403480-82-0Relevant articles and documents
Substrate specificity of beta-primeverosidase, a key enzyme in aroma formation during oolong tea and black tea manufacturing.
Ma,Mizutani,Hiratake,Hayashi,Yagi,Watanabe,Sakata
, p. 2719 - 2729 (2001)
We synthesized nine kinds of diglycosides and a monoglycoside of 2-phenylethanol to investigate the substrate specificity of the purified beta-primeverosidase from fresh leaves of a tea cultivar (Camellia sinensis var. sinensis cv. Yabukita) in comparison with the apparent substrate specificity of the crude enzyme extract from tea leaves. The crude enzyme extract mainly showed beta-primeverosidase activity, although monoglycosidases activity was present to some extent. The purified beta-primeverosidase showed very narrow substrate specificity with respect to the glycon moiety, and especially prominent specificity for the beta-primeverosyl (6-O-beta-D-xylopyranosyl-beta-D-glucopyranosyl) moiety. The enzymes hydrolyzed naturally occurring diglycosides such as beta-primeveroside, beta-vicianoside, beta-acuminoside, beta-gentiobioside and 6-O-alpha-L-arabinofuranosyl-beta-D-glucopyranoside, but were unable to hydrolyze synthetic unnatural diglycosides. The purified enzyme was inactive toward 2-phenylethyl beta-D-glucopyranoside. The enzyme hydrolyzed each of the diglycosides into the corresponding disaccharide and 2-phenylethanol. These results indicate the beta-primeverosidase, a diglycosidase, to be a key enzyme involved in aroma formation during the tea manufacturing process.
Concise synthesis and antidiabetic activity of natural flavonoid glycosides, oroxins C and D, isolated from the seeds of Oroxylum indium
Li, Gang,Wang, Guanghui,Tong, Yangliu,Zhu, Junheng,Yun, Tongtong,Ye, Xiaoping,Li, Fahui,Yuan, Shengli,Liu, Qingchao
, p. 68 - 75 (2020/06/17)
The first concise synthesis of natural flavonoid glycosides, oroxins C (1) and D (2), which were isolated from the seeds of Oroxylum indicum, was efficiently achieved by a convergent strategy. The synthesized natural products 1 and 2 were evaluated for th