First Occurrence of Megastigmane Glucosides in a Plant of Retama Genus.

Chemical investigation of Retama sphaerocarpa collected in Algeria resulted in the isolation of two megastigmane glucosides, compounds 1 and 2, along with a series of isoflavones and phenol derivatives. Compound 1, named retamoside, was new and its structure was determined by extensive application of spectroscopic methods, including HRMS, 1D and 2D NMR and CD. The anti-inflammatory properties of co-occurring main megastigmane, saurobaccioside B (2) and structurally related vomifoliol (3) on LPS-stimulated murine macrophages RAW 274.7 have been evaluated.

The Chemical Constituents of Diaphragma Juglandis Fructus and Their Inhibitory Effect on α-Glucosidase Activity.

In our current investigation, 37 constituents (1-37), including 11 megastigmanes (1-11), 17 flavonoids (12-28) and 9 phenylpropanoids (29-37), were isolated from a 70%-EtOH extract of Diaphragma juglandis Fructus. Among them, compounds 1-3, 12 and 29 were new compounds and their structures were elucidated on the basis of physicochemical evidence and meticulous spectroscopic analysis (NMR, HRESIMS and CD). Compounds 13, 16, 21 and 28 showed moderate inhibitory effect on α-glycosidase inhibitory activities, with IC50 values being in the range of 29.47-54.82 µM and stronger than the positive control (acarbose, 60.01 ± 4.82 µM).

Triterpenoids, megastigmanes and hydroxycinnamic acid derivatives from Anisomeles indica.

Six triterpenoids (1-6), four megastigmanes (7-10) and five hydroxycinnamic acid derivatives (11-15) were isolated from the aerial part of Anisomeles indica (Lamiaceae). Of these components, compound 1 was identified to be a new triterpenoid with the structure of 2α,3α,19α-trihydroxyurs-12,20(30)-dien-28-oic acid based on extensive analysis of MS, 1D and 2D NMR spectroscopic data, while compounds 2-13 were obtained for the first time from Anisomeles species.

Megastigmanes from an aqueous extract of Uncaria rhynchophylla / 药学学报

Five new megastigmanes (1-5) were isolated from a decoction of Uncaria rhynchophylla by separation techniques of column chromatography using a combination of multiple stationary phases, including macroporous adsorbent resin, MCI resin, silica gel, Sephadex LH-20, and Toyopearl HW-40F, and reversed phase HPLC. Their structures were characterized by spectroscopic data analysis of HR-ESI-MS, NMR, and CD, in combination with Mosher's mothed as well as ECD and NMR calculations. The new compounds were named uncarphyllonone A (1), uncarphyllonols A (2) and B (3), and uncarphabscisic acids A (4) and B (5). Although the structures of 3 and 4 were previously reported, the reported NMR spectroscopic data were incorrect or do not support the assigned structures in literatures. This is also the first report of discovery of new megastigmane natural products from the Uncaria genus.

Chemical constituents from the leaves of Broussonetia papyrifera / 药学学报

To separate and identify the chemical constituents from the leaves of Broussonetia papyrifera (Linn.) Vent, various columns including Diaion HP-20, Toyopearl HW-40C, Sephadex LH-20, silica gel were employed for the isolation and purification of compounds from the leaves of B.papyrifera. The structures of the compounds were elucidated by their physiochemical characteristics and spectral data. Nineteen compounds were isolated from the leaves of B.papyrifera and their structures were identified as apigenin (1), apigenin-7-O-β-D-glucopyranoside (2), chrysoerid-7-O-β-D-glucopyranoside (3), apigenin-7-O-β-D-glucopyranuronide (4), vitexin-7-O-β-D-glucopyranoside (5), luteolin (6), 5,7,4′-trihydroxyl-6-C-[a-L-rhamnopyranosyl(1→2)]-β-D-glucopyranosyl flavone (7), 5,7,4′-trihydroxyl-8-C-[a-L-rhamnopyranosyl(1→2)]-β-D-glucopyranosyl flavone (8), saponaretin (9), vitexin (10), benzyl benzoate-2,6-di-O-β-D-glucopyranoside (11), (2R,3R,5R,6S,9R)-3-hydroxy-5,6-epoxy-β-ionol-2-O-β-D-glucopyranoside (12), (2R,3R,5R,6S,9R)-3-hydroxyl-5,6-epoxy-acetyl-β-ionol-2-O-β-D-glucopyranoside (13), ficustriol (14), (6S,9S)-roseoside (15), 3β-hydroxy-5α,6α-epoxy-β-ionone-2α-O-β-D-glucopyranoside (16), icariside B1 (17), sammangaoside A (18), 3-hydroxy-5α,6α-epoxy-β-ionone (19). Compounds 11, 12 and 13 are new compounds, the others are isolated from this genus Broussonetia for the first time.