in order to identify selectively purified tanshinone compound containing extracts from the root of a salvia spp , a number of alternative methodologies were examined . initially , a super critical fluid extraction ( scfe ) and an ethyl acetate extraction ( eae ) were conducted : put the pulverized dry raw material of salvia miltiorrhiza into the sce - co2 extractor . set up the pressure at 20 mpa and temperature at 45 degree c . add 30 % ( relative to the raw material ) ethanol ( 95 %) as the entrainer to the system . set the flow rate at 1 ml / min and continuously extract for 60 min . the dark red crystal obtained was code numbered sme - 1 . the eae methodology used is that set out with reference to fig1 . the danshen raw material ( 50 g ) is crushed and subjected to an ethanol extraction with 95 % ethanol ( added to four times volume ) and left for about 1 hour . the process was repeated 3 times and the solvent extracts combined . any residue was subjected to a water extraction ( added to four times volume ) and left for about an hour . repeat twice . the ethanol extract underwent a percolation extraction in which the extract was dissolved in 15 ml of water and extracted with petroleum ether . the process was repeated three times adding 15 ml of water each time . the water fraction was then extracted with ethyl acetate ( 15 ml ), and the process repeated three times . the resulting ethyl acetate fraction is referred to generally as sme - 2 . the resulting extracts were tested for their antimicrobial activity by the national institute for the control of pharmaceutical and biological products ( nicpbp ), national center for drug resistance of bacteria beijing , pr china . the extracts were tested for antimicrobial activity against 401 strains , over 95 % of which were clinical isolates with drug resistance including 41 strains of mrsa and 17 strains of mrcns . a high activity against gram - positive bacteria , and a low activity against gram - negative bacteria with a strong selective antibacterial action . the samples had a strong action against staphylococcus aureus and staphylococcus epidermidis . the information and numbers of the tested strains are listed in table 1 and the mic50 value and range for the important strains are listed in table 2 . 1 mg of dihydrotanshinone , 1 mg of cryptotanshinone , 1 mg of tanshinone , and 2 mg of tanshinone iia , put them all into a 10 ml flask , add 8 ml of the mixed solution of methanol - methylene dichloride ( 9 : 1 ), ultrasound for 5 minutes , add the methanol - methylene dichloride ( 9 : 1 ) solution to volume , shake thoroughly and allow to stand . measure appropriate amount of bc - sme 1 ( co 2 extract ) and bc - sme 2 ( ethyl acetate extract ) respectively , put them into two 10 ml flasks , add 8 ml of the methanol - methylene dichloride ( 9 : 1 ) solution , dissolve with ultrasound , add the methanol - methylene dichloride ( 9 : 1 ) solution to volume , shaking and filter . the subsequent filtrate was taken as a sample solution . measure precisely 5 μl of each of the reference solution and the sample solution . carry out the hplc as described above . according to the two gradient conditions mentioned above , the peaks of the different tanshinone indicators achieved baseline separation . gradient 2 was used due to the advantage of a shorter detection time , and the saving of solution . the hplc fingerprints of the referent samples are shown in fig2 a and fig2 b ( under the different gradient conditions ) and those of the two extracts are shown with reference to fig3 a and 3 b ( bc sme i ) and fig4 a and 4 b ( bc sme ii ). from left to right the peaks are : the content assay for the samples is given in table 5 below . ( gradient 1 was used for the content assay .) from the hplc content assay , it was found that the total tanshinone content was 48 . 5 % in bc - sme 1 , much higher than that in bc - sme 2 . this result can explain the dissolvability difference of the two samples in polar solvents . the content of tanshinone iia was as high as 39 . 