Gold(i) and gold(iii) carbene complexes from the marine betaine norzooanemonin: inhibition of thioredoxin reductase, antiproliferative and antimicrobial activity.

The natural marine betaine norzooanemonin (1,3-dimethylimidazolim-4-carboxylate) and its methyl and ethyl esters were used as ligand precursors to prepare a systematic series (12 members) of neutral monocarbene gold(i/iii) and cationic dicarbene gold(i/iii) complexes. The complexes were evaluated as inhibitors of bacterial thioredoxin reductase and for their antiproliferative and antimicrobial activities. While gold complexes with the parent norzooanemonin scaffold resulted in overall poor performance, the more lipophilic esters proved to be highly bioactive agents, related to their higher cellular uptake. The monocarbene gold(i/iii) complexes showed significant potency as inhibitors of bacterial thioredoxin reductase. In most assays, the efficacy of both gold(i) and gold(iii) analogues was found to be comparable. The cytotoxicity of dicarbene gold(i/iii) complexes against cancer cells was strong, in some cases exceeding that of the standard reference auranofin.

Synthesis of N-heterocyclic carbene gold(I) complexes from the marine betaine 1,3-dimethylimidazolium-4-carboxylate.

The marine natural product norzooanemonin (1,3-dimethylimidazolium-4-carboxylate) has been used to prepare a series of carboxyl- or carboxylate-functionalized N-heterocyclic carbene (NHC) gold(I) complexes from [(Me2S)AuCl] in the presence of potassium carbonate. The potential of the resulting mono- and dicarbene complexes to act as cytotoxic or antibacterial drugs was investigated.

Synthesis and Antimicrobial Evaluation of 4H-Pyrans and Schiff Bases Fused 4H-Pyran Derivatives as Inhibitors of Mycobacterium bovis (BCG).

The focus of our study is the synthesis and biological activity evaluation of a series of 4H-Pyran compounds and schiff bases fused 4H-Pyran derivatives which are known to possess a wide variety of biological activities. In this paper at first a simple and efficient one-pot synthesis of 4H-Pyran s from the three-component reaction between malononitrile, aldehydes, and active methylene compounds in the presence of N-methylmorpholine (NMM) as catalyst at room temperature is reported, the reaction between these synthesized products and trimethylorthoformateor triethylorthoformateto produce schiff base compounds were also considered. The key advantages of synthesis of 4H-Pyran derivatives are short reaction time, high yield, and simple work-up. Then, these compounds were evaluated for anti-Mycobacterium activity against Mycobacterium bovis (Bacillus Calmette-Guerin). The preliminary results indicated that most of the tested compounds showed relatively good activity against the test organism. Moreover, antifungal activities of these compounds were evaluated. Finally, their effect was more noticeable on Mycobacterium bovis (BCG).

Synthesis and Evaluation of the Antimicrobial Activity of Spiro-4H-pyran Derivatives on Some Gram Positive and Gram Negative Bacteria.

Infections are one of the most important causes of death, disability and inappropriate conditions for millions of people around the world. Therefore, the development in prognosis, prevention and treatment of infectious diseases made a considerable progress in designing and synthesis of new antimicrobial drugs. Nowadays, due to the increase in microbial resistance, discovery of new compounds with broad spectrum effects is granted. 4H-pyran derivatives and spiro compounds are the most important fragments in some effective drugs with antimicrobial activity. Therefore, in this study, 6 compounds with spiro-4H-pyran core were synthesized and evaluated for their antimicrobial activity against four different bacterial species using microbroth dilution and disk diffusion methods. Minimum inhibitory concentration (MIC) has been measured for each compound and also for the standard antibiotic, gentamicin, and they were all compared together. According to our result, one of the spiropyran derivative (5d) containing both the indole and the cytosine ring, has been shown good antibacterial effects against standard and clinical isolates of Staphylococcus aureus and Streptococcus pyogenes.