Macrocarpins A-D, new cytotoxic nor-triterpenes from Maytenus macrocarpa.

Macrocarpins A (1), B (2), C (3) and D (4), four new nor-triterpenes, have been isolated from the roots of Maytenus macrocarpa. The structures were established by spectroscopic examinations. Natural compounds 1, 2, 4 and the acetyl derivative 1a are cytotoxic against four tumoral cell lines with IC50 values ranging between 0.4 and 5.2 microM.

Biological activities of some Argyranthemum species.

Seven species of the genus Argyranthemum were studied for antimicrobial and cytotoxic activities. Argyranthemum adauctum, A. foeniculaceum and A. frutescens showed antimicrobial activity against Gram-positive and Gram-negative and cytotoxic activity against HeLa and Hep-2 cell lines. Two new acetylenic compounds, frutescinol isovalerate and 3'-demethyl frutescinol isovalerate, were isolated from A. frutescens and their structures elucidated by spectroscopic studies.

Biological activity of secondary metabolites from Bupleurum salicifolium (Umbelliferae).

Secondary metabolites from Bupleurum salicifolium were tested against viruses, Gram-positive and Gram-negative bacteria, the yeast Candida albicans, the nematodes Globodera pallida and G. rostochiensis, the insect Spodoptera littoralis and the crustacean Artemia salina. These compounds were also tested against tumoral and non-tumoral cell lines. The polyacetylene 8S-heptadeca-2(Z)-9(Z)-diene-4,6-diyne-1,8-diol exhibited toxicity for A. salina and specific antibiotic activity against Gram-positive bacteria. Nine of the lignans and one coumarin showed toxicity for A. salina, and the lignans bursehernin and matairesinol inhibited the hatching of the two nematode species. These are the first lignans that have been reported as affecting phytoparasitic nematodes, and the first natural products known to have an effect on the hatching of G. pallida. Lignans may play a role in the defence mechanisms of potato plants, as allelopathic substances acting against cyst-forming nematodes.

Antibiotic activity and absolute configuation of 8S-heptadeca-2(Z),9(Z)-diene-4,6-diyne-1,8-diol from Bupleurum salicifolium.

A polyacetylene has been isolated from Bupleurum salicifolium. Its structure and absolute configuration were determined to be 8S-heptadeca-2(Z),9(Z)-diene-4,6-diyne-1,8-diol [1] by means of 1H- and 13C-nmr spectroscopic studies, including 1H-13C heteronuclear correlation (HMQC) and long-range correlation spectra with inverse detection (HMBC). Its absolute configuration was determined by application of the Horeau method. This compound exhibited significant antibiotic activity against the Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis. Also isolated during this investigation were the known compounds; betulin, herniarin, 6,7,8-trimethoxycoumarin, p-hydroxyphenethyl alcohol, pluviatolide, guamaroline, bursehernin, guayadequiol, kaerophyllin, and matairesinol dimethyl ether.

Inhibition of potato cyst nematode hatch by lignans fromBupleurum salicifolium (Unbelliferae).

A series of lignans fromBupleurum salicifolium Soland (Umbelliferae) were tested for nematostatic activity on the cysts and freed secondstage juveniles of the potato cyst nematodesGlobodera rostochiensis andG. pallida. None of the six lignans tested-bursehernin, matairesinol, syringaresinol, the novel product buplerol, guayarol, and a derivative, nortrachelogenin triacetate-showed nematicidal activity in an in vitro analysis with second-stage juveniles, but significant differences were noted when the lignans were assayed for nematostatic activity as cyst hatching inhibitors. Bursehernin and matairesinol showed the greatest activity, at concentrations of 50 ppm. This is the first known instance of a natural product inhibiting the hatch of the nematodeG. pallida. The HID (hatching inhibiting dose) of bursehernin was estimated, and some conclusions were drawn about the structure-activity relationships of the lignans under study.