Three megastigmane glycosides from the stem of Mallotus barbatus

Three undescribed megastigmane glycosides, mallbarbalosides A-C (1-3) together with 3 known analogues (4-6) were isolated from the stem of Mallotus barbatus. Their structures were elucidated using extensive NMR spectroscopic methods (1D and 2D-NMR spectroscopy) and HRESIMS spectroscopic data analyses. The absolute configurations of the undescribed compounds were determined by the experimental circular dichroism spectroscopy. All the compounds were tested for their inhibitory effects on the production of NO in LPS-treated RAW 264.7 cells, and they showed no inhibitory effect to NO release.

Terpenoids from the roots of Alangium chinense

Two new norditerpenoids (1 and 2), four new sesquiterpenoids (3-6), and 22 known compounds (7-28) were isolated from an ethanolic extract of roots of Alangium chinense. The absolute configurations of 1-6 were assigned by experimental and calculated ECD spectra. The skeleton of the compounds (1 and 2) has been reported only one time so far. Compounds 1, 13, and 23 exhibited antiviral activity against coxsackie virus B3 with IC50 values of 38-67 μM. Compounds 8 and 9 displayed neuritis inhibitory activity against microglial inflammation factor, with IC50 values of 6.4 and 10.1 μM, respectively. None of the compounds were cytotoxic in the MTT assay.

Soluble epoxide hydrolase inhibitory and anti-inflammatory components from the leaves of Eucommia ulmoides Oliver (duzhong)

Eucommia ulmoides leaves have been used as a functional food and drink in China. The purpose of this study was to identify the bioactive constituents with soluble epoxide hydrolase (sEH) inhibitory activity and anti-inflammatory properties. Twenty-seven known compounds (1-27) were isolated from the leaves of E. ulmoides Oliver, and their structures were identified by NMR and ESIMS analysis; three of these, 2,5-dimethoxy-3-glucopyranosyl cinnamic alcohol (11), foliasalacioside E2 (26), and icariside F2 (27), were obtained from this plant for the first time. Compounds 1-7 exhibited soluble epoxide hydrolase (sEH) inhibitory activity at 100 μM; among them, quercetin (1) and kaempferol (5) displayed potential activities with IC50 values of 22.5 ± 0.9 and 31.3 ± 2.6 μM, respectively, with noncompetitive inhibition mode. Nuclear factor kappa B (NF-κB) inhibitory activity of the isolated compounds was evaluated by the NF-κB liciferase assay in HepG2 cells. Compounds 1, 9, 20, and 27 displayed potent NF-κB inhibitory effects, with IC50 values of 15.14 ± 2.29, 15.23 ± 2.34, 16.88 ± 2.17, and 16.25 ± 2.19 μM, respectively, whereas other compounds showed weak inhibition of NF-κB transcriptional activity ranging from 17.54 to 92.6 μM. A structure-activity relationship of flavonoids 1-9 was also discussed. The results obtained in this work might contribute to the understanding of pharmacological activities of E. ulmoides leaves and further investigation on its potential application values for food and drug.

A new ursane-type nor-triterpenoid from the leaves of Eucommia ulmoides Oliv

A new ursane-type nortriterpenoid, (11S,12S)-4-methyl-11,12-epoxy-2-hydroxy-3-oxoursa-1,4-dine-28-oic acid γ-lactone (1), named ulmoidol A, together with ten known compounds: ulmoidol (2), corosolic acid (3), 2α,3α-dihydroxy-24-nor-4(23),12-oleanadien-28-oic acid (4), oleanolic acid (5), ursolic acid (6), cycloart-3β, 25-diol (7), foliasalacioside B1 (8), (6R,7E,9R)-9-hydroxy-4,7-megastigmadien-3-one-9-O-α-L-arabinopyranosyl-(1→6)-β-D-glucopyranoside (9), (6R,7E,9R)-9-hydroxy-4,7-megastigma-dien-3-one-9-O-β-D-xylopyranosyl-(1→6)-β-D-glucopyranoside (10), and quercetin 3-O-sambubioside (11) were isolated from the leaves of Eucommia ulmoides Oliv. The structure of compound 1 was determined by extensive spectroscopic analysis, and its absolute configuration was determined by CD experiments and a computational method. Compounds 3, 4, 7–10 were isolated from this plant for the first time. Compounds 3 and 4 showed inhibition to PTPIB activities, with IC(50) values of 0.69 and 3.98 μM, respectively.

Structural revisions of blumenol C glucoside and byzantionoside B

The absolute stereochemistry of blumenol C glucoside and byzantionoside B was revised here as (6R,9S)- and (6R,9R)-9-hydroxymegastigman-4-en-3-one 9-O-beta-D-glucopyranosides, respectively, by modified Mosher's method. The empirical rules of (13)C-NMR chemical shift to determine the absolute stereochemistry of C-9 of 9-hydroxymegastigmane 9-O-beta-D-glucopyranoside were also discussed.