Bioconversion of 7-Hydroxyflavanone: Isolation, Characterization and Bioactivity Evaluation of Twenty-One Phase I and Phase II Microbial Metabolites

Abstract

Microbial metabolism of 7-hydroxyflavanone (1) with fungal culture Cunninghamella blakesleeana (ATCC 8688a), yielded flavanone 7-sulfate (2), 7,4′-dihydroxyflavanone (3), 6,7-dihydroxyflavanone (4), 6-hydroxyflavanone 7-sulfate (5), and 7-hydroxyflavanone 6-sulfate (6). Mortierella zonata (ATCC 13309) also transformed 1 to metabolites 2 and 3 as well as 4′-hydroxyflavanone 7-sulfate (7), flavan-4-cis-ol 7-sulfate (

Improved Release and Metabolism of Flavonoids by Steered Fermentation Processes: A Review

“…Aglycones can be effectively absorbed through the small intestine, while the glycosidic forms, due to their complex structures and large molecular weights, reach the large intestine and are metabolized by human gut microbiota into different more simplified metabolites, which can be later absorbed [ 1 , 13 , 14 ]. Currently, phase I/II metabolites of phenolic compounds such as deglucosides [ 15 , 16 , 17 ], sulfoconjugates [ 18 , 19 ] and glucuronides [ 20 ], can be obtained by a fermentation process. It is therefore interesting to use bacterial or fungal fermentation processes, which not only enhance the release of bound phenolic compounds from the plant cell walls, but also convert phenolic compounds into different metabolites, which can exert other bioactivities.…”

Eleven Microbial Metabolites of 6-Hydroxyflavanone

“…, and 817 in the IR spectrum along with the loss of 80 mass units in the MS spectrum indicated the presence of a sulfate group, the position of which was determined to be at C-6 by HMBC correlation data. It was further supported by the shielding effect of the group on the ipso carbon at C-6 position by 5.12 ppm and the deshielding of C-5 and C-7 carbons ortho to and C-9 para to the sulfation site by values of 7.49, 5.49, 3.15 ppm respectively in the 13 C-NMR spectrum in comparison to that of 1. Thus, the structure flavanone 6-sulfate was assigned for compound 3.…”

“…1). Compounds, flavanone 6-sulfate (3), 16) 6-hydroxyflavanone 7-sulfate (4), 13) 6,4′-dihydroxyflavanone (6),…”

“…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.…”

“…[10][11][12][13] It is noteworthy that the number of microbial metabolites formed with flavanones far exceeds those reported for other classes of flavonoids making them difficult subjects for biological evaluations. Identification of potential metabolites by microbial transformation studies could be a source of valuable information for such investigations.…”