In vitro antiplasmodial activity, cytotoxicity and chemical profiles of sponge species of Cuban coasts.

Aqueous and organic fractions from the crude extracts of 17 sponge species collected at Boca de Calderas, Havana, Cuba were analysed. The organic fractions of Mycale laxissima, Clathria echinata and Agelas cerebrum exhibited values of concentrations causing 50% inhibition of in vitro growth of Plasmodium berghei (IC50) of 42.3 ± 5.

Furfuran lignans and a flavone from Artemisia gorgonum Webb and their in vitro activity against Plasmodium falciparum.

The chemical composition of the aerial parts of the Cape Verdean endemic shrub Artemisia gorgonum Webb (Asteraceae) was careful investigated, which led to the isolation and identification of six known furfuran lignans: eudesmin (1), magnolin (2), epimagnolin A (3), aschantin (4), kobusin (5), sesamin (6) and a flavone: artemetin (7). Compounds 1-7 were evaluated in vitro for their cytotoxicity in a screening panel consisting of various mammalian tumor cell lines, for their antimalarial activity against chloroquine-resistant Plasmodium falciparum (FcB1 strain) and for their cytotoxicity against murine normal cells (CFU-GM). While no promising cytotoxicity against human tumor cells were noticed, marginal potency and selectivity was found for compounds 1-5 against murine colon 38.

Antimalarial activity of new acridinone derivatives.

Malaria is one of the major threats concerning world public health. Resistance to the current antimalarial drugs has led to searches for new antimalarial compounds. Acridinone derivatives have recently demonstrated to be active against malaria parasite.

Polar alkaloids from the Caribbean marine sponge Niphates digitalis.

A method involving flash chromatography, semi-preparative phenylhexyl RP HPLC-DAD-ELSD combined with analytic polar-RP HPLC-DAD, was applied to separate and purify six highly nitrogenated bases and a bicyclic amidine alkaloid, the major components of the marine sponge Niphates digitalis. Their structures were identified as 1,8-diazabicyclo[5.4.

Generation of an affinity matrix useful in the purification of natural inhibitors of plasmepsin II, an antimalarial-drug target.

An affinity matrix containing the antimalarial drug target Plm II (plasmepsin II) as ligand was generated. This enzyme belongs to the family of Plasmodium (malarial parasite) aspartic proteinases, known as Plms (plasmepsins). The procedure established to obtain the support has two steps: the immobilization of the recombinant proenzyme of Plm II to NHS (N-hydroxysuccinimide)-activated Sepharose and the activation of the immobilized enzyme by incubation at pH 4.

Antimalarial activity from three ascidians: an exploration of different marine invertebrate phyla.

Recent research suggests that marine organisms may produce compounds with activity against malaria parasites. Of a total of 27 aqueous extracts from different marine species, collected on the northwest Cuban coast, 20 were considered as showing no significant activity against Plasmodium falciparum F32, with minimum inhibitory concentrations (MIC) >500 microg/ml, while seven extracts (MIC < or =500 microg/ml) were selected for further investigation by determining their selectivity indices and in vivo antimalarial activity. Three species of tunicates were chosen, as more than 50% reduction of P.

A heterogeneous enzymatic assay for quantification of Plasmepsin II activity and the evaluation of its inhibitors.

The emergence and worldwide spreading of Plasmodium falciparum strains that shown to be resistant to traditional drugs is considered a very serious health problem, given the high mortality and morbidity rate of Malaria. In the search for new drugs against this parasite, Hb hydrolyzing enzymes, such as Plasmepsin II (Plm II), have been classified as very promising targets for therapeutic attacks. In this work, it is developed a cheap and high-throughput heterogeneous enzymatic assay for measuring Plasmepsin II activity in order to use it as a tool in the discovery of new inhibitors of this enzyme.