RESUMEN
Sixteen more Amaryllidaceae alkaloids have been isolated from bulbs of Crinum kirkii Baker of which noraugustamine and 4a,N-dedihydronoraugustamine are hitherto unknown. Their structures and those of earlier known alkaloids have been established by physical and spectroscopic analysis. Application of 2D NMR techniques was used for complete characterization of the alkaloids as well as of 3-O-acetylsanguinine. 1,2-Diacetyllycorine and 3-O-acetylsanguinine showed activity against Trypanosoma brucci rhodesiense, the parasite associated with sleeping sickness. 3-O-acetylsanguinine also showed some activity against Trypanosoma cruzi.
Asunto(s)
Alcaloides/química , Crinum/química , Alcaloides/aislamiento & purificación , Alcaloides/farmacología , Antiprotozoarios/aislamiento & purificación , Antiprotozoarios/farmacología , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Estructura Molecular , Raíces de Plantas/química , EspectrofotometríaRESUMEN
The present paper discusses the effects of the crude extracts of Trichoderma spp. on a number of fungal and bacterial organisms. These include Paecilomyces variotii, Penicillium notatum, Nematospora corylii, Mucor miehei, Bacillus brevis, Bacillus subtilis, Enterobacter dissolvens and Sarcina lutea. The culture broth extracts of different isolates of Trichoderma harzianum, T. longibrachiatum and T. koningii cultured in different media were investigated individually for in-vitro antifungal and antibacterial activities by agar diffusion technique. The culture broth extracts of T. harzianum produced definite antifungal and antibacterial activities against most of the test organisms. The results indicate that the extracts were fungicidal and antibacterial at a concentration of 100 microg per 6mm paper disks. Trichoderma harzianum showed the highest activity while T. koningii showed the least activity against most of the test organisms especially the yeast Nematospora coryli. The results of this study indicate that the Trichoderma species especially T. harzianum is a possible source of useful antimicrobial agents against pathogenic microorganisms which include gram-negative, gram-positive, fungi and yeasts.
Asunto(s)
Pruebas de Sensibilidad Microbiana , Trichoderma , Antibacterianos/aislamiento & purificación , Antiinfecciosos , Antifúngicos/aislamiento & purificación , Bacillus subtilis/efectos de los fármacos , Fermentación , Trichoderma/efectos de los fármacosRESUMEN
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.
Asunto(s)
Carbono , Agua Subterránea , Bacterias , Sustancias Húmicas , Kenia , Estaciones del Año , Espectrofotometría , Espectrofotometría UltravioletaRESUMEN
The methanolic extract of the fresh root bark and berries of Solanum aculeastrum showed significant activity against host snails of schistosomiasis. The berries extract was more potent with 100% snail kill at 50 ppm. Fractionation increased activity with 100% mortality at 20 ppm. The aqueous and methanolic extracts of the berries showed moderate antimicrobial activity, increasing by fractionation.
Asunto(s)
Antibacterianos/farmacología , Biomphalaria/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Moluscocidas/farmacología , Fitoterapia , Extractos Vegetales/farmacología , Solanum , Animales , Antibacterianos/administración & dosificación , Antibacterianos/uso terapéutico , Frutas , Humanos , Moluscocidas/administración & dosificación , Moluscocidas/uso terapéutico , Extractos Vegetales/administración & dosificación , Extractos Vegetales/uso terapéutico , Raíces de Plantas , Esquistosomiasis/tratamiento farmacológicoRESUMEN
From the roots of the plant Tephrosia aequilata Baker, five flavonoids were isolated of which, 3,4:8,9-dimethylenedioxypterocarpan is reported for the first time. Its structure and those of the already known flavonoids were established by physical and spectroscopic analysis. Application of 2D NMR techniques was useful for complete characterization of the new pterocarpan as well as the other known flavonoids.
Asunto(s)
Flavonoides/química , Flavonoides/farmacología , Tephrosia/química , Animales , Línea Celular , Flavonoides/aislamiento & purificación , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Concentración 50 Inhibidora , Kenia , Leishmania donovani/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Resonancia Magnética Nuclear Biomolecular/métodos , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Plantas Medicinales/química , Plasmodium falciparum/efectos de los fármacos , Espectrometría de Masa por Ionización de Electrospray , Espectrofotometría Infrarroja , Espectrofotometría Ultravioleta , Trypanosoma/efectos de los fármacos , Trypanosoma/crecimiento & desarrolloRESUMEN
Solanum aculeastrum Dunal was investigated for the presence of molluscicidal compounds. This led to the isolation of solaculine A, from the root bark in addition to known steroidal alkaloids; solamargine and beta-solamarine from the berries. The structures were elucidated by spectroscopic techniques. Molluscicidal activity of the aqueous extracts of the berries and root bark, and the isolated compounds were investigated.
