Investigation of the long-term stability of various tinctures belonging to the lamiaceae family by HPLC and spectrophotometry method

Abstract The aim of the current study was to analyze stability rosmarinic acid in ethanolic tinctures lemon balm ( Melissa officinalis L.), oregano Origanum vulgare peppermint Mentha x piperita ), rosemary Rosmarinus sage Salvia and thyme Thymus vulgaris L.). High-performance liquid chromatography with diode-array detection (HPLC–DAD) employed monitor concentration marker compound over a six month period. Furthermore, were also evaluated for caffeic acid, total phenolic content, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity. We observed that tincture stored closed amber glasses at ambient temperature decreased significantly during 6-month storage. our squarely confirms fact part is converted acid. tested can be listed following order according greatest compound: > sage. results indicated linear relationship between DPPH values R 2 = 0.92) or 0.85) contents.