64849-39-4Relevant articles and documents
Glucosyltransferase Capable of Catalyzing the Last Step in Neoandrographolide Biosynthesis
Li, Yuan,Lin, Hui-Xin,Wang, Jian,Yang, Jian,Lai, Chang-Jiang-Sheng,Wang, Xing,Ma, Bao-Wei,Tang, Jin-Fu,Li, Yong,Li, Xin-Lin,Guo, Juan,Gao, Wei,Huang, Lu-Qi
supporting information, p. 5999 - 6002 (2018/10/20)
ApUGT, a diterpene glycosyltransferase from Andrographis paniculata, could transfer a glucose to the C-19 hydroxyl moiety of andrograpanin to form neoandrographolide. This glycosyltransferase has a broad substrate scope, and it can glycosylate 26 natural and unnatural compounds of different structural types. This study provides a basis for exploring the glycosylation mechanism of ent-labdane-type diterpenes and plays an important role in diversifying the structures used in drug discovery.
A complete specific cleavage of glucosyl and ester linkages of stevioside for preparing steviol with a β-galactosidase from Sulfolobus solfataricus
Chen, Jun-Ming,Xia, Yong-Mei,Wan, Hui-Da,Wang, Hai-Jun,Liu, Xiang
, p. 126 - 131 (2014/06/10)
β-Galactosidases from Sulfolobus solfataricus have been used to synthesize galactooligosaccharide and lactulose. In this work, a β-galactosidase from S. solfataricus with weak β-glucosidase activity but high lipase activity was employed as catalyst to assist hydrolysis of stevioside to obtain steviol, an important starting reagent of synthetic bioactive materials and the main metablite of stevioside in human digistion. The β-galactosidase presented a strict substrate specifity on converting stevioside to steviol in a stoichiometric yield. The β-galactosidase favors the cleavage of glycoside linkages prior to cleavage of glycosyl ester linkage. The hydrolysis is external diffusion controlled and hence has to bear low substrate concentration in regular process, but this can be solved with product removal or enzyme immobilization. The immobilization of the β-galactosidase onto cross-linked chitosan microspheres did not enhance the enzyme's thermal or pH stability but eliminated the external diffusion, and therefore speeded the hydrolysis in 3 folds. The relative reaction activity dropped only 1.75% after 6 runs of using the immobilized β-galactosidase.
Solubilization of steviolbioside and steviolmonoside with γ-cyclodextrin and its application to selective syntheses of better sweet glycosides from stevioside and rubusoside
Ohtani,Aikawa,Fujisawa,Kasai,Tanaka,Yamasaki
, p. 3172 - 3174 (2007/10/02)
1,4-α-Glucosylation at the 13-O-glycosyl moiety of stevioside (S) and rubusoside (RU) results in a significant increase of sweetness. Saponification of the 19-COO-β-glucosyl linkage of S and RU yielded steviolbioside (SB) (= 13-O-β-sophorosyl-steviol) and steviolmonoside (SM) (= 13-O-β-glucosyl-steviol), respectively, both of which are poorly soluble in an acetate buffer. It was found that the solubilities of SM and SB in the buffer solution were remarkably increased in the presence of γ-cyclodextrin (γ-CD). SB was solubilized in the buffer solution with the aid of γ-CD, and the solution was subjected to 1,4-α-transglucosylation by using a cyclodextrin glucanotransferase-starch system to give a mixture of products which were glucosylated at the 13-O-glycosyl moiety. This mixture was acetylated, and the acetate was subjected to chemical β-glucosylation of 19-COOH followed by deacetylation to afford compounds which have superior sweetness to S. In the same way, derivatives with superior sweetness were selectively prepared from RU through SM.
