Enzymatic synthesis of vitexin glycosides and their activity

Vitexin is an active component of many traditional chinese medicines, and is found in various plants. The low solubility of vitexin limits its pharmaceutical usage. In this study, solvent-stable beta-fructosidase was used to glycosylate vitexin in organic solvents. The beta-fructosidase showed high activity and stability in 30-80% (v/v) ethyl acetate with 90-99% yields of vitexin glycosides. Highly efficient synthesis of beta-d-fructofuranosyl-(2 -> 6)-vitexin (1.04 g L-1) and beta-d-difructofuranosyl-(2 -> 6)-vitexin (0.45 g L-1) was attained in 50% (v/v) ethyl acetate solvent system from 1.5 g L-1 vitexin. Two novel vitexin glycosides showed higher anti-tumor activities compared to that of vitexin by employing a human breast cancer cytotoxicity assay.

Automated summary

In this study, vitexin was glycosylated using solvent-stable beta-fructosidase in organic solvents, resulting in a high yield of 90-99%. Two novel vitexin glycosides were synthesized from 1.5 g/L vitexin in a 50% ethyl acetate solvent system, and they showed higher anti-tumor activities compared to vitexin.