Naturally Occurring Flavonoids and Isoflavonoids and Their Microbial Transformation: A Review

Abstract

Flavonoids and isoflavonoids are polyphenolic secondary metabolites usually produced by plants adapting to changing ecological environments over a long period of time. Therefore, their biosynthesis pathways are considered as the most distinctive natural product pathway in plants. Seemingly, the flavonoids and isoflavones from fungi and actinomycetes have been relatively overlooked. In this review, we summarized and classified the isoflavones and flavonoids derived from fungi and actinomycetes and described their biological activities. Increasing attention has been paid to bioactive substances derived from microorganism whole-cell biotransformation. Additionally, we described the utilization of isoflavones and flavonoids as substrates by fungi and actinomycetes for biotransformation through hydroxylation, methylation, halogenation, glycosylation, dehydrogenation, cyclisation, and hydrogenation reactions to obtain rare and highly active biofunctional derivatives. Overall, among all microorganisms, actinomycetes are the main producers of flavonoids. In our review, we also summarized the functional genes involved in flavonoid biosynthesis.

Allelopathic Effect of Quercetin, a Flavonoid from Fagopyrum esculentum Roots in the Radicle Growth of Phelipanche ramosa: Quercetin Natural and Semisynthetic Analogues Were Used for a Structure-Activity Relationship Investigation

“…Compounds 1 and 4 belong to cynnamic acids and flavonols groups of natural occurring substances and are both biosynthesized via shikimic acid pathway [ 28 ]. They are already reported as plant [ 29 , 30 , 31 ] and fungi [ 32 ] bioactive metabolites. Although quercetin is found in many vegetables, it is present in low amounts in Polygonaceae family [ 22 ].…”

Metabolic Engineering of Microbial Cell Factories for Biosynthesis of Flavonoids: A Review

“…Isoflavonoids are a distinctive subgroup of flavonoids existing in abundance in plants belonging to the families Fabaceae and Iridaceae [47]. Some isoflavonoids have also been reported to be isolated from fungi and actinomycetes [48,49]. Isoflavonoids possess a molecular framework formed by 15 carbon atoms with the general structure of C6-C3-C6, but unlike other flavonoids (such as flavones, flavonols, flavanones), the B-ring of isoflavonoids is attached to position 3 of the C-ring.…”

“…Because their structure is similar to estrogen, they can interact with estrogen receptors and exhibit weak estrogenic activity, so isoflavonoids are sometimes called phytoestrogens [50]. In addition, isoflavonoids are extensively reported for their other biological and pharmacological activities, including antidiabetic, antibacterial, antifungal, antiviral, antitumor, anti-inflammatory, and antiaging [48]. Examples of most studied isoflavonoids that have been displayed include daidzein, genistein, biochanin A, glycitein, and formononetin (Table 1).…”

Photophysical Study and Biological Applications of Synthetic Chalcone-Based Fluorescent Dyes

“…Chalcones, α,β-unsaturated aromatic ketones, constitute the central skeleton of many important biological compounds [ 1 ] and are the biosynthetic precursors of flavonoids and isoflavonoids in plants [ 2 , 3 ]. Their diverse structures can cyclize to form various flavonoid compounds with different biological activities [ 4 , 5 ]. In the past decades, many synthetic analogues, such as aza-chalcones and chalcone derivatives containing isoxazole, pyrazole, and indole, [ 6 ] were developed and have shown interesting biological properties, such as antioxidant, anticancer, antimicrobial, antiprotozoal, antiulcer, antiviral, antihistaminic, anti-HIV, cytotoxic, and anti-inflammatory activities [ 7 , 8 , 9 ].…”