Comparison of phenolic acids and flavonoids contents in various cultivars and parts of common lavender (Lavandula angustifolia) derived from Poland

The aim of study was to compare the content of phenolic acids and flavonoids in two cultivars of Lavandula angustifolia: 'Blue River' and 'Ellagance Purple', including flowers and leafy stalks. Total phenolics and total flavonoids contents were determined by UV-Vis spectroscopy. The contents of total phenolics in leafy stalks (3.71-4.06 mg g-1 d.m.) were higher than in flowers (1.13-1.14 mg g-1 d.m.). Similarly, higher total contents of flavonoids were determined in leafy stalks (3.41-3.51 mg g-1 d.m.), as compared with flowers (0.86-0.91 mg g-1 d.m.). Phenolic acids and flavonoids were identified and quantified using HPLC and UPLC methods. Three phenolic acids were determined: rosmarinic, ferulic and caffeic acid. Lavender extracts contained also flavonoids from group of apigenin, luteolin and quercetin. Higher amounts of luteolin diglucuronide and luteolin glucuronide were found in leafy stalks in comparison to flowers. Obtained results indicate that leafy stalks of lavender can be also valuable source of antioxidant compounds.