Antifungal activity of a series of 1,2-benzisothiazol-3(2H)-one derivatives

A series of broad-spectrum antifungal agents based on the 1,2-benzisothiazol-3(2H)-one scaffold is reported. Preliminary structure-activity relationship studies have established the importance of the presence of the heterocyclic ring, a methyl group, and a phenyl ring for optimal manifestation of antifungal activity.     

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.     

Synthesis and evaluation of glycosidase inhibitory activity of octahydro-2H-pyrido[1,2-a]pyrimidine and octahydro-imidazo[1,2-a]pyridine bicyclic diazasugars

An efficient chiron approach for the synthesis of bicyclic diazasugars 4a and 4b having both -CH(2)OH and -OH functionality at the same carbon atom (C-6) is reported. Thus, easily available alpha-D-xylo-pentodialdo-1,4-furanose 5, obtained from D-glucose, on aldol-crossed Cannizzaro reaction followed by hydrogenolysis afforded 7. The regio-selective beta- and alpha-sulfonylation of hydroxymethyl groups in 7 afforded 8a (beta-sulfonylation) and 11 (alpha-sulfonylation) in good yields. The cleavage of the 1,2-acetonide functionality, individually in 8a and 11, followed by reaction with ethylenediamine gave in situ formation of sugar aminals that undergo concomitant nucleophilic displacement of the sulfonyloxy group, by amino functionality, to give hitherto unknown bicyclic diazasugars 4a and 4b, respectively. The inhibitory potency of the earlier reported bicyclic diazasugars 3a,b and 4a,b was evaluated against alpha- and beta-glycosidases and they were found to be potent and specific against the beta-glycosidases with IC(50) and K(1) values in the micro molar range.     

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 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 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.     

Antifungal activity of substituted aurones

Novel antifungals are in high demand as there is a growing resistance to antifungals currently in use. In particular, opportunistic fungal infections caused by Candida spp. are on the rise with infections by this genus accounting for the most severe fungal infections following chemotherapy, implantation procedures, and in patients with HIV/AIDS. A series of simple aurone analogs were synthesized and screened for antifungal activity versus Candida spp. Several compounds displayed activity at 100 μM, with two having IC₅₀ values below 20 μM for three species of Candida. One of the compounds tested here also exhibits anti-biofilm activity for mid-maturation growth.     

Antifungal activity of sesquiterpene lactones

Forty-five sesquiterpene lactones were screened for their antifungal activities against Microsporum cookei, Trichophyton mentagrophytes and Fusarium sp. The screening tests showed that a majority of sesquiterpene examined possess at least weak antifungal activity, the eudesmanolides being the most active. The antifungal activity of sesquiterpene lactones cannot be explained by the presence or absence of two potential active sites (the exocyclic methylene and, in pseudoguaianolides, a β-unsubstituted cyclopentenonel) but other functions must play a role in enhancing or reducing this activity.     

Antifungal activity of Apulia region propolis

A study was carried out to assess the in vitro antifungal activity of some natural Apulian propolis extracts of different origin. Their antifungal activity was compared to the antifungal activity of conifers and commercial propolis extracts. All extracts revealed antifungal activity against dermatophytes and Candida species. The antifungal activity differences found depended on the origin of the propolis and the solvent used for extraction. The best antifungal activity was given by the 'Orimini' propolis. The antifungal activity may have been influenced by the presence of different cinnamic and flavonoid components and their different concentration in the extracts. Further investigations are needed to validate this hypothesis.     

Antifungal activity of nontraditional antifungal agents

Invasive fungal infections are becoming increasingly important in the management of critically ill and immunocompromised patients. As organ and stem cell transplantation becomes more prominent and immune therapies are employed for diseases such as rheumatoid arthritis and plaque psoriasis, the population of patients at risk continues to grow. Many invasive fungal infections are associated with extremely high mortality rates. Antifungal options are limited and novel therapies are intriguing as we attempt to improve patient outcomes and preserve the antifungal armamentarium. Many other classes of pharmaceuticals typically seen as non-antifungal do in fact have significant antifungal activity. Prominent among these are calcineurin inhibitors, antiarrhythmics, antidepressants, antibacterials, and others. Some have activity alone and some augment the activity of conventional antifungals. Unfortunately, clinical data are lacking for most of these agents and their role in therapy remains undefined. This review focuses on several representative non-antifungal agents with antifungal activity.     

Antifungal activity of three spermidine conjugates

Three tri-substituted spermidines, di-p-coumaroyl-caffeoylspermidine, tri-caffeoylspermidine and tri-p-coumaroylspermidine, isolated from pollen of Quercus alba, were examined for antifungal activity. Both di-p-coumaroyl-caffeoylspermidine and tri-p-coumaroylspermidine reduced mycelial growth of the oat leaf stripe pathogen, Pyrenophora avenae and reduced powdery mildew (Blumeria graminis f. sp. hordei) infection of barley seedlings when applied as a post-inoculation treatment. When used as a pre-inoculation treatment, only di-p-coumaroyl-caffeoylspermidine reduced powdery mildew infection significantly. Growth of P. avenae in the presence of 100 microM di-p-coumaroyl-caffeoylspermidine reduced activity of S-adenosylmethionine decarboxylase (AdoMetDC), and led to a reduction in the incorporation of labelled ornithine into spermidine. The other two spermidine conjugates increased AdoMetDC activity and the flux label from ornithine into spermine in P. avenae significantly.     

