Essential oils are volatile oil-like liquids with a characteristic strong smell and taste. They are formed in plants and are then extracted. Essential oils have extremely strong physiological and pharmacological properties, which are used in the medicine, cosmetics, and food industries. In this study, the molecules caryophyllene oxide, β-pinene, 1,8-cineol, α-cubebene, and β-caryophyllene, which are the molecules with the highest contents in the essential oil of the plant mentioned in the title, were selected and theoretical calculations describing their interactions with water were performed. Because oil–water mixtures are very important in biology and industry and are ubiquitous in nature, quantum chemical calculations for binary mixtures of water with caryophyllene oxide, β-pinene, 1,8-cineol, α-cubebene, and β-caryophyllene were performed using the density functional theory (DFT)/B3LYP method with a basis of 6–31 G (d, p). Molecular structures, HOMO–LUMO energies, electronic properties, reactivity (ELF, LOL, and Fukui), and NCI-RDG and molecular electrostatic potential (MEP) on surfaces of the main components of Phlomis bruguieri Desf. essential oil were calculated and described.

This study aims to experimentally and theoretically examine the plant Aethionema sancakense, which was determined as a new species and whose essential oil and fatty acid compositions were characterized by GC/GC-MS technique. Linoleic acid (23.1%), α-humulene (19.8%), camphene (13.9%), and heptanal (9.7%) were found to be the major essential oil components of A. sancakense aerial part structures. The quantum chemical calculations of these four molecules that are very important to this plant were performed using the density functional method (DFT)/B3LYP with the 6-31 G (d, p) basis set in the ground state for the gas phase. The molecular structures, HOMO-LUMO energies, electronic properties, Fukui functions, and molecular electrostatic potential (MEP) surfaces of the major constituents of Aethionema sancakense essential oil were calculated and interpreted. Finally, the RDG-NCI analysis of these molecules was performed to determine the non-covalent interactions present within the molecules.

Medicinal plants and herbal preparations are gaining attention in the scientific community today, as they are often used intermittently in the treatment of various diseases. The genus of Polygonum (Polygonaceae), known locally as “madimak”, is an aromatic plant widely used in world flavors. The chemical composition of the essential oils of dried aerial parts of seven of Polygonum was analyzed by GC-MS. These species are Polygonum lapathifolium L., Polygonum persicaria L., Polygonum arenastrum Bor., Polygonum bellardii All., Polygonum arenarium Waldst. Et Kit., Polygonum aviculare L., and Polygonum cognatum Meissn. Qualitative and quantitative differences were found in the essential oil analysis of the seven Polygonum species. The major compounds were determined as (E)-β-farnesene (19. 46%), dodecanal (15.92%), β-caryophyllene (12.95%), in P. aviculare; (E)-β-farnesene (25.00%), dodecanal (20.45%), β-caryophyllene (9.38%), and caryophyllene oxide (8. 26%) in P. persicaria; dodecanal (25.65%), caryophyllene oxide (13.35%), β-caryophyllene (7.95%), and (E)-β-farnesene (6.20%) in P. lapathifolium, and dodecanal (19.65%), (E)-β-farnesene (13.86%), β-caryophyllene (8.06%), and α-terpineol (7.2%) in P. arenarium, dodecanal (16.23%), β-caryophyllene (16.09%), (E)-β-farnesene (12.26%), caryophyllene oxide (7.94%) in P. bellardii, (E)-β-farnesene (20.75%), dodecanal (17.96%), β-caryophyllene (13.01%), α-terpineol (4.97%) in P. arenastrum, (E)-β-farnesene (9.49%), dodecanal (14.01%), β-caryophyllene (11.92%), geranyl acetate (9.49%), and undecanal (7.35%) in P. cognatum. This study is the most comprehensive study conducted to determine the essential oil components of Polygonum species. In addition, a literature review on the composition of the essential oils of these Polygonum taxa was performed. The essential oil components of the species in our study were revealed for the first time with this study.

The essential oil constituents, antimicrobial properties, and biosystematic characteristics (morphological, palynological, and anatomical features) of six Salvia species from different regions of Turkey were investigated qualitatively and quantitatively in this study. The chemical composition of the essential oils of dried aerial parts of Salvia species, i.e., S. absconditiflora, S. ceratophylla, S. multicaulis, S. verbenaca, S. viridis, and S. syriaca were analyzed by GC-MS. The main constituents of the six Salvia species studied were 1,8-cineol, caryophyllene oxide, spathulenol, and borneol in different ratios. The antimicrobial activity of the essential oil extracted from the aerial parts of species of the genus Salvia was tested by the disc diffusion method. The essential oils of Salvia species showed different antimicrobial activity against the studied microorganisms. The highest antimicrobial activity against E. coli was observed in S. multicaulis and the highest antimicrobial activity against K. pneumoniae was observed in S. verbenaca. The morphology of the stem, leaf, bract, and flower structures of the Salvia species were analyzed in this study. Anatomical investigations focused on the root, petiole, and stem in more detail. Our research has broadened the criteria of anatomical characters unique to the Salvia species. Under light microscopy, the pollen grains of the six species belonging to Salvia were isopolar and radially symmetrical. The properties of the essential oil constituents, antimicrobial properties, and biosystematic data obtained in this study contribute to the bioactive and biosystematic studies of Salvia species used for food, pharmaceutical, and cosmetic purposes.

The genus Opopanax W. Koch (Apiaceae) is represented by four species in Turkey. The composition of the essential oil of Opopanax genus members (Apiaceae) growing in Turkey was investigated in this study. GC-MS was used to analyze the composition of Opopanax essential oil samples that were taken from their natural environments. The Clevenger apparatus was used to hydrodistill the plant’s aerial parts, and the yields were determined to be between 0.2% v/w (for O. siifolius) and 0.4% (for O. hispidus, O. chironium, and O. persicus). The results and the chemical data provided some information and clues on the chemotaxonomy of the genus Opopanax. In this study, γ-elemene, butanoic acid octyl ester, and cylopropane were the main compounds identified in the essential oils of O. chironium, O. hispidus, and O. persicus. In particular, hexynyl n-valerate was most abundant in the essential oil of O. chironium, cyclopropane in that of O. hispidus, γ-elemene in that of O. persicus, and n-hexadecanoic acid/palmitic acid in that of O. siifolius. In a chemotaxonomic approach, the essential oil analysis of the Opopanax species revealed that these species conformed in a cluster analysis with their morphological classification. The constituents of the essential oils of all examined in the genus Opopanax were determined in this study, which is the most thorough one to date. This study provides new information about the composition of the essential oils of the investigated species.

In this study, essential oil components of the Veratrum album L. and the antimicrobial and antioxidant properties of these components were determined. The chemical composition of the essential oils of dried aerial parts of V. album was analyzed using GC and GC-MS. Antimicrobial activity was determined with the disk diffusion method. Total antioxidant status (TAS), total oxidant status (TOS) and 2.2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity were detected for the antioxidant activity of the plant. According to the analysis results, the major essential oil components of the V. album were determined as hexacosane (39.5%), myristic (tetradecanoic) acid (22.8%), heptane (6.5%), anethole (4.9%) and 1,8- cineole (4.8%). The findings showed that the methanol extracts of the stem and leaf parts of the plant inhibited the growth of pathogenic microorganisms at different rates (14±0.1 - 34±0.3 mm). The TAS values of methanol extracts of stem and leaf parts of V. album were calculated as 3.75±0.07 and 3.91±0.01 mmol, while TOS values were calculated as 6.14±0.13 and 6.54±0.05 μmol. The scavenging activity of the DPPH radical increased depending on increasing concentrations of the plant extract.