40 % in bc - sme 1 , but the antibacterial activity level was low . the contents of dihydrotanshinone and cryptotanshinone in bc - sme 2 were higher than those in bc - sme 1 , so it is presumed that the better antibacterial activity level of bc - sme 2 is due to the presence of these compounds . all supplied by national institute for the control of pharmaceutical and biological products . methanol : chromatographic pure ( us fisher ), water : re - distilled , and the rest was analytical pure . take 15 mg each of bc - sme 1 and bc - sme 2 , add 10 ml of the methanol - methylene dichloride ( 9 : 1 ) mixture , dissolve with ultrasound and filter . take 1 mg each of dihydrotanshinone , cryptotanshinone , tanshinone i and tanshinone iia , add 2 ml of the methanol — methylene dichloride ( 9 : 1 ) mixture respectively for the mixed solution standards . following the tlc method ( chinese pharmacopoia 2005 version vol . i appendix vi b ) take 50 of each the test solutions , together with 3 μl each of the above - mentioned mixed solution standards , place them respectively on the same silica gel g plate , using petroleum ether — tetrahydrofuran — methanol ( 10 : 2 : 1 ) as the developing system , examine under the sunlight . put the sample drops on the same silica gel g plate with the reference drops . the spots corresponding to the reference compounds showed the same color at the same positions . the tlc experiment was repeated three times . the results are shown in fig5 a , 5 b and 5 c lane 1 : sme - 1 , lane 2 : sme - 2 and lane : reference compounds . reading bottom to top these are : from the experimental results under these chromatographic conditions , the separation of the mixed reference compounds and samples of the tanshinone compounds were very good , and the clear spots of the reference compounds could be seen in the samples of bc - sme 1 and bc - sme 2 . tanshinone compounds are lipid - soluble , so a high concentration ethanol ( 95 % ethanol ) was used as an extraction medium . a comparison between reflux and percolation extraction was made with a view to determining if a commercially scalable process giving a higher yield rate of cryptotanshinone and reduced impurity could be attained . soak 70 g of danshen raw material in 95 % ethanol for 12 hours and extract with 12 times its volume of 95 % ethanol . the colature was collected and the ethanol recovered . the resulting extract was then dried with a vacuum concentrator and weighed . 40 mg of the dry solid extract was weighed and put it into a 50 ml volumeteric flask , dissolved with the mobile phase solution , diluted to volume , filtered and analysed with hplc . reflux 70 g of danshen raw material with 6 times its own volume of 95 % ethanol twice , for 1 . 5 hours on each occasion . the ethanol was recovered and the extract dried with a vacuum concentrator and weighed . 40 mg of the dry solid extract was placed into a 50 ml volumeteric flask ; dissolved with the mobile phase solution , filtered and analysed with hplc . the results showed that the extraction by using the percolation methods can raise the content and the conversion rate of cryptotanshinone but its yield rate was lower than that with the reflux methods . the different percolation methods selected , the yield rates , and the content and conversion rates of the extracts produced by the two different methods are set out in table 6 below . from the results it can be seen that percolation results in a significantly greater content ( on a mg / g of extract basis ) than reflux . furthermore it is advantageous in that it uses simple equipment , is safe to operate , and is energy efficient . the extraction at room temperature also reduces damage to the active components , which are heat and light sensitive , and easily degraded . in order to optimize the process parameters of percolation extraction an orthogonal test was carried out and the conversion rate of cryptotanshinone used as an investigation indicator . an orthogonal test was designed to determine what factors might influence the conversion rate of cryptotanshinone . ( a ) solvent consumption , ( b ) soaking time , and ( c ) outflow velocity . the conversion rate of cryptotanshinone was selected as the investigation indicator ; analysis was carried out by using direct - vision methods and analysis of variance ( anova ). measure 9 portions , 70 g each of the crude powder of danshen raw material . each portion was soaked respectively in an appropriate quantity of 95 % ethanol for half an hour . carry out the percolation under the conditions set out in table 7 . the respective solutions were collected and dried with vacuum concentration . the ethanol was recovered from each resulting solution and the extracts were dried under vacuum at 60 ° c ., and weighed . 