Dialkylaminoalkyl derivatives of bicyclic compounds with antiplasmodial activity

Dialkylaminoalkyl derivatives of 2-azabicyclo[3.2.2]nonanes and of bicyclo[2.2.2]octanes were prepared and their activities determined in vitro against the multiresistant K₁ strain of Plasmodium falciparum. Several of the new compounds exhibited very promising antiplasmodial activity and selectivity. The results were compared to those of formerly synthesized analogues and of drugs in use. Structure–activity relationships were detected. Some of the more potent compounds were tested in vivo against Plasmodium berghei showing weak to moderate activity. A single compound was able to increase the mean survival days of infected mice.     

Antifungal activity of microbial secondary metabolites

Secondary metabolites are well known for their ability to impede other microorganisms. Reanalysis of a screen of natural products using the Caenorhabditis elegans-Candida albicans infection model identified twelve microbial secondary metabolites capable of conferring an increase in survival to infected nematodes. In this screen, the two compound treatments conferring the highest survival rates were members of the epipolythiodioxopiperazine (ETP) family of fungal secondary metabolites, acetylgliotoxin and a derivative of hyalodendrin. The abundance of fungal secondary metabolites indentified in this screen prompted further studies investigating the interaction between opportunistic pathogenic fungi and Aspergillus fumigatus, because of the ability of the fungus to produce a plethora of secondary metabolites, including the well studied ETP gliotoxin. We found that cell-free supernatant of A. fumigatus was able to inhibit the growth of Candida albicans through the production of a secreted product. Comparative studies between a wild-type and an A. fumigatus ΔgliP strain unable to synthesize gliotoxin demonstrate that this secondary metabolite is the major factor responsible for the inhibition. Although toxic to organisms, gliotoxin conferred an increase in survival to C. albicans-infected C. elegans in a dose dependent manner. As A. fumigatus produces gliotoxin in vivo, we propose that in addition to being a virulence factor, gliotoxin may also provide an advantage to A. fumigatus when infecting a host that harbors other opportunistic fungi.     

Antifungal activity of some mediterranean algae

Summary The antifungal activity of 15 mediterranean algae species on some dermatophyte strains (Epidermophyton floccosum, Microsporum canis, M. gypseum and Trichophyton mentagrophytes) and pathogenic yeasts (Candida albicans, C. guillermondii, C. krusei, C. tropicalis and Torulopsis glabrata) has been tested following a modification of Aubert's technique.Among the algae species studied, Falkenbergia rufolanosa is the most active in front of all the fungi tested.     

Antifungal activity of helenin and isohelenin

Two sesquiterpene lactones, helenin and isohelenin, were examined for their activity against 16 species of fungi. These compounds varied greatly in their antifungal activities. At concentrations of 10 μg/ml, the lactones strongly inhibited the growth of Microsporum cookei, Trichophyton mentagrophytes and Trichothecium roseum, while other fungi were only inhibited by considerably higher levels (100–1000 μg/ml). It is suggested that these secondary plant metabolites might be of potential use as antifungal agents, especially if their activity and specificity could further be enhanced through modifications in their chemical structure.     

Antifungal activity of metal complexes of thiosemicarbazones

¹³C and ¹H NMR relaxation rates were measured for the glutathione-VO²⁺ 2:1 complex in aqueous solution. The kinetics of the dissociation of the peptide from the coordination sphere were delineated and the structure of the complex was determined. The two carboxyl groups were shown to be the main binding sites.     

瑞香狼毒根的抑菌活性研究（Ⅰ）

以苹果干腐病菌、小麦赤霉病菌、番茄早疫病菌、南瓜枯萎病菌、玉米大斑病菌、烟草赤星病菌和辣椒疫霉病菌为供试菌,采用生物活性跟踪法、生长速率测定法和系统溶剂提取法对瑞香狼毒根中的杀菌活性物质进行了筛选和分离。结果表明,杀菌活性物质主要集中在乙酸乙酯提取物和甲醇粗提物中。从乙酸乙酯提取物中分离出两种杀菌活性物质AF1-4和AF1-5,同时还发现瑞香狼毒根中还存在增菌物质。     

Antifungal activity of ovotransferrin towards genus Candida

The inhibiting activity of ovotransferrin was tested towards different species belonging to genus Candida.Of one hundred strains tested, only C. krusei showed a noticeable resistance, while the other species appeared to be more sensitive than bacteria to the action of ovotransferrin. The influence of anions, such as bicarbonate and citrate, on the inhibiting activity of ovotransferrin was also investigated. Moreover it was observed that iron saturated ovotransferrin retained its activity, thus suggesting an interaction between the protein and Candida cells.