RESUMO
A number of crude extracts from folk medicinal plants were screened for cytotoxicity against the human T-cell leukemia cell line. Fixed aliquots from a quantified cell suspension were incubated for three days in the presence of a control and several different concentrations of the given plant extract
Assuntos
Humanos , Azadirachta , Leucemia de Células T , Plantas Medicinais , Trinidad e TobagoRESUMO
A new sesquiterpene derivative named mochiquinone (1) was isolated from the Caribbean gorgonian coral Pseudopterogorgia rigida collected off northeastern Venezuela, along with the known compounds, alpha-curcumene, (-)-curcuphenol, (-)-curcuquinone, and (-)-curcuhydroquinone. The structure of the new compound was determined by spectroscopic analysis of its acetylated derivative and comparison with known compounds.
Assuntos
Cnidários/química , Sesquiterpenos/química , Acetilação , Animais , Região do Caribe , Cromatografia em Camada Delgada , Espectroscopia de Ressonância Magnética , Sesquiterpenos/isolamento & purificação , Espectrofotometria Infravermelho , Espectrofotometria UltravioletaRESUMO
Three new monotetrahydrofuran (mono-THF) acetogenins, anmontanins A-C (1-3) were isolated from the leaves of Annona montana. Anmontanin C (3) is the first stereochemically pure acetogenin reported to have a gamma-hydroxymethyl-gamma-lactone moiety. Two known mono-THF acetogenins, murisolin and annonacin, were isolated from the seeds of the plant. The structures of compounds 1-3 were elucidated by spectral methods and chemical derivatization.
Assuntos
Furanos/isolamento & purificação , Lactonas/isolamento & purificação , Árvores/química , Furanos/química , Lactonas/química , Espectroscopia de Ressonância Magnética , Modelos Químicos , Folhas de Planta/química , Espectrometria de Massas de Bombardeamento Rápido de ÁtomosRESUMO
A previously isolated trihydroxy-gorgosterol derivative (2), a new gorgosterol (3), and the known sterol cholestane-3beta,5alpha, 6beta-triol are reported from the Caribbean octocoral Eunicea laciniata collected off northeast Venezuela. Using high-resolution 2D NMR techniques, the total structural assignment and detailed stereochemistry of 2 is presented for the first time and the full structure of 3 advanced.
Assuntos
Colestanóis/isolamento & purificação , Colesterol/análogos & derivados , Colesterol/isolamento & purificação , Cnidários/química , Animais , Colestanóis/química , Colestanóis/farmacologia , Colesterol/química , Estrutura Molecular , Análise EspectralRESUMO
An investigation of the seeds of Swietenia macrophylla and S. aubrevilleana (Meliaceae) is reported. Three new compounds, augustineolide (1) and 3beta,6-dihydroxydihydrocarapin (2) from S. macrophylla and 6-acetoxyhumilinolide C (3) from S. aubrevilleana were isolated and characterized along with fifteen known compounds. Four of the compounds were subjected to an antifeedant bioassay on the final instar larvae of Spodoptera frugiperda. The antifeedant activity was comparable to that of bicyclononanolides previously tested.
Assuntos
Comportamento Alimentar/efeitos dos fármacos , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Limoninas , Spodoptera/fisiologia , Animais , Depressão Química , Compostos Heterocíclicos de 4 ou mais Anéis/química , Compostos Heterocíclicos de 4 ou mais Anéis/isolamento & purificação , Espectroscopia de Ressonância Magnética , Conformação Molecular , Espectrofotometria UltravioletaRESUMO
Competition experiments, employing 14C-labeled samples of glycerol and glycolaldehyde, indicate that in Escherichia coli B there are two independent pathways leading to pyridoxal. In mutant WG2 (and therefore presumably also in the wild strain) the major pathway utilizes glycerol and related trioses as the sole carbon source in the construction of the C8N skeleton of pyridoxol: C-1, -3 of glycerol yields C-2', -3, -4', -5' and -6, C-2 of glycerol yields C-2, -4, and -5 of the vitamin. In the minor pathway glycolaldehyde and not glycerol supplies C-5 and C-5' of pyridoxol, while glycerol is the source of the other 6 carbon atoms. In mutant WG3 the major route is blocked and the "glycolaldehyde pathway" becomes the sole source of vitamin B6.
Assuntos
Acetaldeído/análogos & derivados , Escherichia coli/metabolismo , Piridoxina/biossíntese , Acetaldeído/metabolismo , Radioisótopos de Carbono , Glicerol/metabolismo , Marcação por Isótopo , Mutação , Especificidade da EspécieRESUMO
A number of crude extracts from folk medicinal plants were screened for cytotoxicity against the human T-cell leukemia cell line. Fixed aliquots from a quantified cell suspension were incubated for three days in the presence of a control and several different concentrations of the given plant extract