Interaction Of Symbiotic Fungus And Exogenous Compounds

Biotransformation is a biochemical processes by using biological systems or enzymes to modify exogenous compounds,and the nature is enzyme-catalyzed reaction to exogenous substrates.It is the frontier crossing of organic chemistry and life sciences as well as an important path to develop new drugs.Since the organisms are rich in enzymes,there is a variety of biological reactions,such as glycosylation,hydroxylation,methylation,esterification,hydrolysis,oxidation,reduction,isomerization and epoxidization.This thesis mainly focused on the biotransformation of two compounds'(resveratrol and benzocaine)by Daldinia eschscholzii TL01 and their mechanisms.A total of 51 compounds were isolated using SiO2,ODS,Sephadex LH-20,LC-MS and HPLC,and their sturctures were identified by IR,MS,'H-NMR,13C-NMR,HMQC,HMBC,COSY,NOESY,CD and X-ray.16 compounds were isolated related to resveratrol and benzocaine,with 15 of them identified as new compounds.35 compounds were isolated at the same time,three of which were isolated for the first time in this fungus,and three of them are new.The mechanism of ribosylation was further studied,as well as the impact of 9576 knockout strain on benzocaine biotransformation.The details were described as follows:1.We first report the 3-0-and 4,-O-a-ribosylation of resveratrol,a exogenous phytoalexin,by TL01.The ribosylation is mechanistically due to the resveratrol-activated expression of the silent or less active fungal genes governing the ribosylation of non-fungal phytophenols.The resveratrol-induced ribosylation is also characterized by an increased expression of ribosyltransferases in concert with a rare ribosylating reaction using nicotinamide mononucleotide(NMN)as a ribose donor.2.Seven compounds was isolated(6-12)from TL01 cocultured with benzocaine,among which 6-11 were novel compounds.Compounds 6-10 was aggregated by benzocaine and DPBD,while 11 by benzocaine and DPHT and 12 as benzocaine glucoside.Combined with previous research,A9576(DPBD related gene)of TL01 was co-cultured with benzocaine,and we found the depict of those products.And no significant change was found in the test of benzocaine's impact on PKS genes.In conclusion,this thesis indicated that using microbial reaction system to modify small molecular compounds can be used as an important means to find lead compounds.The in-depth research of those transformation mechanisms is conducive to the promotion of related subjects.