Phytochemical and Biological Study of Melissa officinalis (Family Lamiaceae) Cultivated in Egypt

Abstract

Phytochemical investigation of 70% aqueous methanol extract of leaves of lemon balm (Melissa officinalisL., Lamiaceae) was subjected to different chromatographic separation techniques. The structures of isolated compounds were determined based on spectral data (UV, 1 H-NMR, 13 CNMR, and mass spectrometry). Also, assessment of the antioxidant, anticonvulsant, anti-inflammatory as well as antimicrobial activities was determined using different techniques. Result: three isoflavones;4'-methoxy genistein Biochanin A] (1),6, 8 dimethoxy-biochanin A -7 -O-α -L-rhamnopyranosyl (1'''-6'') -O - -D-glucopyranoside (2), isoflavone 6, 8dimethoxy 7-O--D rutinoside, 4'-O-α-L-rhamnopyranoside (3).Besides six known flavonoids; hyperin (4), luteolin 7-O-rhamnoside(5), scutellarein -4',7 dimethyl ether(6), nepetin -7-methyl ether(7),luteolin(8),and apigenin (9),in addition to caffeic acid(10), chlorogenic acid (11) isolated for the first time from Melissa officinalis. The examined extract revealed significant anticonvulsant activity, effective in inhibition of both acute & chronic inflammation. Scutellarein -4',7-dimethyl ether (6) showed remarkable inhibition against fungi and exhibited the highest antibacterial effect against both Gram +ve and Gram -ve bacteria. The above evidence suggests that Melissa officinalis leaves are a good supply of natural isoflavones that can be utilized to avoid convulsion, and inflammation, as well as an antioxidant and antimicrobial supplement.