Chemical and biological study of Mentha suaveolens Ehrh. cultivated in Egypt
Abstract
Investigation of the different fractions of the ethanolic extract of the aerial parts of M. suaveolens growing in Egypt yielded nine compounds; two new triterpenes [3β-acetyl -22α-hydroxy ursa-12,20-diene (compound 1) and 2α, 3β-dihydroxy-olean-18-en-29-oic acid (compound 7)] and nine known compounds: a sterol and its glucoside; β-sitosterol (compound 2) and β-sitosterol-3-O- β-D-glucoside (compound 4), a triterpene; oleanolic acid (compound 3), two monoterepenes; dihydrolimonene (compound 5) and 7-hydroxy-p-cymene (compound 6), two flavonoids; isoquercitrin (compound 8) and rutin (compound 9) which were isolated from M. suaveolens Ehrh. for the first time. The structures of the isolated compounds were identified by spectral data (UV, MS, 1D and 2D-NMR) and comparison with authentic samples. Moreover, the ethanolic extract showed potent analgesic activity as compared to indomethacin. The ethyl acetate fraction was the most potent as anti-inflammatory (88%), followed by the ethanolic extract (82.9%) as compared with indomethacin. The ethanolic extract and its four subfractions showed a moderate inhibitory activity against the tested human pathogenic bacteria. Key words: Mentha suaveolens, anti-inflammatory, analgesic, flavonoids, sterols, triterpenes.