RESUMEN
A previously undescribed coumarin and a new coumarino-lignan, together with the known compounds scopoletin and cleomiscosins A, C, and D, have been isolated from the root bark of Hibiscus syriacus, and their structures were assigned on the basis of various spectral studies. The coumarin analogue and scopoletin inhibited monoamine oxidase with moderate IC(50) values. The new coumarino-lignan and cleomiscosin C showed lipid peroxidation inhibitory activity comparable to vitamin E.
Asunto(s)
Antioxidantes/aislamiento & purificación , Cumarinas/aislamiento & purificación , Dioxanos/aislamiento & purificación , Lignanos/aislamiento & purificación , Malvaceae/química , Inhibidores de la Monoaminooxidasa/aislamiento & purificación , Animales , Antioxidantes/química , Antioxidantes/farmacología , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Cromatografía Líquida de Alta Presión , Cumarinas/química , Cumarinas/farmacología , Dioxanos/química , Dioxanos/farmacología , Técnicas In Vitro , Concentración 50 Inhibidora , Corea (Geográfico) , Lignanos/química , Lignanos/farmacología , Peroxidación de Lípido/efectos de los fármacos , Espectroscopía de Resonancia Magnética , Ratones , Microsomas Hepáticos/efectos de los fármacos , Estructura Molecular , Inhibidores de la Monoaminooxidasa/química , Inhibidores de la Monoaminooxidasa/farmacología , Raíces de Plantas/química , Plantas Medicinales/química , Ratas , Escopoletina/farmacología , Espectrofotometría Infrarroja , Espectrofotometría Ultravioleta , Relación Estructura-Actividad , Vitamina E/farmacologíaRESUMEN
A new lignan named as hibiscuside, (+)-pinoresinol 4-O-[beta-glucopyranosyl (1--->2)-alpha-rhamnoside] (1), and a known lignan, syringaresinol (2) were isolated from the root bark of Hibiscus syriacus together with two feruloyltyramines (3,4) and three known isoflavonoids (5,6,7). The structures of these compounds have been established on the basis of their NMR, mass UV spectra. Among these phenolic compounds, 6"-O-acetyldaidzin (5), 6"-O-acetylgenistin (6), and 3-hydroxydaidzein (7) with IC(50) values of 8.2, 10.6, and 4.1 microM, respectively, significantly inhibited lipid peroxidation in rat liver microsomes. Hibiscuside (1), E- and Z-N-feruloyl tyramines (3,4) exhibited moderate antioxidant activity.
Asunto(s)
Antioxidantes/química , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Disacáridos/química , Lignanos/química , Malvaceae/química , Animales , Antioxidantes/aislamiento & purificación , Antioxidantes/farmacología , Compuestos Bicíclicos Heterocíclicos con Puentes/aislamiento & purificación , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Disacáridos/aislamiento & purificación , Disacáridos/farmacología , Furanos/química , Furanos/aislamiento & purificación , Glicósidos , Técnicas In Vitro , Lignanos/aislamiento & purificación , Lignanos/farmacología , Peroxidación de Lípido/efectos de los fármacos , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/metabolismo , RatasRESUMEN
Three new naphthalenes, designated as syriacusins A-C, were isolated from the root bark of Hibiscus syriacus. These compounds were identified as 2,7-dihydroxy-6-methyl-8-methoxy-1-naphthalenecarbaldehyde, 2-hydroxy-6-hydroxymethyl-7,8-dimethoxy-1-naphthalenecarbaldehyde, 1-carboxy-2,8-dihydroxy-6-methyl-7-methoxynaphthalenecarbolactone (1-->8), respectively, on the basis of various spectral studies. The compounds inhibited lipid peroxidation with IC50s of 0.54, 5.90 and 1.02 micrograms ml-1, respectively. The first compound also showed cytotoxicity against some human cancer cell lines with an ED50 of 1.5-2.4 micrograms ml-1.