Essential Oil Composition and Bioactivities of Rhinanthus angustifolius subsp. grandiflorus Collected from Turkey

In this study, the biological activity characteristics of Rhinanthus angustifolius subsp. grandiflorus species with natural distribution in Turkey were tried to be determined. During the 2021 vegetation period, the essential oil profiles of the samples collected from its natural habitat were determined, antimicrobial-antioxidant properties were determined and proliferative activities were studied on various cancer cell lines. Essential oils were isolated by hydrodistillation method and analyzed by GC/MS. In light of the results obtained, the major components of R. angustifolius subsp. grandiflorus essential oil were linoleic acid (26.05%), 2,4-decadienal (22.8%), heptane (9.54%), α-cubebene (9.76%), farnesyl acetone (4.93%) and 1,8-cineole (4.66%). As a result of antimicrobial studies according to the disk diffusion method, the highest antimicrobial effect was observed on E. coli (30mm), while the lowest antimicrobial effect was observed on Trichophyton sp (15mm). However, the methanolic extract was found to be more effective than the standard control against most of the other microorganisms. The TAS values of the methanolic extract of the plant were calculated as 4.27±0.01 mmol, TOS values as 4.66±0.08 µmol. DPPH radical scavenging activity increased with increasing concentrations of the plant extract. While the cytotoxic activity of the methanolic extract acted on 4 cell lines (BEAS-2B, SH-SY5Y, HCT116, A549) at various rates, it showed the strongest cytotoxic effect on SH-SY5Y cell line by killing the cells between 50-20%. This study is the first comprehensive study with R. angustifolius subsp. grandiflorus species.