Flavones and flavone synthases. | Semantic Scholar (2025)

This chapter addresses the requisite structural features of flavones for their biological and pharmacological significance in terms of structure activity relationship and chemical synthesis along with biosynthetic approaches and biological properties of some chemically modified derivatives.

An appraisal of flavone formation in plants is appraised, emphasizing the emerging theme that biosynthesis pathway determines flavone chemistry.

The diverse functions of flavones and flavonols in plants as well as their various roles in the interaction with other organisms offer many potential applications, not only in plant breeding but also in ecology, agriculture, and human nutrition.

In this review, the roles of flavones in various metabolic and systemic disease models are discussed and their structure–activity relationships have generated interest among medicinal chemists.

The results on genetic engineering of flavonoids in tomato fruit demonstrate the possibilities to change the levels and composition of health-related polyphenols in a crop plant and provide more insight in the genetic and biochemical regulation of the flavonoid pathway within this worldwide important vegetable.

OsFNS I-1 encodes a flavone synthase I, the first type I FNS I found outside of the Apiaceae family, and it is found that the cofactors oxoglutarate, FeSO(4), ascorbate and catalase are required for this reaction.

This review discusses the source of the essential flavonoid luteolin in various plants and its biosynthesis, and the potential health benefits of luteolins such as anti-cancer, anti-microbial,Anti-inflammatory, antioxidant, and anti-diabetic effects and their mechanisms are discussed in detail.

The de novo biosynthesis of three important flavonols, myricetin, kaempferol and quercetin are described in the industrially relevant actinomycetes Streptomyces coelicolor and S. albus.

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All references to the occurrence of flavone and flavonol aglycones which have appeared from 1975 to 1980 are listed, and also include such earlier references as were overlooked in the relevant chapters of The Flavonoids’ (1975).

Western medicine has not yet used flavonoids therapeutically, even though their safety record is exceptional, and suggestions are made where such possibilities may be worth pursuing.

Investigation in the possible health benefits of flavonoids has increased owing to their potent antioxidant and free-radical scavenging activities observed in vitro, and there is growing evidence from human feeding studies that the absorption and bioavailability of specific flavonoid is much higher than originally believed.

Flavonoid evolution was preceded by that of the phenylpropanoid and malonyl-coenzyme A pathways, but evolved prior to the lignin pathway.

The plant polyphenol flavone induces effectively programmed cell death, differentiation, and growth inhibition in transformed colonocytes by acting at the mRNA levels of genes involved in these processes.

This is the first report of the isolation and expression of a functional FNS II cDNA clone from any species and CYP93B2 was shown to encode flavone synthase II.

Results indicate that gene expression of a set of anthocyanin biosynthetic enzymes including F3'H is regulated coordinately only in the red form of P. frutescens but not in the green form, whilst FSII gene expression is controlled in a similar manner in red and green forms of P-frutescens.

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