Study of Phytochemical Screening and Thin-layer Chromatography Profile of Leaf Extract of Ocimum kilimandscharicum

Secondary metabolites from medicinal and aromatic plants continue to play significant roles in pharmaceuticals, agriculture and industry. Ocimum kilimandscharicum (camphor basil), a member of the Lamiaceae family, is known for its essential oils and traditional applications; however, comparative phytochemical analyses of its leaf extracts remain relevant. This study aimed to screen and compare the phytochemical constituents of aqueous and ethanolic leaf extracts of O. kilimandscharicum using qualitative chemical tests and thin-layer chromatography (TLC). Leaf samples were prepared and extracted separately using distilled water and ethanol. Qualitative tests for alkaloids, flavonoids, saponins, tannins, phenols, terpenoids and carbohydrates were performed on both extracts using colour-change and precipitation reactions. TLC profiling was performed on precoated silica gel 60 F254 plates using five mobile-phase systems of different polarities: (1) n-butanol:acetic acid:water (4:1:5); (2) chloroform:ethyl acetate:methanol:water (15:8:4:1); (3) hexane:ethyl acetate (8:2); (4) chloroform:methanol (15:1); and (5) hexane alone (100%). All seven phytochemical classes were detected in both aqueous and ethanolic extracts. TLC revealed multiple bands in three of the five systems for the aqueous extract and four systems for the ethanolic extract, whereas hexane alone showed no migration for either extract. The recorded Rf values and chromatographic profiles demonstrated variation in the separation of extract constituents across the solvent systems. These findings provide preliminary phytochemical information relevant to further investigation of the potential use of O. kilimandscharicum extracts in botanical management of the stored-grain pest Sitophilus oryzae; they do not, by themselves, establish insecticidal efficacy.