[Studies on the chemical constituents of Murraya kwangsiensis]

AIM

To investigate the chemical constituents of Murraya kwangsiensis.

METHODS

Compounds were isolated by silica gel column chromatography and TLC method, respectively. Structures of compounds were elucidated by spectral (UV, IR, MS, 1HNMR and 13CNMR) analysis.

RESULTS

Five carbazole alkaloids and two other compounds were isolated and identified. Six of them are known compounds: murrayafoline A, murrayanine, koenine, isomahanine, palmitic acid and beta-sitosterol. One is a new alkaloid, named kwangsine.

CONCLUSION

A new alkaloid, named kwangsine, was isolated from Murraya kwangsiensis Var. Six known compounds were isolated from this plant for the first time.

Vasorelaxing effects of Caesalpinia sappan involvement of endogenous nitric oxide

Methanolic extract and two purified compounds (brazilin and hematoxylin) from Caesalpinia sappan were examined for their relaxant effects in isolated rat thoracic aorta. The methanolic extract significantly and dose-dependently relaxed the alpha1-receptor agonist phenylephrine-precontracted aortic rings, without affecting passive tension of these vessels. Removal of the vascular endothelium, inhibition of nitric oxide (NO) synthase with 0.1 mM Nomega-nitro-L-arginine and of cGMP biosynthesis with 10 microM methylene blue abolished the vasorelaxant effects of the herbal extract at doses up to 30 microg/ml. Similar vasorelaxant effects were observed with brazilin and hematoxylin. Therefore, these results suggest that brazilin and hematoxylin may be responsible for the vascular relaxant effects of C. sappan, via endogenous NO and subsequent cGMP formation. The vascular relaxant effects of the plant may contribute to its therapeutic actions.

A new anti-HIV triterpene from Geum japonicum

Geumonoid (1), a new triterpene, was isolated from Geum japonicum. Its structure was elucidated on the basis of 1D, 2D NMR and MS spectroscopic analysis. Compound 1 showed inhibitory activity against HIV-1 protease.

A new furofuran mono-lactone from Forsythia suspensa

A new furofuran mono-lactone, named forsythenin, was isolated from the fruits of Forsythia suspensa, together with the known compounds, ocotillone, ocotillol monoacetate, (6'-O-palmitoyl)-sitosterol-3-O-beta-D-glucoside and palmitic acid. The structure of the new compound was elucidated on the basis of spectroscopic means and X-ray crystallography.

Two new caffeyol glycosides from Forsythia suspensa

Two new caffeoyl glycosides of phenethyl alcohol, suspensaside A (1) and suspensaside B (2), were isolated from the fruits of Forsythia suspensa. Also obtained in this investigation were two known compounds forsythiaside (3) and suspensaside (4). The structures of compounds 1 and 2 were established by ID and 2D NMR techniques and chemical methods.

New Quinoid Glycosides from Forsythia suspensa

Three novel compounds, suspenolic acid (1), forsythenside A (2), and forsythenside B (3), have been isolated from the fruits of Forsythia suspensa. Their structures were elucidated by spectral methods and chemical reactions.