Sordaricin antifungal agents

Compounds based on sordaricin were prepared via organometallic addition onto a fully protected sordaricin aldehyde. The fungal growth inhibition profiles for these compounds were established and the results are presented here. The synthesis of homologated sordaricin as well as ether and ester derivatives is presented, and structural rearrangement products upon oxidation. These compounds were evaluated as agents to inhibit fungal growth.     

Antifungal agents. Part 5: synthesis and antifungal activities of aminoguanidine derivatives of N-arylsulfonyl-3-acylindoles

In order to discover more promising antifungal agents, a series of aminoguanidine derivatives of N-arylsulfonyl-3-acylindoles (5a-r) were prepared and evaluated in vitro for their antifungal activities against seven phytopathogenic fungi. Especially compounds 5n and 5o exhibited more potent antifungal activities than or comparable to hymexazol, a commercially available agricultural fungicide at the concentration of 100 μg/mL. Preliminary structure-activity relationships study demonstrated that introduction of electron-donating substituents R(1) and R(2), and the proper length of substituent R(3) were usually very important for their antifungal activities.     

New synthetic antifungal agents

Summary New antifungal agents of the aromatic disulphide and sulphenamide type have been investigated by chemosynthesis.A large number of substances has been screened using several tests against various representative micro-organisms.In vitro tests of isomeric disulphides, symmetrically substituted with various groupings, revealed substances with high in vitro activity against human pathogenic fungi, amongst N, N'-monosubstituted bis-amides of 2,2'-diphenyldisulphide-dicarboxylic acid. Some of these substances show activity equal to or greater than that of the best-known natural and synthetic antifungal agents.The postulation of interdependence between the activity of these substances and the possibility in such molecules of tautomeric phenomena with prototropic equilibrium and also the proved importance of the sulphenamide function for antimycotic activity, led to investigation of N-substituted benzisothiazol-3-ones. Also these compounds proved highly active against pathogenic fungi.The level and range of activity of the bis-n.butylamide of 2,2' diphenyl-disulphide-dicarboxylic acid and N-cyclohexyl-benzisothiazol-3-one suggested the therapeutic study of these substances.For this reason, a pilot clinical investigation was carried out, which clearly showed that the two compounds, incorporated in suitable bases, are generally well tolerated by human skin either normal or with epidermomycotic lesions.The two compounds under test, when applied directly to epidermomycotic areas of various types (groin epidermophytia, erythrasma, pityriasis versicolor, monilial intertrigo and perlèche, athlete's foot, etc.) showed high antifungal activity, equal to or greater than that of well-known antifungal drugs in current therapeutic use.Read in the meeting of the First Congress of the International Society for Tropical Dermatology, Naples, June 8–13, 1964.     

Pediatric pharmacology of antifungal agents

Pediatric age groups display important differences in host biology, predisposing conditions, epidemiology, and presentation of fungal infections relative to the adult population. Over the past decade, major advances have been made in the field of medical mycology. Most importantly, an array of new antifungal agents has entered the clinical arena. Although pediatric approval of several of these agents remains to be established, the pediatric development of antifungal agents is moving forward. Invasive fungal infections will remain important causes for morbidity and mortality in immunocompromised pediatric patients. Although the availability of new therapeutic options is an important advance, antifungal therapy has become increasingly complex, and a thorough understanding of the available antifungal armamentarium is essential for the successful management of individual patients.     

Pharmacogenomics of systemic antifungal agents

The genomic era offers a multitude of new technologies that may make the promise of personalized medicine a reality for patients in this century. Numerous new antifungal agents have been developed over the past two decades, but use of these agents requires optimization of pharmacokinetics and dosing to achieve efficacy and minimize toxicity. This article reviews the potential application of pharmacogenomics to the use of antifungal agents, highlighting genetic variation that may affect absorption, distribution, metabolism, and elimination of these compounds.     

