Antioxidant and antimicrobial activities of plant flowers growing in distinct geological habitats (serpentine, gypsum, and limestone)

In this study, the flowers of 20 plant species [Gypsum (Linum flavum, Paracaryum stenolophum, Onobrychis nitida, Gypsophila lepidioides, Psephellus recepii, Tanacetum heterotomum, Verbascum alyssifolium, limestone (Teucrium leucophyllum, Stachys sparsipilosa, Phlomis oppositiflora, Pelargonium endlicherianum, Chrysophthalmum montanum, serpentine (Convolvulus pseudoscammania, Fumana aciphylla, Gladiolus halophilus, Hypericum thymbrifolium, Salvia indica, Artedia squamata, Erysimum pulchellum, Consolida olopetala], including 11 endemic species, growing in various habitats (gypsum, limestone, and serpentine) in Erzincan province were examined. By focusing on the antioxidant capacities and antibacterial activities of these species, the study aims to elucidate the effects of these ecosystems on the biosynthesis of plant secondary metabolites, primarily phenolic compounds and flavonoids, and their adaptive biochemical responses to unique environmental conditions. Antioxidant properties were assessed using DPPH, FRAP, TPC, and TFC assays. Results showed significant differences in antioxidant compound concentrations among plants from different habitats, with the highest levels in serpentine and gypsum regions. Artedia squamata L. from serpentine had the strongest DPPH activity (24.83 ± 1.25 µg/ml), Erysimum pulchellum had the highest TPC (89.44 ± 0.76 mg GAE/g), and Tanacetum heterotomum had the highest TFC (43.48 ± 2.08 mg QE/g) in gypsum. FRAP activity was highest in serpentine species, particularly Consolida olopetala (32.14 ± 1.84 mg TE/g). Furthermore, Antibacterial assays against eight ATTC strains revealed significant inhibitory effects by Stachys sparsipilosa, Tanacetum heterotomum, Teucrium leucophyllum, and Verbascum alyssifolium against Enterococcus faecium and Salmonella enteritidis with Teucrium leucophyllum showing the highest activity (MIC of 31.25 µg/ml against Salmonella enteritidis). The study highlights the influence of habitat on the biosynthesis of bioactive compounds, suggesting that plants from serpentine and gypsum soils have enhanced antioxidant and antimicrobial properties, making them potential candidates for natural therapeutic agents. © 2025 The Royal Society of New Zealand.