3so ) group in the side chain . both gs - 27and gs - 28 had ms spectra containing the diagnostic gucosinolate glucoside fragments at m / z 453 ( 25 and 28 % , respectively ) , 437 ( 100 and 56 % ) , and 421 ( both 100 % ) to confirm their identification . four other compounds ( gs - 30gs - 33 ) also appeared to be analogues of the glucosides of glucosinolates on the basis of their masses and formulas . gs - 30 ( tr = 28.07 min , [ m h ] = 622.1290 da , c21h36o14ns3 , error 0.5 ppm ) might be the glucoside of methylthioethenylpentenyl ( ch3s c = c ( ch2 ) 5 ) or an isomer of methylthioheptenyl . the aglycone with a methylthioethenylpentenyl group is among the 180 predicted new glucosinolates ( no . gs - 31 and gs - 32 ( tr = 22.16 and 21.15 min ) have the same nominal masses , but have different high - accuracy masses . gs - 31 ( [ m h ] = 638.1245 da , c21h36o15ns3 , error 1.2 ppm ) was putatively identified as the glucoside of 7 - methylthio -3-oxoheptylglucosinolate or 7 - methylsulfinylheptenylglucosinolate . gs - 32 ( [ m h ] = 638.1608 da , c22h40o14ns3 , error 1.3 ppm ) might be the glucoside of 8 - methylthiooctylglucosinolate . gs - 33 ( tr = 16.51 min , [ m h ] = 640.1403 da , c21h38o15ns3 , error 0.9 ppm ) might be the glucoside of 7 - ( methylsulfinyl ) heptyl glucosinolate . instead of showing the typical glucosinolate glucoside fragment described above , three of them ( gs - 31gs - 33 ) had base ms or ms fragments at m / z 391 like gs - 23 . consequently , the lack of definitive ms fragments made it impossible to develop a molecular formula for this ion . the putative formula offered in table 1 was based primarily on the close match of the experimentally measured high - resolution masses with calculated values . the aglycones of these three glucosides were known glucosinolates , but not detected in this plant . the 14 glucosinolate glucosides mentioned above have not been previously reported in any other plants . they represent a new family of glucosinolates with a glucosyl connected to the thioglucosyl group . all of the observed ms fragments could be related to the structural elements of the glucosinolate skeleton . for examples , ions a , b , c , and d and thioglucosyl ( m / z 195 ) , as well as fragments obtained from further losses of oxygen , sulfur , or parts of the glucosyl were observed . however , not enough fragments were obtained to determine the structure of the r groups . of course , the r groups for the glucosinolates were not very large ( containing fewer than 12 carbon atoms for the aliphatic gss ) , but they can be arranged in several different ways to form the isomers . for example , the aliphatic structure can be linear or branched , the oxygen atom can be found in the oxo ( keto ) or hydroxy form , and the alkenyl double bond can be located at different positions . as a result , nuclear magnetic resonance ( nmr ) analysis is still the most accurate way to identify gss structurally . the major glucosinolates of r. montana had similar side chains and were well separated , allowing for the measurement of their peak areas at 225 nm ( figure 3 ) . their concentrations were calculated relative to glucocheirolin using mrrf values of 1.0 , on the basis of previous reports that the side chains were similar and did not alter the absorption coefficient of the molecules . the relative peak area ratios for gs - 1 , gs - 8 , gs - 6 , gs - 5 , and gs - 10 were 100.0 , 15.5 , 9.6 , 5.1 , and 4.6 , respectively . the corresponding concentrations for gs - 1 , gs - 8 , gs - 6 , gs - 5 , and gs - 10 were 0.51 , 0.079 , 0.049 , 0.026 , and 0.024 % on a dry weight basis , and their total contents was 0.69 % or 690 mg / 100 g of dried plant materials . table 2 presents the retention times ( recorded on the tic chromatograms ) , hr masses , and formulas for deprotonated molecules [ m h ] , diagnostic ms , ms , ms , and ms product ions , and putative identities of 44 flavonol glycoside , 18 phenolic , and other common compounds . the typical tic and pda ( at 354 nm ) chromatograms are shown in figure 2 . the strategy for identifying phenolic compounds in food samples has been described previously . in this study , only the glycosides of flavonols were observed , and most are reported for the first time . is , isorhamnetin ; km , kaempferol ; qn , quercetin . identified using in - house database . two tetrahydroxyflavone 3 - o - rhamnosylhexosides ( tr = 28.22 and 26.52 min , [ m h ] = 593.1491 ) provided the largest peaks ( f - 1 and f - 2 in figure 2a ) in chromatograms of the r. indica extract . they had uv band i maximum absorbances at 265 and 346 nm and base ms and ms fragments of m / z 447 ( by loss of 146 ) and m / z 284 ( the radical anion species of kaempferol from the loss of 162 + 1 rather than the ion at m / z 285 ) , suggesting that they might be kaempferol glycosides containing a rhamnosylhexose . this radical anion had base ms and ms fragments of m / z 255 ( 100 % ) and 221 ( 100 % ) , which suggested that this flavonol was most likely to be kaempferol . this identification was confirmed by the fact that kaempferol was the tetrahydroxyflavone ( by direct comparison with kaempferol standards ) in the acidic hydrolyzed extract ( chromatogram not shown ) . the close retention times of the flavonol glycoside suggested that they might be kaempferol 3 - o - rhamnosylglucosides with the rhamnosyl at the 6 - position of hexosyl ( glucosyl or galactosyl ) . four other peaks with different retention times ( tr = 17.35 , 21.04 , 30.80 , and 32.13 min ) had high - resolution masses close to 593.1500 da , and all had similar fragments , suggesting they were also kaempferol rhamnosylhexosides . however , they were all minor components of the plant and did not provide sufficient uv data or ms fragments to allow identification of a specific isomeric structure . thus , their position of attachment to the flavone and the type of hexose were not completely identified . similarly , flavonoid f - 3 ( tr = 24.61 min , [ m h ] = 609.1470 da ) had a ms fragment at m / z 447 ( loss of 162 ) and an ms fragment at m / z 301 ( loss of 146 ) and was putatively identified as quercetin 3 - o - hexosylrhamnoside . its isomers ( tr = 23.42 and 25.84 min ) had ms fragments at m / z 463 ( loss of 146 ) and ms fragments at m / z 301 ( loss of 162 ) , suggesting they were quercetin 3 - rhamnosylhexosides . the isomer with tr = 23.42 min was further identified as rutin by direct comparison with an authentic standard . another isomer ( tr = 34.50 min ) had a ms fragment at m / z 301 , and its sugar connection could not be determined . the ms and ms fragments for m / z 301 were 255 ( 2227 % ) , 179 ( 4171 % ) , 151 ( 100 % ) , and 107 ( 100 ) and suggested the aglycone was quercetin . this was confirmed by the fact that the pentahydroxyflavone in the acidic hydrolyzed extract was identified as quercetin . one flavonoid ( tr = 30.31 min , [ m h ] = 623.1611 da ) had a base ms fragment at m / z 477 , a base ms fragment at m / z 314 , and ms and ms ions at m / z 285 and 270 to suggest it was isorhamnetin 3 - o - rhamnosylhexoside . at least one of the rhamnosides and hexosides might have the glycosyl at the 3 - position of kaempferol . another flavonoid ( tr = 33.59 min , [ m h ] = 577.1555 da , c27h29o14 ) had a base ms fragment at m / z 431 and a base ms fragment at m / z 285 to suggest it was kaempferol 3 - o - rhamnosylrhamnoside . the first two flavonoids ( tr = 34.46 and 33.19 min , c32h37o18 ) showed one pentosyl more than that of kaempferol 3 - o - rhamnosylrhamnoside . the first one ( f - 6 ) had a base ms fragment at m / z 563 ( loss of 146 da ) and a base ms fragment at m / z 284 ( loss of 278 da , i.e. , 146 + 132 ) to indicate it was kaempferol 3 - o - rhamnosylpentosylrhamnoside . the second one ( tr = 33.19 ) was very similar to f - 6 but had a base ms fragment at m / z 447 ( loss of 294 da ) for a dirhamnosylpentoside . another three flavonoids ( tr = 34.46 , 33.19 , 24.73 , 26.21 , and 27.94 min , c33h39o20 ) had base ms fragments at m / z 609 da ( loss of 146 da ) , a base ms fragment at m / z 285 da ( loss of 324 da ) , and a base ms fragment at m / z 151 , suggesting them to be isomers of kaempferol 3 - o - rhamnosyldihexosides . the last flavonoid ( tr = 22.95 min [ m h ] = 771.1971 da , c33h39o21 ) had a base ms fragment at m / z 625 ( loss of 146 da ) , indicating it might be quercetin 3 - o - rhamnosyldihexoside . an increased mass close to 146.0366 , 162.0315 , 176.0471 , or 206.0576 da was diagnostic of the presence of a p - coumaroyl , caffeoyl , feruloyl , or sinapoyl group . for example , two kaempferol acylglyocosides ( tr = 37.65 and 39.03 min , [ m h ] close to 755.1826 da , c36h35o18 ) had a base ms fragment at m / z 609 da ( calculated as 609.1460 , with error of 0.177 ppm for c27h29o16 , from loss of 146.0366 da , c9h6o2 for coumaroyl , instead of loss of 146.0576 da , c6h10o4 , rhamnosyl ) and base ms fragments ( m / z 447 , 285 , 257 , 241 , 229 , 151 da ) identifying them as kaempferol 3 - o - p - coumaroyldihexosides . similarly , three acylated flavonoids ( tr = 30.24 , 42.70 , and 46.66 min , [ m h ] close to 769.1975 da , c37h37o18 ) had base ms fragments at m / z 575 ( loss of around 194.0576 da for c10h10o4 , ferulic acid ) suggesting they were kaempferol 3 - o - feruloylrhamnosylhexosides . in the same way , four acylated glycosides were putatively identified as the 3 - o - caffoeyldihexoside ( tr = 31.67 min , [ m h ] = 771.1797 da ) , the 3 - o - sinapoyldihexoside ( tr = 41.60 min , [ m h ] = 831.1974 da ) , the 3 - o - hexoside -7-o - methoxybenzoyldihexoside ( tr = 33.57 min , [ m h ] = 921.2290 da ) , and the 3 - o - sinapoylhydroxyferuoyldihexoside -7-o - hexoside ( tr = 39.84 min , [ m h ] = 1185.2914 da ) of quercetin , respectively . in the same manner , the remaining ones were identified as two 3 - o - sinapoylhexoside -7-o - rhamnosides ( tr = 42.40 and 46.26 min , [ m h ] close to 799.2093 da ) , the 3 - o - hydroxybenzoyldihexoside -7-o - hexoside ( tr = 31.17 min , [ m h ] = 891.2185 da ) , the 3 - o - caffeoyldihexoside -7-o - rhamnoside ( tr = 32.85 min , [ m h ] = 917.2340 da ) , the 3 - o - feruloyldihexoside -7-o - rhamnosides ( tr = 34.95 and 38.95 min , [ m h ] = 931.2504 da ) , two 3 - o - sinapoyldihexoside -7-o - rhamnosides ( tr = 34.46 min , [ m h ] = 961.2604 da ) , and the 3 - o - acetylhexosylrhamnoside ( tr = 31.43 min , [ m h ] = 635.1605 da ) of kaempferol , respectively . as mentioned in a previous publication , dried rutin ( at 354 nm ) was used as the quantification standard and the mrrf values of two main flavonoids were used to determine their concentrations . concentrations of approximately 0.05 and 0.01 % ( or 50 and 10 mg / 100 g of plant material on dry weight basis ) were obtained for flavonoids f1 and f2 , respectively . the total flavonoid content of this plant is 0.10 % because the remaining flavonols were present at very low concentrations and uv peaks were not detectable for absorbance measurements . in addition to the flavonoids , 1 lignan ( lariciresinol 4 - o -- d - glucopyranoside ) and 18 other common compounds , including the glucosides of hydroxybenzoic and hydroxycinnamic acids and their derivatives ( e.g. , bound to sugar , quinic acid , and malic acid ) and organic acids , were identified by comparison of the chromatographic and ms data with those in our in - house flavonoid database . most of the common compounds have previously been detected in other plants analyzed in this laboratory . the results of this study showed that r. indica is a rich source of glucosinolates . these compounds were reasonably separated using the uhplc conditions described here and identified by their high - accuracy mass measurement and multistage mass fragments . the uv absorbance of the major glucosinolates was used to compute their concentration . in summary , 33 glucosinolates , over40 flavonoids , and more than 20 other phenolic and organic compounds were identified .
