基于真菌14α-去甲基化酶的非氮唑类抗真菌先导化合物的设计、合成及其体外抗真菌活性研究

基于真菌羊毛甾醇14α-去甲基化酶(CYP51)活性位点的三维结构设计并合成了新型四氢异喹啉类抗真菌先导化合物. 体外抗真菌活性研究显示: 设计的先导化合物具有较好的抗真菌活性. 其中化合物5f和5g对于5种测试菌的抗真菌活性强于或相当于对照药物氟康唑. 先导分子通过与靶酶活性腔氨基酸残基的非共价键结合产生抗真菌作用, 避免与血红素辅基Fe原子发生配位结合, 为一类具有新作用机理的非氮唑类抗真菌先导化合物. 本研究为抗真菌药物研究提供了新的结合方式及结构类型.     

新型三唑醇衍生物的合成及抗真菌活性

依据三唑醇类化合物的构效关系, 保留基本药效团三唑环、叔醇羟基和2,4-二氟苯基, 引入新的含哌嗪侧链结构, 设计合成了12个1-(1H-1,2,4-三唑-1-基)-2-(2,4-二氟苯基)-3-取代-2-丙醇类化合物.     

Design and synthesis of novel triazole antifungal derivatives based on the active site of fungal lanosterol 14a-demethylase （CYP51）

A series of 1-(1H-1,2,4-triazole-1-y1)-2-(2,4-difluorophenyl)-3-(N-isoproyl-N-substituted-amino)-2-propanols have been designed and synthesized on the basis of the active site of lanosterol 14a-demethylase(CYP51).Their structures were confirmed by MS and ~1H NMR.In vitro antifungal activities of these synthesized compounds were evaluated against eight human pathogenic fungi.The results showed that all title compounds exhibited activity against fungi tested to some extent.Compounds 3c,3d,7a,7b and 7c exhi...     

Design, synthesis of novel antifungal triazole derivatives with high activities against Aspergillus fumigatus

Based on the active site of Aspergillus fumigatus lanosterol 14a-demethylase(AF-CYP51),novel triazole compounds weredesigned.Their chemical synthesis and the antifungal activities were reported.The results showed that all the target compoundsexhibited excellent activities with broad spectrum;in which compounds 4,12 and 15 showed comparable activities against A.fumigatus to the control drug itraconazole.     

Sterol 14alpha-demethylase as a potential target for antitrypanosomal therapy: enzyme inhibition and parasite cell growth

Sterol 14alpha-demethylases (CYP51) serve as primary targets for antifungal drugs, and specific inhibition of CYP51s in protozoan parasites Trypanosoma brucei (TB) and Trypanosoma cruzi (TC) might provide an effective treatment strategy for human trypanosomiases. Primary inhibitor selection is based initially on the cytochrome P450 spectral response to ligand binding. Ligands that demonstrate strongest binding parameters were examined as inhibitors of reconstituted TB and TC CYP51 activity in vitro. Direct correlation between potency of the compounds as CYP51 inhibitors and their antiparasitic effect in TB and TC cells implies essential requirements for endogenous sterol production in both trypanosomes and suggests a lead structure with a defined region most promising for further modifications. The approach developed here can be used for further large-scale search for new CYP51 inhibitors.     

Synthesis and biological evaluation of novel triazole derivatives as antifungal agents

A series of 1-(benzylamino)-2-(2,4-difluorophenyl)-3-(1H-1,2,4-triazol-l-yl)propan-2-ols compounds were synthesized and evaluated for their antifungal activities in vitro.The results showed that compounds 6A and 6B exhibited good antifungal activity.Compound 6A8 showed the strongest antifungal activity,which was significantly higher than that of the lead compounds and positive-control drugs Fluconazole and Itraconazole.In particular,the antifungal activity of compound 6A8 against Candida albicans and Candida krusei(MIC80 both at 0.00097μg/mL) was 515 and 64 times that of Fluconazole,respectively.The structure-activity relationships of the synthesized compounds were discussed,and the docking model of the target compounds with fungal lanosterol 14α-demethylase (CYP51) was analyzed.     

