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Flavonoids are a class of phenolic compounds that are widely distributed in nature. They have a variety of physiological and pharmacological activities. They exist in free form or in the form of glycosides. The glycosylation occurs by glycosyltransferases, which is a common modification of plant secondary metabolites and the last step of their biosynthesis. Glycosylation can increase the diversity of the structure and function of flavonoids, and is currently a research hotspot. Based on the classification of flavonoids, this paper describes and summarizes the biotransformation and characteristics of glycosylation modification of flavonoids with different structural types, and describes the effects of enzymatic glycosylation using different types of glycosyltransferases on the biological activity and function of flavonoids depending on sugar connection position, sugar quantity, and type. This paper provides a reference for the development and application of flavonoids glycosylation and glycosyltransferases and also opens up a new direction for plant breeding.

The electrochemical behavior of the antitumor herbal drug apigenin was studied in 0.1 M B-R buffer solution (50% ethanol, pH 9.0) by cyclic voltammetry (CV), normal pulse voltammetry (NPV), chronoamperometry (CA) and chronocoulometry (CC) at glassy carbon electrode. In CV, only one irreversible anodic peak with Ep = 0.580V was appeared at scan rate of 50 mV/s and a new electroanalytical method for this herbal drug was established according to this anodic peak. The peak currents are linearly relationship with apigeninconcentrations in a range from 5.0×10-6 M to 9.0×10-5 M. Using the established method without pre-separation,apigenin in herbal drug was determined with satisfactory results. Moreover, the electrode process dynamics parameters were also investigated by electrochemical techniques and the possible electrode reaction mechanism was deduced. We also study the interaction of apigenin with DNA by DPV and Ultraviolet –Visible (UV) spectra. The results show apigenin doesn’t interact with DNA under the conditions.