192827-13-7

Upstream product

• 60-12-8 2-phenylethanol 
• 192827-11-5 2,3,4-tri-O-benzoyl-β-D-xylopyranosyl-(1->6)-2,3,4-tri-O-benzoyl-α-D-glucopyranosyl bromide 
• 14262-83-0 2,3,4-tri-O-benzoyl-α-D-xylopyranosyl bromide 
• 192827-10-4 2,3,4-tri-O-benzoyl-β-D-xylopyranosyl-(1->6)-1,2,3,4-tera-O-benzoyl-β-D-glucopyranose 
• 104707-01-9 1,2,3,4-tetra-O-benzoyl-β-D-glucopyranose 
• 98-88-4 benzoyl chloride 

Downstream Products

• 129932-48-5 2-phenylethyl β-primeveroside 

Relevant academic research and scientific papers

Substrate specificity of beta-primeverosidase, a key enzyme in aroma formation during oolong tea and black tea manufacturing.

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.

The Role of Diglycosides as Tea Aroma Precursors: Synthesis of Tea Diglycosides and Specificity of Glycosidases in Tea Leaves

Two general synthetic routes were established in order to synthesize two diglycosides, primeverosides (1) and vicianosides (2), found in tea leaves. Procedure 1 is based on the Koenig-Knorr type of condensation of aglycon alcohols and 1-α-bromohexabenzoylprimeverose (6) and is suitable for the condensation of primary alcohols. Procedure 2 is to combine tribenzoyl-β-D-glucoside (8) and 1-α-bromotribenzoylxylose (4). The primeveroside of a tertiary alcohol was synthesized by this method which is also applicable to the synthesis of vicianosides. The hydrolysis rate of each of the 12 synthesized glycosides by a crude tea enzyme was evaluated, which suggest that the main glycosidase is primeverosidase and the enzyme mixture shows substrate specificity to both the carbohydrate and aglycon moieties.