GNPS - 15_fungal isolates_bioconversion_EGCG

ABSTRACT: Dark teas are prepared by a microbial fermentation process. Flavan-3-ol B-ring fission analogues (FBRFAs) are some of the key bioactive constituents that characterise dark teas. The microbes and biosynthetic precursors involved in the formation of FBRFAs are not known. Using a unique solid-state fermentation system with beta-cyclodextrin inclusion complexation, as well as targeted chromatographic isolation, non-targeted spectroscopic identification, and Feature-based Molecular Networking (FBMN) on the Global Natural Products Social Molecular Networking (GNPS) web-platform, we reveal that dihydromyricetin and the FBRFAs, including teadenol A and fuzhuanin A, are derived from epigallocatechin gallate upon exposure to fungal strains isolated from Fuzhuan brick tea. In particular the strains from subphylum Pezizomycotina were key drivers for these B-/C-ring oxidation transformations. These are the same transformations seen during the fermentation process of dark teas. These discoveries set the stage to enrich dark teas and other food products for these health promoting constituents.

INSTRUMENT(S): micrOTOF-Q II, Q Exactive

ORGANISM(S): Trametes Hirsuta (ncbitaxon:5327) Cladosporium Sp. (ncbitaxon:1707700) Cladosporium Tenuissimum (ncbitaxon:70808) Aspergillus Niger (ncbitaxon:5061) Eurotium Cristatum (ncbitaxon:41421) Candida Metapsilosis (ncbitaxon:273372) Penicillium Steckii (ncbitaxon:303698) Penicillium Oxalicum (ncbitaxon:69781) Aspergillus Sp. (ncbitaxon:5065) Bjerkandera Adusta (ncbitaxon:5331) Aspergillus Ochraceus (ncbitaxon:40380) Penicillium Sp. (ncbitaxon:5081)

SUBMITTER: Tie-Jun Ling  

PROVIDER: MSV000085360 | GNPS | Sat May 02 03:07:00 BST 2020

REPOSITORIES: GNPS