Antimicrobial activity of novel synthesized coumarin based transitional metal complexes

Abstract

Objectives To synthesize new transitional metal complexes derived from 3-aryl-azo-4-hydroxy coumarin analogues and to evaluate their antimicrobial activities. Methods The syntheses of complexes of coumarin analogues were accomplished by mixing a hydro-alcoholic solution of 3-aryl-azo-4-hydroxy coumarin analogues with transition metal chlorides. The structural environment of the synthesized molecules was characterized using different instrumental methods. The antimicrobial activity of the compounds was determined by the agar well diffusion method. Results The cobalt complexes of ( E )-3-((4-chlorophenyl) diazenyl)-4-hydroxy-2H-chromen-2-one (HL 1 ): ( 4a ) and ( E )-3-((4-methoxyphenyl) diazenyl)-4-hydroxy-2H-chromen-2-one (HL 2 ): ( 4e ) showed excellent antimicrobial activities compared with their ligands. Conclusion The reports of the antimicrobial investigation showed that the cobalt complexes of 3-aryl-azo-4-hydroxy coumarin analogues exhibited potential antimicrobial activity that was stronger than that of their ligands.

An Efficient One‐Pot Synthesis of 7,7‐Dimethyl‐2‐(2‐oxo‐2H‐chromen‐3‐yl)‐4‐aryl‐7,8‐dihydroquinolin‐5(6H)‐one Derivatives Using Chitosan–SO3H as Biodegradable Organocatalyst

“…To explore the generality and feasibility of CS-SO 3 Hcatalyzed MCRs, we investigated the optimization of the reaction conditions using 4-fluorobenzaldehyde (1b), 3acetylcoumarin (2), dimedone (3), and ammonium acetate as model reactants. Various catalysts were examined, and the results are summarized in Table 1.…”

“…We then tested the reaction in the presence of CS-SO 3 H. CS-SO 3 H was found to be the best catalyst for this process, and the desired product was formed in 93% yield in 60 min (Table 1, entry 7). We think that in addition to the SO 3 H group, the presence of multiple SO 3 H groups in the structure of CS-SO 3 H plays an important role for the formation of product because of the stabilization of the corresponding intermediates.…”

“…The reaction was also carried out using different amounts of the catalyst, and the results showed that 10 mol% of catalyst was the best choice for completing the reaction in solvent-free condition. By decreasing the amount of catalyst to 5 mol% relative to substrate, the yield of product decreased to 61% ( Furthermore, the model reaction was conducted in a range of different temperatures, including room temperature, 50, 60, 70, 80, and 90°C, in the presence of 10 mol% CS-SO 3 H catalyst under solvent-free condition ( Table 2, entries 10-14). As can be concluded from Table 2, the reaction proceeded slowly at room temperature.…”

“…To broaden the scope of the designed protocol, we subjected 3-acetylcoumarin, dimedone, various aryl aldehydes bearing electron-donating or electronwithdrawing groups, and ammonium acetate in the presence of 10 mol% of CS-SO 3 H as biodegradable catalyst to our optimized conditions, and the results are presented in Table 3. Gratifyingly, in all the cases, these four components congregated successfully into the corresponding 7,7-dimethyl-2-(2-oxo-2H-chromen-3-yl)-4-aryl-7,8-dihydroquinolin-5(6H)-one derivatives in excellent yields ( Table 3, entries 1-14).…”

In vitro Antimicrobial Investigations of Newly Synthesized Transitional Bivalent Metal Complexes Derived from 8-Hydroxyquinoline

“…16 Azo derivatives and their metal complexes are also very important pigments for synthetic leather and vinyl polymers. 17 They are the potent pharmaceuticals agents which having versatile therapeutic activities like antiseptic, 18 antimicrobial [19][20][21][22] antidiabetic, 23 antineoplastic, 24 antitumor 25 activities, DNA, RNA, and protein synthesis, nitrogen fixation, and carcinogenesis. 26 The azo compounds based on 8-hydroxyquinoline play a central role as chelating agents for large number of metal ions, as they can form a stable six-member ring after complexation with the metal ion.…”