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At least 307 records · Page 17Linked to original sources
PubMed1983

Minimal inhibitory concentrations of lucknomycin, a new polyenic derivative, for Candida and Aspergillus spp.

The minimal inhibitory concentrations (MICs) of lucknomycin, a new polyenic derivative, were determined for 101 clinical isolates of Candida, 38 clinical or environmental strains of Aspergillus fumigatus, and 30 isolates of A. niger. The most susceptible species were Candida albicans and Candida tropicalis (mean MIC, 0.4 micrograms/ml). Aspergillus spp. were less susceptible, with mean MICs of 0.60 micrograms/ml for Aspergillus niger and 9.2 micrograms/ml for Aspergillus fumigatus.

Anti-Bacterial Agents↗
PubMed1989

Antibodies to nystatin demonstrate polyene sterol specificity and allow immunolabeling of sterols in Saccharomyces cerevisiae.

Polyclonal antibodies elicited by injection into rabbits of a nystatin-bovine serum albumin conjugate were reactive with both nystatin and amphotericin B. Upon labeling of polyene-treated Saccharomyces cerevisiae sterol auxotrophs grown on various sterols, nystatin reacted specifically with ergosterol, while amphotericin B did not react preferentially with ergosterol, cholesterol, or cholestanol. Time course labeling experiments demonstrated the rate of ergosterol transport into cholesterol-grown cells.

Animals↗
PubMed1998

In vitro activity of a new polyene, SPA-S-843, against yeasts.

The in vitro activity of a new water-soluble polyene, SPA-S-843, was evaluated against 116 strains of Candida, Cryptococcus, and Saccharomyces spp. and compared with that of amphotericin B. SPA-S-843 demonstrated better inhibitory activity against all of the yeasts examined and better fungicidal activity against Candida albicans, Candida glabrata, Candida krusei, and Candida tropicalis than did amphotericin B.

Amphotericin B↗
PubMed1974

Polyene-resistant mutants of Aspergillus fennelliae: identification of sterols.

Four mutants strains of Aspergillus fennelliae resistant to various polyene antibiotics have been analyzed for their sterol content. The mutant strains contained Delta(7,22,24(28))-ergostatrien-3beta-o1 and Delta(7,22)-ergostadien-3beta-o1 as the major sterols, whereas the wild types contained ergosterol, indicating that the mutants contain metabolic blocks for C(5)-C(6) dehydrogenation and C(24)-C(28) reduction in the biosynthesis of ergosterol. Revertant sectors arising from the mutant colonies contained either more Delta(7,22)-ergostadien-3beta-o1 than the parent mutant strain or showed the reappearance of ergosterol. The revertant sectors also showed lower resistance to amphotericin B and a higher rate of sporulation than the parent mutant strain. These results confirm our previous observations that the presence of ergosterol is directly related to the drug susceptibility and the normal rate of sporulation in this species.

Anti-Bacterial Agents↗
PubMed1975

New polyene antifungal antibiotic produced by a species of Actinoplanes.

A new species of Actinoplanes, which has been deposited with the designation NRRL 5325 at the Northern Utilization Research and Development Division of the U. S. Department of Agriculture, produces a polyene antifungal complex designated as Sch 16656. The complex, consisting of one major and three minor components, is isolated from the fermentation broth by a solvent extraction procedure and purified by precipitation methods. The major component is a heptaene and is highly active in vitro and in vivo against Candida albicans. It is active also against strains of Torulopsis and is significantly more potent orally than candicidin in mice against Candida infections.

Actinomycetales↗
PubMed1975

Candihexin polyene macrolide complex: physicochemical characterization and antifungal activities of the single components.

The candihexin complex produced by a natural mutant of Streptomyces viridoflavus has been resolved into eight components. At least six of them, having hexaene chromophores, can be separated directly by thin-layer chromatography. The four major components, candihexins A, B, E, and F, account for about 90% of the total complex. They have been isolated and purified to homogeneity. All the major components were found to have macrolide lactone rings with all-trans hexaene chromophores. Candihexins A and B have compositions and molecular weights similar to candidin, the heptaene polyene macrolide produced by the parent S. viridoflavus, whereas candihexins E and F show smaller molecular weights and rather different elementary compositions. Candihexins A and B yield the amino sugar mycosamine upon hydrolysis, but no sugar was found in hydrolysates of candihexins E and F. Candihexins A and B have high antifungal activity against yeasts and filamentous fungi. The amino sugar-lacking candihexins E and F show no antifungal activity at levels of 100 mug/ml.