output:

agent
an uhplc - pda - esi / hrmsn profiling method was used to identify the glucosinolates and flavonoids of rorippa indica ( cruciferae ) , a wild vegetable and chinese herb used to treat cough , diarrhea , and rheumatoid arthritis . thirty - three glucosinolates , more than 40 flavonol glycosides , and 18 other phenolic and common organic compounds were identified . the glucosinolates and polyphenols were separated by uhplc . high - resolution deprotonated molecules provided high accuracy mass values that were used to determine formulas and provide putative identification of the glucosinolates and flavonoids . the fragments from multistage mass spectrometry were used to elucidate the structures . the concentrations of the main components were based on uv peak areas and molar relative response factors with a single calibration standard . this study found this plant to be a rich source for glucosinolates , containing 24 new glucosinolates , including 14 glucosylated glucosinolates that were previously unidentified .
***task***
the task is to summarize an input biomedical literature in six sentences

***input***
the input is a biomedical literature

***output***
the output is the summary of an input biomedical literature in six sentences

***documentation***

***examples***

input: glucosinolates ( gss ) are sulfur - and nitrogen - containing secondary metabolites found in cruciferous plants . a central carbon is connected to a thioglucose , to a sulfate via a nitrogen atom , and to a side chain ( r ) ( figure 1 ) . the side chain determines whether the glucosinolate is defined as aliphatic ( straight - or branched - chain alkyl , alkenyl , and oxo - , hydroxyl forms ) , aromatic , or indole . many glucosinolates also contain one or two more sulfur atoms in the side chain to form another sulfur - containing unit , such as methyl - thio - ( s ) , methyl - sulfinyl - ( so ) , methyl - or benzyl - sulfonyl - ( so2 ) , mercapto - ( hs ) , glucosyl - disulfanyl ( s s ) , and cysteinyl - thio - [ hooc ch ( nh2 ) ch2s ] . the glucosinolates and their enzyme - hydrolyzed products ( thiocyanates , isothiocyanates , and nitriles ) have shown important human health benefits , especially with respect to cancer prevention . thus , many studies have been carried out on the isolation and structural elucidation of glucosinolates and their hydrolyzed products with respect to their biological activities and distribution in the plant kingdom . an electronic database of the structures , formulas , and accurate masses of 200 knownn and a further 180 predictedn gss has been established . desulfoglucosinolates , glucosinolate - related nitriles , and isothiocyanates ( figure 1 ) formed by the loss of so3 or other functional groups through the action of sulfatase and myrosinase have been isolated from plants . glucosinolates , widely distributed in many plants of the cruciferae family , have also been found in plants from other familiesn although at significantly reduced levels . the glucosinolate profiles of many foods derived from cruciferous plants have been studied qualitatively and quantitatively to establish their dietary intake and relationship to health outcomes in biological , epidemiological , and clinical studies . the fragmentation patterns of glucosinolates have been studied using multistage mass spectrometry ( ms ) , primarily in the negative ionization mode . high - performance liquid chromatography and ms with electrospray ionization ( hplc - esi / ms ) has been widely used to identify the intact glucosinolate components of plants . most glucosinolates have an ultraviolet ( uv ) absorbance maximum wavelength ( max ) between 219 and 228 nm . they can be quantified directly from the uv absorbance at 225 nm when they are well separated . however , in most cases , quantification has been based on absorbance of the desulfoglucosinolates following sulfatase hydrolysis . quantification is based on calibration with a single compound and predetermined relative response factors ( rrfs ) . rorippa indica ( linn . ) hiern . is a perennial plant of the cruciferae family that is widely distributed throughout the world . its fresh spear - shaped leaves and tender seedlings are used as a healthy food , and the whole plant is used as an animal feed in china . the dried whole plant material is used as a chinese traditional herb with purported diuretic , anti - inflammatory , antifever , and anticough properties and to help with blood circulation and rheumatoid arthritis . ronifore ( 9 - methylsulfonylnonyl nitrile ) and its related amide ( rorifamide ) were isolated as the anticough components of rorippa montana . fifteen isothiocyanates and desulfoglucosinolates were isolated from the roots of rorippa plants , and several flavonol glycosides , phenolic acids , and derivatives , and other organic compounds have been reported . this paper presents a comprehensive study of the glucosinolate and polyphenolic components of r. indica . phenolic compounds are widely distributed in plant - derived foods , whereas the glucosinolates are among the biologically active components of cruciferous plants . both types of compounds are known to have many potential benefits to human