Synthesis and Biological Evaluations of Prop-2-enone and Penta-1, 4-dien-3-one Chalcones and their Hydrazone Derivatives
Bill Ekolama *
Department of Pharmaceutical and Medicinal Chemistry, Faculty of Pharmacy, Niger Delta University, Wilberforce Island, Nigeria.
Oyeintonbara Miediegha
Department of Pharmaceutical and Medicinal Chemistry, Faculty of Pharmacy, Niger Delta University, Wilberforce Island, Nigeria.
Abraham Sisein Eboh
Department of Biochemistry, Faculty of Basic Medical Sciences, College of Health Sciences, Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria.
Victory Tabowei
Department of Pharmaceutical and Medicinal Chemistry, Faculty of Pharmacy, Niger Delta University, Wilberforce Island, Nigeria.
Samuel Bunu
Department of Pharmaceutical and Medicinal Chemistry, Faculty of Pharmacy, Niger Delta University, Wilberforce Island, Nigeria and State Key Laboratory of Drug Research, Drug Discovery, and Design Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai -201203, China.
Diepreye Ere
Department of Pharmaceutical and Medicinal Chemistry, Faculty of Pharmacy, Niger Delta University, Wilberforce Island, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Chalcones are naturally coloured compounds found in plants, characterized by a distinctive chemical structure with two aromatic rings linked by a three-carbon α, β-unsaturated carbonyl bridge. Chalcones synthesis was achieved via modified Claisen-Schmidt condensation utilizing aromatic aldehydes and ketones, giving a yield of 80 – 98 % and was then combined with 2, 4-dinitrophenyl hydrazine (2, 4-DNPH) to form hydrazones yielding 58 – 86 %. Products formed were characterized accordingly using 1H-NMR, FTIR, UV, and elemental analysis. The biochemical assay involving antimicrobial activity by employing the agar well diffusion method indicated that the chalcones exhibited no activity against the selected isolates (E. coli, S. aureus, P. aeruginosa, and B. subtilis), while the compounds showed good analgesic properties as well as good antioxidant properties as indicated in the DPPH radical scavenging assay with one of the products BE6 showing (IC50=11.68 µM) and the Nitric Oxide bioavailability of BE1A indicating high activity. The total antioxidant determination indicated that the chalcones were better than the hydrazones with BE7 giving a value of TAC=8724.02. This indicates that coupled chalcones may exhibit good analgesic and antioxidant properties but still not a good antimicrobial properties.
Keywords: Antioxidant, DPPH scavenging, nitric oxide scavenging, TAC, analgesic, antimicrobial