ABSTRACT
Objective: To investigate the bioactive chemical constituents of the aerial parts of Eclipta prostrata. Methods: The compounds were isolated and purified by macroporous absorption resin, silica gel, Sephadex LH-20 and semi-preparative HPLC chromatography. Their structures were determined by MS and NMR data. The α-glucosidase inhibitory activities of compounds 1 and 2 were tested by in vitro screening assay. Results: A total of eight compounds were isolated from the ethyl acetate partition of the ethanol extract of E. prostrata. They were identified as 7β-hydroxystigmasterol 3-O-β-D-glucopyranoside (1), 7α-hydroxystigmasterol 3-O-β-D-glucopyranoside (2), 7α-hydroxysitosterol 3-O-β-D-glucopyranoside (3), 3β,23-dihydroxy-30-norolean-12,20 (29)-dien-28- oic acid (4), camellenodiol (5), echinocystic acid-3-O-(6-O-acetyl)-β-D-glucopyranoside (6), eclalbasaponin I (7) and eclalbasaponin IV (8). Compound 2 exhibited strong inhibition against α-glucosidase with an IC50 value of (11.7 ± 4.2) μmol/L. Conclusion: Compound 1 is a new compound named eclalbasaponin XIV and compounds 3-5 are reported from this herb for the first time. Steroidal glycosides could be the anti-hyperglycaemic components in E. prostrata by inhibiting α-glucosidase.
ABSTRACT
A phytochemical investigation of Allium macrostemon Bunge (Liliaceae) afforded the new pregnane steroidal glycoside, named allimacroside F (1), along with three known glycosides, benzyl-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (2), phenylethyl-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (3), (Z)-3-hexenyl-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (4). The identification and structural elucidation of a new compound (1) was carried out based on spectral data analyses (¹H-NMR, ¹³C-NMR, ¹H-¹H COSY, HSQC, HMBC, and NOESY) and HR-FAB-MS.
Subject(s)
Allium , Glycosides , Liliaceae , Statistics as TopicABSTRACT
ABSTRACT A new C21 steroidal glycoside, paniculatumoside G, together with neocynapanogenin C isolated for the first time from the natural source and two known compounds were isolated and characterized from the roots and rhizomes of Cynanchum paniculatum (Bunge) Kitag. ex H.Hara, Apocynaceae, a commonly used Traditional Chinese Medicine. On the basis of spectroscopic analysis, including HR-ESI-MS, 1D and 2D NMR spectral data, the structure of the new C21 steroidal glycoside was elucidated as neocynapanogenin H 3-O-β-D-oleandropyranoside.
ABSTRACT
Objective: To investigate the chemical structures of glycosides in the roots of Cynanchum otophyllum (Asclepiadaceae) and to find new glycosides. Methods: The total glycosides in the roots of C. olophyllum were separated by silica gel column chromatography. The structures of the resulting compounds were determined by NMR and FAB-MS spectra. Results: Three C21 steroidal glycosides were separated. Their structures were determined as caudatin 3-O-(4-O-methyl-β-D-cymaropyranosyl)-(1→4)-α-D-oleandropyranosyl-(1→4)-β-D-glucopyranosyl-(1→4)-α-L-rhamnopyranoside (1), caudatin 3-O-β-D-digitoxopyranosyl-(1→4)-α-D-oleandropyranosyl-(1→4)-β-Ddiginopyranosyl-(1→4)-β-D-glucopyranoside (2), and caudatin 3-O-β-D-diginopyranosyl-(1→4)-α-D-oleandropyranosyl-(1→4)-α-D-oleandropyranosyl-(1→4)-β-D-glucopyranoside (3), respectively. Conclusion: Glycosides 1-3 are new compounds.
ABSTRACT
Objective: To investigate the structures of compounds in the rhizome of Cynanchum otophyllum (Asclepiadaceae), and to find new C21 steroidal glycosides. Methods: The ethyl acetate extract from the rhizome was subjected to acidic hydrolysis and isolated by column chromatography; The structures of the purified compounds were determined by spectral methods. Literature search confirmed whether those compounds were of new structures. Results: Three compounds were isolated and their structures were deacetylmetaplexigenin 3-. O-β-. D-oleandropyranosyl-(1→4)-α-. D-oleandropyranosyl-(1→4)-α-. D-oleandropyranoside (1), deacetylmetaplexigenin 3-. O-α-. D-oleandropyranosyl-(1→4)-β-. D-thevetopyranosyl-(1→4)-α-. D-oleandropyranoside (2), and deacetylmetaplexigenin 3-. O-β-. D-cymaropyranosyl-(1→4)-α-. D-oleandropyranoside (3), respectively. Conclusion: Compounds 1-3 are new compounds.
ABSTRACT
Objective To study the chemical constituents of Cynanchum auriculatum. Methods Two steroidal glycosides were purified by column chromatography and their structures were elucidated by spectroscopic analysis. Results and Conclusion Compound 1 is a new steroidal glycoside, named kidjoranin-3-O-β-D-cymaropyranoside. Compound 2 is isolated from this plant for the first time.