Journal of Pharmacognosy & Natural Products

Phytochemical Analysis and Antimicrobial Investigation of Root Bark Extracts of La'ot (Acacia nubica Benth.) from Sudan

Abstract

Bushra Elfatih Bushra Suliman*

Plant compounds are of interest as a source of safe and effective substitutes of the classic synthetically produced antimicrobial agents. Hence, this study aims to investigate the phytochemical constituents and antimicrobial activity present in Acacia nubica root bark extracts. The plant was extracted by maceration using ethanol (70%). The crude extract was used for the detection of the phytochemical constituents. The antibacterial activity was measured by the agar well diffusion method. The qualitative chemical analysis of the crude organic extracts confirmed the presence of diterpenes, cardiac glycosides, tannins, flavonoids, saponins and phenols. The chemical ingredients were identified by Gas Chromatography-Mass Spectrometry (GC-MS). The major constituents in crude ethanol extract were 5-hydroxymethylfurfural (3.96%), di-n-octyl phthalate (4.33%), n-hexadecanoic acid (1.6%), and 4-O-methylmannose (81.11%). While the major constituents of aqueous methanol fraction were 4-O-methylmannose (74.98%), 5 hydroxymethylfurfural (12.45%), and 3-buten-2-one, 4-(4-hydroxy-3-methoxyphenyl) (3.74%), and of the hexane fraction were Di-n-octyl phthalate (54.92%), hexanedioic acid, bis (2-ethylhexyl) ester (9.9%), and hexadecanoic acid, ethyl ester (8.18%). A. nubica crude ethanolic extract produced clear zone of inhibition (9.00-12.5 mm) in the antimicrobial assay. The aqueous methanol fraction produced clear zone of inhibition of 11.00-13 mm against Staphylococcus aureus (ATCC 25923), while the hexane fraction was found to be devoid of activity. Escherichia coli (ATCC 25927) proved to be resistant to the crude extract and its fractions. On the other hand, ethanol (70%) extract showed antifungal activity with minimal inhibitory effect of 12.2-13.2 mm against C. albicans clinical isolates, while the aqueous methanol fraction produced 13.3–14.43 mm clear zone of inhibition. The hexane fraction produced no inhibition of the fungal growth. Further, studies on phytochemical, antimicrobial and mechanism of action are needed.