40 mg of dried extract was weighed into a 50 ml volumetric flask , dissolved into the mobile phase solution to volume , and filtered . the solutions were used for hplc analysis . from the analysis of variance ( anova ), three factors affected the conversion rate of cryptotanshinone ; the 3 influence degrees were a & gt ; c & gt ; b . the optimization grouping was a2b3c2 , that is , in the conditions of 95 % ethanol of 12 folds its volume , soaking for 24 hours , outflow velocity : 15 ml / min based on the results of the orthogonal test , three validation tests were carried out for the optimized process . the results are illustrated in table 9 the applicant sought a methodology to selectively enhance the content of tanoshinone compounds in the extract and the methodology in this example demonstrates a process which , in the first instance increases the content of tanoshines approximately two fold but significantly increases the relative content of cryptotanoshinone content by an even greater factor . this is particular advantageous from a pharmaceutical activity perspective . the process is illustrated in fig6 and comprises the following steps : 1 . extract danshen raw material with 95 % ethanol with percolation and concentrate using vacuum drying ; select 106 . 5 g of clean raw material and crush to a powder . soak in an appropriate quantity of 95 % ethanol for 24 hours , distribute it well into the percolator , and extract with percolation with a flow rate of 15 ml / min . collect the colature of 12 times the raw material , i . e . 1280 ml . recover the ethanol under vacuum . vacuum dry at 70 ° c . to get the final extract , 10 . 2 g . the final percolation extract of danshen was given a batch number — sl0601 . take the final extract of danshen mentioned in 5 . 1 . 1 above , add 100 ml water and extract it with 150 ml ethyl acetate twice ; combine the two ethyl acetate solutions and dehydrate . wash it with 100 ml and 50 ml water respectively and dehydrate . concentrate the ethyl acetate extract under vacuum to obtain 5 . 765 g of a solid extract which was given a batch number — yy0601 . measure 2 . 0022 g of danshen ethyl acetate extract ( as 5 . 1 . 2 ), dissolve it with acetone , mix it fully with silica gel and remove the solvent . apply the sample to a silica gel column , elute with petroleum ether — acetone in different proportions . collect 50 ml eluate in each fraction each fraction was applied on silica gel tlc plates , and petroleum ether — acetone was used as the developing system . examination was under natural sunlight . the tlc fingerprints are shown in fig7 based on the tlc result a number of consecutive fractions were merged as follows : 2nd and 3rd ; 5th to 8th ; 10th to 13th ; 14th and 5th ; 16th to 18th ; 19th to 21st ; 23rd and 24th ; 25th and 26th ; 28th to 30th ; 31st to 34th ; 35th and 36th . the resulting 20 new fractions were analyzed with silical gel tlc and the results are shown in fig8 . the fractions showing the highest contents of cryptotanshinone and dihydrotanshinone , i . e . the 7th to the 13th samples , were combineed as “ purified tanshinones ” ( 0 . 420 g ). this purified tanshinone containing compound extract was given a batch number : jz0601 . the ethyl acetate extract of danshen ( lane 1 ), the purified tanshinones ( lane 2 ) and the mixed tanshinone standards were examined with silica gel tlc . the tlc fingerprint is shown in fig9 . the compounds from bottom to top are respectively : the chromatographic conditions were as described in 3 . 1 . 3 above ( table 3 gradient 1 ). danshen percolation extract , sl0601 , danshen ethyl acetate extract , yy0601 , and purified tanshinones , jz0601 , were additionally subjected to hplc chromatographic analysis as described in 3 . 1 . danshen percolation extract 50 . 8 mg , danshen ethyl acetate extract 19 . 3 mg and purified tanshinones 11 . 9 mg , put them into a 10 ml volumetric flask respectively ; add 8 ml of the methanol - methylene dichloride ( 9 : 1 ) solution , dissolve with ultrasonication , add the methanol — methylene dichloride ( 9 : 1 ) solution to volume , shake thoroughly and filter . carry out hplc analysis . the resulting hplc fingerprints are shown in fig1 a to 10 d . : fig1 a is an hplc chromatogram of a percolation extract under conditions as set out in table 3 ( gradient 1 ) ( sl0601 ); fig1 b is an hplc chromatogram of a ethyl acetate purified extract under conditions as set out in table 3 ( gradient 1 ) ( yy0601 ); fig1 c is an hplc chromatogram of a silica gel purified extract under conditions as set out in table 3 ( gradient 1 ) ( jz0601 ); and the comparator fig1 d is an hplc chromatogram of reference compounds under conditions as set out in table 3 ( gradient 1 ). the content of each compound from hplc analysis is shown in table 11 . silica gel column chromatography was demonstrated to be an effective method for purifying cryptotanshinone . the content of cryptotanshinone rose significantly to eliminate the non - active compounds from the ethyl acetate extraction . this purified tanshinones fraction was further studied for its antibacterial activity . test lab : national institute for the control of pharmaceutical and biological products ( nicpbp ), national center for drug resistance of bacteria beijing , pr china . 