Integrated GC–MS Phytochemical Profiling and Bioactivity Assessment of Leaf and Fruit Extracts of Psidium cattleyanum (Cherry Guava)

Psidium cattleyanum (Cherry Guava, family Myrtaceae) is traditionally used for its medicinal and nutritional value; however, comparative chemical and bioactivity profiling of its leaf and fruit extracts remain limited. In this study, a sequential solvent extraction using hexane, dichloromethane, and methanol was employed to characterize the phytochemical composition. The combined extracts were analyzed by gas chromatography–mass spectrometry (GC–MS). Phytochemical screening, total phenolic content (TPC), total flavonoid content (TFC), DPPH radical scavenging assay, and brine shrimp lethality bioassay were conducted. GC–MS analysis identified terpenoids enriched in leaf extracts, while fruit extracts exhibited relatively higher contribution of lipid-derived compounds. Phytochemical screening revealed a higher diversity of secondary metabolites in leaf extracts compared to fruits. The leaf extract exhibited significantly higher TPC (31.96 ± 0.05 mg GAE/g) and TFC (51.43 ± 0.22 mg CE/g) than the fruit extract (8.87 ± 0.11 mg GAE/g and 1.98 ± 0.07 mg CE/g, respectively), correlating with stronger antioxidant activity (IC50 = 47.10 ± 0.06 ppm for leaves, 357.30 ± 0.64 ppm for fruits). Cytotoxicity assessment revealed mild to moderate bioactivity, with LC50 values of 522.14 ± 17.00 µg/mL (leaf) and 402.60 ± 9.00 µg/mL (fruit). Overall, this study highlights Psidium cattleyanum extracts as sources of antioxidant-associated phytochemicals exhibiting preliminary biological activity and provides a basis for future phytochemical and bioactivity investigations.