Qingyan Sun

Design, synthesis and antifungal activities of novel 1,2,4-triazole derivatives.

A series of novel 1,2,4-triazole derivatives with a 4-(4-substitutedphenyl) piperazine side chain were designed and synthesized based on the structure of lanosterol 14α-demethylase (CYP51). Their antifungal activities against eight human pathogenic fungi were evaluated in vitro by measuring the minimal inhibitory concentrations. Nearly all tested compounds were found to be more potent against Candida albicans than control drug fluconazole. Noticeably, the MIC(80) value of compounds 6,7,9,14 and 29 is 16 times lower than that of voriconazole against C. albicans. The activities of compounds 7 and 21 against Cryptococcus neoformans in vitro are comparable to that of voriconazole with a MIC(80) value of 0.0156 μg/mL. Moreover, the molecular model for the binding between compound 7 and the active site of CACYP51 was provided based on the computational docking results.

Construction of 2-substituted-3-functionalized benzofurans via intramolecular Heck coupling: application to enantioselective total synthesis of daphnodorin B.

A novel approach was developed for the synthesis of 2-substituted-3-functionalized benzofurans, using an intramolecular Heck reaction which was further applied in the first enantioselective total synthesis of Daphnodorin B.

Design, synthesis, and biological evaluation of novel triazole derivatives as inhibitors of cytochrome P450 14α-demethylase

Based on the results of computational docking to the active site of the cytochrome P450 14alpha-demethylase (CYP51), a series of 1-(1H-1,2,4-triazole-1-yl)-2-(2,4-difluorophenyl)-3-substituted-2-propanols as analogs of fluconazole were designed, synthesized, and evaluated as antifungal agents. The MIC(80) values indicate that compounds 1a-n exhibited higher activity against nearly all fungi tested except Aspergillus fumigatus than fluconazole, while compounds 2a-f, 3a-f showed no activity or only moderate activity against all fungi tested. Noticeably, the MIC value of compounds 1a, 1b and 1g is 64 times lower than that of fluconazole against Microsporum gypseum in vitro. And compounds 1a, 1b and 2b showed 128 times higher activity (with the MIC(80) value of 0.0039 microg/mL) than that of fluconazole against Candida albicans and also showed higher activity than that of the other positive controls. Computational docking experiments indicated that the inhibition of CYP51 involves a coordination bond with iron of the heme group, the hydrophilic H-bonding region, the hydrophobic region, and the narrow hydrophobic cleft. In addition, the activity of the compounds would be enhanced when the side chains were shorter.

Synthesis and antifungal evaluation of novel triazole derivatives as inhibitors of cytochrome P450 14α-demethylase

A series of 1-(1H-1,2,4-triazol-1-yl)-2-(2,4-difluorophenyl)-3-substituted-2-propanols (1a-v, 2a-w), which are analogues of fluconazole, have been designed and synthesized as the potential antifungal agents by the click reaction. Click reaction approach toward the synthesis of two sets of novel 1,2,3-triazolyl linked triazole antifungal derivatives 1a-v, 2a-w was achieved by Cu(I)-catalyzed 1,3-dipolar cycloaddition of propargylated intermediate 8 with substituted azidomethyl benzene. The 1,2,3-triazolyl group was inserted into the side chain of the target molecule which can increase the antifungal activity of compounds.

Design, synthesis and molecular docking studies of novel triazole as antifungal agent.

In order to meet the urgent need for novel antifungal agents with improved activity and broader spectrum, a series of 1-(1H-1,2,4-triazol-1-yl)-2-(2,4-difluorophenyl)-3-[(4-substituted trifluoromethyl phenyl)-piperazin-1-yl]-propan-2-ols were designed, synthesized and evaluated as antifungal agents. The MIC(80) values indicate that the compounds 7a-7q, 8a-8d showed higher antifungal activities against Candida albicans than 5a-5i, 6a-6j. Moreover, the molecular model for the binding between compound 5a, 7a and the active site of CACYP51 was provided based on the computational docking results, and the structure-activity relationship was analyzed.

New azoles with antifungal activity: Design, synthesis, and molecular docking

In order to search for many target compounds with excellent activities, a series of 1-(1H-1,2,4-triazol-1-yl)-2-(2,4-difluoro-phenyl)-3-[(4-substituted phenyl)-piperazin-1-yl]-propan-2-ols were designed, synthesized, and evaluated as antifungal agents. Results of preliminary antifungal tests against eight human pathogenic fungi in vitro showed that all the title compounds exhibited excellent activities with broad spectrum. Moreover, a molecular model for the binding between 5a and the active site of CACYP51 was provided based on the computational docking results.

Synthesis, in vitro evaluation and molecular docking studies of new triazole derivatives as antifungal agents.

On the basis of the active site of lanosterol 14α-demethylase from Candida albicans (CACYP51), a series of 1-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-1H-1,2,4-triazol-5(4H)-one derivatives were synthesized as fluconazole analogs. Results of the preliminary antifungal tests against eight human pathogenic fungi in vitro showed that these compounds exhibited activities to some extent, and some displayed excellent antifungal activities against C. albicans than reference drug fluconazole. Flexible molecular docking was used to analyze the structure-activity relationships (SARs) of the target compounds. The designed compounds interact with CACYP51 through hydrophobic, van der Waals and hydrogen-bonding interactions.

Synthesis and SAR studies of biaryloxy-substituted triazoles as antifungal agents.

A series of 1-(substituted biaryloxy)-2-(2,4-difluorophenyl)-3-(1H-1,2,4-triazol-1-yl) propan-2-ol were synthesized and their antifungal activities were evaluated against eight human pathogenic fungi in vitro. Seventeen compounds showed activity 4- to 64-fold higher than voriconazole against Candida albicans. SAR clearly suggested that introduction of a biaryloxy side chain greatly enhanced the antifungal activity of triazole analogs against Candida species.

Design, synthesis and antifungal evaluation of 1-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-1H-1,2,4-triazol-5(4H)-one.

Based on the structure of the active site of cytochrome P450 14α-demethylase (CYP51) and the conclusions of the structure-activity relationships of azole antifungals, a series of 1-(2-(2,4-difluoro-phenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-1H-1,2,4-triazol-5(4H)-one of fluconazole analogs was synthesized. All compounds were characterized by IR, HRMS, (1)HNMR and (13)C NMR spectroscopic analysis. Results of preliminary antifungal in vitro test using eight human pathogenic species showed that some compounds displayed comparable or even better antifungal activities than reference drug fluconazole and that compound 3i exhibited significant activity against Candida albicans being worthy of further optimization.

Triazole derivatives with improved in vitro antifungal activity over azole drugs

A series of triazole antifungal agents with piperidine side chains was designed and synthesized. The results of antifungal tests against eight human pathogenic fungi in vitro showed that all the compounds exhibited moderate-to-excellent activities. Molecular docking between 8d and the active site of Candida albicans CYP51 was provided based on the computational docking results. The triazole interacts with the iron of the heme group. The difluorophenyl group is located in the S3 subsite and its fluorine atom (2-F) can form H-bonds with Gly307. The side chain is oriented into the S4 subsite and formed hydrophobic and van der Waals interactions with the amino residues. Moreover, the phenyl group in the side chain interacts with the phenol group of Phe380 through the formation of π–π face-to-edge interactions.