Table 1 Polyphenolic compounds identified in Melissa officinalis ethanol leaf extracts by HPLC-ESI-MS in negative ion mode
Peak no. | Rt (min) | Phenolic compound | UV-Vis maxima (nm) | [M-H]- | [2M-H]- |
|---|---|---|---|---|---|
I | 10.04 | 3,4-dihydroxyphenyl lactic acid | 230, 284 | 197.1 | 395.2 |
II | 12.56 | 3,4-dihydroxybenzoic acid | 225, 260, 295 | 153.1 | 307.1 |
III | 21.94 | caffeic acid | 220, 240, 295(sh), 325 | 179.2 | 359.0 |
IV | 22.03 | luteolin-7-O-glucoside | 250, 345 | 447.3 | 895.4 |
V | 32.98 | rosmarinic acid glucoside | 220, 280, 325 | 521.1 | 1043.2 |
VI | 36.85 | methyl caffeate | 225, 290 (sh), 320 | 193.1 | 387.0 |
VII | 38.11 | rosmarinic acid | 220, 280, 325 | 359.1 | 719.2 |
VIII | 41.11 | isolithospermic acid | 220, 285 (sh), 320 | 537.1 | 1075.2 |
IX | 41.69 | methyl rosmarinate | 220, 280, 325 | 373.1 | 747.2 |
X | 42.48 | lithospermic acid | 225, 285 (sh), 325 | 537.1 | 1075.2 |
XI | 43.49 | methyl isolithospermate | 225, 285 (sh), 325 | 551.1 | 1103.2 |
XII | 44.94 | methyl lithospermate | 225, 285 (sh), 325 | 551.1 | 1103.2 |