1 . place 6 . 40 mg of the sample into a 50 ml volumetric flask and add 15 ml dmf solution ( n , n - dimethylformamide ) 2 . ultrasonicate for 10 minutes . 3 . add 15 ml of water to dilute the solution and ultrasonicate immediately for 5 minutes . 4 . add water to the volume and shake well , then ultrasonicate for another 5 minutes to obtain the testing solution of 0 . 128 mg / ml ( 30 % dmf concentration ). 107 strains collected and kept by national monitoring center for antibiotic resistant bacterial ( china ) were used to test the activity . the strains were evaluated with the phoenix - 100 automated microbiology system . the testing strains included : 87 strains of staphylococcus aureus ( sa ) including 52 strains of methicillin resistant sa ( mrsa ) and 35 strains of methicillin susceptible sa ( mssa ); 23 strains of coagulase - negative staphylococci ( cns ) ( mrcns 4 and mscns19 ); and 7 strains of streptococcus ( 5 strains of streptococcus pneumoniae ). a microtitre broth dilution method ( mh broth , oxoid ltd uk ) was used in the testing . the minimum inhibitory concentrations ( mics ) of flucloxacillin / ampicillin on the isolated strains were tested based on the methods described on america clsi / nccls antimicrobial susceptibility testing ( ast ) ( 2006 ) 1 . the mic of penicillin against staphylococcus aureus , ( atcc 29213 ) and streptococcus pneumoniae ( atcc49619 ) were conformed to clsunccls ( 2006 ). 2 . the mics of jz0601 against staphylococcus and streptococcus were as set out in tables 12 . jz0601 showed good activity against staphylococcus including methicillin susceptible and resistant strains , as well as streptococcus , particularly streptococcus pneumoniae . the mics of jz0601 on all strains are as set out in tables 13 - 16 : the above data demonstrates the benefits of using an extract which is not only characterized by its high tanoshinone compounds content but more particularly one with enhanced levels of particularly cryptotanoshinone . however , the methodology described to obtain this highly purified extract was not suitable for scale up and accordingly an alternative scalable methodology had to be developed . this is described below : the preferred commercial scale production process for obtaining a selectively purified tanshinone compounds containing extract from the root of salvia spp , and more particularly one specifically enriched in cryptotanshinone , is set out with reference to fig1 2 . soak it with a sufficient volume of high concentration , typically 95 %, ethanol for a time sufficient to solubilise the desired compounds , typically 24 hours ; 3 . place the material into a percolator and extract using a percolation method ; 4 . collect the ethanol solution with , typically , 12 times volume of its raw material at the desired percolation speed , preferably , 15 ml · min - 1 ; 5 . concentrate the liquid extract under vacuum and recover the ethanol to obtain the ethanol extract . 1 . dissolve the ethanol extract with about 10 times of water , the yield rate is about 40 % and the content of the total tanshinones is about 20 %. 3 . dissolve the precipitates with 60 % ethanol and place the material onto an ab - 8 macroporous resin column . 4 . elute with 60 % ethanol and dispose of the fraction 5 . elute with 70 % ethanol to obtain the selectively purified fraction containing tanshinones . the resulting purified extract has a specification as set out in table 17 inject 5 μl each of both the test solution and the reference solution respectively into an hplc column and run . the profile for the extract is illustrated in fig1 and compared to the reference sample fig1 from this the four tanshinones were calculated to be 42 . 89 % of the extract , calculated as : dihydrotanshinone ( 3 . 65 %), cryptotanshinone ( 18 . 95 %), tanshinone i ( 3 . 82 %), and tanshinone iia ( 16 . 47 %) to evaluate the in vitro activity of a selectively purified tanshinone compounds containing extract against the anaerobic bacteria propionibacterium acnes ( p . acnes ). a selectively purified tanshinone compounds containing extract was added to wells containing p . acnes ( atcc 6919 ; 1 × 10 4 to 5 × 10 5 cfu / ml ) in culture , grown under controlled conditions ( reinforced clostridial medium , 37 ° c .). final inoculum concentration was determined by reference to a standard optical density curve and adjusted as necessary . wells were incubated for 48 hours at 37 ° c . and examined for growth of culture . wells were scored positive (+) for inhibition of growth , or negative (−) for no effect on growth . eight different concentrations ranging from 0 . 