in the below , the process for the isolation of compound ( i ) from the dragon &# 39 ; s blood resin , the identification of compound ( i ) and the antifungal activity of the compound ( i ) on the plants is described by some examples . however , it is to be understood that these examples are only for description purpose , but not to be used as a limitation of the present invention . the scope of the present invention should be determined by the appended claims . the process of the isolation of compound ( i ) ( 5 - methoxy - 7 - hydroxyflavan ) from the dragon &# 39 ; s blood resin is depicted in the following scheme . ## str2 ## dragon &# 39 ; s blood ( 2 . 7 kg ) was extracted with n - hexane overnight . the n - hexane was then evaporated under vacuum . the defatted samples were soxhleted by ethanol : h 2 o ( 1 : 1 ) overnight and evaporated by a rotary vacuum evaporator . samples were partitioned between ethyl acetate ( etoac ) and water ( h 2 o ). the etoac fraction was concentrated and loaded on a silica gel ( 35 - 70 mesh ) column ( 6 * 60 cm ) and eluted with n - hexane , benzene and etoac as depicted in scheme 1 . a quick in vitro assay against pythium spinosum was made with fractions a to d . fraction b , c , and d showed antifungal activity . the fractions b and c were absorbed on silica gel ( 70 - 230 mesh ) and placed on top of a chromatographic column ( 2 * 60 cm ) of the same gel and eluted with hexane : etoac ( 5 : 1 ). the active fraction was purified by ptlc with hexane : etoac ( 3 : 2 ) and crystallized in benzene : hexane ( 1 : 1 ), and then compound ( i ) was obtained . fraction d was rechromatographed on silica gel ( 35 - 70 mesh ) and eluted with n - hexane : etoac . the fraction d -( 1 ), fraction d -( 2 ) and fraction d -( 3 ) were collected and loaded on a silica gel ( 70 - 230 mesh ) column ( 2 * 60 cm ) chromatograph separately and eluted with n - hexane : etoac ( 5 : 1 ). the amount of etoac was increased stepwisely to change the polarity of the elution solvent . the active fraction was obtained and purified by ptlc with hexane : etoac ( 3 : 2 ) and crystallized by hexane : benzene ( 1 : 1 ), and then compound ( i ) was obtained . the resulting compound ( i ) was isolated as a white needle - shaped crystal , m . p . 90 ° c ., molecular weight 256 , [ α ] d 25 =- 5 . 85 ( c = 0 . 002 g / ml in chcl 3 ). spraying the compound ( i ) on silica gel chromatoplate with ehrlich &# 39 ; s reagent shows a purple color , which is the characteristics of flavan . the elemental analysis of the resulting compound was as following : c 16 h 16 o 3 : calculated c , 74 . 98 , h , 6 . 29 . found c , 74 . 55 , h , 6 . 34 . for further identification , acetylation of the resulting compound ( 0 . 98 g ) was carried out by treatment with sodium acetate ( 0 . 3 g ) and acetic anhydride ( 10 ml ) on a steam bath for 2 hours . the reaction moisture was then evaporated to dryness and dissolved in acetone . then ether was added to the solution to form the acetate of compound ( i ), which was then identified and found to be a compound having the structure of formula ( ii ): ## str3 ## acetylation of the compound ( i ) gave the monoacetate , c 18 h 18 o 4 ( m / z ) indicating only one oh group in compound ( i ). structures of both compound ( i ) and compound ( ii ) were identified spectroscopically . infrared ( ir ) spectra of both compound ( i ) and compound ( ii ) were recorded on a perkin - elmer 882 infrared spectrophotometer . fast atom bombardment ( fab )- mass spectrum ( diethanol amine ) and high resolution electron impact ( hrei )- mass spectrum were determined by jeol jms - hx 110 . nmr spectra and 13 - 1 h 2d homonuclear shift correlation experiment ( cosy ) were run with a brucker am - 300 wb ft - nmr spectrometer . tms ( in deuterized chloroform ) was used as an internal standard for all samples analyzed in nmr . the above spectra data are shown in fig1 - 6 . as shown in fig1 the fragmentation pattern of fab mass spectra of compound ( i ) was 257 ( m + h ) + , 256 , 239 , 177 , 165 ( m - 91 ) + , 152 ( m - 104 ) + , 135 , 124 , 104 and 91 . it revealed a flavan skeleton . the ir spectrum of the resulting compound in cdcl 3 is shown in fig2 . the 13 c - nmr spectrum of the compound ( i ) was combined with dept studies ( fig3 ). it provided evidence for two methylenes ( 19 . 