Assessment of Lavender Essential Oil Quality: Insights from Lithuanian Cultivation

Abstract

Introduction. Plants are known sources of bioactive components with potent healing effects. Epilobium species are widely distributed throughout the Eastern part of the European Union. They are rich in polyphenols such as oenothein B, ellagic acid, quercetin, and myricetin-3-O-β-D-glucuronide. The small-flowered Willow-herb or E. parviflorum contains high levels of β-sitosterol, oenothein B, and hyperoside. It is used to treat benign prostatic hyperplasia (BPH) or enlarged prostate, bladder and kidney disorders. It showed anti-bacterial, anti-inflammatory and antioxidant properties (1). However, despite the wide use of these plants, they are not included in any pharmacopeia in the world. Only the Herbal Medicines Committee (HMPC) made some conclusions and published documents (2)(2, 3) regarding the medical use of E. parviflorum, but not its chemical content. These documents are based on the European Union manufacturers of herbal products containing these plants. The purpose of this work is to apply the high-performance thin layer chromatography (HPTLC) method to evaluate the E. parviflorum quality. Materials and methods. E. parviflorum samples collected in Ukraine and Lithuania were used for the current comparative analysis. Polyphenolics were studied using HPTLC for the methanol (50%, v/v) extracts. Reference standards including chlorogenic acid, gallic acid, isoquercitrin, and hyperoside were used. The analysis was carried out using HPTLC plates Si 60 F254 (Merck) with a mobile phase of ethyl acetate: formic acid: acetic acid: water (67.5:7.5:7.5:17.5). The detection of compounds was performed at 365 nm after derivatization by 2-aminoethyldyphenylborinate 1% solution followed by 5% macrogol 400 in methanol. Results and discussion. HTPLC showed the presence of all four compounds in E. parviflorum extracts. In the light blue fluorescent (Rf = 0.54), chlorogenic acid was identified as. In the light yellow fluorescent zone (Rf = 0.67), isoquercitrin was detected. In the yellow fluorescent zone (Rf = 0.60) hyperoside was suggested. In the blue fluorescent zone (Rf = 0.82), gallic acid was identified. The fluorescence was more intense in the sample from Ukraine. Conclusions. The presented method can be further applied to assess Epilobium sp. chemical content.