Structure Modification of an Active Azo-Compound as a Route to New Antimicrobial Compounds

Abstract

Some novel (phenyl-diazenyl)phenols (3a-g) were designed and synthesized to be evaluated for their antimicrobial activity. A previously synthesized molecule, active against bacteria and fungi, was used as lead for modifications and optimization of the structure, by introduction/removal or displacement of hydroxyl groups on the azobenzene rings. The aim of this work was to evaluate the consequent changes of the antimicrobial activity and to validate the hypothesis that, for these compounds, a plausible mechanism could involve an interaction with protein receptors, rather than an interaction with membrane. All newly synthesized compounds were analyzed by 1 H nuclear magnetic resonance (NMR), DSC thermal analysis and UV-Vis spectroscopy. The in vitro minimal inhibitory concentrations (MIC) of each compound was determined against Gram-positive and Gram-negative bacteria and Candida albicans. Compounds 3b and 3g showed the highest activity against S. aureus and C. albicans, with remarkable MIC values of 10 µg/mL and 3 µg/mL, respectively. Structure-activity relationship studies were capable to rationalize the effect of different substitutions on the phenyl ring of the azobenzene on antimicrobial activity.

Conventional and Microwave Assisted Synthesis of New Triazole Derivatives and Evaluation of Their Antimicrobial Activities

“…All of the compounds synthesized were 2-naphthyl derivatives. The H1 proton of the naphthalene ring was observed as a singlet about 8.18-8.25 ppm, while the protons of H 6,7 were observed as a multiplet between 7.34-7.58 ppm, and H [3][4][5]8 were observed as a multiplet between 7.59-7.96 ppm in accordance with literature data ( Figure 5) [25,26]. The aromatic ring protons in the structure of the synthesized compounds were observed between 7.40-7.80.…”

“…Therefore, development of new antifungal agents with better activity profile is an attractive area for medicinal chemists. The azole group of antifungals are a rapidly expanding family of antifungal drugs and have maintained a key role in the treatment of immunocompromised patients who need oral therapy [6]. Triazole derivatives have a special importance among the azole derivatives.…”

Synthesis, characterization and evaluation of azobenzene nanogels for their antibacterial properties in adhesive dentistry

“…Aromatic compounds (such as polyphenols, antimicrobial stilbenes, and azophenols) can prevent the growth of bacterial biofilms [17][18][19]. Azophenols belong to a class of compounds classified as azobenzenes, which encompass a range of molecules that contain a core azo compound of two phenyl rings interconnected by an N = N linkage [20].…”

Study of the Interaction of a Novel Semi-Synthetic Peptide with Model Lipid Membranes

“…The choice of azobenzene in the peptide chain was determined by its hydrophobicity and intrinsic antimicrobial properties. In our previous works [ 18 , 19 ], we have already studied the antibacterial and antifungal activity of the azobenzene group. Therefore, a modified peptide might have antimicrobial activity due to the presence of azobenzene, and it might act as a prodrug, releasing the antimicrobial azo compound in vivo.…”