ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Bovine β-1,4-galactosyltransierase is an efficient catalyst for the regioselective transfer of galactose from UPD-galactose, generated in situ with the UDP-glucose/UDP-glucose-4-epimerase system, to the kaurane glycosides stevioside (1) and Steviolbioside (2), affording the corresponding galactosyl derivatives 3 and 4 in high yields. By a combination of 2D NMR techniques (COSY, TOCSY, ROESY, HMQC, and HMBC), the structure of the products is established as 13-[(β -D-galactopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 2)- β -D-glucopyranosyl)oxy]kaur-16-en-19-oic acid β -D-glucopyranosyl ester (3) and 13-[(β-D-galactopyranosyl-(1 → 4)- β-D-glu-copyranosyl-(1 → 2)- β-D-glucopyranosyl)oxy]kaur-16-en-19-oic acid (4).
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19970800412
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