Integrated Phytochemical Profiling and Antioxidant Evaluation of Methanolic Leaf Extract of Meyna spinosa Using HPTLC, HPLC, FTIR, and GC–MS Analyses

Meyna spinosa Roxb. ex Link, a medicinally important plant belonging to the family Rubiaceae, has long been used in traditional healthcare systems to treat various ailments, including inflammation, microbial infections, diabetes, liver disorders, and gastrointestinal diseases. The present investigation aimed to evaluate the phytochemical constituents, antioxidant activity, and bioactive compounds in the methanolic leaf extract of Meyna spinosa using qualitative and quantitative phytochemical analyses, the DPPH free radical scavenging assay, HPTLC, HPLC, FTIR, and GC–MS. Preliminary phytochemical screening confirmed the presence of alkaloids, flavonoids, phenols, tannins, glycosides, saponins, terpenoids, steroids, proteins, and amino acids. Quantitative analysis demonstrated a high concentration of total phenolics and flavonoids, indicating strong antioxidant potential. The DPPH assay exhibited concentration-dependent radical scavenging activity with significant inhibitory effects at higher extract concentrations. HPTLC and HPLC analyses confirmed the occurrence of important phenolic compounds, including gallic acid, catechin derivatives, and tannic acid. FTIR spectroscopy revealed the presence of characteristic functional groups associated with phenolic, aromatic, and carbonyl compounds. GC–MS analysis identified several biologically active constituents such as oleic acid, lupeol, β-sitosterol, α-linolenic acid, phytol, and vitamin E derivatives, which are known for antioxidant, antimicrobial, anti-inflammatory, and therapeutic properties. The findings suggest that Meyna spinosa leaves constitute a rich source of pharmacologically active phytochemicals and may serve as a promising candidate for the development of natural antioxidant and therapeutic formulations.