UNLABELLED: This study investigated the anticancer phytocompounds in leaf extracts of Kunth. Quantitative analysis of the phytochemical composition showed high levels of primary metabolites: carbohydrates (45.11 ± 2.15 GLE mg/100 mg), proteins (28.13 ± 0.94 BSA mg/100 mg), and amino acids (13.25 ± 1.16 LE mg/100 mg). Ethyl acetate extracts had the highest concentrations of secondary metabolites, including phenolic content (122.52 ± 4.27 GAE mg/100 mg), total flavonoids (91.86 ± 2.65 QE mg/100 mg), and alkaloids (82.18 ± 0.72 COLE mg/100 mg). In addition, strong antioxidant activities were observed in the DPPH scavenging assay (IC 11.51 ± 2.28 µg/mL), ABTS radical cation scavenging activity (97.42 ± 7.19 µM TE/g), and FRAP assay (14.34 ± 1.24 mM Fe(II)/mg). Based on preliminary analysis, the ethyl acetate extract was fractionated using thin-layer chromatography (TLC), yielding two distinct fractions with Rf values of 0.31 and 0.76. GC-MS analysis of these fractions identified 33 bioactive compounds. These fractions exhibited anticancer activity against the A549 lung cancer cell line, with IC values of 47.25 µg/mL and 48.31 µg/mL, as determined by the MTT assay. Furthermore, absorption, distribution, metabolism, excretion, and toxicity (ADMET) studies on 25 selected compounds indicated favorable pharmacokinetic properties and drug-likeness. In silico molecular docking showed strong binding affinities of these bioactive compounds to the p21 protein, comparable to the synthetic drug Cisplatin-quercetin. The results highlight the potential of in anticancer therapy, particularly through modulation of the p21 pathway, supported by in vitro cytotoxicity assessments, molecular docking, and ADMET analysis. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-024-04167-4.