Objectives: In new antimicrobial drug development studies, indole and its derivatives create an important class of compounds. In addition, azoles and their derivatives were recognized to be associated with a variety of biologic activities such as antibacterial and antifungal. In this study antimicrobial activities of some indole derivatives mainly substituted with 1,2,4-triazole, 1,3,4-thiadiazole and hydrazinecarbothioamide were investigated to evaluate their efficacy. Materials and Methods: The efficacy of new compounds was evaluated using 2-fold serial dilutions against Staphylococcus aureus, MRSA, Escherichia coli, Bacillus subtilis, Candida albicans, and Candida krusei. Results: The MIC was determined for test compounds and for the reference standards sultamicillin, ampicillin, fluconazole, and ciprofloxacin. Conclusion: The compounds possessed a broad spectrum of activity having MIC values of 3.125-50 mu g/mL against the tested microorganisms. This study provides valuable evidence that the indole-triazole derivative compound 3d holds significant promise as a novel antibacterial and antifungal lead compound.

Melatonin (MLT) is a well-known free-radical scavenger, involving in the prevention of cellular damage that can lead to cancer, ageing and a variety of neurodegenerative diseases. Research on MLT-related compounds has been required to optimise the maximum pharmaceutical activity with the lowest side effects. In our ongoing research, we have synthesized new indole-based MLT analogues as potential antioxidant agents by modifying the MLT molecule. In this study, we build on previous findings, through the synthesis, characterization and in vitro antioxidant profiling of a series of new indole-based MLT analogues which possess triazole, thiadiazole and carbothioamides on the third position on the indole ring. In vitro antioxidant activity was investigated by evaluating their reducing effect against oxidation of a redox sensitive fluorescent probe and their radical scavenging activity was assessed via the DPPH assay. In addition, in vitro cytotoxic effects of newly synthesized compounds were investigated in CHO-K1 cells using the MTT assay.

Acetylcholinesterase (AChE) and paraoxonase 1 (PON1) are two important serum ester hydrolases that have antiatherosclerotic effect by inhibiting the oxidation of lipid peroxides. In addition, AChE inhibitors are target molecules for the treatment of Alzheimer's. Naphthalene derivatives are important molecules in the field of pharmacology due to their wide range of biological activities. In this study, the inhibition effects of naphthalenylmethylen hydrazine derivatives on these two metabolic enzymes were investigated. IC ₅₀ values of these molecules were determined in the range of 0.158 μM to 6.862 μM against PON1, 0.0214 μM to 0.675 μM against AChE. As a result, naphthalenylmethylen hydrazine derivatives had strong inhibition effect on both enzymes. In this context, we hope that the results obtained in this study contribute to the determination of the side effects of current and new naphthalene‐based pharmacological compounds to be developed. And also be effective in the synthesis studies of new AChE inhibitors.

Melatonin (MLT) is a strong free radical scavenger that protects the body from the deleterious effects of excess oxidants. Synthesis of MLT analogue compounds with antioxidant potency has recently attracted the interest of researchers. In general, the strategy consists of modifying the groups in the different sites of the indole ring or replacing the indole ring with an analogue. As part of our ongoing research, the antioxidant capacity and cytotoxicity of newly synthesized MLT analogue naphthalene derivatives were evaluated. The radical scavenging activity was tested by a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Most of the synthesized compounds showed significant antioxidant activity in comparison to MLT. The structure-activity relationship was identified. The in vitro cytotoxic effects of the synthesized compounds were also investigated in CHO-K1 cells using the MTT assay.

In clinical microbiology and antibacterial research, the significance of drug-resistant pathogens is growing up. Hydrazine-type compounds constitute the main classes of chemicals for the investigation of multidrug resistant agents which causes microbial infections. In the current study antimicrobial activities of certain Naphthalenylmethylen Hydrazine derivatives were examined to appraise their efficacy. The effectiveness of new compounds were evaluated using 2-fold serial dilutions against Staphylococcus aureus, Methicillin-Resistant-Staphylococcus aureus (MRSA), Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. Minimum inhibitory concentration (MIC) was determined for test compounds and for the reference standards Ciprofloxacin, ampicillin, and miconazole. According to the results, although the new compounds demonstrated poor antibacterial effects in general, the 1e and 1h compounds showed off significant antibacterial effects, especially against MRSA strains.