Synthesis, Antifungal Evaluation and Molecular Docking Studies of Some Tetrazole Derivatives.

A facile and simple protocol for the [3+2] cycloaddition of alkyl nitriles (RCN) with sodium azide (NaN3) in the presence of copper bis(diacetylcurcumin) 1,2-diaminobenzene Schiff base complex, SiO2-[Cu-BDACDABSBC] as a heterogeneous catalyst in the presence of ascorbic acid and a solution of water/i-PrOH (50:50, V/V) media at reflux condition is described. The supported catalyst was prepared by immobilization of a copper bis(diacetylcurcumin) 1,2-diaminobenzene Schiff base complex [Cu-BDACDABSBC] on silica gel. The complex has high selectivity, catalytic activity, and recyclability. The significant features of this procedure are high yields, broad substrate scope and simple and efficient work-up procedure. According to this synthetic methodology, excellent yields of 5-substituted 1H-tetrazoles having bioactive N-heterocyclic cores were synthesized. The in vitro antifungal activities of title compounds were screened against various pathogenic fungal strains, such as Candida species involving C. albicans, C. glabrata, C. krusei, C. parapsilosis as well as filamentous fungi like Aspergillus species consisting of A. fumigatus and A. flavus. The molecular docking analysis is discussed for one most potent compound against fungi. The docking study determined a remarkable interaction between the most potent compounds and the active site of Mycobacterium P450DM.

Design, synthesis and biological evaluation of novel 1,2,3-triazolyl ß-hydroxy alkyl/carbazole hybrid molecules.

The design, synthesis and biological study of several novel 1,2,3-triazolyl [Formula: see text]-hydroxy alkyl/carbazole hybrid molecules as a new type of antifungal agent has been described. In this synthesis, the N-alkylation reaction of carbazol-9-ide potassium salt with 3-bromoprop-1-yne afforded 9-(prop-2-ynyl)-9H-carbazole. The 'Click' Huisgen cycloaddition reaction of 9-(prop-2-ynyl)-9H-carbazole with diverse [Formula: see text]-azido alcohols in the presence of copper-doped silica cuprous sulphate led to target molecules in excellent yields. The in vitro antifungal and antibacterial activities of title compounds were screened against various pathogenic fungal strains, Gram-positive and/or Gram-negative bacteria. In particular, 1-(4-((9H-carbazol-9-yl) methyl)-1H-1,2,3-triazol-1-yl)-3-butoxypropan-2-ol (10e) proved to have potent antifungal activity against all fungal tests compared with fluconazole and clotrimazole as studied reference drugs. Our molecular docking analysis revealed an appropriate fitting and a potential powerful interaction between compound 10e and an active site of the Mycobacterium P450DM enzyme. The strong hydrogen bondings between [Formula: see text]-hydroxyl and ether groups in 10e were found to be the main factors that drive the molecule to fit in the active site of enzyme. The in silico pharmacokinetic studies were used for a better description of 10a-10n as potential lead antifungal agents for future investigations.

Design, synthesis, and biological activities of novel azole-bonded ß-hydroxypropyl oxime O-ethers.

The synthesis and biological effects of 15 novel azole-bonded ß-hydroxypropyl oxime O-ethers have been described. In this synthesis, the oximation of aromatic ketones followed by an O-alkylation reaction with epichlorohydrin and/or epibromohydrin led to the corresponding O-oxime ether adducts. Subsequently, the attained O-oxime ether adducts were used to synthesize the target molecules after treating them with the appropriate azole derivatives. The in vitro antifungal and antibacterial activities of title compounds were obtained against several pathogenic fungi, Gram-positive and/or Gram-negative bacteria. Benzophenone O-2-hydroxy-3-(2-phenyl-1 H-imidazol-1-yl) propyl oxime and 9H-fluoren-9-one O-2-hydroxy-3-(2-phenyl-1 H-imidazol-1-yl)propyl oxime proved to have considerable antifungal activity against Candida albicans, Candida krusei, Aspergillus niger, and Trichophyton rubrum. These two compounds demonstrated comparable antifungal activity to clotrimazole and fluconazole (standard drugs). All compounds were also tested against Escherichia coli and Staphylococcus aureus as Gram-negative and Gram-positive bacteria, respectively, and their activities were compared to gentamycin and ampicillin (reference drugs). In general, marginal antibacterial activity against tested bacteria was observed for the title compounds. A molecular docking study is also discussed for the two most potent compounds against fungi. The docking study reveals a considerable interaction between the two most potent compounds and the active site of Mycobacterium P450DM. Moreover, these two compounds are much strongly bound to the active site of Mycobacterium P450DM compared to fluconazole.

Ph3P/CCl4 as a highly efficient reagent for one-pot N-alkylation of sulfonamides from alcohols: a rapid route to N-alkyl sulfonamides synthesis.

A mild, efficient, and selective protocol for the one-pot N-alkylation of sulfonamides with alcohols using triphenylphosphine and carbon tetrachloride is described. In this method, treatment of alcohols with a mixture of triphenylphosphine, carbon tetrachloride, and potassium sulfonylamide salts in refluxing anhydrous DMF furnishes the corresponding N-alkyl sulfonamides in good to excellent yields. This protocol is highly efficient for various structurally diverse alcohols and potassium sulfonylamide salts. In this paper the influence of solvents and various reagents as sources for electrophilic-halogen instead of carbon tetrachloride in combination with triphenylphosphine have been examined. This protocol demonstrates the selectivity between primary and secondary alcohols. A plausible mechanism for this protocol has been described.

The base-free chemoselective ring opening of epoxides with carboxylic acids using [bmim]Br: a rapid entry into 1,2-diol mono-esters synthesis.

A facile and highly convenient base-free protocol for the chemoselective preparation of 1,2-diol mono-esters is described. In this method, the regioselective ring opening of epoxides with carboxylic acids in the presence of [bmim]Br furnishes the corresponding 1,2-diol mono-esters in excellent yields. This method is efficient for various structurally diverse epoxides and carboxylic acids and it can be efficiently applied for the scale up synthesis of 1,2-diol mono-esters in reasonable to good yields. [bmim]Br remarkably influences the reaction progress and acts as both solvent and catalyst in this protocol.

Organic functionalization of single-walled carbon nanotubes (SWCNTs) with some chemotherapeutic agents as a potential method for drug delivery.

The grafting of drugs to the single-walled carbon nanotube (SWCNT) was attained by the initial conversion of carboxylic groups in SWCNT to corresponding acyl chlorides. The active acyl chlorides in SWCNT were subsequently mixed with chemotherapeutic agents having NH, NH2, and OH functional groups to afford the formation of relevant amide and ester, respectively. The covalently grafted drugs to SWCNT were identified by infrared and UV-visible spectroscopy and transmission electron microscopy methods. From a clinical aspect, the grafting of drugs to the SWCNT can be used as a new tool and useful method for potential drug delivery in patients.