Glycosides from the Stem Bark of Fraxinus sieboldiana

Abstract

A norditerpene glucopyranoside with a novel carbon skeleton (1), eight new aromatic glycosides (2-9), and 25 known glycosides have been isolated from a H2O-soluble portion of an ethanolic extract of the stem bark of Fraxinus sieboldiana. Their structures were determined by spectroscopic and chemical methods. Based on analysis of the NMR data of threo- and erythro-arylglycerols in different solvents, an application of Delta delta C8-C7 values to distinguish threo-arylglycerol and erythro-arylglycerol isomers was proposed. In the in vitro assays, compound 5 displayed TNF-alpha secretion inhibitory activity with an IC50 value of 1.6 microM, compound 6 showed antioxidative activity inhibiting Fe+2-cystine-induced rat liver microsomal lipid peroxidation with an IC50 value of 0.9 microM, and plantasioside (10) showed selective activity against the human colon cancer cell line (HCT-8) with an IC50 value of 3.4 microM.

Neolignans, lignans and glycoside from the fruits of Melia toosendan

“…The absolute configuration at C-7 and C-8 of 2 was assigned to be S and R based on the positive CD Cotton effects at 281 nm, 260 nm and 235 nm and negative Cotton effect in the 200-220 nm range [24][25][26]. Furthermore, according to the literatures [31][32][33], the chemical shifts of the C-8′ and C-7′ and the value of Δδ C8′-C7′ are different due to the threo and erythro isomers. The relative configuration of C-7′ and C-8′ in 2 was determined to be erythro by its 13 C NMR data at δ C 76.2 (C-7′) and 76.7 (C-8′) and the value of Δδ C8′-C7′ b 1.0 ppm.…”

Inhibitory alkaloids from Dictamnus dasycarpus root barks on lipopolysaccharide-induced nitric oxide production in BV2 cells

“…The molecular formula was determined to be C 18 alkaloid derivative by comparing its spectroscopic data with previously reported information 13,14 . Hydrolysis of 1 with β-glucosidase yielded D-glucose ([α] 20 D +48.2°) 15 . The glucose was determined to be at C-13 from the HMBC correlation between H-1′ and C-13 ( Figure 3).…”

“…The efr.5 was subjected to RP CC with MeOH−H 2 O step gradient (10% MeOH → 100% MeOH) to yield nineteen subfractions (efr.5-1−efr. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. The efr.5-5 was subjected to reversed-phase HPLC (YMCPack Pro C 18 , 10 × 250 mm) using CH 3 CN:H 2 O (33:67, 2 mL/min) as an eluent to give compound 8 (7.0 mg).…”

Inhibitory Effects of Coumarins from the Stem Barks of <i>Fraxinus rhynchophylla</i> on Adipocyte Differentiation in 3T3-L1 Cells

“…[16][17][18][19] In the course of screening adipocyte differentiation-inhibitory activity of natural products employing the mouse preadipocyte cell line, 3T3-L1 as an in vitro assay system, the EtOAc fraction of F. rhynchophylla showed significant inhibitory activity on adipogenesis. Thus, in the present study, we attempted to isolate the active constituents from F. rhynchophylla and evaluate their inhibitory activity.…”