ABSTRACT. In this study, the attempts were made to isolate secondary metabolites from the solvent extract of the dried leaves of Premna schimperi (P. schimperi). Thus, six compounds, namely, ent-8b,12-epidioxy-12b-hydroxylabda-9(11),13-dien-15-oic acid-g-lactone (1), 3,5,5'-trihydroxy-6,7,3',4'-tetramethoxyflavone (2) and 3,5,7,5'-tetrahydroxy-6,3',4'-trimethoxyflavone (3), p-hydroxycinnamic acid (4), luteolin (5) and 1-nonacosanol (6) were isolated and characterized by NMR, UV-Vis, MS and FTIR spectroscopic techniques. All the compounds; except luteolin (5) were reported for the first time from the leaves of P. schimperi. In addition, the GC-MS analysis of the essential oil of the plant leaves revealed 47 compounds, of which a-curcumene (16.38%), caryophyllene (10.73%), eugenol (6.85%), b-sesquiphellandrene (4.65%), g-gurjunene (4.55%), terpinen-4-ol (2.9%), g-eudesmol (4.43%), linalool (2.2%) and caryophyllene oxide (2.67%) were the major compounds. Furthermore, assessment of the antioxidant activities of the MeOH extract and compound 1 using the DPPH assay revealed 95.3% and 62.2% DPPH inhibition, respectively, at concentration of 100 μg/mL.
KEY WORDS: P. schimperi, GC-MS, DPPH radical scavenging assay, Antioxidant activity, Acetylation
Bull. Chem. Soc. Ethiop. 2023, 37(6), 1471-1486.DOI: https://dx.doi.org/10.4314/bcse.v37i6.14