Diabetes mellitus, a common metabolic disorder, demands the development of safe and affordable therapeutic agents. Traditional medicinal plants provide valuable bioactive compounds with antidiabetic and antimicrobial potential. Ctenolepis garcinii, a climber from the Cucurbitaceae family used in South Indian and Sri Lankan medicine, remains scientifically underexplored. This study investigates its phytochemical composition and biological activities using phytochemical, chromatographic, antimicrobial, and molecular docking approaches, emphasizing its antidiabetic and antimicrobial efficacy. Ethanolic extracts of C. garcinii underwent qualitative and quantitative phytochemical screening, FTIR, UV–Vis, HPLC flavonoid profiling, GC-MS volatile compound identification, antimicrobial testing against Streptococcus aureus and Candida albicans, and molecular docking targeting SPA and Sky proteins. Phytochemical analysis revealed major constituents such as alkaloids (25.90%), flavonoids (21.50%), and phenols (18.40%). FTIR confirmed hydroxyl, aliphatic and aromatic hydrocarbons, ethers, halogens, and disulfides. UV–Vis analysis showed strong absorption at 353 nm and 407 nm, indicating phenolic and flavonoid presence. HPLC detected flavonoids including naringin (15.45 µg/mL), quercetin, kaempferol, and luteolin. GC–MS identified 20 compounds, notably tetracosanal (39.55%), 3-methylene-1-oxa-spiro[3,6]decane, and 3-methyl-2-(2-oxopropyl)furan. Antimicrobial assays showed moderate inhibition zones (8 mm for S. aureus, 7 mm for C. albicans). Docking studies revealed strong binding affinities of 3-methyl-2-(2-oxopropyl)furan with SPA (-7.4 kcal/mol) and Sky proteins (−8.3 kcal/mol). Overall, C. garcinii demonstrates a rich phytochemical profile with promising antidiabetic and antimicrobial potential. The identified compounds, supported by docking results, highlight its ethnomedicinal relevance and warrant further pharmacological and toxicological studies for drug development.
