Indole and aminoimidazole moieties appear as key structural units in antiplasmodial molecules.

From a library of compounds of natural sources, a big series of molecules was chosen by random sampling to evaluate their in vitro antimalarial activity against Plasmodium falciparum and their antifungal activity against Candida sp. From 184 molecules tested, no molecules were active against Candida sp. (MIC>10μg/ml) whereas 13 clearly showed high antiplasmodial activity in vitro, with an IC(50) less than 1μg/ml against the chloroquine-resistant strain of P.

Homophymines B-E and A1-E1, a family of bioactive cyclodepsipeptides from the sponge Homophymia sp.

Nine new cyclodepsipeptides, homophymines B-E (2-5) and A1-E1 (1a-5a), were isolated from the polar extracts of the sponge Homophymia sp. The new structures, featuring new polyketide-derived end groups, were determined by interpretation of NMR and MS data. The configurations of the new end groups was secured by the application of J-based configurational analysis.

Homophymine A, an anti-HIV cyclodepsipeptide from the sponge Homophymia sp.

A new anti-HIV cyclodepsipeptide, homophymine A, was isolated from a New Caledonian collection of the marine sponge Homophymia sp. The structure of homophymine A was determined by interpretation of spectroscopic data, acid hydrolysis, and LC-MS analysis. Homophymine A contains 11 amino acid residues and an amide-linked 3-hydroxy-2,4,6-trimethyloctanoic acid moiety.

Girolline: a potential lead structure for antiplasmodial drug research.

Girolline is a 2-aminoimidazole derivative extracted from Cymbastela cantharella (a New-Caledonian sponge) that has shown antitumor activity. In this study, we investigated its antimalarial activity and the point of action within the erythrocytic cycle of Plasmodium falciparum. Initially, we tested girolline and some synthetic analogues in vitro against four P.

Girolline interferes with cell-cycle progression, but not with translation.

Girolline is a 2-aminoimidazole derivative with cytotoxic activity. It affects the survival of exponentially growing leukaemic cultured cells and has a significant antitumour activity on grafted murine tumours in vivo. In vitro studies showed that girolline affected protein synthesis by interfering with the translation termination process.

Time-dependent inhibitors of trypanothione reductase: analogues of the spermidine alkaloid lunarine and related natural products.

The macrocyclic spermidine alkaloid lunarine 1 from Lunaria biennis is a competitive, time-dependent inhibitor of the protozoan oxidoreductase trypanothione reductase (TryR), a promising target in drug design against tropical parasitic diseases. Various molecules related to 1 and the alkaloid itself have been synthesized in racemic form and evaluated against TryR in order to determine the key features of 1 that are associated with time-dependent inhibition. Kinetic data are consistent with an inactivation mechanism involving a conjugate addition of an active site cysteine residue onto the C-24-C-25 double bond of the tricyclic nucleus of 1.