Microbial transformations of flavanone and 6-hydroxyflavanone by Aspergillus niger strains

Eleven Microbial Metabolites of 6-Hydroxyflavanone

“…Compounds 3 and 9 however, had been identified only by means of MS data. 16,18) We have therefore provided further spectroscopy evidence to support the structures. The structure elucidations of the new metabolites (2, 5, 10-12) were based on spectroscopic data as given below.…”

“…17) 2,4-cis-6-hydroxyflavan-4-ol (8), 18) 2,4-trans-6-hydroxyflavan-4-ol (9) 19) have been reported in the literature. Compounds 3 and 9 however, had been identified only by means of MS data.…”

“…Viewing the reported data, it could be said that microbial transformation efficiency of a given compound could be improved by using a variety of microbial strains. [10][11][12][13]18,27) 1 and its metabolites showed no activity against available test such as antibacterial and antifungal assays. However, weak antileishmanial activity was observed for metabolite 11 when tested against Leishmania donovani.…”

Enantioselective reduction of flavanone and oxidation of cis- and trans-flavan-4-ol by selected yeast cultures

“…In our previous papers we described biotransformations of (±)-flavanone in the cultures of Aspergillus and Penicillium strains [23][24][25]. Except from achiral flavones we obtained mainly the products of hydroxylation of flavanone at C-6 and C-4 (with the enantiomeric excesses not exceeding 36%) [23].…”

Biotransformation of chalcones by the endophytic fungus Aspergillus flavus isolated from Paspalum maritimum trin

“…22 Biotransformation of flavanones by one wild strain of A. niger KB and three UV mutants of A. niger resulted in the reduction of carbonyl group and dehydrogenation at C-2 and C-3 positions; reduction of carbonyl group and hydroxylation at C-7; and dehydrogenation at C-2 and C-3 and hydroxylation at C-3 producing flavonol. 23 In the high molecular weight fraction of the culture extract of Aspergillus oryzae, genistein was transformed into shoyuflavone B in the presence of (±)-transepoxysuccinic acid. 24 Epigallocatechin gallate (EGCG) has been reported to be converted into epigallocatechin (EGC) by a hydrolase from Aspergillus oryzae and the yield of EGC could reach at least 70%.…”