Gas chromatography-mass spectrometric profiling of hexane fraction of whole plant Tragia involucrata L. and methanol fraction of Psidium guajava L. leaves

Background: Medicinal plants are an important source of bioactive compounds with significant therapeutic potential, forming the basis of many traditional and modern pharmacological preparations. Tragia involucrata and Psidium guajava are widely used in traditional medicine for treating gastrointestinal, respiratory, metabolic, and infectious conditions. Despite their traditional relevance, a detailed chemical characterization of specific solvent fractions, particularly using advanced analytical methods, remains limited. Gas chromatography–mass spectrometry (GC-MS) offers a powerful tool for the identification of volatile and semi-volatile phytochemicals that may contribute to the pharmacological properties of these plants. Objective: This study aimed to identify and characterize the bioactive phytoconstituents present in the hexane fraction of Tragia involucrata whole plant and the methanol fraction of Psidium guajava leaves using GC-MS analysis, and to highlight their potential pharmacological relevance. Materials and Methods: Whole plant material of T. involucrata and leaves of P. guajava were collected from Kollam, Kerala, authenticated through DNA barcoding, shade-dried, powdered, and extracted using methanol. The crude extracts were successively fractionated with solvents of increasing polarity, and the hexane fraction of T. involucrata and methanol fraction of P. guajava were selected for GC-MS profiling. Analyses were carried out using a Shimadzu Nexus GC-2030 system under optimized temperature and carrier gas conditions. Compounds were identified based on retention time, mass spectral data, and comparison with the NIST 20 library. Results: GC-MS analysis of the T. involucrata hexane fraction identified fourteen phytoconstituents representing diverse chemical classes. These included alkylated phenols (2,4-di-tert-butylphenol; benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy, methyl ester), terpenoids (neophytadiene), diterpene alcohols (3,7,11,15-tetramethyl-2-hexadecen-1-ol), and fatty acid derivatives such as hexadecanoic acid methyl ester, methyl stearate, 9,12-octadecadienoic acid (Z,Z) methyl ester, 9,12,15-octadecatrienoic acid (Z,Z,Z) methyl ester, and n-hexadecanoic acid. Higher-chain esters, including hexadecanoic acid bis(2-ethylhexyl) ester, were also present. Additionally, phytol, squalene, and the antioxidant dl-α-tocopherol were detected, reflecting the chemical richness and potential bioactivity of the extract. The methanol fraction of P. guajava identified 10 bioactive compounds, predominantly saturated fatty acids (tetradecanoic, pentadecanoic, octadecanoic acids, oleic acid), long-chain hydrocarbons (dotriacontane, pentacosane), triterpene (squalene) and saturated fatty acids namely 13-docosenamide, and tetradecyl palmitate. The presence of these structurally diverse metabolites in both the T. involucrata hexane fraction and the P. guajava methanolic fraction highlights their notable phytochemical abundance and potential relevance for broad pharmacological applications. Conclusion: GC-MS profiling of T. involucrata and P. guajava demonstrates a diverse array of pharmacologically important metabolites, including diterpenes, terpenoids, phenolic derivatives, fatty acid esters, squalene, and α-tocopherol. These findings support their traditional medicinal relevance and indicate their promise as sources of bioactive lead molecules for drug development. Further biological evaluation is recommended to validate their therapeutic potential.