Antimycobacterial and antifungal isosters of salicylamides

A set of 40 derivatives of 3-hydroxypicolinic acid and 2-sulfanylbenzoic acid, isosteric to salicylanilides was synthesized. The compounds were evaluated for in vitro activity against Mycobacterium tuberculosis, Mycobacterium kansasii and Mycobacterium avium, Candida albicans, Candida tropicalis, Candida krusei, Candida glabrata, Trichosporon beigelii, Aspergillus fumigatus, Absidia corymbifera, Trichophyton mentagrophytes and Microsporum gypseum. Structure-activity relationships of antimycobacterial activity and antifungal activity against T. mentagrophytes and M. gypseum were analyzed by the Free-Wilson method. An increase in antimycobacterial activity was observed only for the sulfanylbenzoic acid derivatives, especially those with the benzyl moiety. The antifungal activity was not significant.     

Substances with antibacterial and antifungal activity. VII. Synthesis and microbiologic activity of new derivatives of 1,5-diarylpyrrole

The synthesis and antifungal activities of new 1,5-diarylpyrrole derivatives are reported. Antimicrobial data in comparison with pyrrolnitrin show that N-methylpiperazinylamides exhibit very poor activity against Candida albicans and Candida sp. while acid and ester derivatives are inactive. Vice-versa many acid or amide derivatives show interesting antibacterial activity. The results obtained are discussed on the basis of structure-activity relationships.     

S-Acyl derivatives of thiosalicylamides having antifungal activity. II]

Some S-acyl derivatives of N-alkylthiosalicylamides [Table I: substances (I leads to XXXI)] were prepared and tested for antifungal activity. The substances, most of which had not been previously reported, were prepared by condensation of 2-mercapto-N-alkylbenzamides with suitable acylating agents. The antifungal activity of the compounds was tested in vitro against Candida albicans and Trichophyton mentagrophytes. For some compounds the was tested activity against the above strains fungicidal, Candida tropicalis and Saccharomyces cerevisiae. Many of the compounds proved to have high antifungal activity comparable with that of Clotrimazol. The results extended knowledge on the structure-antifungal activity relationships of this class of compounds. The compounds with the highest antifungal activity were: 2-acetylmercapto-N,n-heptylbenzamide (XXVIII); 2-acetylmercapto-5-Cl-N,n-propylbenzamide (XIV); 2-acetylmercapto-N,n-octylbenzamide (XXXI); 2-acetylmercapto-N,n-pentylbenzamide (XXV); 2-acetylmercapto-N,n-hexylbenzamide (XXVII).     

Design, synthesis and antifungal activity of some new imidazole and triazole derivatives

Triazole and imidazole are incorporated into the structures of many antifungal compounds. In this study a novel series of 1,2,4-triazole, imidazole, benzoimidazole, and benzotriazole derivatives was designed as inhibitors of cytochrome P450 14α-demethylase (14DM). These structures were docked into the active site of MT-CYP51, using Autodock program. Sixteen compounds with the best binding energy were synthesized. The chemical structures of the new compounds were confirmed by elemental and spectral ((1) H-NMR and Mass) analyses. All compounds were investigated for antifungal activity against Candida albicans, Candida tropicalis, Candida glabrata, Candida parapeilosis, Candida kruzei, Candida dubliniensis, Aspergillus fomigatus, Aspergillus flavus, Microsporum canis, Microsporum gypseum, Trichophyton mentagrophyte, Epidermophyton floccosum. Some compounds showed excellent in-vitro antifungal activity against most of the tested fungi. Compounds 2, 9, and 10 had antifungal activity against several resistant fungi against fluconazole and itraconazole.     

Synthesis of some hydroxamic acid derivatives of benzimidazole and their antibacterial and antifungal activities.

A number of 1H-benzimidazole-2-propanoic acid derivatives have been synthesized by Phillips method, and their antibacterial and antifungal activities have been tested. The chemical structures of the synthesized compounds were elucidated by spectroscopic (IR, NMR, mass) and elementary analysis. Investigation of antimicrobial activity of the compounds was done by agar dilution technique using bacteria (Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Mycobacterium smegmatis ATCC 607) and yeast-like fungi (Candida albicans, Candida tropicalis, Candida pseudotropicalis, Candida kruzei, Candida globrata). Among the compounds tested N-hydroxy-3-(1H-benzimidazol-2-yl)-propionamide (Compound 6) showed considerable activity against both Candida albicans and Candida tropicalis.     

