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
Ovalbumin was detected in developing chicken eggs. The large majority of these ovalbumin molecules was found to be in a heat-stable form reminiscent of S-ovalbumin. About 83 and 90% of the ovalbumin population was in a heat-stable form in day 14 or stage 40 amniotic fluid and day 18 or stage 44 egg yolk, respectively, whereas ovalbumin in newly deposited eggs was in the heat-unstable, native form. Purified preparations of stable ovalbumin from egg white and amniotic fluid showed a less ordered configuration than native ovalbumin, as analyzed by circular dichroism and differential scanning calorimetry. In addition, mass spectrometric analysis exhibited distinct size microheterogeneity between the stable and native forms of ovalbumin. Immunohisotochemical study revealed that ovalbumin was present in the central nervous system and other embryonic organs. These results indicated that egg white ovalbumin migrates into the developing embryo while changing its higher order structure.
Assuntos
Ovalbumina/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Varredura Diferencial de Calorimetria , Embrião de Galinha , Cromatografia por Troca Iônica , Dicroísmo Circular , Primers do DNA , Clara de Ovo , Eletroforese em Gel de Poliacrilamida , Embrião não Mamífero , Temperatura Alta , Ovalbumina/química , Ovalbumina/genética , Ovalbumina/isolamento & purificação , RNA Mensageiro/genéticaRESUMO
The root bark of Melia toosendan afforded four new limonoids with a C-19/C-29 bridged acetal structure, together with two known limonoids, 12α-hydroxyamoorastatone and its 12-acetate. The new compounds were elucidated as 1-O-acetyltrichilin H and 29-O-substituted amoorastatone derivatives, named neoazedarachins A, B and D, by spectroscopic and chemical means. Their antifeedant activity was also studied.
