Purification of the dichloromethane (CH2Cl2) fraction of the aqueous extract of Rubus suavissimus resulted in the isolation of two sterols namely stigmasterol and ?-sitosterol. The structures of the isolated compounds were characterized on the basis of extensive spectral data (1D and 2D NMR; and MS) and in comparison with their literature data.DOI: http://dx.doi.org/10.3329/icpj.v1i9.11613 International Current Pharmaceutical Journal 2012, 1(9): 239-242

Three novel diterpene glycosides were isolated for the first time from the commercial extract of the leaves of Stevia rebaudiana, along with several known steviol glycosides, namely stevioside, rebaudiosides A-F, rubusoside and dulcoside A. The new compounds were identified as 13-[(2-O-β-d-glucopyranosyl-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl)oxy] ent-kaur-15-en-19-oic acid (1), 13-[(2-O-β-d-glucopyranosyl-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl)oxy]-16β-hydroxy-ent-kauran-19-oic acid (2) and 13-methyl-16-oxo-17-nor-ent-kauran-19-oic acid-β-d-glucopyranosyl ester (3) on the basis of extensive 2D NMR and MS spectroscopic data as well as chemical studies.

Two new new diterpene glycosides, 13-[(2-O-(6-O-β-D-glucopyranosyl)-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] kaur-16-en-18-oic acid β-D-glucopyranosyl ester (1) and 13-[(2-O-β-D-glucopyranosyl-3-O-β-D-fructofuranosyl-β-D-glucopyranosyl)oxy] kaur-16-en-18-oic acid β-D-glucopyranosyl ester (2) were isolated from the leaves of Stevia rebaudiana, along with the known steviol glycosides stevioside, rebaudiosides A-F and dulcoside A. The structures of the two new compounds were established on the basis of extensive 2D NMR (COSY, HSQC, and HMBC), MS and chemical studies.

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From the commercial extract of the leaves of Stevia rebaudiana, a new diterpene glycoside was isolated besides the known steviol glycosides including stevioside, rebaudiosides A-F, rubusoside and dulcoside A. The new compound was identified as 13-[(2-O-β-d-glucopyranosyl-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-(2-O-α-l-rhamnopyranosyl-β-d-glucopyranosyl) ester (1) on the basis of extensive spectroscopic (NMR and MS) and chemical studies.

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