health . as a part of our project to systematically identify and quantify these compounds , both standardized hplc - pda - esi / ms and uhplc - pda - esi / hrms methods were developed to identify and quantify the phenolics using their molar relative response factors ( mrrfs ) for uv absorbance . in this study , the uhplc - pda - esi / hrms method was used to analyze the phenolic and glucosinolate profiles of r. indica and led to the identification of 33 glucosinolates , including 24 for the first time , and more than 40 flavonol glycosides . this study found that r. indica was a rich plant source for glucosinolates on the basis of its structural variety and total concentration of glucosinolates . glucocheirolin potassium salt [ 3 - ( methylsulfonyl ) propyl glucosinolate - k , mw = 439 + 39 da ] , rutin 3h2o ( mw = 610 + 54 da ) , quercetin , kaempferol , and isorhamnetin were obtained from chromadex , inc . formic acid , hydrochloric acid ( 37 % ) , hplc grade methanol , and acetonitrile were purchased from vwr international , inc . hplc grade water was prepared from distilled water using a milli - q system ( millipore lab . , the stock standard solution consisted of dried rutin ( 1.27 mg ) and glucocheriolin - k ( 1.43 mg ) in 10.0 ml of methanol / water ( 60:40 , v / v ) . the stock solution was prepared at three concentrations ( 1 , 1/2 , and 1/4 ) to provide a range of signals suitable for the quantification of the main glucosinolates and phenolics of this sample . each of the solutions ( 2 l ) was injected in triplicate , and the relative standard deviation ( rsd ) for each peak was 5.0 % . the three standards provided a linear calibration curve for estimating the concentration of the main compounds of the extract . the dried r. indica plant materials were purchased by the longjin pharmaceutical co. , ltd . , from local herb stores in chongqing , china . the plant materials were ground into powders and passed through 60 mesh sieves prior to extraction . the ground powder ( 200 mg ) was extracted with 5.0 ml of methanol / water ( 60:40 , v / v ) using an fs30 ultrasonic sonicator ( fisher scientific , pittsburgh , pa , usa ) for 60 min at room temperature . the slurry mixture was centrifuged at 2500 rpm for 15 min ( iec clinical centrifuge , damon / iec division , needham , ma , usa ) , and the supernatant ( 4.000 ml ) was filtered through a 17 mm ( 0.45 m ) pvdf syringe filter ( vwr scientific , seattle , wa , usa ) . two microliters of the extract was injected in triplicate into the hplc for analysis . the filtered extracts ( 0.50 ml ) were mixed with concentrated hcl ( 37 % , 0.1 ml ) and heated in a capped tube at 85 c for 2 h. then , 0.4 ml of methanol was added to the mixture , and the solution was sonicated for 10 min . the solution was refiltered prior to hplc injection . the uhplc - dad - esi / hrms - ms system used consisted of an ltq orbitrap xl mass spectrometer with an accela 1250 binary pump , a pal htc accela tmo autosampler , a diode array detector ( dad ) ( thermoscientific , san jose , ca , usa ) , and a g1316a column compartment ( agilent , palo alto , ca , usa ) . the separation was carried out on an uhplc column ( 200 mm 2.1 mm i.d . , hypersil gold aq rp - c18 , 1.9 m ) ( thermoscientific ) with an hplc / uhplc precolumn filter ( ultrashield analytical scientific instruments , richmond , ca , usa ) at a flow rate of 0.3 ml / min . the mobile phase consisted of a combination of a ( 0.1 % formic acid in water , v / v ) and b ( 0.1 % formic acid in acetonitrile , v / v ) . the linear gradient was from 4 to 20 % b ( v / v ) at 40 min , to 35 % b at 60 min , to 100 % b at 61 min , and held at 100 % b to 65 min . the pda recorded spectra from 200 to 700 nm , and peak intensities at 225 and 354 nm were used for the quantification of the main glucosinolates and flavonoids , respectively . the ms was operated in the negative ionization mode using the following conditions : sheath gas at 70 ( arbitrary units ) , auxiliary and sweep gas at 15 ( arbitrary units ) , spray voltage at 4.8 kv , capillary temperature at 300 c , capillary voltage at 15 v , and tube lens at 70 v. the scan range was from m / z 100 to 1500 with a resolution of 15000 , ftms agc target at 2e5 , ft - ms / ms agc target at 1e5 , isolation width of m / z 1.5 , and maximum ion injection time of 500 ms . high - accuracy ion mass values were determined for all primary ions ( i.e. , the deprotonated molecular ions ) . the most intense ion was selected for the data - dependent scan to provide msan additional separate data - dependent scan with high - energy collisional dissociation ( hcd ) at 75 % was also carried out for high - accuracy measurement of some of the ms ions with the resolution of 7500 . figure 1 lists the identification codes , putative identification , retention times ( recorded on the tic chromatogram ) , deprotonated molecule high - resolution mass , formula , error between the experimental and calculated values , and main and important fragments from ms , ms , and ms fragmentations for each peak . the tic and pda ( at 225 nm ) chromatograms are shown in figure 2 . thirty - three of the compounds were putatively identified , and nine compounds could not be