03 μg / ml - 100 μg / ml were screened . ampicillin was run at a concentration of 0 . 1 μg / ml as a positive control . mic and mbc were calculated . the extract was tested at half - log concentrations of 0 . 03 μg / ml to 100 μg / ml for potential bactericidal activity against p . acnes . from this , a minimum inhibitory concentration ( mic ) of 10 μg / ml was determined , and a minimum bactericidal concentration ( mbc ) of 30 μg / ml was calculated . the results are shown in table 18 . this experiment was conducted to test for the rapid development of resistance in staphylococcus aureus in the presence of sub - inhibitory doses of the active extract . oxford staphylococcus aureus ( nctc 6571 ) and 3 clinical isolates of mrsa were tested , t3 , 102 and mrsa 99 . all clinical strains were from the royal london , st bartholomew &# 39 ; s or newham hospitals in london . each strain had been identified as an mrsa . the standard method using dmf was used . manufacturer &# 39 ; s method using dmf where the solution was unfiltered prior to use . solution — 640 mg / 1 was added to 3 ml dmf , sonicated in a sonic water bath then made up to 10 ml with water as per instructions . high concentrations of organisms ( 10 7 cfu / m1 − 1 ) were grown in sub — inhibitory concentrations 0 , 2 and 8 mg l − 1 of the active extract . mics had been determined previously as 16 mg l −‘ . organisms were sub - cultured into fresh active extract media at day 4 and again at day 7 . mics were checked weekly using standard methods . subcultures were carried out in triplicate . no change in mic was observed over the 3 week test period . no growth indicates the mic level . three mrsa clinical isolates have been tested and control strain oxford staphylococcus aureus tables 19 , 20 , 21 and 22 . table 23 shows the comparative development of resistance with ciprofloxicin and table 24 for gentamicin . there was no development of resistance for the active extract or gentamicin . the mics to ciprofloxacin increased after 2 weeks treatment . the extract is active against mrsa at inhibitory levels of 16 mg l − 1 and above . there was no change in the mic level over the test period for the strains tested . no rapid development of resistance occurred and the test period was beyond that used by boos m . et al . ( in vitro development of resistance to six quinolones in streptococcus pneumoniae , streptococcus pyogenes , and staphylococcus aureus . antimicrob . agents chemother . 45 , 938 - 942 ) to demonstrate a seven fold increase in resistance to quinilones within 10 days . 9 . 0 experiment to determine activity of pyn 6 in a gel formulation a number of different gel formulations containing extracts of the invention were prepared and tested on clinical mrsa isolates to determine the suitability of the active extract for topical delivery . agar diffusion tests ( based on bsac standard methods ) were used to compare the relative activity of different gels against mrsa . zones of inhibition around each 100 μl sample were compared . pyn6 was prepared by dissolving in dmf and then water , final concentration 500 mg / l . fig1 illustrates graphically of the effect of pyn6 in water and in gel formulations against 10 different strains of mrsa all gels showed activity at a level of 500 mg / l . all were comparable to the activity of 500 mg / l pyn6 in water . pyn6 works in gel or water formulation and has potential as a topical antimicrobial against mrsa . 10 . 0 experiment to determine activity of pyn 6 against individual compounds minimum inhibitory and minimum bactericidal activities ( mic and mbc ) of pyn6 were determined for 2 strains of mrsa using standard microtitre well methods . mics were determined by measuring growth over 201us using spectroscopy at 490 nm . mbcs were determined by subculture from these microtitre plates onto solid media after 20 hrs and determining survival of bacteria grown in the presence of pyn6 . test 1 mic and mbc comparing pyn6 to a , b , c and d against mrsa 98 test 2 mic and mbc comparing pyn6 to a , b , c and d against mrsa 2 the results demonstrate that pyn 6 an extract enriched in cryptotashinone and dyhydrotashinone ( compared to tashinone i and iia - table 5 ) performed very effectively .
the present invention relates to a selectively purified tanshinone compounds containing extract from the root of a salvia spp comprising cryptotanshinone , dihydrotanshinone , tanshinone i , and tanshinone iia . it comprises at least 15 %, by weight of the said identified tanshinone compounds and at least 4 % by weight , of cryptotanshinone . the extract and formulations thereof have been found to exhibit excellent anti - microbial properties against , in particular mrsa .