RESUMO
Organic extracts of the leaves of Azadirachta indica A. Juss. yielded ten antitrypanosomal terpenoids. Three of these (1-3), are novel and are derivatives of nimbolide and nimbin. They were extracted from chloroform fraction of methanol extract. These compounds were found to exhibit strong antitrypanosomal activities against Trypanosoma brucei rhodesiense with MIC values ranging of 6.9, 15.6 and 7.8 µg/ml respectively and were more active than Cymerlarsan (a standard drug), which had an MIC value of 187.5 µg/ml when tested against T. b. rhodesiense. The structures were elucidated by spectroscopic methods including; NMR, MS, UV and IR.
Assuntos
Azadirachta/química , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Tripanossomicidas/farmacologia , Trypanosoma brucei rhodesiense/efeitos dos fármacos , Tripanossomíase Africana/tratamento farmacológico , Arsenicais/uso terapêutico , Cromatografia , Humanos , Limoninas/química , Tripanossomicidas/análise , Tripanossomicidas/uso terapêuticoRESUMO
Most people in areas surrounding Nairobi use untreated underground waters for their domestic chores. A study was carried out during the wet season (April-June) and the dry season (September-November) of the year 1994 to find out if these untreated underground waters contain dissolved organic carbon (DOC) and coliform bracteria. Out of the 40 sites sampled during both the wet and dry seasons, 11 contained colifrorm bacteria during the wet season, while only 2 contained the microbes during the dry season. The microbes were detected only in the wells. DOC was detected in 37 sites during the wet season and in 31 sites during the dry season within a range of 2.0-30.8 mg L(-1 ). DOC which mainly consists of humic and fulvic acids was quantified by measuring their absorbance at 360nm by UV-VIS spectrophotometry. The presence of coliform bacteria was detected by use of microbiological techniques.