Ultra‐performance Liquid Chromatography Coupled with Quadrupole Time‐of‐Flight Mass Spectrometry‐Based Profiling and Evaluation of Antioxidant, Antityrosinase, Antimicrobial and Antiproliferative Activities of <i>Eulophia nuda</i> Lindl.: A Medicinal

Eulophia nuda Lndl., a terrestrial medicinal orchid, is well known for its ethnomedicinal applications in treating bronchitis, tuberculosis, tumours, snake bites and arthritis. This study aimed to identify the phytoconstituents of E. nuda extract (ENE) and evaluate its antioxidant, antityrosinase, anticancer and antimicrobial activities. Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry analysis identified 33 compounds, 31 of which were reported for the first time, with phenols, terpenoids and carboxylic acids as dominant classes. ENE exhibited strong antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radicals with half-maximal inhibitory concentration (IC₅₀) values of 40.42 ± 0.31 and 12.94 ± 0.22 µg/mL, respectively. Antimicrobial studies against six bacterial strains showed zones of inhibition ranging from 11 to 15 mm, with strong inhibitory activity against E. faecalis (minimum inhibitory concentration: 31.25 µg/mL). The extract demonstrated moderate antityrosinase activity (IC₅₀: 357.36 µg/mL) compared to Kojic acid. Additionally, ENE showed significant antiproliferative effects against Panc-1, HepG2, and PC3 cancer cell lines, with IC₅₀ values of 29.39, 38.13 and 46.97 µg/mL, respectively. These findings highlight the therapeutic potential of ENE, supported by its diverse phytoconstituents and bioactivities, paving the way for its development in both traditional and modern medicine.