Microbial biotransformation of bioactive flavonoids.

Area of Science:

• Biochemistry and Biotechnology
• Natural Product Chemistry
• Microbiology

Background:

• Bioactive flavonoids are crucial phytochemicals in food, offering significant health benefits.
• Microbial biotransformation offers a pathway to synthesize novel flavonoid structures not found in nature.

Purpose of the Study:

• To review and summarize current knowledge on microbial production and biotransformation of flavonoids.
• To detail the various enzymatic reactions microbes employ in modifying flavonoid structures.

Main Methods:

• Review of scientific literature on microbial biotransformation of flavonoids.
• Identification and categorization of common microbial reactions including hydroxylation, methylation, glycosylation, and cyclization.
• Highlighting key microbial genera and species, such as Cunninghamella, Penicillium, and Aspergillus, particularly Aspergillus niger.

Main Results:

• Microbes catalyze a wide array of reactions on flavonoids, including hydroxylation, dehydroxylation, O-methylation, O-demethylation, glycosylation, deglycosylation, dehydrogenation, hydrogenation, C ring cleavage, cyclization, and carbonyl reduction.
• Aspergillus niger demonstrates versatility, transforming flavanone into various derivatives like flavan-4-ol and hydroxyflavanones.
• Specific hydroxylation, methylation, and glycosylation patterns are observed across different flavonoid subclasses (flavones, flavonols, flavanones, isoflavones, chalcones).

Conclusions:

• Microbial biotransformation is a powerful tool for generating diverse and novel flavonoid compounds.
• Understanding microbial enzymatic capabilities allows for targeted synthesis of specific flavonoid derivatives with potential applications.
• Further research into reactions like dehydrogenation could expand the scope of microbial flavonoid synthesis.