Variation in VOCs, phenolics, flavonoids and antioxidant activity among natural populations of Centaurea kosaninii in Kosovo

Endemic plant species, characterised by a narrow geographic range, are increasingly threatened by global changes due to the complex ecological interactions with their environments. Ecometabolomic studies can reveal detailed insights into the molecular functioning of these interactions, providing fundamental implications for conservation efforts. We assessed the chemical variation in Centaurea kosaninii, a plant species endemic to the Balkan Peninsula. Plant materials were collected from five wild-growing populations in Kosovo to investigate the genetic variability, chemical diversity, composition of the volatile organic compounds (VOCs), total phenolics content (TPC), total flavonoids content (TFC) and antioxidant activity. The nuclear and chloroplast loci were amplified and sequenced, showing minimal genetic diversity among the examined populations. VOCs were extracted using hydro-distillation and analyzed using gas chromatography, revealing the separation of 107 VOC constituents. Principal component analysis, principal coordinates analysis, discriminant analysis, and Boruta, based on random forest variable selection, demonstrated distinct chemical compositions of VOCs across different populations. Additionally, spectrophotometric methods were utilised to determine TPC, TFC, and antioxidant activities, revealing significant differences between the leaves and inflorescences of C. kosaninii. We also found strong correlations between TPC and TFC with DPPH radical scavenging activity, while the correlations with FRAP activity were more moderate. This study provides the first insights into the genetic and chemical diversity of C. kosaninii, contributing to scientific understanding and laying the groundwork for future research initiatives, focusing on its ecological roles, adaptive traits, population dynamics, conservation strategies and potential biotechnological applications.