Cryptobuchanosides A-G: seven previously undescribed triterpene glycosides from Cryptolepis buchananii R.Br. ex Roem. and Schult. with nitric oxide production inhibition activity.

In this study, nine triterpene glycosides including seven previously undescribed compounds (1-7), were isolated from leaves of Cryptolepis buchananii R.Br. ex Roem. and Schult. using various chromatographic methods. The chemical structures of the compounds were elucidated to be 3-O-ß-D-glucopyranosyl-(1 → 6)-ß-D-glucopyranosyluncargenin C 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (1), 3-O-ß-D-glucopyranosyl-(1 → 2)-ß-D-glucopyranosyluncargenin C 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (2), 3-O-ß-D-glucopyranosyl-(1 → 2)-ß-D-glucopyranosyluncargenin C 28-O-ß-D-glucopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (3), 3-O-ß-D-glucopyranosyl-(1 → 2)-ß-D-glucopyranosylhederagenin 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (4), 3-O-ß-D-glucopyranosylarjunolic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (5), 3-O-ß-D-glucopyranosyl-(1 → 2)-ß- D-glucopyranosyl-6ß,23-dihydroxyursolic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (6), 3-O-ß-D-glucopyranosyl-6ß,23-dihydroxyursolic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (7), asiatic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (8), and 3-O-ß-D-glucopyranosylasiatic acid 28-O-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (9), through infrared, high-resolution electrospray ionization mass spectrometry, one- and two-dimensional nuclear magnetic resonance spectral analyses. The isolates inhibited nitric oxide production in lipopolysaccharide-activated RAW 264.7 cells, with half-maximal inhibitory concentration (IC50) values of 18.8-58.5 µM, compared to the positive control compound, dexamethasone, which exhibited an IC50 of 14.1 µM.

Pregnane glycosides from the leaves of Dregea volubilis and their α-glucosidase and α-amylase inhibitory activities.

Three new pregnane glycosides, drevoluosides O-Q (1-3) along with five known volubiloside C (4), dreageoside A11 (5), 17ß-marsdenin (6), stavaroside H (7), and hoyacarnoside G (8) were isolated from the methanol extract of the Dregea volubilis leaves. Their structures were elucidated by chemical and spectroscopic methods. Compounds 6-8 showed significant anti α-glucosidase activity with the inhibitory percentages ranging from 32.6 to 47.1% at the concentration of 200 µM. Compound 3 showed significant inhibitory α-amylase activity with IC50 value of 51.3 ± 2.1 µM.

Flavonoid glycosides from Barringtonia acutangula.

Using various chromatographic separation techniques, ten flavonoid glycosides, including six new compounds namely barringosides A-F (1-6), were isolated from a methanol extract of the Barringtonia acutangula leaves. The structure elucidation was confirmed by spectroscopic analyses, including 1D and 2D NMR, and HR ESI MS. Their inhibitory effects on LPS-induced NO production in RAW264.7 cells were also evaluated. Among the isolated compounds, quercetin 3-O-ß-d-(6-p-hydroxybenzoyl)galactopyranoside (9) showed significant effect with an IC50 of 20.00±1.68µM. This is the first report of these flavonoid glycosides from Barringtonia genus and their inhibition on LPS-induced NO production in RAW264.7 cells was reported here for the first time.

Labdane-type diterpenoids from the rhizomes of Hedychium coronarium inhibit lipopolysaccharide-stimulated production of pro-inflammatory cytokines in bone marrow-derived dendritic cells.

The rhizomes of Hedychium coronarium have been used for the treatment of inflammation, skin diseases, headache, and sharp pain due to rheumatism in traditional medicine. From this plant, two new labdanes, 15-methoxylabda-8(17),11E,13-trien-16,15-olide (1) and 16-methoxylabda-8(17),11E,13-trien-15,16-olide (3), named hedycoronens A and B, as well as four known, labda-8(17),11,13-trien-16,15-olide (2), 16-hydroxylabda-8(17),11,13-trien-15,16-olide (4), coronarin A (5), and corronarin E (6) were isolated. Their chemical structures were elucidated by mass, 1D- and 2D-nuclear magnetic resonance (NMR) spectroscopy. They were evaluated for inhibitory effects on the lipopolysaccharide (LPS)-stimulated production of pro-inflammatory cytokines in bone marrow-derived dendritic cells. Among of them, compounds 1-3 were potent inhibitors of LPS-stimulated interleukin-6 (IL-6) and IL-12 p40, with IC(50) ranging from 4.1±0.2 to 9.1±0.3 µM. Compounds 1 and 3 showed moderate inhibitory activity on the tumor necrosis factor-α (TNF-α) production with IC(50) values of 46.0±1.3 and 12.7±0.3 µM. The remains of compounds showed inactivity. These results warrant further studies concerning the potential anti-inflammatory benefits of labdane-diterpenes from H. coronarium.

Chemical constituents of the rhizomes of Hedychium coronarium and their inhibitory effect on the pro-inflammatory cytokines production LPS-stimulated in bone marrow-derived dendritic cells.

The rhizomes of Hedychium coronarium have been used for the treatment of inflammation, skin diseases, headache, and sharp pain due to rheumatism in traditional medicine. From this plant, three new labdane-type diterpenes 1-3, named coronarins G-I as well as seven known 4-10, coronarin D, coronarin D methyl ether, hedyforrestin C, (E)-nerolidol, ß-sitosterol, daucosterol, and stigmasterol were isolated. Their chemical structures were elucidated by mass, 1D- and 2D-nuclear magnetic resonance spectroscopy. They were evaluated for inhibitory effects on lipopolysaccharide-stimulated production of pro-inflammatory cytokines in bone marrow-derived dendritic cells. Among of them, compounds 1, 2, and 6 were significant inhibitors of LPS-stimulated TNF-α, IL-6, and IL-12 p40 productions with IC(50) ranging from 0.19±0.11 to 10.38±2.34 µM. The remains of compounds showed inactivity or due to cytotoxicity. These results warrant further studies concerning the potential anti-inflammatory benefits of labdane-type diterpenes from H. coronarium.