identified . chromatograms ( a , tic ; b , pda at 354 nm ; and c , pda at 225 nm ) of rorippa indica ( only the main glucosinolates and flavonoids are labeled ) . the main glucosinolates of this plant consisted of methylsulfonyl straight alkyl chain compounds ( ch3s ( o ) 2 ( ch2 ) n ) ( figure 1 ) . the most concentrated glucosinolate ( gs - 1 ) had tic and uv peaks with retention times ( tr ) at 18.88 and 18.83 min ( figure 2 ) , uv max at 225 nm , and a [ m h ] of 522.1134 da for c17h32o11ns3 ( calcd 522.1129 da , with the error of 1.72 ppm ) for 9 - ( methylsulfonyl ) nonylglucosinolate ( gs - 1 ) . the assignment of this compound as 9 - ( methylsulfonyl ) nonyl glucosinolate ( gs - 1 ) was based on the fact that the hydrolyzed products , desulfoglucosinolate , isothiocynate , and nitrile ( rofifone ) , had been previously isolated from this plant . furthermore , the authors in china isolated the related nitrile from the same plant material and confirmed the structure by nuclear magnetic resonance . gs - 1 had major ms fragments at m / z 291 ( 100 % , [ c6h11o9s2 ] ) , 275 ( 28 % , [ c6h11o8s2 ] ) , and 259 ( 73 % , [ c6h11o9s ] ) , ions a , c , and b in figures 3 and 4a . ms had a major fragment at m / z 97 ( 100 % , [ hso4 ] ) , ion d in figure 4b . the compositions for ions a , c , and b were confirmed by the experimentally determined masses of 290.9842 ( error 2.7 ppm ) , 274.9890 ( error 3.9 ppm ) , and 259.0117 ( error 4.8 ppm , figure 3 ) , respectively , from the additional data - dependent scan with activation in hcd . ms ( a ) and ms ( b ) spectra of 9 - ( methylsulfonyl ) nonylglucosinolate ( gs - 1 ) . figure 3 illustrates the fragmentation pathway leading to the four product ions through the loss of rcn and rncs groups . some glucosinolates , such as 4 - methoxyglucobrassin , glucobrassicin , 3 - hydroxyglucoisatisin , glucoisatinsin , and sinalbin , were reported to present an ms fragment ( b , 291 da ) with a relative intensity of 661 % . these diagnostic ions fully supported the identification of this compound as a glucosinolate . two minor peaks ( gs - 2 and gs - 3 , tr = 10.39 and 21.00 min ) had the same high - resolution deprotonated molecular ion masses as gs - 1 and similar ms and ms fragments . three glucosinolates , gs4 , gs - 5 , and gs - 6 , are analogues of gs - 1 and identified as 7 - methylsulfonylheptyl - ( tr = 6.67 min , [ m h ] = 494.0823 da ) , 8 - ( methylsulfonyl ) octyl - ( tr = 12.24 min , [ m h ] = 508.0978 da ) , and 10 - methylsulfonyldecylglucosinolates ( tr = 27.25 min , [ m h ] = 536.1301 da ) , respectively . their retention times correlate with increasing mass , suggesting that the r groups are straight chains and the increasing number results in increased retention times as the polarity decreases . four other glucosinolates ( gs - 7gs - 10 ) containing methylsulfinyl ( ch3so ( ch2 ) n ) were detected . they were putatively identified as 8 - ( methylsulfinyl ) octyl - ( tr = 11.39 time , [ m h ] = 492.1031 da ) , 9 - ( methylsulfinyl ) nonyl - ( tr = 17.66 and 18.71 min , [ m h ] close to 506.1189 da , two isomers , gs - 8 and gs - 9 ) , and 10 - ( methylsulfinyl ) decyl glucosinolates ( tr = 25.28 min , [ m h ] = 520.1347 da ) , respectively . all of them showed the same diagnostic fragments , confirming them as glucosinolates , and their elution time increased with increasing numbers of ch2 units . gs - 11 ( tr = 11.85 min ) contained an indole function and was putatively identified as 4 - methoxyindol -3-ylmethylglucosinolate on the basis of its high - resolution mass value of 477.0635 da . eight of the above glucosinolates ( gs - 1 , gs - 4 , gs - 5 , gs - 6 , gs - 7 , gs - 8 , gs - 10 , and gs - 11 ) were previously reported , and gs - 7 , gs - 8 , and gs - 11 were found in rorippa plants . furthermore , the desulfoglucosinolates and / or isothiocyanates of the above glucosinolates ( except gs - 4 ) were previously isolated from the roots of this plant . the remaining 21 peaks were putatively identified as glucosinolates and will be discussed in detail . gs - 12 ( tr = 33.33 min , [ m h ] = 488.1622 da ) had a deprotonated molecular ion of c18h34o10ns2 ( error 0.49 ppm ) and showed the classic glucosinolate ms fragments at m / z 259 ( 100 % ) , 275 ( 44 % ) , and 291 ( 33 % ) . after subtraction of ion b ( m / z 259 , c6h11o9s ) or ion a ( m / z 291 , c6h11o9s2 ) from the deprotonated molecule ( figure 3 ) , the masses for r - ncs or r - cn were obtained . each showed a formula for r = ho ( ch2 ) 11 , that is , c11h23o , the same as that obtained directly from r = c18h34o10ns2 c7h11o9ns2 ( figure 3 ) . in this way , the structures for the glucosinolates can be figured out easily . this glucosinolate was not among the predicted 180 new glucosinolates in the electronic database of clarke because the number of ch2 groups ( n ) is 11 and 10 was the largest considered in the prediction set . the first group ( gs - 13gs - 16 ) contained four isomers ( tr = 5.41 , 6.47 , 7.74 , and 10.55 min , [ m h ] = 538.1081 da ) . they showed product ions of m / z 291 , 275 , 259 , and 97 and were identified as 9 - ( methylsulfonyl ) hydroxynonylglucosinolates . they had one more hydroxyl group than that of related 9 - ( methylsulfonyl ) nonylglucosinolate ( gs - 1 ) and its isomers ( gs - 2 and gs - 3 ) . the second group ( gs - 17 and gs - 18 ) consisted of two isomers ( tr = 10.97 and 13.34 min , [ m h ] = 552.1236 da ) . they showed the same diagnostic gs fragments and were putatively identified as 10 - methylsulfonylhydroxydecylglucosinolates and to be the hydroxyl derivatives of 10 - methylsulfonyldecylglucosinolate ( gs - 6 ) and its isomers . the r groups for the isomers can be determined in the same manner as described previously for gs - 12 . among them , gs - 13 and gs - 17 ( with suggested straight chains for the r group ) were among the predicted 180 new glucosinolates in the electronic database of clarke with code numbers 245 and 246 , respectively . four minor peaks ( gs - 19gs - 22 ) had different retention times ( tr = 17.68 , 16.08 , 16.84 , and 20.92 min ) but a similar mass ( [ m h ] = 684.1658684.1663 da ) corresponding to a formula of c23h42o16ns3 ( errors less than 2.0 ppm ) . gs - 19 had major ms fragments at m / z 522 ( 77 % , [ m h ] 162 , loss of glucosyl ) , 453 ( 100 % , 291 + 162 , ion ag , the g means the fragment contained a glucosyl , c6h10o5 , figure 3 ) , 437 ( 23 % , 275 + 162 , ion cg ) , 421 ( 94 % , 259 + 162 , ion bg , figure 3 ) , and 259 ( 14 % , ion b ) ( figures 4 and 5 and table 1 ) . the detection of ions a , b , and c plus a glucosyl is reasonable , and [ m h ] = 421.0670 ( error of 3.0 ppm ) for ion b confirmed its composition as c12h21o14s . thus , the data suggest that these compounds are the glucosides of 9 - ( methylsulfonyl ) nonyl glucosinolate ( the glucoside of gs - 1 ) . ms spectra of the glucosides ( a , gs - 19 ; and b , gs - 22 ) of 9 - ( methylsulfonyl ) nonylglucosinolate . gs - 20 , gs - 21 , and gs - 22 also showed the typical glucosinolate glucoside fragments at m / z 453 , 437 , and 421 ( figures 3 and 5 and table 1 ) . on the basis of both of the high - resolution mass values and the presence of the gluocosinolate glucoside characteristic fragments , they were identified as the glucosides of 9 - ( methylsulfonyl ) nonylglucosinolates ( the glucosides of gs - 1gs - 3 ) . because there was no hydroxyl function on the r group , this glucosyl was most likely connected to the thioglucoside and most likely at the 6 - position as that for a monoacylated glucosinolate . similarly , four other compounds ( gs - 23gs - 26 ) were recognized as the glucosides of glucosinolates on the basis of the fact that they presented the same diagnostic fragments at m / z 453 , 437 , and 421 . gs - 23 ( tr = 22.55 min , [ m h ] = 654.1554 da , c22h40o15ns3 , error less than 2 ppm ) was putatively identified as a glucoside of 9 - ( methylsulfinyl ) nonylglucosinolate ( the glucoside of gs - 8 ) . gs - 24gs - 26 ( tr = 23.37 , 24.29 , and 28.18 min , [ m h ] = 698.1915 da , c24h44o16ns3 , error 1.8 ppm ) were putatively identified as the glucosides of 10 - methylsulfonyldecylglucosinolates ( the glucosides of gs - 6 and its isomers ) . one pair of isomers , gs - 27 and gs - 28 ( tr = 16.43 and 18.58 min , [ m h ] = 668.1712 da , c23h42o15ns3 , error 1.5 ppm ) were putatively identified as glucosides of 9 - ( methylsulfinyl ) nonylglucosinolate ( the glucosides of gs - 5 or its isomer ) . gs - 29 ( tr = 22.79 min , [ m h ] = 682.1868 da , c23h44o15ns3 , error 1.5 ppm ) was thought to be the glucoside of 10 - ( methylsulfinyl ) decylglucosinolate ( the glucosides of gs - 10 or its isomer ) . the base ms fragments ( m / z 604 for gs - 27 and gs - 28 and m / z 618 for gs - 29 ) showed a loss of 64 da ( loss of ch3 so h ) , indicating that these glucosinolates contained a methylsulfinyl ( ch3so ) group in the side chain . both gs - 27and gs - 28 had ms spectra containing the diagnostic gucosinolate glucoside fragments at m / z 453 ( 25 and 28 % , respectively ) , 437 ( 100 and 56 % ) , and 421 ( both 100 % ) to confirm their identification . four other compounds ( gs - 30gs - 33 ) also appeared to be analogues of the glucosides of glucosinolates on the basis of their masses and formulas . gs - 30 ( tr = 28.07 min , [ m h ] = 622.1290 da , c21h36o14ns3 , error 0.5 ppm ) might be the glucoside of methylthioethenylpentenyl ( ch3s c = c ( ch2 ) 5 ) or an isomer of methylthioheptenyl . the aglycone with a methylthioethenylpentenyl group is among the 180 predicted new glucosinolates ( no . gs - 31 and gs - 32 ( tr = 22.16 and 21.15 min ) have the same nominal masses , but have different high - accuracy masses . gs - 31 ( [ m h ] = 638.1245 da , c21h36o15ns3 , error 1.2 ppm ) was putatively identified as the glucoside of 7 - methylthio -3-oxoheptylglucosinolate or 7 - methylsulfinylheptenylglucosinolate . gs - 32 ( [ m h ] = 638.1608 da , c22h40o14ns3 , error 1.3 ppm ) might be the glucoside of 8 - methylthiooctylglucosinolate . gs - 33 ( tr = 16.51 min , [ m h ] = 640.1403 da , c21h38o15ns3 , error 0.9 ppm ) might be the glucoside of 7 - ( methylsulfinyl ) heptyl glucosinolate . instead of showing the typical glucosinolate glucoside fragment described above , three of them ( gs - 31gs - 33 ) had base ms or ms fragments at m / z 391 like gs - 23 . consequently , the lack of definitive ms fragments made it impossible to develop a molecular