Abstract
The analogue of brevifolin carboxylic acid and its methyl ester were isolated and identified from the aqueous ethanolic extract of the leaves of Chrzophora brocchiana in addition to eight known compounds identified as gallic acid, methyl and ethyl gallate, ellagic acid, monomethoxy and methylenedioxy ellagic acid, apigenin 7-O-glucoside and luteolin 7-O-glucoside. The structures were determined primarily by ESI-MS and NMR spectroscopy. The assignment of NMR signals was preformed by means of 1H–H COSY, HMQC and HMBC experiments. The antioxidant activity of the new compounds was determined by checking the scavenging activity against DPPH free radical.
Acknowledgements
We would like to thank Prof. Dr Benjamin Rodriguez (Instituto de Quimica Organica General, Madrid, spain) and Dr Alaa Gafar (NMR lab., NRC, Cairo, Egypt) for the NMR analysis.