Aminoglycosides↗
PubMed2006

Granadaene: proposed structure of the group B Streptococcus polyenic pigment.

The goal of this work was to determine the chemical nature of the red pigment produced by Streptococcus agalactiae, which has been thought to be a carotene. We extracted the pigment with 0.1 M KOH and purified it by column chromatography on Sephadex LH. Data from elemental analysis and mass and nuclear magnetic resonance spectra lead us to propose the structure to be that of a new ornithine rhamno-polyene with 12 conjugated double bonds, to which we have assigned the trivial name granadaene.

Magnetic Resonance Spectroscopy↗
PubMed1997

Late treatment with polyene antibiotics can prolong the survival time of scrapie-infected animals.

Amphotericin B (AmB) is one of the few drugs able to prolong survival times in experimental scrapie and delays the accumulation of PrPres, a specific marker of this disease in the brain in vivo. Previous reports showed that the AmB effect is observed only if the drug is administered around the time of infection. In the present study, intracerebrally infected mice were treated with AmB or one of its derivatives, MS-8209, between 80 and 140 days postinoculation. We observed an increased incubation time and a delay in PrPres accumulation and glial fibrillary acidic protein gene expression. Treatment starting at 80 days postinoculation was as efficient as long-term treatment starting the day of inoculation. Our results indicate that polyene antibiotics may interfere, throughout the course of the experimental disease, with the propagation of the scrapie agent.

Amino Acid Sequence↗
PubMed1977

Sterol content and polyene antibiotic resistance in isolates of Candida krusei, Candida parakrusei, and Candida tropicalis.

Three isolates, one from each species of Candida krusei, C. parakrusei, and C. tropicalis, obtained from infected patients, were more tolerant of significantly higher concentrations of polyene antibiotics than the corresponding reference wild types. The resistant strains isolated had the same sterols as their wild-type counterparts but in lower concentrations.

Amphotericin B↗
PubMed2000

Polyene hydrocarbons and epoxides: a second major class of lepidopteran sex attractant pheromones.

Polyene hydrocarbons and epoxides are used as pheromone components and sex attractants by four macrolepidopteran families: the Geometridae, Noctuidae, Arctiidae, and Lymantriidae. They constitute a second major class of lepidopteran pheromones, different from the C10-C18 acetates, alcohols, and aldehydes commonly found in other species. They are biosynthesized from diet-derived linoleic or linolenic acids and are characterized by C17-C23 straight chains, 1-3 cis double bonds separated by methylene groups, and 0, 1, or 2 epoxide functions. Pheromone blends are created from components with different chain lengths, numbers of double bonds, and functional groups, or from mixtures of epoxide regioisomers or enantiomers, with several examples of synergism between enantiomers. Behavioral antagonists also limit interspecific attraction, with numerous examples of antagonism by enantiomers. This review summarizes the taxonomic distribution, mechanisms used to generate unique pheromone blends, and the identification, synthesis, and biosynthesis of these compounds.

Animals↗
PubMed2001

Lipid formulations of polyene antifungal drugs and attenuation of associated nephrotoxicity.

Amphotericin B is an effective broad-spectrum antifungal agent, but various side effects, especially nephrotoxicity, have restricted its use. Recently, lipid formulations of amphotericin B have been developed in order to reduce its toxic side effects. Clinical trials, although in the early stages, suggest promising results, and that some of these lipid formulations are potent and less toxic, even at higher doses. We summarize herein the existing information about newer lipid formulations of polyene antifungal drugs, which could attenuate associated nephrotoxicity.

Amphotericin B↗
PubMed1980

Saponin and other haemolysins (vitamin A, aliphatic amines, polyene antibiotics) as adjuvants for SRBC in the mouse. Evidence for a role for cholesterol-binding in saponin adjuvanticity.

The hypothesis that the adjuvant, as well as the haemolytic, activity of saponin depends on binding to cholesterol in cell membranes is supported by showing that cholesterol absorbs out adjuvant activity, and inhibits immunopotentiation in vivo when added to the injection mixture. Also, out of a range of haemolytic substances, chosen for their known properties as adjuvants or for cholesterol binding, the only materials which displayed a comparable activity to saponin were the polyene antibiotics Nystatin and Amphotericin B, whose binding to membrane cholesterol causes similar morphological changes to that of saponin.

Absorption↗
PubMed1985

Susceptibility of Candida spp. of clinical origin to lucknomycin, a new polyenic antibiotic.

