Cornigerin, a new sesqui-lignan from the hepatoprotective fractions of Cynara cornigera L.

The ethanol extract of Cynara cornigera L. was fractionated and the fractions were subjected to hepatoprotective assays using Wistar albino rats at a dose of 500 and 250mg/kg. The liver injury was induced in rats using carbon tetrachloride. Biochemical parameters such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and total bilirubin were estimated as reflections of the liver condition, with silymarin as a positive control. Phytochemical investigation and chromatographic separation of the hepatoprotective fractions led to the isolation of a new sesqui-lignan namely cornigerin (1), along with eight known compounds: apigenin (2), luteolin (3), β-sitosterol glycoside (4), apigenin 7-O-β-D-glucopyranoside (5), luteolin-7-O-β-D-glucopyranoside (6), apigenin-7-O-rutinoside (7), cynarin 1,5-di-O-caffeoylquinic acid (8), and apigenin-7-O-β-D-glucuronide (9). This is the first report for the isolation of 8 and 9 from this plant.