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At least 253 records · Page 14Linked to original sources
PubMed1994

Screening for non-polyenic antifungal antibiotics produced by rare Actinomycetales.

Strains of Actinomycetales (286 in toto) belonging to thirteen genera other than Streptomyces were isolated from different ecosystems in the Algerian Sahara. Among these strains, 32 showed antibiotic activity against at least one of the test organisms comprising four bacteria, two yeasts and several filamentous fungi, and twelve were antagonistic against both bacteria and fungi. The characteristic UV spectra of active extracts revealed that six strains produced non-polyenic antifungal substances and four synthetized polyenic substances. One strain of Spirillospora produced a pentaene antifungal substance. The only antibiotic so far known to be produced by this genus is spirillomycin.

Actinomycetales↗
PubMed1995

[The effect of polyene phosphatidylcholine administration on lipid metabolism and glucose tolerance in patients with hyperlipoproteinemia IIB].

BACKGROUND: Up to now, clinical and experimental studies have brought only inconsistent data about the effectiveness of polyene phosphatidylcholine (PPC) in treatment of dyslipidemia. The aim of this randomized, double blind study was to verify the effects of the polyene phosphatidylcholine preparation Lipostabil forte R (Rhone-Poulenc-Röhrer, Köln, FRG), given orally in a daily dose 2.7 g for three months to patients with hyperlipoproteinemia type IIB and hypoalfacholesterolemia both on the plasma lipids, lipoproteins, apolipoproteins and the parameters of glucose tolerance. METHODS AND RESULTS: Administration of PPC to 30 patients with hyperlipoproteinemia type IIB and hypoalfacholesterolemia led to a significant rise of HDL-cholesterol, HDL3-cholesterol and plasma apolipoprotein A-I concentrations in comparison with the group treated with placebo. At the same time, plasma apolipoprotein B concentration slightly increased. Blood glucose, immunoreactive insulin and non-esterified fatty acid concentrations during the oral glucose tolerance test didn't change significantly after PPC administration. CONCLUSIONS: It seems PPC could be the appropriate supplement to the treatment of patients with decreased concentrations of HDL-cholesterol and plasma apolipoprotein A-I.

Double-Blind Method↗
PubMed1996

[Use of the fish oil "Polyen" in pediatric practice].

The effects of supplementation of basic diets with 'Polyen' in daily doses of 2.5-4.0 g during 30-40 days together with antioxidants were studied in patients with kidney diseases (diet No7, n = 14), different allergies (hypoallergenic diet, n = 37) and in control children (n = 12). It was shown positive dynamics in fatty acid contents in plasma and red blood cell membranes, in humoral and cell immunity indicators and in improving of clinical symptoms of diseases. 'Polyen' is recommended for wide use in pediatric practice.

Antibody Formation↗
PubMed1997

Leishmanicidal activity of Nystatin (mycostatin): a potent polyene compound.

The susceptibility of promastigote of Leishmania major to Nystatin in vitro was examined. L. major (MHOM/PK/88/DESTO) promastigote were cultured in medium 199 supplemented with 10% heat inactivated foetal bovine serum and 2% urine. The growth of the promastigote was monitored in the absence and presence of the experimental compound (Nystatin) for upto 5 days post-inoculation. The EC50 value (the concentration of drug necessary to inhibit the growth rate of cells to 50% of the control value) obtained for Nystatin against the promastigote of L. major was less than 9.76 iu ml. Certain polyene compounds like Amphotericin-B and Nystatin (mycostatin) are familiar for their fungicidal activity. Amphotericin-B is used since long as antileishmanial drug as well. Results obtained suggest that Nystatin has a very good anti leishmanial activity in vitro. The mode of action proposed for this drug is same as for Amphotericin-B as both of these polyene compounds interact with the various sterols present on the surface of the parasite, thus unusual gaps and pores are formed on the surface that results in the leakage of the ions. This leakage finally leads to the destruction of the parasite.

Amphotericin B↗
PubMed1976

[Effect of polyene antibiotics on isolated dog kidney nuclei].

