Study On Biologically Active Substances Of Microbiological Transformation Of Huaijiao And Polygonum Cuspidatum

Microbial biotransformation is one of the hotspots in current modernization of Chinese traditional medicine. In this work, biotransformation of Fructus Sophorae and Polygonum cuspidatum was studied.Fructus Sophorae is rich in flavonoid and isoflavone. Genistein is one of the strongest biological activity isoflavones. It is a weak estrogen-like effect of non-estrogen compounds, widely used in pharmaceuticals, health products and other fields.5,7,8,4’-tetrahydroxyisoflavone is one of the metabolite of genistein, which has a strong tyrosinase inhibitory activity. It has broad application prospects in the field of food, health care cosmetic and so on.Polygonum cuspidatum Sieb.et Zucc is Chinese traditional herb medicine. Resveratrol is the main medicinal ingredient in Polygonum cuspidatum. The content of resveratrol is0.45%at most while piceid is about2.55%. So conversion of piceid can make the content of resveratrol increased by3.3times in theory.Two functional strains were screened in the work. One could transform genistin to genistein, the other could convert genistein to new isoflavone. The latter strain was identified as Aspergillus aculeatus on the basis of colony morphology features and ITS sequence analysis. Preserved number is CCTCC NO:M2011264. Incubated in the Fructus Sophorae extract, the strain could convert genistin to genistein, which was then metabolized to5,7,8,4’-tetrahydroxyisoflavone.The5,7,8,4’-tetrahydroxyisoflavone with purity of98%was produced by preparative liquid chromatography with AQ-C18(22mm×250mm,5μm) by55%linear elution. In addition, its structure was detected and identified by liquid chromatography-mass spectrometry, Infrared spectroscopy (IR) and NMR spectrometer methods.Using the orthogonal design, the optimum condition for extraction of piceid and resveratrol was20times of extraction solvent,temperature was60℃, and the time was40min, the yield were2.32%and0.412%. A fungus was screened to convert piceid, which was identified as penicillium on the basis of colony morphology features. Inoculated in the Polygonum cuspidatum extract, the strain could completely converted piceid to resveratrol for32h, and the pecent was100%.Enzymatic properties were studied. The optimum pH is5.0and it maintained a higher stability between pH4.0-6.0. The optimum temperature is60℃, and it had good temperature stability. Fe2+、Na+and Ca2+are activation of the enzyme. Piceid is ideal substrate. Percent conversion of piceid was100%after12h transformation of raw herb by enzyme. Polygonum cuspidatum powder was directly converted into the enzyme solution. After12h, piceid was completely degraded, the percent was100%.