Insight into the Glycosylation Methods of the Flavonoids as an Approach to Enhance its Bioavailability and Pharmacological Activities

Background: Flavonoids are a kind of polyphenol having a diverse set of pharmacological applications, but their bioavailability is limited due to their poor stability, poor solubility, quick clearance, and low intrinsic characteristics. According to the prior study, the flavonoids containing the sugar moiety have better solubility and stability (for example rutin) as they maintain greater plasma levels and a longer mean residence duration than the flavonoids have no glycoside moiety. Aim: This review focus on the enhancement of solubility and bioavailability of flavonoids by the various glycosylation techniques. Materials and Methods: In this review study, we discussed the various glycosylation approaches to improve solubility and bioavailability, such as microbial biotransformation, enzyme pathway manipulation, metabolic engineering, and chemical synthesis. Results: Glycosylation is one of the most efficient methods for increasing flavonoid solubility and stability, as a result the pharmacological activity also enhanced. The glycosylated compound such as scutellarin, quercetin 3-O-glucoside, Cyanidin 3-O-glucoside, kaempferitrin, baicalein 7-O-glucuronide and so on, shows the increased solubility and better pharmacological activities. Conclusion: The flavonoids need more attention to overcome their limitations, as they have plethora of applications on human health such as free radical scavenging property, anti-cancer activity, anti-diabetic, anti-inflammatory.