N-pyrazolyl-2-nitrobenzamides with antifungal activity

Novel N-pyrazolyl-2-nitrobenzamides variously substituted on the pyrazole nucleus were prepared. The products obtained together with some other N-substituted 2-nitrobenzamides were tested for their antifungal activity against Cryptococcus neoformans and Candida albicans. The results of the antimicrobial assay showed different behaviours of the organisms used with regard to the derivatives tested.     

Preparation and antifungal activity of carbamic and thiocarbamic esters of thiophenols

A series of N-substituted carbamic and thiocarbamic esters of thiophenols [substances (I leads to XLII)] was prepared and tested for in vitro antifungal activity. The substances were obtained by condensation of thiophenols with suitable isocyanates and isothiocyanates. The antifungal activity of the products was tested in vitro against the following strains: Candida albicans, Candida tropicalis, Saccharomyces cerevisiae and Trichophyton mentagrophytes. The results obtained, given in the Table I, show that the carbamic and thiocarbamic esters of the thiophenols examined have marked antifungal activity. The results give some information on structure-activity relationships and also show that in general the derivatives of dithiocarbamic acid are more active than the bioisosteric derivatives of thiocarbamic acid. Of the compounds examined the most active were esters of N-benzyl and N-allyldithiocarbamic acid.     

Researches on antibacterial and antifungal agents, XII: Analogues of bifonazole with two imidazole moieties and related azoles

Analogues of bifonazole bearing two imidazole rings and other related azoles have been synthesized and tested as antifungal agents against Candida albicans and Candida spp.. Only a slight part of the antifungal power of the parent drug is retained by some derivatives as evinced by the comparison of new compounds with bifonazole, miconazole, and ketoconazole.     

Researches on antibacterial and antifungal agents, XIV: Thiophene analogues of bifonazole.

Some thiophene analogues of bifonazole have been synthesized by standard procedures and their antifungal activity has been tested against Candida albicans. Among test derivatives biphenyl-4-yl-5-chloro-thien-2-ylimidazol-1-ylmethane and its 5-deschlorothien-2-yl analogue resulted to be the most active. Their antifungal potency was almost comparable to that of control substances, such as miconazole, ketoconazole, and bifonazole. Replacement of benzene by the pyrrole ring in the biphenyl portion retained almost quantitatively the antifungal activity, whereas substitution with other azoles and with nitrogen alicyclic rings led always to less potent derivatives.     

The antifungal activities of some 6-[N-(halophenyl)amino]-7-chloro-5,8-quinolinediones againstCandida species

A series of 6-[N-(halophenyl)amino]-7-chloro-5,8-quinolinedione derivatives 1-10 were tested for antifungal susceptibilities, in vitro, against pathogenic Candida species such as C. albicans, C. glabrata, C. krusei, C. parapsilosis and C. tropicalis. The MICs were determined by the standard macrodilution techniques, according to the NCCLS 1992 guidelines. The 6-[N-(halophenyl)amino]-7-chloro-5,8-quinolinedione derivatives showed generally potent antifungal activities against pathogenic Candida species. Among them, derivative 1, 2, 5 and 7 showed more potent antifungal activities than ketoconazole. All derivatives 1-10 had specially potent activities against C. tropicalis. Derivative 1 and 2 containing (N-3,4-dihalo-phenyl)amino moiety exhibited the potent antifungal activities. Derivative 2 with (3,4-dichlorophenyl)amino substituent was the most effective in preventing the growth of Candida species at MICs 4 micrograms/ml respectively.     

FR227244, a novel antifungal antibiotic from Myrothecium cinctum No. 002. II. Biological properties and mode of action

FR227244 is a novel triterpene glycoside that exhibits in vitro antifungal activity against filamentous fungi such as Aspergillus sp. and Trichophyton sp. and yeast such as Candida utilis and Candida parapsilosis but shows low activity against Candida albicans, Candida krusei and Candida tropicalis. Specifically, FR227244 exhibits in vitro and in vivo antifungal activity against Aspergillus fumigatus. The minimum effective concentration (MEC) of FR227244 against A. fumigatus FP1305 in a micro-broth dilution test was 0.031 microg/ml. FR227244 showed good efficacy by subcutaneous injection and oral administration against A. fumigatus in a murine systemic infection model, with ED(50)s of 1.9 and 18 mg/kg, respectively. FR227244 inhibited glucan synthesis in a 1,3-beta-glucan synthase assay weakly and in whole cells strongly, but did not effect other macromolecule synthesis, including protein, nucleic acids, mannan and chitin. These results and the effect on hyphal morphology of A. fumigatus suggested that FR227244 showed antifungal activity based on inhibition of glucan synthesis.     

