Willow (Salix L.) species are widely spread in Lithuanian natural dendroflora. Willow bark contains active substances known for anti-inflammatory properties and is known as a phytotherapeutic precursor of aspirin. Bark extracts are components of analgesic and antirheumatic preparations. Therapeutic effectiveness is associated with salicin (2-(hydroxymethyl) phenyl-β-D-glucopyranoside), which turns into salicylic acid. Increasing attention to natural preparations gives primary importance to research of plants. This study focused on 12 willow taxa and employed routine pharmacopoeia methods. High-performance liquid chromatography method was applied for the analysis of bark extractions. The investigation revealed that not all willow species accumulated a therapeutically sufficient amount of salicin. Bark samples were investigated after 1- and 2-year growth in autumn and spring. Salicin content ranged from 0.08 to 12.6%. Higher contents of active materials were determined in autumn and in 2-year-old willows. Certain willow taxa (Salix alba L., Salix mollissima L., Salix triandra L., Salix viminalis “Americana”, Salix dasyclados L.) possessed extremely low salicin amounts. In the second year, analysis covered 32 willow species. Results indicated striking differences in salicin amounts (from 0.04% in Salix viminalis “Americana” to 12.06% in Salix acutifolia). Willow species, plant age, and season should be considered when collecting medicinal plant material. The amount of salicylates in 2-year-old willow bark collected in autumn exceeded by 25% that in 1-year-old willow bark collected in spring. Bark of some analyzed willow species contained the amount of salicylates too low for using as anti-inflammatory or antipyretic remedy.

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

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.

Walnut septa, traditionally discarded as waste in walnut processing because they primarily serve a structural function in the walnut fruit, have recently gained attention for their potential abundance of phenolic compounds, suggesting their overlooked value. This study aimed to optimise extraction parameters to maximise the extraction yield of bioactive compounds and explore regional variations in antioxidant activity and chemical composition of Juglans regia L. septa. The experimental variables included extraction methods (maceration, dynamic maceration, ultrasound processing, and reflux extraction), temperature, solvent type (methanol, acetone, and ethanol), and the percentage of water in the solvent. The optimal conditions were determined based on the total phenolic content—reflux extraction using 60% ethanol as a solvent for a duration of 60 min. Samples from 12 different regions in Lithuania, Armenia, and Ukraine were analysed for their phenolic and proanthocyanidin content and antioxidant activity using the CUPRAC method. The total phenolic content ranged from 131.55 to 530.92 mg of gallic acid equivalents per g of dry weight of plant material (mg GAE/g dw), while the proanthocyanidin content varied from 1.14 to 7.65 mg of (–)-epicatechin equivalents per g dry weight of plant material (mg EE/g dw). Among all the regions studied, the Šiauliai sample demonstrated the highest concentrations of phenolic compounds, proanthocyanidins, and antioxidant activity, with statistically significant differences compared to the other samples (p < 0.05). These findings demonstrate that walnut septa are a valuable source of phenolic compounds and antioxidants, with significant potential for developing natural nutraceuticals and antioxidant products.

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.