Chemical and biological significance of naturally occurring additives on African black soap and its performance

Abstract

The potassium ester (C11H23COO-K+) commonly known as African black soap was prepared by the action of palm kernel oil on cocoa pods. This was divided into four portions. Sample A contained the African Black soap without any modification, sample B was black soap modified with honey, sample C and sample D were modified with shear butter and coconut oil respectively. The pH, FTIR and phytochemical analyses of the samples were carried out. They were also screened for in-vitro antibacterial activities against two Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli). The pH determinations showed that all the samples were alkaline in nature with sample A having the lowest pH of 8.90, while sample B had the highest pH of 9.58. FTIR analyses of sample A revealed strong bands assigned to the υ (C=O) frequency of a keto group at 1668 and 1560 cm-1 and a strong band at 1379 cm-1 assigned to the υ (C-O) frequency of the ester oxygen. The spectra of samples B, C and D showed no complexation through these oxygen donor atoms, but rather some interactions with other present molecules. Phytochemical analyses showed that samples A and D were rich in saponin, all the samples were rich in both flavonoids and terpenoids, while tannins and steroids were absent in all the samples. Antimicrobial studies showed that only sample B was active against Staphylococcus aureus, while samples A, C and D were inactive against all tested microorganisms.