Synthesis of some benzimidazole derivatives and their antibacterial and antifungal activities.

A number of new benzimidazole derivatives were synthesized by the reaction of benzimidazole with appropriate alkyl halides. The compounds synthesized were intensified by 1H-NMR, Fourier Transformation Infrared (FT-IR) and micro analysis. All new and related compounds studied in this work were screened for their in vitro antimicrobial activities against the standard strains: Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 29213), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and the yeasts Candida albicans and Candida tropicalis. Eleven of the compounds were found effective to inhibit the growth of Gram-positive bacteria (E. faecalis and S. aureus) at MIC values between 12.5-400 micrograms/ml. None of the compounds exhibited antimicrobial activity against Gram-negative bacteria (E. coli and P. aeruginosa) at the concentrations studied (6.25-800 micrograms/ml). All compounds (except compound 3) were significantly effective against C. tropicalis with MIC values of 6.25-400 micrograms/ml. Eight of the tested compounds showed an antifungal activity against C. albicans with a range of the MICs between 50 and 400 micrograms/ml.     

Researches on antibacterial and antifungal agents. IX--Pyrrole analogues of bifonazole with potent antifungal activities

The synthesis and antifungal activities of pyrrole analogues of bifonazole are reported. Reduction of 4-nitrobenzophenone to the corresponding alcohol, reaction with phosphorus tribromide of the latter compound and condensation of the bromonitroderivative with imidazole led to 1-[alpha-(4-nitrophenyl)-4'-benzyl]-1H-imidazole. Hydrogenation of the nitro group to amino and reaction with 2,5-dimethoxytetrahydrofuran according to the Clauson-Kaas procedure afforded the pyrrole analogue of bifonazole. This compound and the related chloroderivative were also prepared by a similar pathway starting from 4-(1H-pyrrol-1-yl)benzophenone and its 4'-chloroderivative. Microbiological screening against Candida albicans and Candida spp showed 1-(alpha-[4-(1H-pyrrol-1-yl)phenyl]benzyl)-1H-imidazole to be the most active compound among the tested derivatives.     

氨基丁酸联合卡泊芬净的体外抗白色假丝酵母菌协同作用研究

目的探讨氨基丁酸联合卡泊芬净体外抗白色假丝酵母菌的协同作用。方法采用CLSI公布的M27-A方案微量棋盘液基稀释法测定氨基丁酸单用以及联合卡泊芬净对白色假丝酵母菌标准株SC5314的MIC80值和FICI值。采用抗真菌试管敏感性实验,考察给药24h后,卡泊芬净单用以及氨基丁酸联合卡泊芬净对白色假丝酵母菌SC5314生长的影响。采用生长曲线实验,测定氨基丁酸联合卡泊芬净抗白色假丝酵母菌SC5314的生长曲线。结果氨基丁酸单用对白色假丝酵母菌SC5314的MIC80>20μmol·L-1,说明氨基丁酸单用对SC5314没有抑菌作用;但1.25μmol·L-1氨基丁酸与卡泊芬净合用的FICI<0.5,说明氨基丁酸与卡泊芬净合用表现出协同关系。另外,在抗真菌试管敏感性实验中,1.25μmol·L-1的氨基丁酸联合0.012 5μg·mL-1的卡泊芬净与0.012 5μg·mL-1的卡泊芬净单用组相比,可以直观地观察到试管内浑浊程度明显减弱,SC5314的生长受到抑制。在生长曲线实验中,1.25μmol·L-1氨基丁酸联合0.012 5μg·mL-1卡泊芬净的生长曲线显著低于同浓度下两药单用的生长曲线(P<0.05)。结论氨基丁酸本身对白色假丝酵母菌标准株SC5314没有抑菌作用,但氨基丁酸能显著增强卡泊芬净对白色假丝酵母菌SC5314的杀菌作用。     

Synthesis, antibacterial and antifungal activities of bifonazole derivatives

Two series of chlorinated benzhydryl imidazole and triazole derivatives were synthesized and tested in vitro against representative strains of potent pathogenic bacteria (Staphylococcus aureus CIP 4.83, Escherichia hirae CIP 5855, Pseudomonas aeruginosa CIP 82118, Escherichia coli CIP 53126) and fungi (Aspergillus niger IP 1431.83, Candida albicans IP 48.72, Candida krusei IP 208.52, Trichophython rubrum IP 1657.86). Most of these compounds were devoid of any antimicrobial activity, but several of them inhibited T. rubrum with MIC values in the range of 0.125 to 32 μg/mL, similar or superior to those of bifonazole and clotrimazole, used as standard controls. The replacement of the imidazole ring with a triazole moiety in these compounds led to derivatives with less antifungal activity. A preliminary SAR was undertaken on the effect of the number and the position of chlorine atoms on the distribution of negative charge on the surface of some compounds on antifungal activity.     

