Biotransformation of 5,7-Methoxyflavones by Selected Entomopathogenic Filamentous Fungi

Abstract

5,7-Dimethoxyflavone, a chrysin derivative, occurs in many plants and shows very low toxicity, even at high doses. On the basis of this phenomenon, we biotransformed a series of methoxy-derivatives of chrysin, apigenin, and tricetin obtained by chemical synthesis. We used entomopathogenic fungal strains with the confirmed ability of simultaneous hydroxylation/demethylation and glycosylation of flavonoid compounds. Both the amount and the place of attachment of the methoxy group influenced the biotransformation rate and the product’s amount nascent. Based on product and semi-product structures, it can be concluded that they are the result of cascading transformations. Only in the case of 5,7,3′,4′,5′-pentamethoxyflavone, the strains were able to attach a sugar molecule in place of the methoxy substituent to give 3′-O-β-d-(4″-O-methylglucopyranosyl)-5,7,4′,5′-tetramethoxyflavone. However, we observed the tested strains’ ability to selectively demethylate/hydroxylate the carbon C-3′ and C-4′ of ring B of the substrates used. The structures of four hydroxyl-derivatives were determined: 4′-hydroxy-5,7-dimethoxyflavone, 3′-hydroxy-5,7-dimethoxyflavone, 3′-hydroxy-5,7,4′,5′-tetramethoxyflavone, and 5,7-dimethoxy-3′,4′-dihydroxyflavone (5,7-dimethoxy-luteolin).

Flavonoid Constituents and Alpha-Glucosidase Inhibition of Solanum stramonifolium Jacq. Inflorescence with In Vitro and In Silico Studies

“…The obvious difference was the C-4′ chemical shift of 5, which was downfield than 1 . The data were also compared with 3′- O - β -D-(4″- O -methylglucopyranosylo)-5, 7, 4′, 5′-tetramethoxylavonone [ 10 ], except for the presence of sugar at C-3′. The HMBC correlation from H-1″ to C-3′ ( Figure 3 ) indicated glucose substitution.…”

Hydroxylation of Progesterone and Its Derivatives by the Entomopathogenic Strain Isaria farinosa KCh KW1.1

“…The ability of Isaria farinosa strains to hydroxylate and 4-O-methylglycosylate flavonoid compounds was also described [18][19][20]. In our previous work, we also observed that they perform demethylation and then 4-O-methylglycosylation of methoxyflavones [19,21].…”

Biotransformation of Patchouli Alcohol by Cladosporium cladosporioides and the Anti-Influenza Virus Activities of Biotransformation Products

“…At the same time, the extensive application of filamentous fungi in biotransformation has attracted much attention. 41 In order to find more strains for biotransformation of natural products and enrich the microbial strain library, we try to obtain filamentous fungi from common sources in daily life. The results showed that C. cladosporioides (Figure 2) derived from moldy food had an excellent biotransformation effect on PA.…”