Abstract
M.Tech. (Biotechnology)
The use of plants for medicinal purposes has over the years come under the spotlight of scientists throughout the world. It is estimated that about 60-80% of the world’s population in developing countries depend on traditional medicine for their primary health care. Some of the prescribed medicines contain some form of ingredients derived from phytochemicals, mostly inspired by indigenous knowledge systems. Zantedeschia aethiopica is a plant native to South Africa, with little biological and phytochemical information and currently regarded as an ornamental plant. The present study was carried out to evaluate its phytochemical and antimicrobial properties. Phytochemical screening and extraction were performed using chloroform/methanol, water, hexane and ethyl acetate separately. Based on the phytochemical tests, the chloroform/methanol and ethyl acetate extracts were shown to be abundant in alkaloids, flavonoids, saponins, steroids and tannins, while the water extract showed little or no presence of phytochemicals. Antibacterial activities tested on a range of gram negative and positive bacteria species (Bacillus cereus, Bacillus subtilis, Enterobacter cloacae, Enterobacter aerogenes, Enterococcus faecalis, Escherichia coli, Klebsiella oxytoca, Klebsiella pneumonia, Mycobacterium smegmatis, Proteus mirabilis, Proteus vulgaris, Pseudomonas aeruginosa, Staphylococcus epidermidis and Staphylococcus aureus) were performed using the disc diffusion susceptibility assay and the minimum inhibitory concentration (MIC) methods. Zantedeschia aethiopica organic solvent crude extracts concentrations ranging from 8 mg/mL to 16 mg/mL inhibited the growth of all the bacterial species listed, except for Staphylococcus aureus. Whereas, Bacillus subtilis, Enterobacter aerogenes and Mycobacterium smegmatis were inhibited at concentrations ranging between 1 mg/mL to 16 mg/mL with Proteus mirabilis showing more susceptibility (MIC of 0.25 mg/mL). A two-dimension gas chromatography coupled with time of flight mass spectroscopy (GCxGC/TOF-MS) was used to preliminarily identify the plant’s secondary metabolites. Interestingly, although the data obtained showed compounds such as 27.84 Allyl decanoate; 44, 2-aminobenzoate; Aziridine, 2,2-dimethyl-;1-Dodecyne; docosanoic acid-methyl ester; E-1,8-Dodecadiene; Undecane; 2(3H)-Furanone, dihydro-4-methyl-; 9-Octadecenoic acid (Z)-; 17-Octadecynoic acid; 9,12-Octadecadienal; 9,12-Octadecadienoyl chloride, (Z,Z)-; Oleic acid; 2-Oxabicyclo[2.2.2]octane, 1,3,3-trimethyl-;2-Oxetanone, 3,3-dimethyl-; Phenol, 2-methyl-5-(1-methylethyl)-; Phenol, 5-methyl-2-(1-methylethyl)-; Octadecanoic acid and 2-...