RESUMO
A visible light mediated, but photocatalyst-free method for the oxidative α-CH functionalization of tertiary amines with a broad scope of carbon- and heteroatom nucleophiles using polyhalomethanes has been developed. In addition, the pivotal visible light triggered activation of polyhalomethanes offers mild conditions for efficient Kharasch-type additions onto non-activated olefins. Preliminary mechanistic studies are reported.
RESUMO
The latex of Croton draco, its extracts and several latex components have been investigated for their influence on both classical (CP) and alternative (AP) activation pathways of the complement system using a hemolytic assay. The best inhibition was found for the classical pathway. The latex, ethyl acetate and ethyl ether extracts exhibited extremely high inhibition on the CP (94, 90 and 77%, respectively) at a concentration of 1 mg/ml. The flavonoid myricitrin, the alkaloid taspine and the cyclopeptides P1 and P2 showed high inhibition on CP (83, 91, 78 and 63%, respectively) at a concentration of 0.9 mM.
Assuntos
Ativação do Complemento/efeitos dos fármacos , Proteínas Inativadoras do Complemento/isolamento & purificação , Croton/química , Hemólise/efeitos dos fármacos , Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Sequência de Aminoácidos , Animais , Catequina/isolamento & purificação , Catequina/farmacologia , Proteínas Inativadoras do Complemento/farmacologia , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Espectroscopia de Ressonância Magnética , Peptídeos Cíclicos/química , Peptídeos Cíclicos/isolamento & purificação , Peptídeos Cíclicos/farmacologia , SuínosRESUMO
The fruits of Myrsine africana afforded two new benzoquinone derivatives, methylvilangin and methylanhydrovilangin. On the other hand, from the fruits of Maesa lanceolata two more novel compounds; 2,5-dihydroxy-3-(nonadec-14-enyl)-benzoquinone and lanciaquinone were isolated. Their structural elucidation was achieved by spectroscopic measurements including 2D NMR experiments.
Assuntos
Benzoquinonas/química , Benzoquinonas/isolamento & purificação , Primulaceae/química , Acetilação , Frutas/química , Metilação , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
From the roots of Millettia erythrocalyx, 6-methoxy-[2",3":7,8]-furanoflavanone, 2,5-dimethoxy-4-hydroxy-[2",3":7,8]-furanoflavan, and 3,4-methylenedioxy-2',4'-dimethoxychalcone were isolated, along with ten other known flavonoids. Their structures were elucidated on the basis of analyses of their spectroscopic data.
Assuntos
Chalcona/química , Chalcona/isolamento & purificação , Flavanonas , Flavonoides/química , Flavonoides/isolamento & purificação , Millettia/química , Raízes de Plantas/química , Chalcona/análogos & derivados , Chalconas , Espectroscopia de Ressonância Magnética , Estrutura MolecularRESUMO
From the stem bark of Millettia erythrocalyx, three new compounds, namely, millettocalyxins A-C (1-3), and the new natural product pongol methyl ether (4) were isolated, along with 10 other known compounds. The structures of the new isolates were elucidated on the basis of spectroscopic data interpretation.