- Reaction coupling separation for isosteviol production from stevioside catalyzed by acidic ion-exchange resin
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Abstract: Isosteviol, a prodrug used to be obtained via Wagner–Meerwein rearrangement from steviol with low yield and long reaction?time. Herein, an in-situ separation-coupling-reaction is presented to prepare isosteviol from the natural sweetener stevioside. Simply with in-situ water-washing, the product containing 92.98% purity of isosteviol was obtained with a stevioside conversion of 97.23% from a packet bed reactor without further separation. Within the assayed inorganic acid, organic acids and acidic ionic liquids, the acidic ion-exchange resins provided higher product specificity towards isosteviol. Furthermore, comparing to 5-Fluorouracil, the product presented similar and even stronger inhibition on proliferation of the assayed human cancer cells in a time and dose-dependence by causing cell phase arrest. Isosteviol treatment caused G1 arrest on SGC-7901, HCT-8 and HCT-116 cells, S arrest on HepG2, Huh-7 and HepG3B cells, and G2 arrest on MGC-803 cells, respectively. Graphic abstract: Reaction coupling separation for isosteviol production catalyzed by acidic ion-exchange resin.[Figure not available: see fulltext.]
- Hu, Xueyi,Zhou, Zhuoyu,Zhang, Zongying,Wang, Xiaoxia,Sui, Xiaochen,Chen, Junming,Xia, Yongmei,Zhang, Jue,Lin, Jianguo
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p. 151 - 159
(2020/09/01)
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- Endocyclic double bond isomers and by-products from rebaudioside A and stevioside formed under acid conditions
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The hydrolysis reaction of rebaudioside A and stevioside was studied under mild and strong acidic conditions at different temperatures and times. Exposure of rebaudioside A to vigorous acid conditions yielded three different aglycone cores which were puri
- Perera, Wilmer H.,Docampo, Maite L.,Wiggers, Frank T.,Hufford, Charles D.,Fronczek, Frank R.,Avula, Bharathi,Khan, Ikhlas A.,McChesney, James D.
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p. 163 - 170
(2018/04/20)
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- A complete specific cleavage of glucosyl and ester linkages of stevioside for preparing steviol with a β-galactosidase from Sulfolobus solfataricus
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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.
- Chen, Jun-Ming,Xia, Yong-Mei,Wan, Hui-Da,Wang, Hai-Jun,Liu, Xiang
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p. 126 - 131
(2014/06/10)
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- Enzymatic preparation of a natural sweetener rubusoside from specific hydrolysis of stevioside with β-galactosidase from Aspergillus sp.
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Rubusoside is a precious bioactive sweetener which mainly exists in Chinese sweet tea plant (Rubus suavissimus S. Lee), while stevioside is an abundant natural sweetener with bitter aftertaste. In this work, a β-galactosidase from Aspergillus sp. presented specific hydrolytic activity on β-1,2 glucosidic linkage of stevioside, and converting stevioside to rubusoside. The hydrolytic activity was weak on the natural stevioside analogs, which makes the process a promising approach to produce rubusoside and utilize stevioside. The highest steviosides conversion was 98.3%, accompanying with a rubusoside yield of 91.4%.
- Wan, Hui-Da,Tao, Guan-Jun,Kim, Doman,Xia, Yong-Mei
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experimental part
p. 12 - 17
(2012/10/08)
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- Minor diterpenoid glycosides from the leaves of Stevia rebaudiana
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From the commercial extract of the leaves of Stevia rebaudiana, three new diterpenoid glycosides were isolated besides eight known steviol glycosides including stevioside, rebaudiosides A-F and dulcoside A. The structures of the three compounds were identified as 13-[(2-O-β-d-glucopyranosyl-β-d- glucopyranosyl) oxy]-kaur-16-en-18-oic acid-(6-O-β-d-xylopyranosyl-β- d-glucopyranosyl) ester (1), 13-[(2-O-β-d-glucopyranosyl-β-d- glucopyranosyl) oxy]-17-hydroxy-kaur-15-en-18-oic acid β-d-glucopyranosyl ester (2), and 13-[(2-O-β-d-glucopyranosyl-β-d-glucopyranosyl) oxy]-17-oxo-kaur-15-en-18-oic acid β-d-glucopyranosyl ester (3) on the basis of extensive NMR and MS spectral studies. Another known diterpenoid glycoside, 13-[(2-O-β-d-glucopyranosyl-β-d-glucopyranosyl) oxy]-kaur-15-en-18-oic acid β-d-glucopyranosyl ester (4) was also isolated and its complete NMR spectral assignments were made on the basis of COSY, HSQC and HMBC spectral data.
- Chaturvedula, Venkata Sai Prakash,Clos, John F.,Rhea, Joshua,Milanowski, Dennis,Mocek, Ulla,Dubois, Grant E.,Prakash, Indra
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experimental part
p. 209 - 212
(2012/05/04)
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- ENZYMATIC DETERMINATION OF STEVIOSIDE IN STEVIA REBAUDIANA
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A simple enzymatic method is described for the determination of stevioside in Stevia rebaudiana.The method is based on the hydrolysis of stevioside with crude hesperidinase.The reaction is followed by monitoring the production of glucose with a glucose oxidase-peroxidase-2,2'-azino-di-(3-ethylbenzothiazoline-6-sulfonic acid) system.The results for the stevioside content in S. rebaudiana leaves correlate with those obtained by other methods.The stevioside content in S. rebaudiana plants showed large variation.Key Word Index - Stevia rebaudiana; Compositae; enzymatic assay; diterpene glucoside; stevioside; natural sweetener.
- Mizukami, Hajime,Shiiba, Keiko,Ohashi, Hiromu
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p. 1927 - 1930
(2007/10/02)
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