Augmenting the activity of antifungal agents against aspergilli using structural analogues of benzoic acid as chemosensitizing agents

A number of benzoic acid analogues showed antifungal activity against strains of Aspergillus flavus, Aspergillus fumigatus and Aspergillus terreus, causative agents of human aspergillosis, in in vitro bioassays. Structure-activity analysis revealed that antifungal activities of benzoic and gallic acids were increased by addition of a methyl, methoxyl or chloro group at position 4 of the aromatic ring, or by esterification of the carboxylic acid with an alkyl group, respectively. Thymol, a natural phenolic compound, was a potent chemosensitizing agent when co-applied with the antifungal azole drugs fluconazole and ketoconazole. The thymol-azole drug combination demonstrated complete inhibition of fungal growth at dosages far lower than the drugs alone. Co-application of thymol with amphotericin B had an additive effect on all strains of aspergilli tested with the exception of two of three strains of A. terreus, where there was an antagonistic effect. Use of two mitogen-activated protein kinase (MAPK) mutants of A. fumigatus, sakAΔ and mpkCΔ, having gene deletions in the oxidative stress response pathway, indicated antifungal and/or chemosensitization activity of the benzo analogues was by disruption of the oxidative stress response system. Results showed that both these genes play overlapping roles in the MAPK system in this fungus. The potential of safe, natural compounds or analogues to serve as chemosensitizing agents to enhance efficacy of commercial antifungal agents is discussed.     

真菌耐药的分子机制及新型抗真菌药物

真菌耐药性的发生率日益增多,严重影响了抗真菌药物的治疗效果。在分子水平上了解真菌耐药性的发生机制对控制其耐药性的发展和新型抗真菌药物的研究和开发十分重要。本文介绍了近年来真菌耐药性研究的新进展,以及目前正处于研究阶段的新型抗真菌药物。     

Novel broad-spectrum metal-based antifungal agents

Summary Copper(II) complexes of the type [Cu(L)X], where L=tridentate anion of 2-acetylpyridineN⁴-diethyl thiosemicarbazone and X=C1 or Br, were screened against seven fungal strains pathogenic to man viz.Aspergillus niger, Aspergillus fumigatus, Candida albicans, Cryptococcus neoformans, Tricophyton rubrum, Epidermophyton foccosum andMicrosporum canis. The greater growth inhibition exhibited by the bromo complex can be explained on the basis of its lower Cu(II)/Cu(I) redox couple and greater covalent bonding. These compounds represent a novel class of metal-based antifungal agents which provide opportunities for a large number of synthetic variations for modulation of the activities.     

Therapeutic drug monitoring of antifungal agents

Despite a dramatic increase in the number of commercially available agents to treat invasive fungal infections, they remain a common and devastating problem in a variety of patients. The impact of these infections has furthered interest in optimizing antifungal therapy. Therapeutic drug monitoring has emerged as a potentially important area allowing the efficacy of select antifungals to be optimized. This article reviews emerging data examining the utility and rationale for voriconazole and posaconazole therapeutic drug monitoring.     

Clinical efficacy of new antifungal agents

Several new options are now available for treating serious fungal infections. All three echinocandin agents currently available have been shown in randomized, blinded clinical trials to be efficacious in treating candidemia and invasive candidiasis. By contrast, the demonstrated efficacy of the echinocandins for the treatment of invasive aspergillosis has been based on historically controlled salvage treatment trials in patients failing or intolerant of other therapies. The new triazole agents, voriconazole and posaconazole, have a broad spectrum of antifungal activity. Voriconazole has become the agent of choice for invasive aspergillosis. On the basis of compassionate treatment data, posaconazole appears to be effective for treatment of zygomycosis. These agents have also been shown to be effective in the treatment of non-Aspergillus mould infections, several of the endemic mycoses and serious Candida infections.     

Antifungal activity of coumarins

The antifungal activity of 40 coumarins was tested against the fungal strains: Candida albicans (ATCC 14053), Aspergillus fumigatus (ATCC 16913) and Fusarium solani (ATCC 36031), using the broth microdilution method. Osthenol showed the most effective antifungal activity among all the compounds tested, with a MIC value of 125 microg/ml for Fusarium solani and 250 micro/ml for Candida albicans and Aspergillus fumigatus. The antifungal potential of this prenylated coumarin can be related to the presence of an alkyl group at C-8 position.     

