Seul Bi Lee

Novel synthesis of leucoside by enzymatic hydrolysis of tea seed extract

BACKGROUND The application of tea seed extract (TSE) has been widely investigated owing to its biological activities. In this paper, two flavonol triglycosides found in TSE, camelliaside A (CamA) and camelliaside B (CamB), were subjected to hydrolysis in the presence of three commercial enzyme complexes of the Pectinex® series, 5XL, XXL and Ultra SP-L (Ultra). RESULTS XXL and 5XL induced stepwise deglycosylation of CamA and CamB to yield kaempferol diglycoside (nicotiflorin), kaempferol monoglycoside (astragalin) and kaempferol, while Ultra produced an additional new compound (1) that had not been observed in earlier studies. Upon hydrolysis of isolated CamA and CamB, compound (1) was obtained only from CamB. Both the molecular ion peak in liquid chromatography/mass spectrometry and the ¹H and ¹³C nuclear magnetic resonance spectra of (1) isolated by Ultra-induced hydrolysis of TSE indicated that (1) was kaempferol 3-O-β-xylopyranosyl (1 → 2)-β-glucopyranoside (leucoside), formed by selective hydrolysis of the rhamnosyl moiety of CamB. CONCLUSION Pure leucoside can be prepared by enzymatic partial hydrolysis of TSE. This is the first study to address the synthesis of pure leucoside from a natural source.

Synthesis and Purification of Kaempferol by Enzymatic Hydrolysis of Tea Seed Extract

We have made an in-depth study on elucidating selective hydrolysis reaction by enzyme on two kinds of flavonol triglycosides, camelliaside A (CamA) and camelliaside B (CamB). In this paper, we employ five kinds of commercial enzyme complexes and report their effect on the hydrolysis reaction of CamA and CamB. Ultraflo, Celluclast and Shearzyme selectively hydrolyze the xylosyl moiety of CamB, producing primarily kaempferol diglycoside, while Dextrozyme yielding monoglycoside. Whereas, Viscozyme transform CamA and CamB into kaempferol (KR) by non-specific hydrolysis. We recover KR with 95.4% purity from a scale-up reaction with Viscozyme followed by recrystallization of crude KR.