Evaluation of phytochemical composition of fresh and dried raw material of introduced Chamerion angustifolium L. using chromatographic, spectrophotometric and chemometric techniques

Abstract

Due to the wide spectrum of biological activities, Chamerion angustifolium L. as medicinal plant is used for the production of food supplements. However, it should be kept in mind that quality (biological activity) of the herb depends on its geographic origin, the way of raw material preparation or extraction and chemotype. The purpose of this study was to evaluate and compare the compositions of volatile, non-volatile compounds and antioxidant activities of C. angustifolium grown in Kaunas Botanical Garden after the introduction from different locations in Lithuania. The compositions of fresh and air-dried samples were compared. The profile of volatile compounds was analyzed using headspace solid phase microextraction coupled with GC/MS. trans-2-Hexenal (16.0-55.9% of all volatiles) and trans-anethole (2.6-46.2%) were determined only in the dried samples, while cis-3-hexenol (17.5-68.6%) only in fresh samples. Caryophyllenes (α- and β-) were found in all analyzed samples, contributing together from 2.4% to 52.3% of all volatiles according to the origin and preparation (fresh or dried) of a sample. Total amount of phenolic compounds, total content of flavonoids and radical scavenging activity (using 2,2-diphenyl-1-picrylhydrazyl (DPPH)) were determined using spectrophotometric assays. The variation of total phenolic compounds content was dependent on the sample origin, moreover, drying reduced amount of phenolics 1.5-3.5 times. The DPPH free radical scavenging activity was in the range of 238.6-557.1mg/g (expressed in rutin equivalents) in the fresh samples and drastically reduced to 119.9-124.8 mg/g after drying. The qualitative analysis of phenolic compounds in the aqueous methanolic extracts of C. angustifolium was performed by means of HPLC with UV detection. Oenothein B and rutin were predominant in the samples; also caffeic and chlorogenic acids, and quercetin were determined. Chemometric methods, namely principal component analysis, hierarchical cluster analysis and K-means clustering analysis, were applied for evaluation of the results. Chemometric analysis showed existence of different chemotypes of C. angustifolium L. and their relation to the geographic origin.

Keywords: Chamerion angustifolium L.; Chemometric analysis; Flavonoids; Introduction; Phenolic compounds; Volatile compounds.