Comparative determination of enzyme, insecticide, antibacterial activities of different extracts of Diplotaxis tenuifolia and chemical components analysis

This study aimed to evaluate the insecticidal, enzymatic, antimicrobial activities, and phytochemical composition of extracts derived from the flowers and leaves of Diplotaxis tenuifolia (DTF and DTL) grown in gypsum-rich soils of Çankırı, utilizing various solvents. LC-MS/MS analysis identified vanillic acid as the major component in the Diplotaxis tenuifolia flower ethyl acetate (DTF-EA), Diplotaxis tenuifolia flower acetone (DTF-Ace), Diplotaxis tenuifolia leaf (DTL-EA), and Diplotaxis tenuifolia leaf acetone (DTL-Ace) extracts, naringin in Diplotaxis tenuifolia leaf n-butanol (DTL-nBu), and hesperidin in Diplotaxis tenuifolia flower n-butanol (DTF-nBu). The DTF-EA extract showed high efficacy in insecticidal assays against Sitophilus granarius and Rhizopertha dominica, achieving 90% and 83.3% mortality, respectively. Similarly, the DTF-Ace extract exhibited 86.6% and 66% mortality against S. granarius and R. dominica, respectively. Enzyme inhibition assays revealed that the DTF-EA extract exhibited potent inhibitory effects against xanthine oxidase (IC50: 27.83 µg/ml) and tyrosinase (IC50: 58.25 µg/ml), surpassing standard inhibitors such as acarbose. In antimicrobial assays, the DTF-EA extract demonstrated broad-spectrum antibacterial activity, exhibiting inhibition zones of 16.5, 15.5, 12.9, and 12.4 mm against Pseudomonas aeruginosa, Listeria monocytogenes, Bacillus cereus, and Salmonella enterica, respectively. The DTL-EA extract displayed significant activity against Escherichia coli (13.1 mm), while the DTL-Ace extract was most effective against Pseudomonas fluorescens (13.3 mm). These findings suggest that D. tenuifolia extracts possess notable antibacterial, insecticidal, and enzyme inhibitory activities, highlighting their potential as natural therapeutic agents and eco-friendly pest control and microbial management alternatives.