Quantitative analysis of major isoflavonoids in the leaves of white kwao krua Pueraria mirifica

Abstract

The RP-HPLC analysis of 5 major isoflavonoids including puerarin, diadzin, genistin, daidzein and genistein was applied to Pueraria mirifica leaves derived from 3 plant cultivars; PM-III, PM-IV and PM-V in every month from March, 2007 to August, 2007. The results indicated that there were only puerarin, daidzin and genistin, not daidzein and genistein present in P. mirifica leaves. The highest isoflavonoid contents during the 6 months were daidzin in PM-V (5,059.96+-365.61 mg/100g powder). The maximum amount of puerarin (468.19+-83.55 mg/100g powder) and genistin (3,062.35+-382.13 mg/100g powder) were found in PM-V, while the maximum daidzin amount was found in PM-V. The total isoflavonoid contents of PM cultivar in June 2007 were the highest (5,766.34+-411.27 mg/100g powder) and in April 2007 was the lowest (509.03+-45.06 mg/100g powder). The lowest puerarin (62.88+-15.02mg/100g powder) and daidzin (194.63+-18.32 mg/100g powder respectively) were found in PM-III where as the minimum genistin was found in PM-V (131.59+-18.22 mg/100g powder). The results demonstrated that the leaf isoflavonoid contents were under the influence of plant genetics and monthly climatic change. The highest total isoflavonoid amount in PM-V was found in June 2007 which was 11.33 times higher than the lowest amount of PM-III in April 2007. The isoflavonoid contents of PM cultivar in June 2007 were the highest which was 2.93 times higher than in April 2007. The study demonstrates the highly biotechnological potential of manufacturing puerarin, daidzin and genistin from the cultivated P. mirifica leaves.