498-05-5

Upstream product

• 129932-48-5 2-phenylethyl β-primeveroside 
• 18604-54-1 eugenyl 6-O-β-D-xylopyranosyl-β-D-glucopyranoside 
• 649758-25-8 4-(-2-nitroethyl)-1-<(6-O-β-D-xylopyranosyl-β-D-glucopyranosyl)oxy>benzene 

Relevant academic research and scientific papers

Isolation and characterization of a β-primeverosidase-like enzyme from Penicillium multicolor

p-Nitrophenyl and eugenyl β-primeveroside (6-O-β-D-xylopyranosyl- β-D-glucopyranoside) hydrolytic activity was found in culture filtrate from Penicillium multicolor IAM7153, and the enzyme was isolated. The enzyme was purified as a β-primeverosidase-like enzyme by precipitation with ammonium sulfate followed by successive chromatographies on Phenyl Sepharose, Mono Q, and β-galactosylamidine affinity columns. The molecular mass was estimated to be 50 kDa by SDS-PAGE and gel filtration. The purified enzyme was highly specific toward the substrate p-nitrophenyl β-primeveroside, which was cleaved in an endo-manner into primeverose and p-nitrophenol, but a series of β-primeveroside as aroma precursors were hydrolyzed only slightly as substrates for the enzyme. In analyses of its hydrolytic action and kinetics, the enzyme showed narrow substrate specificity with respect to the aglycon and glycon moieties of the diglycoside. We conclude that the present enzyme is a kind of β-diglycosidase rather than β-primeverosidase.

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.

Structural studies of a polysaccharide isolated from the green seaweed Chaetomorpha anteninna

Extraction of the green seaweed Chaetomorpha anteninna with water, followed by fractionation using the copper complex, gave a sulphated heteropolysaccharide, 27D +84 deg, that contained arabinose (57.7 percent), galactose (38.5 pe

UN NOUVEL HETEROSIDE NITRE EXTRAIT D'ANNONA SQUAMOSA

A new glycoside was isolated from a 60percent methanol extract of dried leaves and stems of Annona squamosa.Its chemical structure was determined as 4-(-2-nitroethyl)-1-benzene.Key Word Index -- Annona squamosa; Annonaceae; primeveroside; 4-(-2-nitroethyl)phenol; 4-(-2-aminoethyl)phenol; tyramine.