6种抗真菌药物对皮肤癣菌体外抗真菌活性评价

目的评价6种抗真菌药物对皮肤癣菌体外抗真菌活性。方法采用CLSI推荐的M-38P方案对分离自足癣和体、股癣的皮肤癣菌进行联苯苄唑、硝酸舍他康唑、硝酸异康唑、盐酸布替萘芬、阿莫洛芬、利拉萘酯6种抗真菌药物敏感性测定。结果联苯苄唑MIC范围为0．03—4mg／L,MIC50为1mg／L,MIC90为2mg／L。硝酸舍他康唑分别为0．06—16mg／L、0．5mg／L和2mg／L。硝酸异康唑分别为0．03～2mg／L、0．25mg／L和0．5mg／L。盐酸布替萘芬分别为0．0025～0．04mg／L、0．01mg／L和0．02mg／L。阿莫罗芬分别为0．01～〉0．08mg／L、0．02mg／L和0．04mg／L。利拉萘酯分别为0．004—0．625mg／L、0．039mg／L和0．312mg／L。结论6种抗真菌药物对皮肤癣菌均有强的抗菌活性,由强到弱依次为布替萘芬、阿莫罗芬、利拉萘酯和咪唑类药物。     

Antifungal activity of rhizospheric bacteria

Fluorescent Pseudomonad spp. were isolated from the rhizosphere of potato plants (Algeria) by serial dilutions of rhizosphere soils on Kings B medium and were tested for their antifungal activity. The antifungal activity of the Pseudomonas isolated from Potatoes rhizosphere was tested against Pythium ultimum, Rhizoctonia solani and Fusarium oxysporum in dual culture with bacteria on PDA. The Petri dish was divided into tow, on one the bacteria was spread and on the opposite side fungal plugs were inoculated and incubated for one week. Fourteen bacteria were isolated; only one isolate inhibited the growth of Pythium ultimum, Rhizoctonia solani, Fusarium solani; Fusarium oxysporum f.sp. albedinis and Fusarium oxysporum f. sp. Lycopersici with inhibition zones of 39.9, 33.7, 30.8, 19.9 and 22.5 mm respectively.     

Antifungal activity of some Discomycetes

The antifungal activity was investigated in culture filtrates of 131 strains (41 genera and 104 species) of Ascomycetes — Discomycetes by testing against 6 fungal species which causes diseases in man. The anti-fungal spectrum was established for a Ciboria rufo-fusca strain, the only one found to inhibit all test organisms. This strain was also active against several gram-positive and gram-negative bacteria.     

Antifungal effect of 4-arylthiosemicarbazides against Candida species. Search for molecular basis of antifungal activity of thiosemicarbazide derivatives

The in vitro antifungal potency of six series of 4-arylthiosemicarbazides was evaluated. Two isoquinoline derivatives with an ortho-methoxy or ortho-methyl group at the phenyl ring were the most potent antifungal agents. Molecular modeling studies and docking of all 4-arylthiosemicarbazides into the active sites of sterol 14α-demethylase (CYP51), topoisomerase II (topo II), L: -glutamine: D: -fructose-6-phosphate amidotransferase (GlcN-6-P), secreted aspartic proteinase (SAP), N-myristoyltransferase (NMT), and UDP-N-acetylmuramoyl-L: -alanine:D: -glutamate ligase (MurD) indicated the importance of both structural and electronic factors in ligand recognition and thus for the antifungal effectiveness of 4-arylthiosemicarbazides. A possible antifungal target was identified (NMT) and isoquinoline-thiosemicarbazides showed more favorable affinity than the native ligand.     

Antifungal agents as tools in expermental mycology

Both natural and synthetic substances are conveniently used for studying metabolism, genetic aspects, morphogenesis of cell structures, life cycle and differentiation of fungi.     

Antifungal activity of transferrin.

Inhibitory effects of transferrin on fungal growth were successfully estimated by measuring fungal ATP content. By this method, it was demonstrated that both human and rabbit transferrin possessed the inhibitory effect in the absence of any other factor on yeast-like and filamentous fungi. However, rabbit stimulation factor enhanced the inhibitory effect. The inhibitory effect of transferrin was nonspecific and correlated with unsaturated iron binding capacity (UIBC) of transferrin. Human transferrin was more inhibitory than rabbit transferrin.     

Antifungal activity of some discomycetes

An antifungal glycoprotein compound was obtained from the culture filtrate of Ciboria rufo-fusca, by ultrafiltration and fractionation through D.E.A.E. cellulose and ultrogel Ac A34 chromatography. The purified material was homogeneous on polyacrylamide gel electrophoresis and was sensitive to the action of glucuronidase and catalase, and partly denatured by urea.The antifungal properties of the discomycete: Ciboria rufo-fusca was described in the first part of this work (6). The second part deals with the nature of the antifungal substance produced by Ciboria rufo-fusca.