Design,synthesis and in silico study of pyridine based 1,3,4-oxadiazole embedded hydrazinecarbothioamide derivatives as potent anti-tubercular agent

Development of novel, safe and effective drug candidates combating the emerging drug resistance has remained a major focus in the mainstream of anti-tuberculosis research. Here, we inspired to design and synthesize series of new pyridin-4-yl-1,3,4-oxadiazol-2-yl-thio-ethylidene-hydrazinecarbothioamide derivatives as potential anti-tubercular agents. The anti-tubercular bioactive assay demonstrated that the synthesized compounds exhibit potent anti-tubercular activity (MIC = 3.9–7.81 μg/mL) in comparison with reference drugs Rifampicin and Isoniazid.We employed pharmacophore probing approach for the identification of CYP51 as a possible drug target for the synthesized compounds. To understand the preferable binding mode, the synthesized molecules were docked onto the active site of Sterol 14 α-demethylases (CYP51) target. From the binding free energy of the docking results it was revealed that the compounds were effective CYP51 inhibitors and acts as antitubercular agent.     

Synthesis of antimicrobial azoloazines and molecular docking for inhibiting COVID-19

Diverse new azoloazines were synthesized from the reaction of fluorinated hydrazonoyl chlorides with heterocyclic thiones, 1,8-diaminonaphthalene, ketene aminal derivatives, and 4-amino-5-triflouromethyl-1,2,4-triazole-2-thiol. The mechanistic pathways and the structures of all synthesized derivatives were discussed and assured based on the available spectral data. The synthesized azoloazine derivatives were evaluated for their antifungal and antibacterial activities through zone of inhibition measurement. The results revealed promising antifungal activities for compounds 4 , 5 , 17a , b , 19 , and 25 against the pathogenic fungal strains used; Aspergillus flavus and Candida albicans compared to ketoconazole. In addition, compounds 4 , 5 , 19 , and 25 showed moderate antibacterial activities against most tested bacterial strains. Molecular docking studies of the promising compounds were carried out on leucyl-tRNA synthetase active site of Candida albicans, suggesting good binding in the active site forming stable complexes. Moreover, docking of the synthesized compounds was performed on the active site of SARS-CoV-2 3CLpro to predict their potential as a hopeful anti-COVID and to investigate their binding pattern.     

新型四氢萘类化合物合成及体外抗真菌活性研究

根据真菌羊毛甾醇14α-去甲基化酶的三维结构模型设计、合成了48个新型四氢萘类化合物, 所有化合物的结构经过IR, ¹H NMR和MS确证. 体外抗真菌活性研究表明所有化合物对7种临床致病真菌都有抗真菌活性, 特别是化合物18, 21, 22, 24的抗真菌活性最强. 对接研究显示设计的先导化合物与靶酶活性腔中氨基酸功能残基结合, 作用模式不同于氮唑类化合物. 结果表明新型四氢萘类化合物是一类全新结构类型的抗真菌化合物.     

Chromenol Derivatives as Novel Antifungal Agents: Synthesis,In Silico and In Vitro Evaluation

Herein we report the synthesis of some new 1H-1,2,4-triazole functionalized chromenols (3a–3n) via tandem reactions of 1-(alkyl/aryl)-2-(1H-1,2,4-triazole-1-yl) with salicylic aldehydes and the evaluation of their antifungal activity. In silico prediction of biological activity with computer program PASS indicate that the compounds have a high novelty compared to the known antifungal agents. We did not find any close analog among the over 580,000 pharmaceutical agents in the Cortellis Drug Discovery Intelligence database at the similarity cutoff of 70%. The evaluation of antifungal activity in vitro revealed that the highest activity was exhibited by compound 3k, followed by 3n. Their MIC values for different fungi were 22.1–184.2 and 71.3–199.8 µM, respectively. Twelve from fourteen tested compounds were more active than the reference drugs ketoconazole and bifonazole. The most sensitive fungus appeared to be Trichoderma viride, while Aspergillus fumigatus was the most resistant one. It was found that the presence of the 2-(tert-butyl)-2H-chromen-2-ol substituent on the 4th position of the triazole ring is very beneficial for antifungal activity. Molecular docking studies on C. albicans sterol 14α-demethylase (CYP51) and DNA topoisomerase IV were used to predict the mechanism of antifungal activities. According to the docking results, the inhibition of CYP51 is a putative mechanism of antifungal activity of the novel chromenol derivatives. We also showed that most active compounds have a low cytotoxicity, which allows us to consider them promising antifungal agents for the subsequent testing activity in in vivo assays.     

Synthesis,docking and ADMET prediction of novel 5-（（5-substituted- 1 -H- 1,2,4-triazol-3-yl ） methyl ）-4, 5,6,7-tetrahydrothieno [ 3,2-c ] pyri- dine as antifungal agents

A novel series of 5-((5-substituted-1H-1,2,4-triazol-3-yl)methyl)-4,5,6,7-tetrahydrothieno[3,2-c]pyridines 5(a–i) has been synthesized from thienopyridine hydrazide, substituted aromatic nitriles using 4-dimethylaminopyridine(DMAP) as a catalyst under microwave irradiation and evaluated for their in vitro antifungal activity. Compound 5g is found to be more potent against Candida albicans when compared with miconazole. Docking study of the newly synthesized compounds was performed, and results showed good binding mode in the active site of fungal enzyme P450 cytochrome lanosterol 14 ademethylase. ADMET properties of synthesized compounds were also analyzed and showed good drug like properties. The results of in vitro antifungal activity, docking study and ADMET prediction revealed that the synthesized compounds have potential antifungal activity and can be further optimized and developed as a lead compound.     

