RESUMO
Three new rings B and D opened limonoids, two mexicanolides named khayanone (1) and 2-hydroxyseneganolide (2) and one rearranged phragmalin limonoid of 1-O-acetylkhayanolide A (3), were isolated together with six known B,D-seco compounds from the acetone extract of the stem bark of Khaya senegalensis. Structures of new compounds were elucidated by spectroscopic means, and the absolute stereochemistry of 1 was established by CD study of the dibenzoate derivative. The insect antifeedant and antiviral activities of the new compounds were also determined.
Assuntos
Fármacos Anti-HIV/isolamento & purificação , Limoninas , Meliaceae/química , Extratos Vegetais/isolamento & purificação , Triterpenos/isolamento & purificação , Animais , Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Cromatografia em Camada Fina , Relação Dose-Resposta a Droga , Egito , Comportamento Alimentar/efeitos dos fármacos , HIV-1/efeitos dos fármacos , Larva/metabolismo , Espectroscopia de Ressonância Magnética , Conformação Molecular , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Caules de Planta/química , Plantas Medicinais/química , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta , Spodoptera/metabolismo , Estereoisomerismo , Triterpenos/química , Triterpenos/farmacologia , Células Tumorais Cultivadas/efeitos dos fármacosRESUMO
A new bis-quinolizidine alkaloid, xestosin A (1), possessing cis- and trans-quinolizidine nuclei, has been isolated from the Papua New Guinean sponge Xestospongia exigua. The structure was determined by spectrometric and single-crystal X-ray analyses.
Assuntos
Alcaloides/isolamento & purificação , Poríferos/química , Quinolizinas/isolamento & purificação , Alcaloides/química , Animais , Estrutura Molecular , Quinolizinas/química , Análise Espectral , Difração de Raios XRESUMO
Six new xenicane diterpenes have been isolated from the acetone extract of the soft coral Xenia florida. Two of them are diterpenes containing a bicyclic [4.3.1] ring system. Three of them seem to be precursors for diterpenes possessing the bicyclic [4.3.1] ring system. One is a common monocarbocyclic diterpene with a cyclononane skeleton.
Assuntos
Cnidários/química , Diterpenos/química , Acetona , Animais , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Diterpenos/isolamento & purificação , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Conformação Molecular , Solventes , Espectrofotometria Infravermelho , Espectrofotometria UltravioletaRESUMO
Three new cembranes, including one with a 13-membered carbocyclic ring, have been isolated from the soft coral Sarcophyton sp.
RESUMO
Seven new xenia diterpenes have been isolated from the soft coral, Xenia florida. Four of them possess a bicyclic [4.3.1] ring system. The three others, which contained a cyclononane skeleton with an epoxide, seem to be precursors for diterpenes with a bicyclic [4.3. 1] ring system.
RESUMO
Two new bromopyrroles and a new diterpene possessing a 9-methyladenium moiety have been isolated from the Papua New Guinean sponge Agelas nakamurai Hoshino.
RESUMO
Three growth inhibitors which might be involved in phototropism of Sakurajima radish (Raphanus sativus var. hortensis f. gigantissimus Makino) hypocotyls, were isolated as crystalline forms from light-exposed radish seedlings and identified as cis- and trans-raphanusanins and 6-methoxy-2,3,4,5-tetrahydro-1,3-oxazepin-2-one (designated raphanusamide). The cis- and trans-raphanusanins inhibited growth of etiolated radish hypocotyls at concentrations higher than 1.5 micromolar, raphanusamide at concentrations higher than 20 micromolar.
RESUMO
A neutral growth inhibitor, for which the name raphanusanin is proposed, has been isolated in crystalline form from light-exposed Sakurajima radish (Raphanus sativus var. hortensis f. gigantissimus Makino) seedlings and identified as a new compound, 3-methoxy-4-methylthio-2-piperithione by spectrometric analyses.Applied raphanusanin inhibited the hypocotyl growth of etiolated radish and lettuce seedlings at concentrations higher than 1.5 x 10(-6) molar.The endogenous raphanusanin contents in cotyledons and hypocotyls of radish seedlings increased more under red light, but decreased or maintained the initial level in the dark. Its content in roots showed almost no change between the light and dark materials.