Abstract:
Tamarindus indica is one of the tropical medicinal plants that has been attributed curative
potential of numerous diseases. Nonetheless, not much research has been done on T. indica's
phytochemical analysis, antibacterial, and, antioxidant activities. Thus, the aim of this work is to
examine the phytochemical components of T. indica stembark and assess its antioxidant and
antibacterial properties. Using a 1:1 methanol to chloroform ratio and cold maceration for 24
hours, the extraction was carried out three times. To separate the pure compounds from the crude
extract, column chromatography was used. Spectroscopic techniques (IR, 1HNMR,13CNMR, and
DEPT-135) were used to elucidate the structures of the isolated compounds. The antimicrobial
activity of the crude extract and isolated compounds from T. indica was carried out against four
bacterial strains and one fungal strain; Bacillus cereus (ATCC25923), Salmonella typhimurium
(ATCC13311), Escherichia coli (ATCC25922), Staphylococcus aureus (ATCC25923) and
Candida albican (ATCC14053) using the disk diffusion method. The free radical scavenging
ability of the extracts was tested by a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging
assay. Two new compounds, methyl octadecanoate and hylodiglyceride, and two known
compounds, β-sitosterol and lupeol were isolated through the fractionation of the crude extract
on silica gel column chromatography, followed by purification on Sephadex LH-20 and small
column chromatography. The antimicrobial activity result showed that compound TI-D had
significant antimicrobial activity among the tested compounds. Isolated compounds exhibited
lower antimicrobial activity than that of the crude extract. The antioxidant activity result showed
that stembark extract of T. indica had significant antioxidant activity. Comparing of T. indica
with standard ascorbic acid the stembark extract, this study showed that they both had
comparable free radical scavenging activities. The results suggest that T. indica used in this study
has thepotential for the production of drugs against microbial infections. Further study on the use
of different organic solvents for the extraction and isolation of more bioactive compounds is
recommended.
