Phytochemical Screening and GC-MS Analysis of Methanolic and Aqueous Extracts of Ocimum kilimandscharicum Leaves

Abstract

Kenyans have long utilized Ocimum kilimandscharicum , an East African permanent evergreen plant, to treat measles, stomachaches, diarrhea, mosquito bites (anti-insect), congested chest, cough, and colds. Using conventional qualitative and quantitative techniques, this study was done to identify the secondary metabolites in O. kilimandscharicum leaf extracts. The chemical content of the crude extracts from the leaves of O. kilimandscharicum has also been investigated and characterized using gas chromatography–mass spectrometry (GC-MS). By using a 1:20 dilution in methanol, in cold maceration, a fine powder of O. kilimandscharicum was first extracted then filtered and concentrated after 72 h utilizing a rotary evaporator. By using also a 1:20 dilution in water at 80 °C, a fine powder of O. kilimandscharicum was extracted and then filtrated and lyophilized 1 h later. Each extract underwent further gas chromatography–mass spectrometry testing. We found that both extracts contain secondary metabolites such as alkaloids, phenolics, flavonoids, saponins, and tannins. However, the overall amount of phytochemicals in each solvent varied significantly. Total phenolics contents (TPCs) were 5.6 ± 1.20 and 10.8 ± 1.00 mg, total flavonoid contents (TFCs) were 8.2 ± 0.4 and 39.6 ± 2.2 mg, total tannin contents (TTCs) were 0 ± 0.00 and 10.5 ± 0.4 mg, the total alkaloid content (TAC) was 49.2 ± 0.40%, and the total saponin content (TSC) was 38 ± 2.00%. Additionally the gas chromatography–mass spectrometry, revealed a number of high- and low-molecular-weight bioactive molecules at various concentrations for each extract. We also found an inhibitory effect on adhP and chbR gene expression of Staphylococcus aureus and Salmonella choleraesuius , respectively. Hence, these chemicals could potentially have a biological and pharmacological significance. Therefore, the discovery of many physiologically active chemicals in the leaf extracts of O. kilimandscharicum justifies future biological and pharmaceutical research.

Silver nanoparticle biosynthesis utilizing Ocimum kilimandscharicum leaf extract and assessment of its antibacterial activity against certain chosen bacteria

“…Our analysis revealed the existence of alkaloids, phenolics, flavonoids, and saponins in both aqueous and methanolic extracts of O. kilimandscharicum leaves. On the other hand, our findings suggest the absence of tannins in aqueous leaf extract, which is not surprising given that the content of tannins are optimal in hydro-alcoholic extracts [ 1 ]. Our research uncovered significantly elevated levels of phenolics and tannins in the methanol extract compared to the aqueous extract.…”

“…The difference in optimal synthesis times for silver nanoparticles (AgNPs) using O. kilimandscharicum methanolic and aqueous extracts can be attributed to variations in the chemical composition and properties of the extracts. Methanolic extracts typically contain a higher concentration of phytochemicals such as polyphenols, tannins, and terpenoids [ 1 ], which may facilitate a faster reduction of silver ions and promote nanoparticle formation. This accelerated reduction process could result in the earlier attainment of optimal synthesis conditions, evidenced by the distinct peak observed at ninety minutes (90 min) in Fig 4 .…”

“…Our research uncovered significantly elevated levels of phenolics and tannins in the methanol extract compared to the aqueous extract. Hence, we propose the utilization of the methanolic extract for forthcoming nano formulation investigations [ 1 ].…”

“…The genus Ocimum, renowned globally among the numerous traditionally significant plants, has been utilized for thousands of years due to its diverse medicinal properties [ 1 ].…”

Green Synthesis of Au‐Ag@TiO2 Nanocomposite for Photocatalytic Oxidation of Substituted Benzyl Alcohols

“…The qualitative assessment of phytochemicals, such as phenols, tannins, flavonoids, saponins, glycosides, steroids and alkaloids, was conducted as per standard procedures. [58][59][60] Test for Phenols and Tannins…”