0 , 29 . 3 ppm ), one methine ( 77 . 6 ppm ) and one methoxy carbon ( 55 . 3 ppm ) as well as ten olefinic carbons . the 1 h - nmr spectrum of compound ( i ) confirmed these general assignments . the above nmr spectra were shown in table 1 . table 1__________________________________________________________________________assignment of carbon and hydrogen of compound ( i ) * andcompound ( ii ) by analysis between . sup . 13 c -. sup . 1 h2dcosy and . sup . 1 hnmrcarbonsignal ( ppm ) c . h . number . sup . 13 c - nmr . sup . 1 h - nmr assignment proton__________________________________________________________________________3 19 . 0 2 . 04 ( 1h , m ) ch . sub . 2 & lt ; 2h 2 . 23 ( 1h , m ) 4 29 . 3 2 . 78 ( 2h , m ) ch . sub . 2 & lt ; 2h17 55 . 3 3 . 78 ( 3h , s ) ch . sub . 3 -- o 3h2 77 . 6 5 . 01 ( 1h , dd , 1h j = 10 . 4 , 2 . 2hz ) 6 91 . 3 6 . 24 ( 1h , d , j = 2 . 2hz ) ═ ch 1h8 96 . 0 6 . 38 ( 1h , d , j = 2 . 2hz ) ═ ch 1h10 103 . 3 ═ c -- 12 - 16125 . 7 7 . 33 ( 5h , m ) ═ ch x2 5h127 . 7 ═ ch x1128 . 3 ═ ch x211 141 . 4 ═ c -- 9 154 . 3 ═ c -- 5 156 . 1 ═ c -- 18 159 . 5 ═ c -- 19 21 . 9 2 . 29 ( 3h , s ) ch . sub . 3 3h__________________________________________________________________________ * compound ( i ) is different from compound ( ii ) by the carbon number 7 ( substituting of carbon 19 ), the signal of . sup . 1 hnmr is 6 . 80 ppm ( 1h , br , s ), shows one oh group and 1h . fig5 is the uv spectrum of compound ( i ) in acetonitrile . the uv spectrum consisted of two major absorption maxima , one of which occured at 238 nm while the other was less intense at 278 nm . the whole structure of compound ( i ) was finally proved by the 13 c - 1 h2d cosy technique . the 13 c - 1 h2d cosy spectrum was shown in fig6 . in the following , the effect in inhibiting the growth of fungi is further proved by examples . compound ( i ) was dissolved in acetone and a sequential dilution ( 50 % each time ) was made to result in 13 different concentrations . compound ( i ) of different concentration was added into glucose peptone media ( glucose 20 g , yeast extract 2 g , mgso 4 0 . 5 g , kh 2 po 4 5 g , polypeptone 1 g , and agar 15 g per liter ) and placed in a 24 - well plate . four mm agar disc of 16 different species of fungi culture was placed on top of the media . tests with each concentration of compound ( i ) and the individual fungi species were repeated 3 times . the tested culture was incubated at room temperature for 48 hours to record the radial growth of the fungal mycelium and the minimal concentration of inhibition exerted by compound ( i ) was determined . the results were shown in table 2 . table 2______________________________________the minimal inhibitory concentration ( mic ) ofcompound ( i ) on the target fungifungi mic ( g / ml ) ______________________________________alternaria tenus & gt ; 400aspergillus fumigatus 50aspergillus niger 50botrytis cinerea & gt ; 400colletotrichum musae 400fusarium oxysporium fsp . niveum 100fusarium oxysporum fsp . cubense & gt ; 400phoma asparagi 25phytophthora capsici 100pythium aphanidermatum 100pythium spinosum 50pythium sylvaticum 50rhizoctonia solani ag 1 400rhizoctonia solani ag 4 & gt ; 400sclerotium rolfsii 100sclerotinia sclerotiorum 100______________________________________ it is seen from table 2 that the compound ( i ) of the present invention is particularly potent in the inhibition of phoma asparagi , pythium spinosum , pythium sylvaticum , aspergillus fumigatus , and aspergillus niger . the mic of compound ( i ) against the above fungi was less than 50 ug / ml . in contrast , compound ( i ) was slightly less active against sclerotium rolfsii and sclerotinia sclerotiorum . the in vivo evaluation on the protection of whole plants from the fungal infection was performed with two sets of experiments . in the first set of experiments , mung bean ( vigna radiata ( l .) cv . wilczek ) was chosen as plant material and the pathogen was sclerotium rolfsii . the effect of compound ( i ) on the control of s . rolfsii was measured by mixing twenty pieces of sclerotia with 50 g of soil in a 4 inch pot and 10 ml of compound ( i ) of different concentrations ( 500 ppm or 1000 ppm ) were mixed into the soil . after being cultured for 48 hours at room temperature , 10 mung bean seeds were planted in the pot . each treatment included 4 replications . the experiments were conducted in a growth chamber set at 30 ° c . for 7 days . the germination rate of and survival rate were recorded at the third and seventh days of incubation . the results were shown in table 3 . table 3______________________________________effects of compound ( i ) on the control of sclerotiumrolfsii infection on mung bean germination of mung beantreatment sclerotia (%) emergence (%) survival (%) ______________________________________compound ( i )( 1000 ppm ) 0 b * 80 . 0 b 70 . 0 b ( 500 ppm ) 0 b 72 . 5 b 62 . 5 b * ch 1 72 . 5 a 2 . 5 c 0 c ( distilled water ) ck 2 60 . 0 a 5 . 0 c 0 c ( acetone ) ck 3 100 . 0 a 100 . 0 a ( nonifested soil ) ______________________________________ * the same letter indicated no significant difference at p = 0 . 05 level * ck : control it is seen from the above table that the compound ( i ) of the present invention can significantly improve the emergence of the mung bean (& gt ; 70 %). in addition , the compound of the present invention can completely inhibit the germination of scleotia . the survival of mung bean is also good . in an another set of experiments , cabbage ( brassica oleracea cv . capitata dc .) was selected as plant material and the pathogen was pythium aphanidermatum . the pathogen was grown on potato dextrose broth for 3 days . the spores were washed out by distilled water and mixed with 3 ml mycelia plus 50 g of natural soil . the mixture was filled into a 4 inch pot . in each pot , 100 seeds of cabbage were planted and 10 ml of compound ( i ) ( 250 ppm or 500 ppm ) was poured into the pot . the germination rate of cabbage seeds was recorded after 2 days of incubation . the results were shown in table 4 . table 4______________________________________effects of compound ( i ) on the control of pythiumaphanidermatum infection on cabbagetreatment emergence (%) ______________________________________compound ( i ) ( 500 ppm ) 59 . 6 a *( 250 ppm ) 61 . 6 a ** ck 1 ( distilled water ) 32 . 6 b * ck 2 ( acetone ) 28 . 0 b ck 3 ( noninfested soil ) 69 . 3 a______________________________________ * the same letter indicated no significant difference at p = 0 . 05 level by ducan &# 39 ; s multiple range test . * ck : control effects of compound ( i ) on the seed germination at various concentration seed germination tests were conducted with purified compound . the compound was diluted to various concentration . the effect of compound ( i ) on the seed germination was measured by mixing 70 g of soil and 10 ml of compound ( i ) at different concentrations . thirty radish seeds , one houndred cabbage seeds and one houndred rape seeds were planted in each pot . each treatment included 3 replications . seed germination rate was recorded at 7 days after incubation in a growth chamber set at 24 ° c . the results were shown in table 5 . table 5______________________________________effects of compound ( i ) on the seed germination atvarious concentrationtreatment germination rate (%)( ppm ) radish cabbage rape______________________________________500 66 . 7 b * 85 . 0 a 79 . 0 a250 76 . 7 a 86 . 3 a 81 . 7 a125 75 . 6 ab 85 . 7 a 88 . 0 a 62 . 5 72 . 2 ab 87 . 3 a 87 . 0 a 31 . 5 75 . 6 ab 86 . 3 a 89 . 0 a 15 . 6 75 . 6 ab 84 . 7 a 88 . 3 ack 1 ( acetone ) 77 . 7 a 85 . 7 a 84 . 3 ack 2 73 . 3 ab 84 . 0 a 87 . 3 a ( distilled water ) ______________________________________ * the same letter indicated no significant difference at p = 0 . 05 level by duncan &# 39 ; s multiple range test . in addition , toxicology experiments with compound ( i ) by brion research institute of taiwan showed no effect to animals dosed at 300 mg / kg perorally or 100 mg / kg intraperitoneally . from current test data , it appears that compound ( i ) is a safe and potent fungicide .