Design and Synthesis of New Aryloxy‐linked Dimeric 1,2,3‐Triazoles via Click Chemistry Approach: Biological Evaluation and Molecular Docking Study

A quest for more potent new antitubercular agents has prompted to design and synthesize aryloxy‐linked dimeric 1,2,3‐triazoles ( 4a – j ), from azides ( 2a‐e ) and bis(prop‐2‐yn‐1‐yloxy)benzene ( 3a – b ) on 1,3‐dipolar cycloaddition reaction via copper (I)‐catalyzed click chemistry approach with good to better yields. The titled compounds ( 4a – j ) were designed using molecular hybridization approach by assembling various bioactive pharmacophoric fragments in a single molecular framework. All the synthesized compounds have been screened for their in vitro antitubercular, antifungal, and antioxidant activities against their respective strains. Among them, 4h and 4i show the highest antifungal activity, whereas compounds 4h , 4i , and 4j have revealed promising antitubercular activity against their respective strains. In addition to this, most of the synthesized compounds were found as potent antifungal and antioxidant agents. A significant network of bonded and non‐bonded interactions stabilized these molecules into the active site of fungal CYP51 that is realized from the obtained well‐placed docking poses and the associated thermodynamic interactions with the enzyme. The synthesized compounds have also been analyzed for absorption, distribution, metabolism, and excretion properties.     

Design and synthesis of novel triazole derivatives containing γ-lactam as potential antifungal agents

A series of novel triazole derivatives containing γ-lactam were designed and synthesized, and their structures were confirmed by ~1H NMR,~(13)CNMR and HRMS. The in vitro antifungal activities of the target compounds were evaluated. The results showed that all of the compounds exhibited stronger activity against the six clinically important fungi tested than fluconazole. 3D and 3E showed comparative activity against the fungi tested except for Candida glabrata and Aspergillus fumigatus as voriconazole. In addition,the docking model for 2A and CYP51 was investigated.     

Design, synthesis and molecular docking studies of novel triazole antifungal compounds

Based on the active site of Candida albicans lanosterol 14α-demethylase (CACYP51), novel triazole compounds structurally different from the current triazole drugs were designed and synthesized. In vitro antifungal activities showed that compounds 10,11, 16 and 20 exhibited strong activities. In addition, compounds 10,11 and 16 also displayed certain activities against fluconazole-resistant fungi.     

Investigation of binding features: Effects on the interaction between CYP2A6 and inhibitors

A computational investigation has been carried out on CYP2A6 and its naphthalene inhibitors to explore the crucial molecular features contributing to binding specificity. The molecular bioactive orientations were obtained by docking (FlexX) these compounds into the active site of the enzyme. And the density functional theory method was further used to optimize the molecular structures with the subsequent analysis of molecular lipophilic potential (MLP) and molecular electrostatic potential (MEP). The minimal MLPs, minimal MEPs, and the band gap energies (the energy difference between the highest occupied molecular orbital and lowest unoccupied molecular orbital) showed high correlations with the inhibition activities (pIC₅₀s), illustrating their significant roles in driving the inhibitor to adopt an appropriate bioactive conformation oriented in the active site of CYP2A6 enzyme. The differences in MLPs, MEPs, and the orbital energies have been identified as key features in determining the binding specificity of this series of compounds to CYP2A6 and the consequent inhibitory effects. In addition, the combinational use of the docking, MLP and MEP analysis is also demonstrated as a good attempt to gain an insight into the interaction between CYP2A6 and its inhibitors. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010     

Synthesis,Characterization, and Molecular Docking Study of Some Novel Imidazole Derivatives as Potential Antifungal Agents

The azole pharmacophore is still regarded as a viable lead structure for the synthesis of more effective antifungal agents. In this study, two novel series of imidazole derivatives containing dithiocarbamate (5a–5g) and (benz)azolethiol (6a–6n) side chains that are structurally related to the famous antifungal azole pharmacophore were synthesized, and the structures of them were characterized by spectral (IR, ¹H NMR, ¹³C NMR, and MS spectra) analyses. The synthesized compounds were screened in vitro antifungal activity against pathogenic strains fungi. Theoretical ADME (absorption, distribution, metabolism, and excretion) predictions were calculated for final compounds. A molecular docking study of the most active compound with target “lanosterol 14α‐demethylase” (CYP51) was performed to unravel the mode of antifungal action. Compound 5e , which features imidazole and 4‐methoxybenzyl piperazine scaffolds, showed the most promising antifungal activity with an MIC₅₀ value of 0.78 μg/mL against C. krusei. Effect of the compound 5e against ergosterol biosynthesis was observed by LC–MS–MS method, which is based on quantification of ergosterol level in C. krusei.     