formula for this ion . the putative formula offered in table 1 was based primarily on the close match of the experimentally measured high - resolution masses with calculated values . the aglycones of these three glucosides were known glucosinolates , but not detected in this plant . the 14 glucosinolate glucosides mentioned above have not been previously reported in any other plants . they represent a new family of glucosinolates with a glucosyl connected to the thioglucosyl group . all of the observed ms fragments could be related to the structural elements of the glucosinolate skeleton . for examples , ions a , b , c , and d and thioglucosyl ( m / z 195 ) , as well as fragments obtained from further losses of oxygen , sulfur , or parts of the glucosyl were observed . however , not enough fragments were obtained to determine the structure of the r groups . of course , the r groups for the glucosinolates were not very large ( containing fewer than 12 carbon atoms for the aliphatic gss ) , but they can be arranged in several different ways to form the isomers . for example , the aliphatic structure can be linear or branched , the oxygen atom can be found in the oxo ( keto ) or hydroxy form , and the alkenyl double bond can be located at different positions . as a result , nuclear magnetic resonance ( nmr ) analysis is still the most accurate way to identify gss structurally . the major glucosinolates of r. montana had similar side chains and were well separated , allowing for the measurement of their peak areas at 225 nm ( figure 3 ) . their concentrations were calculated relative to glucocheirolin using mrrf values of 1.0 , on the basis of previous reports that the side chains were similar and did not alter the absorption coefficient of the molecules . the relative peak area ratios for gs - 1 , gs - 8 , gs - 6 , gs - 5 , and gs - 10 were 100.0 , 15.5 , 9.6 , 5.1 , and 4.6 , respectively . the corresponding concentrations for gs - 1 , gs - 8 , gs - 6 , gs - 5 , and gs - 10 were 0.51 , 0.079 , 0.049 , 0.026 , and 0.024 % on a dry weight basis , and their total contents was 0.69 % or 690 mg / 100 g of dried plant materials . table 2 presents the retention times ( recorded on the tic chromatograms ) , hr masses , and formulas for deprotonated molecules [ m h ] , diagnostic ms , ms , ms , and ms product ions , and putative identities of 44 flavonol glycoside , 18 phenolic , and other common compounds . the typical tic and pda ( at 354 nm ) chromatograms are shown in figure 2 . the strategy for identifying phenolic compounds in food samples has been described previously . in this study , only the glycosides of flavonols were observed , and most are reported for the first time . is , isorhamnetin ; km , kaempferol ; qn , quercetin . identified using in - house database . two tetrahydroxyflavone 3 - o - rhamnosylhexosides ( tr = 28.22 and 26.52 min , [ m h ] = 593.1491 ) provided the largest peaks ( f - 1 and f - 2 in figure 2a ) in chromatograms of the r. indica extract . they had uv band i maximum absorbances at 265 and 346 nm and base ms and ms fragments of m / z 447 ( by loss of 146 ) and m / z 284 ( the radical anion species of kaempferol from the loss of 162 + 1 rather than the ion at m / z 285 ) , suggesting that they might be kaempferol glycosides containing a rhamnosylhexose . this radical anion had base ms and ms fragments of m / z 255 ( 100 % ) and 221 ( 100 % ) , which suggested that this flavonol was most likely to be kaempferol . this identification was confirmed by the fact that kaempferol was the tetrahydroxyflavone ( by direct comparison with kaempferol standards ) in the acidic hydrolyzed extract ( chromatogram not shown ) . the close retention times of the flavonol glycoside suggested that they might be kaempferol 3 - o - rhamnosylglucosides with the rhamnosyl at the 6 - position of hexosyl ( glucosyl or galactosyl ) . four other peaks with different retention times ( tr = 17.35 , 21.04 , 30.80 , and 32.13 min ) had high - resolution masses close to 593.1500 da , and all had similar fragments , suggesting they were also kaempferol rhamnosylhexosides . however , they were all minor components of the plant and did not provide sufficient uv data or ms fragments to allow identification of a specific isomeric structure . thus , their position of attachment to the flavone and the type of hexose were not completely identified . similarly , flavonoid f - 3 ( tr = 24.61 min , [ m h ] = 609.1470 da ) had a ms fragment at m / z 447 ( loss of 162 ) and an ms fragment at m / z 301 ( loss of 146 ) and was putatively identified as quercetin 3 - o - hexosylrhamnoside . its isomers ( tr = 23.42 and 25.84 min ) had ms fragments at m / z 463 ( loss of 146 ) and ms fragments at m / z 301 ( loss of 162 ) , suggesting they were quercetin 3 - rhamnosylhexosides . the isomer with tr = 23.42 min was further identified as rutin by direct comparison with an authentic standard . another isomer ( tr = 34.50 min ) had a ms fragment at m / z 301 , and its sugar connection could not be determined . the ms and ms fragments for m / z 301 were 255 ( 2227 % ) , 179 ( 4171 % ) , 151 ( 100 % ) , and 107 ( 100 ) and suggested the aglycone was quercetin . this was confirmed by the