FR209602 and related compounds, novel antifungal lipopeptides from coleophoma crateriformis no. 738. II. In vitro and in vivo antifungal activity

The biological activities of the novel echinocandin-like lipopeptides, FR209602, FR209603 and FR209604, were evaluated. These compounds showed antifungal activity against Candida albicans and Aspergillus fumigatus attributed to inhibition of 1,3-beta-glucan synthesis. The minimum effective concentrations of these compounds against C. albicans and A1. fumigatus ranged from 0.02 to 0.04 microg/ml by microbroth dilution assay, and the IC50 values on C. albicans 1,3-beta-glucan synthase were 0.49, 0.64 and 0.72 microg/ml, respectively. FR209602 and FR209603 showed good efficacy by subcutaneous injection against C. albicans in a murine systemic infection model, with ED50 values of 2.0 and 1.9 mg/kg, respectively.     

Quantitative structure-activity relationships study of a series of imidazole derivatives as potential new antifungal drugs

The Quantitative Structure-Activity Relationships (QSAR) has been developed to relate antifungal activity against Candida albicans and Rhodotorula glutinis of new imidazole derivatives with their physico-chemical and structural properties. For 265 imidazole derivatives the most significant statistically equations has been obtained with correlation coefficients R=0.800 and R=0.820 in case of activity against Ca. and Rh.g., respectively. The overall antifungal activity has been described by means of size and bulkiness related parameters as well as polar and lipophilic interactions. The significance of lipophilicity in terms of n-octanol/water partition coefficient, ClogP, on antifungal potency against both fungi has been investigated. QSAR equations for different classes of antifungal activity have been obtained. With a very high probability level (92% and 96%) the weak or very weak antifungal potency against C.a. can be determined and thus the number of required experiments can be reduced.     

五倍子鞣质提取物对白假丝酵母的抗菌活性研究

目的 研究五倍子鞣质提取物对白假丝酵母的体外抗茵活性.方法 通过超声波提取五倍子有效成分鞣质,福林-酚比色法检测鞣质含量,采用微量稀释法检测五倍子鞣质提取物对白假丝酵母的最低抑菌浓度(MIC)和最低杀菌浓度(MFC),以最低抑茵浓度药物作用白假丝酵母6、12、24h,通过普通光学显微镜直接观察白假丝酵母形态结构的变化,并用吖啶橙/溴化乙锭染色,通过荧光显微镜观察白假丝酵母的死亡方式.结果 五倍子鞣质提取物对白假丝酵母的最低抑菌浓度为10.76 mg/mL,最低杀菌浓度为21.52mg/mL;五倍子鞣质提取物可导致白假丝酵母细胞变形,形态结构改变,最终导致其死亡;同时抑制细胞发芽和假菌丝的形成.结论 五倍子鞣质提取物对白假丝酵母有抑制和杀灭作用.     

Synthetic acetylenic antifungal agents.

Several monoamino bis(propynyloxy)benzenes were prepared by a Mannich reaction and tested for antifungal activity against Trichophyton schoenleini, T. mentagraphytes, T. tonsurans, Candida albicans, and Epidermophyton flocossum. In addition, the bis(propynyloxy)benzene intermediates were tested and comparisons were made with standing drugs. The intermediates were found to be the most active, although two Mannich bases possessed considerable activity.     

FR901469, a novel antifungal antibiotic from an unidentified fungus No.11243. II. In vitro and in vivo activities

FR901469 is a water-soluble macrocyclic lipopeptidolactone (C71H116N14O23) that has inhibitory activity against 1,3-beta-glucan synthase and exhibits in vitro and in vivo antifungal activity against both Candida albicans and Aspergillus fumigatus. The MICs of FR901469 against Candida albicans FP633 and Aspergillus fumigatus FP1305 in a micro-broth dilution test were 0.63 and 0.16 microg/ml, respectively. FR901469 showed excellent efficacy by subcutaneous injection against both Candida albicans and Aspergillus fumigatus in a murine systemic infection mode, with ED50s of 0.32 and 0.2 mg/kg, respectively. This compound also showed potent anti-Pneumocystis activity in the nude mice model with experimental Pneumocystis pneumonia. The hemolytic activity of FR901469 towards mouse red blood cells, is about 30-fold weaker than that of amphotericin B.