Influence of location and season on phenolic composition and antioxidant activity of <i>Sempervivum tectorum</i>

<i>Sempervivum tectorum</i> (houseleek) is a flowering plant from the Crassulacuae family, commonly used in folk medicine. This study aimed to evaluate the HPLC profile, total phenolic, and flavonoid content as well as antioxidant activity of houseleek extracted using various ethanol/water mixtures. Houseleek samples were collected in three different locations during two vegetative periods. Seasonal variations in phenolic content and antioxidant activity, and linkage the phenolic composition versus antioxidant activity were assessed. Increased water share in extraction mixture resulted in phenolic compounds higher yield extraction. The major phenolic compound in analysed samples was K-hexoside (5.382 ± 0.030 mg/100 g f.w. in samples collected in September 2018 in Vlasotince). Multivariate techniques were applied to discriminate samples collected in various locations and vegetative periods and to perceive relations between the phenolic profile of each sample and different season/location.