Isolation and Characterization of Humulene-Glucoside, Quercetagetin-3,7-Dimethyl Ether, Kaempferol-6-Hydroxy-3,7-Dimethyl Ether, and Quercetin-3-O-Glucoside from Pulicaria laciniata with In Vitro and In Silico Assessment of Their Antioxidant, Antidiabetic, and Anti-Alzheimer Activities

Despite its traditional medicinal use, Pulicaria laciniata remains largely unexplored for its therapeutic potential. This study aims to fill that gap by identifying and evaluating its bioactive compounds through a combination of experimental and computational approaches. The extracted and purified compounds—quercetin-3-O-glucoside, humulene-glucoside, quercetagetin-3,7-dimethyl ether, and kaempferol-6-hydroxy-3,7-dimethyl ether—exhibited strong antioxidant, antidiabetic, and neuroprotective activities. Among them, quercetin-3-O-glucoside displayed the highest antioxidant activity, humulene-glucoside demonstrated strong acetylcholinesterase inhibition, and quercetagetin-3,7-dimethyl ether showed significant α-amylase inhibition, highlighting their potential in managing oxidative stress, Alzheimer's disease, and diabetes. Molecular docking and density functional theory (DFT) analyses provided insights into their structural properties and interactions with biological targets, while pharmacokinetic and toxicity assessments confirmed their drug-likeness. By integrating in vitro and in silico methods, this research not only expands the phytochemical profile of P. laciniata but also underscores its promise for developing new treatments for oxidative stress-related diseases, metabolic disorders, and neurodegenerative conditions.