Phytochemical Investigation and Antioxidant Activity of Onopordum acanthium L. in Different Regions of Western Iraq Using GC-MS Analysis

The present study undertakes the phytochemical analysis of Onopordum acanthium L., commonly named Scotch thistle, collected from five different places in the western region of Iraq, for its antioxidant activities. Consequently, an attempt to identify the chemical composition of the plant for Al-Karmah, Ramadi, Hit, Fallujah, and Al-Qaim, respectively, was stated on the strength of GC-MS technology. The outcomes showed a region-inducing, high variability in the chemical profile of this plant with active compounds in the range of 18 to 29, which is the highest number in Hit and Al-Karmah, indicating the richer biodiversity or favorable environmental conditions of the area. Compounds detected in all the regions included neovitadiene and hexadecanoic acid methyl ester, which are critical building blocks of the plant's metabolic framework for survival at different scales. Antioxidant activity of O. acanthium was also performed, and the plant sample from Ramadi presented the highest scavenging activity, 86% ± 0.05, reflecting higher antioxidant potential. In contrast, the lowest activity was found for the samples from Fallujah, 51% ± 0.32, probably due to less appropriate environmental conditions. The present study underlines the importance of regional environmental factors affecting the biosynthesis of secondary metabolites in O. acanthium. Consequently, such environmental conditions have a pronounced impact on the antioxidant properties of this plant, which might be of interest for pharmacy and agriculture. Also, the presence of ascorbic acid in the samples shows that this plant can be very useful for natural antioxidants; thus, other studies could be developed from its medicinal and nutritional use.