Chemical and Biological Profile and Allergenicity of Thymus baicalensis Plant of Mongolian Origin

Thymus baicalensis is a medicinal plant recognized as a traditional Mongolian therapeutic and health-promoting food supplement. The aim of the study was to check the suitability of the tested plant for supporting the treatment of certain diseases. The following study is the first one to showcase the versatile scope of characteristics of T. baicalensis, including its volatile oil composition, polyphenolic composition, lipid composition, phenolic and flavonoid contents, antioxidant activity, antimicrobial properties and ingestive allergenicity. Myrcene, at 26.15%, was shown to be the most abundant component of the volatile oil. Compounds known as inherent components of the Thymus genus: thymol and carvacrol made up only about 0.24% of the extracted oil. As much as 10.11 g kg⁻¹ of polyphenol compounds were identified as derivatives of luteolin-7-O-glucuronide. The lipid extract was found to be rich in palmitic acid (31.05%), while unsaturated fatty acids were not reported. Spectrophotometric determination of the phenols and flavonoids indicated 7.541 mg of gallic acid g⁻¹ and 4.345 mg of quercitin g⁻¹, respectively. The free radical scavenging activity was determined by the 2,2-difenylo-1-pikrylohydrazyl method at IC₅₀ = 206.97 µg mL⁻¹. The extracts also had a strong inhibitory effect on M. flavus and P. fluorescenes bacteria, as well as S. cerevisiae yeasts. The Bet v 1 and profilin allergens in T. baicalensis were reported at 175.17 ng g⁻¹ and 1.66 ng g⁻¹, respectively.

Chemical Characterization and Antibacterial Activity of Essential Oil of Medicinal Plants from Eastern Serbia

The objective of this study was to evaluate wild growing Satureja kitaibelii, Thymus serpyllum, Origanum vulgare, Achillea millefolium and Achillea clypeolata with respect to their essential oil (EO) content, composition and antimicrobial activity. The five species were collected at Mt. Rtanj and the village of Sesalac, Eastern Serbia. The main EO constituents of Lamiaceae plants were p-cymene (24.4%), geraniol (63.4%) and germacrene D (21.5%) in Satureja kitaibelii, Thymus serpyllum and Origanum vulgare ssp. vulgare, respectively. A. millefolium EO had multiple constituents with major ones being camphor (9.8%), caryophyllene oxide (6.5%), terpinen-4-ol (6.3%) and 1,8-cineole (5.6%), while the main EO constituents of A. clypeolata were 1,8-cineole (45.1%) and camphor (18.2%). Antimicrobial testing of the EO showed that Staphylococcus aureus (Gram-positive) was more sensitive to all of the tested EOs than Escherichia coli (Gram-negative). S. kitaibelii EO showed the highest antimicrobial activity against both tested bacterial strains. This is the first study to characterize the EO composition and antimicrobial activity of these five medicinal species from Eastern Serbia in comparison with comprehensive literature data. The results can be utilized by the perfumery, cosmetics, food and pharmaceutical industries, but also for healing purposes in self-medication.