fact that the pentahydroxyflavone in the acidic hydrolyzed extract was identified as quercetin . one flavonoid ( tr = 30.31 min , [ m h ] = 623.1611 da ) had a base ms fragment at m / z 477 , a base ms fragment at m / z 314 , and ms and ms ions at m / z 285 and 270 to suggest it was isorhamnetin 3 - o - rhamnosylhexoside . at least one of the rhamnosides and hexosides might have the glycosyl at the 3 - position of kaempferol . another flavonoid ( tr = 33.59 min , [ m h ] = 577.1555 da , c27h29o14 ) had a base ms fragment at m / z 431 and a base ms fragment at m / z 285 to suggest it was kaempferol 3 - o - rhamnosylrhamnoside . the first two flavonoids ( tr = 34.46 and 33.19 min , c32h37o18 ) showed one pentosyl more than that of kaempferol 3 - o - rhamnosylrhamnoside . the first one ( f - 6 ) had a base ms fragment at m / z 563 ( loss of 146 da ) and a base ms fragment at m / z 284 ( loss of 278 da , i.e. , 146 + 132 ) to indicate it was kaempferol 3 - o - rhamnosylpentosylrhamnoside . the second one ( tr = 33.19 ) was very similar to f - 6 but had a base ms fragment at m / z 447 ( loss of 294 da ) for a dirhamnosylpentoside . another three flavonoids ( tr = 34.46 , 33.19 , 24.73 , 26.21 , and 27.94 min , c33h39o20 ) had base ms fragments at m / z 609 da ( loss of 146 da ) , a base ms fragment at m / z 285 da ( loss of 324 da ) , and a base ms fragment at m / z 151 , suggesting them to be isomers of kaempferol 3 - o - rhamnosyldihexosides . the last flavonoid ( tr = 22.95 min [ m h ] = 771.1971 da , c33h39o21 ) had a base ms fragment at m / z 625 ( loss of 146 da ) , indicating it might be quercetin 3 - o - rhamnosyldihexoside . an increased mass close to 146.0366 , 162.0315 , 176.0471 , or 206.0576 da was diagnostic of the presence of a p - coumaroyl , caffeoyl , feruloyl , or sinapoyl group . for example , two kaempferol acylglyocosides ( tr = 37.65 and 39.03 min , [ m h ] close to 755.1826 da , c36h35o18 ) had a base ms fragment at m / z 609 da ( calculated as 609.1460 , with error of 0.177 ppm for c27h29o16 , from loss of 146.0366 da , c9h6o2 for coumaroyl , instead of loss of 146.0576 da , c6h10o4 , rhamnosyl ) and base ms fragments ( m / z 447 , 285 , 257 , 241 , 229 , 151 da ) identifying them as kaempferol 3 - o - p - coumaroyldihexosides . similarly , three acylated flavonoids ( tr = 30.24 , 42.70 , and 46.66 min , [ m h ] close to 769.1975 da , c37h37o18 ) had base ms fragments at m / z 575 ( loss of around 194.0576 da for c10h10o4 , ferulic acid ) suggesting they were kaempferol 3 - o - feruloylrhamnosylhexosides . in the same way , four acylated glycosides were putatively identified as the 3 - o - caffoeyldihexoside ( tr = 31.67 min , [ m h ] = 771.1797 da ) , the 3 - o - sinapoyldihexoside ( tr = 41.60 min , [ m h ] = 831.1974 da ) , the 3 - o - hexoside -7-o - methoxybenzoyldihexoside ( tr = 33.57 min , [ m h ] = 921.2290 da ) , and the 3 - o - sinapoylhydroxyferuoyldihexoside -7-o - hexoside ( tr = 39.84 min , [ m h ] = 1185.2914 da ) of quercetin , respectively . in the same manner , the remaining ones were identified as two 3 - o - sinapoylhexoside -7-o - rhamnosides ( tr = 42.40 and 46.26 min , [ m h ] close to 799.2093 da ) , the 3 - o - hydroxybenzoyldihexoside -7-o - hexoside ( tr = 31.17 min , [ m h ] = 891.2185 da ) , the 3 - o - caffeoyldihexoside -7-o - rhamnoside ( tr = 32.85 min , [ m h ] = 917.2340 da ) , the 3 - o - feruloyldihexoside -7-o - rhamnosides ( tr = 34.95 and 38.95 min , [ m h ] = 931.2504 da ) , two 3 - o - sinapoyldihexoside -7-o - rhamnosides ( tr = 34.46 min , [ m h ] = 961.2604 da ) , and the 3 - o - acetylhexosylrhamnoside ( tr = 31.43 min , [ m h ] = 635.1605 da ) of kaempferol , respectively . as mentioned in a previous publication , dried rutin ( at 354 nm ) was used as the quantification standard and the mrrf values of two main flavonoids were used to determine their concentrations . concentrations of approximately 0.05 and 0.01 % ( or 50 and 10 mg / 100 g of plant material on dry weight basis ) were obtained for flavonoids f1 and f2 , respectively . the total flavonoid content of this plant is 0.10 % because the remaining flavonols were present at very low concentrations and uv peaks were not detectable for absorbance measurements . in addition to the flavonoids , 1 lignan ( lariciresinol 4 - o -- d - glucopyranoside ) and 18 other common compounds , including the glucosides of hydroxybenzoic and hydroxycinnamic acids and their derivatives ( e.g. , bound to sugar , quinic acid , and malic acid ) and organic acids , were identified by comparison of the chromatographic and ms data with those in our in - house flavonoid database . most of the common compounds have previously been detected in other plants analyzed in this laboratory . the results of this study showed that r. indica is a rich source of glucosinolates . these compounds were reasonably separated using the uhplc conditions described here and identified by their high - accuracy mass measurement and multistage mass fragments . the uv absorbance of the major glucosinolates was used to compute their concentration . in summary , 33 glucosinolates , over40 flavonoids , and more than 20 other phenolic and organic compounds were identified .
output:
