RESUMO
Two new sesterterpene sulfates, hipposulfates A (1) and B (2), have been isolated from an Okinawan sponge, Hippospongia cf. metachromia and their structures elucidated by interpretation of spectroscopic data. Both compounds contain an enolsulfate functionality. Hipposulfate A (1) showed moderate cytotoxicity.
Assuntos
Poríferos/química , Terpenos/isolamento & purificação , Animais , Antineoplásicos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Células HT29 , Humanos , Leucemia P388 , Espectroscopia de Ressonância Magnética , Sesterterpenos , Terpenos/química , Células Tumorais CultivadasRESUMO
Two new ellagitannins, thonningianins A (1) and B (2), have been isolated from the African medicinal herb Thonningia sanguinea and their structures elucidated by interpretation of spectroscopic data. Both 1 and 2 showed strong free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) as shown by ESR analysis.
Assuntos
Antioxidantes/isolamento & purificação , Taninos Hidrolisáveis , Picratos , Plantas Medicinais/química , Taninos/isolamento & purificação , África , Antioxidantes/farmacologia , Bepridil/análogos & derivados , Bepridil/química , Compostos de Bifenilo , Sequestradores de Radicais Livres/isolamento & purificação , Sequestradores de Radicais Livres/farmacologia , Radicais Livres/química , Espectroscopia de Ressonância Magnética , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta , Taninos/farmacologiaRESUMO
We previously reported that the mold Monascus anka, traditionally used for fermentation of food, showed antioxidant and hepatoprotective actions against chemically induced liver injuries. In the present study, the antioxidant component of M. anka was isolated and identified. The antioxidant was elucidated to be dimerumic acid. DPPH (1,1-diphenyl-2-picrylhydrazyl) radical was significantly scavenged by the antioxidant whereas hydroxyl radical and superoxide anion were moderately scavenged. When the antioxidant (12 mg/kg) was given to mice prior to carbon tetrachloride (CCl(4), 20 microl/kg, ip) treatment, the CCl(4)-induced liver toxicity in mice seen in an elevation of serum aspartate aminotransferase and alanine aminotransferase activities was depressed, suggesting the hepatoprotective action of the antioxidant. The liver microsomal glutathione S-transferase activity, which is known to be activated by oxidative stress or active metabolites, was increased by CCl(4) treatment and the increase was also depressed by pretreatment with the mold antioxidant. Thus these data confirmed that the dimerumic acid isolated from M. anka is the potential antioxidant and protective against CCl(4)-induced liver injury.
Assuntos
Antioxidantes/química , Sequestradores de Radicais Livres/química , Piperazinas/química , Leveduras/química , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Tetracloreto de Carbono/toxicidade , Espectroscopia de Ressonância de Spin Eletrônica , Glutationa Transferase/metabolismo , Radical Hidroxila/metabolismo , Fígado/efeitos dos fármacos , Fígado/patologia , Espectroscopia de Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos , Estrutura Molecular , Estresse Oxidativo , Piperazinas/farmacologia , Superóxidos/metabolismoRESUMO
Ptilomycalin A inhibited the brain Na+, K(+)-ATPase and Ca2(+)-ATPase from skeletal sarcoplasmic reticulum with an IC50 value of 2 microM and 10 microM, respectively. Kinetic analysis of the inhibitory effects of ptilomycalin A suggests that the inhibition of Na+, K(+)-ATPase is a competitive-, an uncompetitive- and an anticompetitive-type with respect to ATP, Na+ and K+, respectively. The inhibition of Ca2(+)-ATPase by ptilomycalin A is a competitive- or an uncompetitive-type with respect to ATP or Ca2+, respectively. These results suggest that ptilomycalin A interacts with ATP at the ATP binding site of Na+, K(+)-ATPase or Ca2(+)-ATPase. Ptilomycalin A has become a useful biochemical tool for clarifying the ATP binding site in both enzymes.