Antiplasmodial and cytotoxic activity of galipinine and other tetrahydroquinolines from Galipea officinalis.

The antimalarial and toxicological properties of four tetrahydroquinoline alkaloids from Galipea officinalis trunk bark were studied. Crude extracts and pure alkaloids were tested for in vitro antimalarial activity on Plasmodium falciparum. The IC50 were evaluated after 24 and 72 h contact between compounds and the parasite culture, and ranged from 1.

Iridoids from Caryopteris x clandonensis.

In continuation of our phytochemical studies on Caryopteris x clandonensis (Lamiaceae), three further iridoids were isolated from the methanolic extract of the stems. Their structures were established by 1D and 2D NMR and MS analysis as a C-6 epimer of 8-O-acetylharpagide (6-epi-8-O-acetylharpagide), a derivative of harpagide which contained the unusual feature of a 3',4' seco-glycopyranosyl moiety (clandonoside II) and a methyl cetal of 8-O-acetylharpagide aglucone hydrate named clandonensine.

In vitro antimalarial activity of penduline, a bisbenzylisoquinoline from Isopyrum thalictroides.

Two bisbenzylisoquinolines, tetrandrine and penduline, were purified from Isopyrum thalictroides. When tested for antimalarial activity in vitro, penduline was efficient at concentrations fivefold lower than those of tetrandrine. In highly synchronized parasite cultures, penduline mostly interfered between the 8th and the 32nd hours of the parasite cycle.

Acridones from Vepris fitoravina and Vepris macrophylla.

Four acridones were isolated from the leaves of VEPRIS FITORAVINA and VEPRIS MACROPHYLLA (Rutaceae). Three of these alkaloids were identified as arborinine, evoxanthine, and 1,3-dimethoxy-10-methylacridan-9-one by comparison with authentic samples or by comparison of their properties with published data. The remaining alkaloid was identified on the basis of its spectral data as a new compound, 1-hydroxy-2,3,4-trimethoxyacridan-9-one.

[New furoquinolins from Monnieria trifolia].

Four new furoquinoline alkaloids (evolatine, evoxine, 6-methoxy-7-hydroxy-dictamnine, haplopine) are isolated from the leaves of Monnieria trifolia. The structures are elucidated by spectrometric methods and some chemical transformations.