Lucknomycin is a new polyenic derivative antifungal agent obtained from a Streptomyces diastatochromogenes culture. The in vitro activity of the compound was tested against 403 strains of different Candida species of clinical origin by the Sabouraud Agar dilution method. The mean geometrical value of the minimal inhibitory concentrations (MIC) for Candida albicans was 0.85 microgram/ml, 6 times lower than the corresponding value of nystatin (5.29 micrograms/ml) and very close to that of amphotericin B (0.56 microgram/ml). Lucknomycin was also 4-10 times more active than nystatin on other Candida species, with an MIC similar to those obtained with amphotericin B.

Anti-Bacterial Agents↗
PubMed2003

Structural studies and antifungal activity of unique polyene amides, clathrynamide A and three new derivatives, from a marine sponge, Psammoclemma sp.

Known polyene amide, clathrynamide A, and three novel related metabolites, debromoclathrynamide A, (4E,6E)-debromoclathrynamide A and (6E)-clathrynamide A, were isolated from an Okinawan marine sponge, Psammoclemma sp. The absolute stereochemistry of clathrynamide A was determined to be 3R,12R by the modified Mosher method. The structures of the three new compounds were elucidated by spectroscopic analyses as debromo derivatives and geometrical isomers. Their antifungal activities were also evaluated with a phytopathogenic fungus, indicating that both the bromine atom and double-bond geometry affected the activity.

Amides↗
PubMedDate not supplied

Melanocrocin, a polyene pigment from Melanogaster broomeianus (Basidiomycetes).

A new polyene pigment, melanocrocin, has been isolated either from fruit bodies or mycelial cultures of the subterranean fungus Melanogaster broomeianus. The structure of the pigment was determined by spectroscopic methods and chemical transformations. Melanocrocin is the N-acyl derivative of L-phenylalanine methyl ester with a polyolefinic carboxylic acid.

Basidiomycota↗
PubMedDate not supplied

Mechanisms of photoisomerization of polyenes in confined media: from organic glasses to protein binding cavities.

Photochemical reactivities of model organic systems (stilbene and diphenylbutadiene) in organic glasses were first examined and compared with those in solution and in organized media. These observations were in turn compared with reactivities of polyene chromophores in protein binding cavities (specifically PYP, rhodopsin and bacteriorhodopsin). The obvious conclusion is that the preference for the most volume-conserving Hula-twist mechanism isomerization in organic glasses is because of the close interaction between the guest and the host molecules. In organized media (zeolites, crystals and protein binding cavities), the residual empty space coupled with any specific guest-host interactions that are characteristic of a given system, could lead to involvement of the more volume-demanding one-bond-flip (i.e. torsional relaxation) or bicycle-pedal or an extended HT process in photoisomerization.

Bacterial Proteins↗
PubMed2003

Variability in polyene content and cellular toxicity among deoxycholate amphotericin B formulations.

STUDY OBJECTIVE: To evaluate the toxicity of amphotericin B deoxycholate formulations. DESIGN: In vitro experiment. SETTING: University research center. MATERIAL: Human mononuclear THP-1 cells. INTERVENTION: The human mononuclear cells were exposed in vitro for 2 hours to the following deoxycholate formulations of amphotericin B, in 2.5- and 5-micro/ml concentrations: Apothecon, Pharmacia, Sigma, Gensia, Pharma-Tek, and VHA. MEASUREMENTS AND MAIN RESULTS: Toxicity of the amphotericin B formulations were assessed by measuring interleukin (IL)-1beta expression in an in vitro model. Amphotericin B content was measured by enzyme-linked immunosorbent assay (ELISA), and amphotericin A and B contents were assessed by spectrophotometry. Endotoxin contamination was evaluated in all reagents. Expression of IL-1beta from Sigma, Pharmacia, and Pharma-Tek formulations was increased approximately 250%, 50%, and 25%, respectively, compared with amphotericin A. Amphotericin B content of Sigma, Pharmacia, Pharma-Tek, and Gensia formulations, as measured by ELISA, was increased approximately 450%, 200%, 200%, and 100%, respectively, compared with Apothecon. This variation could not be explained by differences in amphotericin A or B content as measured by spectrophotometry. CONCLUSION: Amphotericin B is obtained from a fermentation plant and manufactured as a pharmaceutical at different facilities. Both previous clinical observations and the current in vitro evaluation revealed significant differences among the formulations. Likely, other polyenes or pyrogenic toxins in differing amounts are in these formulations, thus explaining the variability in toxicity observed among the formulations.

Amphotericin B↗