Phytochemical Screening, GC-MS Characterization, Docking Evaluation, and Antioxidant Activity of Spermacoce latifolia
Shankar M, Sivasubramanian PIntroduction:
Spermacoce latifolia (Rubiaceae) is a traditional medicinal plant used for inflammation and infection, yet its chemistry and the mechanistic basis of its neurological and antioxidant activities are uncharacterized. This study addresses that gap by profiling phytochemicals, identifying GC-MS constituents, evaluating antioxidant capacity, and exploring Acetylcholinesterase (AChE) inhibitory potential by molecular docking, offering a multi-target rationale grounded in the established link between oxidative stress and cholinergic dysfunction.
Methods:
Leaves were extracted hydroalcoholically using a Soxhlet apparatus. Standard qualitative tests identified major phytochemical classes, and total flavonoid and terpenoid contents were quantified colorimetrically. Individual constituents were identified by GC-MS. Ligand interactions with acetylcholinesterase were evaluated by molecular docking (AutoDock Vina), and antioxidant activity by the DPPH radical scavenging assay.
Results:
Alkaloids, flavonoids, terpenoids, phenols, tannins, and saponins were detected. Flavonoid and terpenoid contents were 74.23 mg/g and 86.4 mg/g, respectively. GC-MS resolved the major constituents. In docking, β-sitosterol gave the best score (-12.1 kcal/mol), and the extract showed high free-radical scavenging activity (IC50 18.36 μg/mL).
Discussion:
The high flavonoid and terpenoid contents, with the GC–MS constituents, provide a chemical basis for the DPPH activity, while strong predicted AChE binding of phytosterols such as β-sitosterol supports an antioxidant-cholinergic dual-target rationale. As the docking ligands were derived from documented Spermacoce/Rubiaceae phytochemistry rather than being confirmed in the extract, they are preliminary and require LC-MS/HPLC confirmation and enzymeinhibition assays.
Conclusion:
The extract is chemically diverse, dominated by flavonoids and terpenoids, with β- sitosterol an AChE-inhibition lead and notable antioxidant potential, warranting bioassay-guided fractionation and in vivo validation.