Antimicrobial, Antioxidant, and Anti-inflammatory Evaluation of Synthesised Azo Compounds based on β-naphthol, Catechol and Quinol Nucleus
Claudia Naa Dedei Attoh
Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Joseph Adu
Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Cynthia Amaning Danquah
Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Yakubu Jibira
Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Patrick Gyan
Department of Pharmaceutical Chemistry, School of Pharmacy, University of Health and Allied Sciences, Ho., Ghana.
Emmanuel Bentil Asare Adusei
Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Cedric Dzidzor Amengor *
Department of Pharmaceutical Chemistry, School of Pharmacy, University of Health and Allied Sciences, Ho., Ghana.
*Author to whom correspondence should be addressed.
Abstract
A series of 10-aryl substituted azo dyes were synthesized by coupling of β-naphthol, catechol, and quinol with different aromatic amines. The synthetic compounds were screened for their in vitro antimicrobial, antioxidant, and anti-inflammatory activities. The characterization of the synthesized compounds was carried out by UV, IR, 1H NMR and Mass spectroscopy. 13C NMR was employed to confirm the structural identity of some of the compounds. After screening for the presence of antimicrobial constituents in the azo compounds using HTSPOTi culture method, quinol compounds 7 [(E)-2(2nitrophenyl) diazenyl) benzene-1,4-diol] and 10 [(E)-2-(3-nitrophenyl) diazinyl) benzene-1,4-diol] were the most active in terms of broad spectrum activity against Gram-positives [Staphylococcus aureus (ATCC 25923), Streptococcus pyrogenes (clinical strain), Enterococcus faecalis (ATCC 29212)],, Gram-negatives [Salmonella typhi (clinical strain), Escherichia coli (ATCC 251922)] and Pseudomonas aeruginosa (ATCC 27853) and the Candida albicans at minimum inhibitory concentrations of 15.63-31.25 µg/mL. A quinol derivative, [(E)-2-(2nitrophenyl) diazinyl) benzene-1, 4-diol], exhibited the best anti-inflammatory activity in the heat-denatured egg albumin assay. Compounds [ethyl (Z)-4-(3-hydroxynapthalen-1-yl (diazinyl) benzoate] and (E)-2-((3-nitrophenyl) diazenyl) benzene-1,4-diol showed high DPPH free radical scavenging activity during the antioxidant assay.
Keywords: Azo compounds, antimicrobial, anti-inflammatory, DPPH assay