Molecular design of two sterol 14α-demethylase homology models and their interactions with the azole antifungals ketoconazole and bifonazole

Summary Sterol 14α-demethylase (CYP51) is one of the known major targets for azole antifungals. Therapeutic side effects of these antifungals are based on interactions of the azoles with the human analogue enzyme. This study describes for the first time a comparison of a human CYP51 (HU-CYP51) homology model with a homology model of the fungal CYP51 of Candida albicans (CA-CYP51). Both models are constructed by using the crystal structure of Mycobacterium tuberculosis MT-CYP51 (PDB code: 1EA1).The binding mode of the azole ketoconazole is investigated in molecular dynamics simulations with the GROMACS force field. The usage of special parameters for the iron azole complex binding is necessary to obtain the correct complex geometry in the active site of the enzyme models. Based on the dynamics simulations it is possible to explain the enantioselectivity of the human enzyme and also to predict the binding mode of the isomers of ketoconazole in the active site of the fungal model.     

Design synthesis and biological evaluation of 3-substituted triazole derivatives

Based on the active site of lanosterol 14α-demethylase of azole antifungal agents,sixteen 1-(1H-1,2,4-triazole-1-yl)- 2-(2,4- difluorophenyl)-3-(N-n-butyl-N-1-substitutedbenzyl-4-methylene-1H-1,2,3-triazole)-2-propanols have been designed,synthesized and evaluated as antifungal agents.Results of preliminary antifungal tests against eight human pathogenic fungi in vitro showed that some of the compounds exhibited excellent activities with broad spectrum.     

Design, synthesis and antifungal activity of novel triazole derivatives

Twenty-three 1 -(1H-1,2,4-triazole-1 -y1)-2-(2,4-difluorophenyl)-3-(iV-cycloproyl-N-substituted-amino)-2-propanols were designed and synthesized on the basis of the active site of lanosterol 14α-demethylase. In vitro antifungal activities showed that some of the title compounds had higher antifungal activity and broader antifungal spectrum than fluconazole.     

Ligand- and protein-based modeling studies of the inhibitors of human cytochrome P450 2D6 and a virtual screening for potential inhibitors from the Chinese herbal medicine, Scutellaria baicalensis (Huangqin,Baikal Skullcap)

We have previously examined the binding patterns of various substrates to human cytochrome P450 2D6 (CYP2D6) using a series of molecular modeling methods. In this study, we further explored the binding modes of various types of inhibitors to CYP2D6 using a combination of ligand- and protein-based modeling approaches. Firstly, we developed and validated a pharmacophore model for CYP2D6 inhibitors, which consisted of two hydrophobic features and one hydrogen bond acceptor feature. Secondly, we constructed and validated a quantitative structure-activity relationship (QSAR) model for CYP2D6 inhibitors which gave a poor to moderate prediction accuracy. Thirdly, a panel of CYP2D6 inhibitors were subject to molecular docking into the active site of wild-type and mutated CYP2D6 enzyme. We demonstrated that 8 residues in the active site (Leu213, Glu216, Ser217, Gln244, Asp301, Ser304, Ala305, and Phe483) played an important role in the binding to the inhibitors via hydrogen bond formation and/or π-π stacking interaction. Apparent changes in the binding modes of the inhibitors have been observed with Phe120Ile, Glu216Asp, Asp301Glu mutations in CYP2D6. Finally, we screened for potential binders/inhibitors from the Chinese herbal medicine Scutellaria baicalensis (Huangqin, Baikal Skullcap) using the established pharmacophore model for CYP2D6 inhibitors and molecular docking approach. Overall, 18 out of 40 compounds from S. baicalensis were mapped to the pharmacophore model of CYP2D6 inhibitors and most herbal compounds from S. baicalensis could be docked into the active site of CYP2D6. Our study has provided insights into the molecular mechanisms of interaction of synthetic and herbal compounds with human CYP2D6 and further benchmarking studies are needed to validate our modeling and virtual screening results.