Cornigerin, A new Lignan from the Hepatoprotective Active Fractions of Cynara cornigera
The 70% ethanol and aqueous extracts of the aerial parts of Cynara cornigera and its fractions were subjected to hepatoprotective assays using Wistar albino rats at a dose of 500 and 250 mg/kg. Liver injury was induced in rats using carbon tetrachloride. The biochemical parameters such as aspartate aminotrans-ferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and total bilirubin were estimated as reflections of the liver condition. The ethyl acetate and n-butanol fractions of the 70% ethanolic extracts showed promising hepatoprotective activity. Phytochemical investigation of these active fractions led to the isolation of a new lignan, cornigerin (1) along with dicaffoeyl quinic acid and four known flavones. The chemical structure of the new compound was established by UV, HRESIMS, EIMS, 1D and 2D NMR experiments as 7,8-trans -7',8'-trans- 7'',8''-cis-8,8'- trans-4,4'',9,9''- tetrahydroxy-3,3',3''-trimethoxy-4',8''-5',7''-dioxy-7,9'-epoxy-lignane-7'-ol (1).
Acknowledgements: We are thankful to Dr. Bharthi Avula and Dr. Maged Saad Abdel Kader for HRESMS and hepatoprotective assays respectively. SME is thankful to the Egyptian government for funding