Isolation of a Lauryl Alcohol (1-Dodecanol) from the Antioxidant Bioactive Fractions of Justicia insularis (Acanthaceae) Leaves

Background Scientific and ethnopharmacological studies have shown that Justicia insularis leaves are used in the treatment of oxidative stress, heart problems, labour pains, and dysmenorrhoea. Therefore, this study was geared towards the investigation of the antioxidant claims of this plant leaves as well as the isolation and characterization of the components responsible for its antioxidant activities.Method The leaves of the plant were collected, air-dried, pulverized, and subjected to successive extraction with n-hexane, dichloromethane, ethyl acetate, and methanol for 72 h; thereafter, the fractions were subjected to in vitro antioxidant assays. The dichloromethane fraction (10 g) that had the best activity underwent thin layer and column chromatography, and the eluents were characterized with spectroscopic techniques (1H-NMR, 13C-NMR, and EI-MS).Results The results obtained showed that the dichloromethane fraction had the best activity in all the assays except for the DPPH-radical scavenging assay. The chromatographic analyses yielded three oily sub-fractions (F1, F7, F8) and one pure compound (JID2) identified as lauryl alcohol (1-dodecanol). The GC-MS analysis of the oils revealed the presence of 1-Nonadecene, 1-Heneicosanol, Octacosanol, phytol, 1,54-dibromo-tetrapentacontane, 1-Eicosanol, hexadecanoic acid methyl ester, 2-methyltetracosane, and 2,4-Bis(1,1-dimethylethyl)-Phenol with already reported pharmacological activities.Conclusion The high levels of antioxidant activity seen in this study could be exclusively attributed to 1-dodecanol or to its beneficial interactions with other substances. (Word counts: 210)