Heterologous Expression Of The Fungi Meroterpenoid Pyripyropene A And Mining Of Drimane Type Sesquiterpenes

Terpenoids are a kind of natural products widely existed in nature.Among them,sesquiterpenoids are the largest group of terpenoids in terms of quantity and structure type,and have a variety of important biological functions and medicinal values.They have been widely concerned in food,daily chemicals,medicine and other fields,and have huge application potential and broad market prospects in the research and development of active natural products.Pyripyropenes are mixed sesquiterpenoids produced by fungi,which contain pyridine ring structure and α-pyranone structure.Afidopyropen,A green biopesticide,has been developed by BASF company and Meiji Fruit company with pyripyropene A as its precursor.At present,the high-yield strain and technology of pyripyropene A are monopolized by related companies in Japan and Germany.Therefore,it is of great significance to study the efficient heterologous expression of pyripyropene A to break the foreign patent monopoly,create economic benefits,promote the technical level of afidopyropen industry,and reduce the environmental burden of sustainable agricultural development.In this study,the fungus Neosartorya fischeri DSM 3700 was identified by genome scanning as possessing A cluster of genes for the biosynthesis of pyripyropene A,and production of pyripyropene A was also detected in fermentation broth.The nine genes responsible for the synthesis of pyripyropene A in this strain were gradually transferred into the heterognomic host Aspergillus oryzae for heterologous expression,and the recombinant Aspergillus oryzae strain that can directly produce pyripyropene A was successfully constructed with an initial yield of 26 mg/L.Then,the optimized culture conditions were used to further increase the yield of pyripyropene A,and the final yield was 263.5 mg/L,which was about 13 times higher than the maximum yield of 20 mg/L in the original strain reported in the literature.Therefore,the high-yield engineering strain of pyripyropene A was preliminarily constructed.Secondly,in order to further excavate terpenoids,expand the structural diversity of terpenoids and enrich the treasure house resources of terpenoids.a series of drimane-type sesquiterpenoids were isolated and identified from the Aspergillus parasiticus SDU001 strain by using One Strain Many Compounds(OSMAC)strategy,among which 1-6(aparalactonoid A-F)were new compounds.Compound 1 has an uncommon cage-like pentacyclic system,and compound 2 has a niacin structural unit rare in drimane-type sesquiterpenes.The IC50 values of aparalactonoid C and aparalactonoid E were 6.09 μM and 6.84 μM.respectively.This study further expanded the structural diversity of drimane-type sesquiterpenes and showed the possibility of mining novel sesquiterpenes from microorganisms.