Summary.Willow (Salix L.)

The aim of our research is to investigate the qualitative and quantitative composition and antioxidant activity of flavonoids in leaf samples of Ginkgo biloba L. (G. biloba) growing in Lithuania and also to provide practical recommendations for the pharmaceutical industry to determine the optimum harvesting time and growth location of G. biloba leaves. The obtained results indicate that the growth location and time of sample collection have a significant influence ( ≤ 0.05) on the content of active compounds. July and August are the best months to harvest G. biloba leaves for industry. To ensure the rational collection of G. biloba raw material, the location of plantations is recommended in the western and southwestern phytoregions. The obtained results also indicate that the flavonoid content in G. biloba leaf has a significantly positive correlation ( = 0.952, ≤ 0.001) with antioxidant activity. The aqueous acetonic extracts from green leaves scavenge radicals to a greater degree than those from yellow Ginkgo leaves. The results of this investigation provide information regarding the most suitable Lithuanian growing location to produce G. biloba with an optimized content of health-promoting compounds.

No abstract

Studies of the composition of vegetable oils are expedient in order to achieve quality product modelling. The goal of this research was to determine the composition of fatty acids using gas chromatography (GC) and antioxidant activity using DPPH and ABTS spectrophotometric methods. Analysed oils were castor seed, sunflower seed, sesame seed, fibrous hemp seed, black radish seed and olive oils. Different classes of fatty acids were determined: polyunsaturated, monounsaturated and saturated; omega-3, omega-6 and omega-9 acids and individual constituents. The study results showed that the dominant acids in all oils were oleic and linoleic fatty acids. The best ratio of omega-6 to omega-3 acids was found in fibrous hemp seed oil – 3:1. All analysed vegetable oils demonstrated a high antioxidant activity.

There are a few new researches on the pharmaceutical and nutraceutical application of Cirsium vulgare, but they do not reflect the full potential use of this plant. For the best of our knowledge, no study has been conducted so far to determine the impact of extraction methods and conditions on the extraction yields of phenolic compounds from Cirsium vulgare. We aimed to investigate a simple and sensitive HPLC-PDA method to determine phenolic compounds in Cirsium vulgare extracts. Three extraction techniques as maceration (ME), ultrasound-assisted extraction (UAE) and heat-reflux extraction (HRE) were applied and compared for sample preparation to obtain a high recovery of the phenolic compounds. The developed HPLC-PDA method can be used for the preparations of extracts with a high content of bioactive compounds for both pharmaceutical and nutraceutical applications. Moreover, it was validated and used for the qualitative and quantitative evaluation of phenolic compounds. A simple extraction procedure for phenolic compounds from Cirsium vulgare leaves was optimized in this work through the use of the heatreflux extraction method with 50% ethanol and extraction time of 1.5 h.