Isolation and Characterization of Nicotiflorin Obtained by Enzymatic Hydrolysis of Two Precursors in Tea Seed Extract

Abstract

Two flavonol triglycosides, camelliaside A (CamA) and camelliaside B (CamB), of tea seed extract (TSE) were subjected to enzymatic hydrolysis. Among five kinds of glycosidases investigated, beta-galactosidase (Gal) induced selective hydrolysis of CamA. On the other hand, pectinase (Pec) and cellulase (Cel) induced hydrolysis of CamB. For Gal and Pec, only kaempferol diglycoside (nicotiflorin, NF) was produced; on the other hand, significant amounts of kaempferol monoglycoside (astragalin, AS) and kaempferol (KR) were also detected for Cel. The combination of the use of Gal and Pec in the enzymatic hydrolysis of TSE afforded NF with high specificity. Crude NF with 22% purity was recovered from the enzymatic reaction mixture by extraction with organic solvent, and pure NF with >95% purity was obtained by crystallized in water. The chemical structure of NF was confirmed by (1)H and (13)C NMR analyses.

Isolation and anti-inflammatory effect of astragalin synthesized by enzymatic hydrolysis of tea seed extract

“…TSE itself showed only CamA and CamB, and the HPLC profile (Fig. 2(a)) was almost identical to that previously reported 13, 14, 16. The ESI mass spectra of CamA and CamB exhibited molecular ion peaks at m / z 756.27 [M − ] and 726.22 [M − ], respectively, in negative ion mode.…”

“…Accordingly, only CamA and CamB have been discussed for enzymatic hydrolysis in earlier literature 13, 14. The amounts of CamA and CamB in TSE, which were isolated by preparative HPLC, were found to be 96.7 and 117.3 g kg −1 , respectively 16…”

“…The mole‐based yield of AS from CamA and CamB in TSE was calculated according to the following equation: where Pu and Wt are the purity (%) and weight (g) of crude AS obtained at each step, and MW( X ) signifies a molecular weight of X . The values of 9.67 g and 11.73 g are the weights of CamA and CamB contained in 100 g TSE 16…”

“…Recently, it was reported that NF can be synthesized by enzymatic partial hydrolysis of CamA and CamB in TSE 16. The combination use of β‐galactosidase (Gal) and pectinase (Pec) in the enzymatic hydrolysis of TSE yielded NF with high specificity.…”

“…The combination use of β‐galactosidase (Gal) and pectinase (Pec) in the enzymatic hydrolysis of TSE yielded NF with high specificity. Crude NF was recovered from the enzymatic reaction mixture by extraction with organic solvent and recrystallization in water afforded pure NF with > 95% purity and 18% mole‐based yield 16…”