Advances on Resource, Biosynthesis, Biotransformation, Function, and Application of Dihydromyricetin

(+)-Dihydromyricetin (DMY), (2R,3R)-3,3′,4′,5,5′,7-hexahydroxy-2,3-dihydroflavanonol, a flavanonol, has great pharmaceutical and health protective potential based on their abundant beneficial bioactivities. The present chapter provides a comprehensive summary of the research progress of DMY on its resource, biosynthetic pathway and biotechnology, physicochemical properties, pharmacokinetics and bioavailability, biotransformation and metabolism, pharmacological effects and molecular mechanisms of action, clinical trial and human studies, toxicology and safety, marketed products, as well as patents. DMY is rich in several natural sources, especially Ampelopsis grossedentata. The DMY biosynthesis pathways and related biosynthetic enzymes of DMY in A. grossedentata have been clearly identified and characterized. Biotechnological approach presents a potential tool for the production of DMY using microbial cell factories. Stereoisomerism of DMY should be considered for better indication of its efficacy. DMY high instability is related to its powerful antioxidant capacity due to pyrogallol moiety in ring B, and whether preparation of other analogues could demonstrate improved properties. DMY demonstrates poor bioavailability based on its low solubility and permeability. DMY possesses various pharmacological effects, which have been proven by many in vitro and in vivo experiments, while clinical trials are relatively few. Consequently, to maximize the usefulness of DMY in pharmaceuticals, improvement in bioavailability, and better understanding of its actions, mechanisms and drug interactions ought to be examined in the future along with more clinical evidence.