Studies On Analysis Of Chemical Constituents During Biotransformation Of Fungus With Discorea Nipponica And Solid State Fermentation Of Discorea Zingiberensis

Dioscorea nipponica is the drying rhizome of perennial vine Dioscorea nipponica Makino which belongs to Dioscoreaceae and Dioscorea and contains abundant diosgenin.Diosgenin is one of the most important precursors to synthetize many kinds of steroid hormones and contraceptives.But with the development of the pharmaceutical industry and the increasing demand of domestic and international market for diosgenin,the resources of Dioscorea nipponica have become more failure.It was found that Dioscorea diosgenin content was in a substantial increase by microbial conversion method.This method has the clean,efficient,etc.,and to some extent alleviated the shortage of yam and other medicinal resources satus.Now,the endophytic fungi C39 was isolated from the rhizome and leaf of D.nipponica Makino and then fermented it with herbs,which significantly improve the content of the diosgenin.To study more about the mechanism of biotransformation by C39 and find the precursors of biotransformation,based on the liquid fermentation,the steroidal saponins from Dioscorea nipponica were studied.using the fungi C39,petroleum ether parts,ethyl acetate parts,n-butyl alcohol parts and water parts of the herbs dioscorea extract are fermented.According to changes of diosgenin content,it is found that the ingredients exist in n-butyl alcohol parts of the herbs extract in the biotransformation.This experiment is based on liquid state fermentation,which does a preliminary research on biotransformation of steroidal saponins in herbal ingredients by the fungi C39.Second,the liquid fermentation of n-butanol part with C39 was did and the TLC and UPLC results were analyzed.Combined with the TLC and HPLC results of the steroidal saponins from liquid fermentation product,We found that furostanol saponins was gradually reduce,but spirostanol saponins is gradually increasing.So a conclusion was drew that furostanol saponins transformed into spirostanol saponins in the process of biotransformation.And precursor substances came from two parts,one was derived from the n-butanol part,the other was from the secondary metabolites which was produced by endophytic fungi C39.Therefore,the next target was separating furostanol saponins of n-butanol part and metabolic component of endophytic fungi C39.Through pre-test samples of C39 fermentation in different days,it was found that saponins detection methods showed positive.Then it was found that such saponins was spirostanol saponins but there was no diosgenin when the sample was measured for acid hydrolysis of diosgenin.So spirostanol saponins from the metabolism of endophytic fungi C39 is not the precursor.Third,the technologies of macroporous adsorption resin and slica column chromatography.etc was applied to separate the possible substrate.These possible substrate was transformed by C39.Compound with standards,the TLC and HPLC results of the biotransformation by C39 which increased the content of diosgenin in Dioscorea nipponica found and authenticated two kinds of furostanol saponins—Protodioscin and Pseudoprotodioscin.The furostanol saponins converted to two compounds.One is dioscin,the other is unknown.Finally,diosgenin was increased by 147.85%with soild state fermentation in Discorea zingiberensis C.H.Wright.It was suggested that endophytic fungi C39 could not only improve the content of diosgenin in Dioscorea,but also increase the content of the same genus Dioscorea Dioscorea yam diosgenin in Discorea zingiberensis C.H.Wright.