RESUMO
Fungal pathogens continue to pose challenges to humans and plants despite efforts to control them. Two coumarins, robustic acid and thonningine-C isolated from Millettia thonningii, show promising activity against the fungus Candida albicans with minimum fungicidal concentration of 1.0 and 0.5 mg/mL, respectively. Molecular modelling against the putative bio-molecular target, lanosterol 14α-demethylase (CYP51), revealed a plausible binding mode for the active compounds, in which the hydroxyl group binds with a methionine backbone carboxylic group blocking access to the iron catalytic site. This binding disrupts the synthesis of several important sterols for the survival of fungi.
Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Cumarínicos/farmacologia , Millettia/química , Esterol 14-Desmetilase/química , Antifúngicos/química , Domínio Catalítico/efeitos dos fármacos , Cumarínicos/química , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Isoflavonas/química , Isoflavonas/farmacologia , Testes de Sensibilidade Microbiana , Modelos Moleculares , Simulação de Acoplamento Molecular , Estrutura Molecular , Ligação Proteica , Esterol 14-Desmetilase/metabolismo , Relação Estrutura-AtividadeRESUMO
Bioactivity-guided fractionation of extracts of roots and leaves of Cajanus cajan afforded 8 compounds: betulinic acid, biochanin A, cajanol, genistein and 2'-hydroxygenistein, longistylin A and C, and pinostrobin. The two stilbenes, longistylin A and C, and betulinic acid showed a moderately high in vitro activity against the chloroquine-sensitive Plasmodium falciparum strain 3D7.
Assuntos
Antimaláricos/farmacologia , Cajanus , Fitoterapia , Extratos Vegetais/farmacologia , Plasmodium falciparum/efeitos dos fármacos , Animais , Antimaláricos/administração & dosagem , Antimaláricos/uso terapêutico , Humanos , Malária Falciparum/tratamento farmacológico , Testes de Sensibilidade Parasitária , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Folhas de Planta , Raízes de PlantasRESUMO
Bioguided fractionation of extracts of Aframomum latifolium and A. sceptrum (Zingiberaceae) resulted in isolation of (+)-( S)-nerolidol and seven labdanes, coronarin B, galanal A and B, galanolactone, ( E)-8beta,17-epoxylabd-12-ene-15,16-dial, (+)-( E)-labda-8(17), 12-diene-15,16-dial and its diethyl acetal, the latter being presumably an isolation artefact. The labdanes show a modest in vitro activity against a chloroquine-sensitive Plasmodium falciparum strain.