Effect of amphotericin B and nistation on caryoplasmic proteins, nuclear membrane-bound chromatin (DNPm) and soluble DNP (DNP0) from dog kidney isolated nuclei is studied in vitro. The yield of caryoplasmic proteins from nuclei is found to be increased during incubation with amphotericin B and nistatin, the content of some fraction in caryoplasmic proteins being decreased while their qualitative composition being unchanged. It is found that the treatment of nuclei with amphotericin B contributes the association of DNP particles with nuclear membrane and the increase of protein/DNA and RNA/DNA ratios in DNPm. No such effects are observed in the presence of nistatin. Both antibiotics do not affect protein/DNA and RNA/DNA ratios in DNP0 fraction. Polyene antibiotics are shown to change considerably the composition of acid soluble proteins in DNP0 and DNPm and in non-histone proteins in DNP0, and not to affect the content of lipids and their fatty acid composition in DNPm. The data obtained are of certain value for explanation of the mechanism of toxic effect of polyene antibiotics on animal cells.

Amphotericin B↗
PubMed1980

Field desorption mass spectrometry in structural studies of polyene macrolide antibiotics: isolation and early identification of a pentaene macrolide antibiotic.

Isolation of a pentaene macrolide antibiotic (NSC-277813) from Streptomyces griseus (FCRC-21) fermentation broth is described. Using field desorption mass spectrometry and high resolution field desorption mass spectrometry on the intact and derivatized antibiotic and degradation products, the antibiotic was identified as fungichromin. The application of field desorption mass spectrometry in the identification of polyene antibiotics is discussed.

Antibiotics, Antineoplastic↗
PubMed1994

Na+, K+ and Cl- selectivity of the permeability pathways induced through sterol-containing membrane vesicles by amphotericin B and other polyene antibiotics.

Membrane diffusion potentials induced by amphotericin B (AmB), amphotericin B methyl ester (AmE), N-fructosyl AmB (N FruAmB) and vacidin, an aromatic polyene antibiotic, in ergosterol- or cholesterol-containing egg yolk phosphatidylcholine large unilamellar vesicles (LUV), were measured in various media, in order to determine the relative selectivity of Na+, K+, Cl- and other ions in these environments. Changes in the membrane potential were followed by fluorescence changes of 3,3'-dipropylthiadicarbocyanine (diS-C3-(5)). Subtle changes in intercationic selectivity were monitored by measuring biionic potentials, using the fluorescent pH sensitive probe pyranine. In all the cases studied, the intercationic selectivity of the permeability pathways induced by the four antibiotics was weak compared to that of specific biological channels, though distinct differences were noted. With AmB the selectivity appeared to be concentration dependent. Above 5 x 10(-7) M, the sequence determined for sterol-free small unilamellar vesicles (SUV) and cholesterol-containing SUV and LUV, Na+ > K+ > Rb+ > or = Cs+ > Li+ (sulfate salts), corresponded closely to Eisenman selectivity sequence number VII. At 5 x 10(-7) M and below the selectivity switched from Na+ > K+ to K+ > Na+. In contrast, Li+ was the most permeant ion for AmB channels in the presence of ergosterol. The selectivity between Na+ or K+ vs. Cl- varied with the antibiotic. It was very strong with vacidin at concentrations below 5 x 10(-7) M, smaller with AmB, nil with AmE and N FruAmB. The selectivities observed were antibiotic, concentration and time dependent, which confirms the existence of different types of channels.

Amphotericin B↗
PubMed1979

Coupled transepithelial sodium and potassium transport across isolated frog skin: effect of ouabain, amiloride and the polyene antibiotic filipin.

Addition of the polyene antibiotic filipin (50 microM) to the outside bathing solution (OBS) of the isolated frog skin resulted in a highly significant active outward transport of K+ because filipin per se increases the nonspecific Na+ and K+ permeability of the outward facing membrane. The K+ transport was calculated from the chemically determined changes in K+ concentrations in the solution bathing the two sides of the skin. The active transepithelial K+ transport required the presence of Na+ in the OBS, but not in the inside bathing solution (IBS), and it was inhibited by the Na+, K+-ATPase inhibitor ouabain. The addition of Ba++ to the IBS in the presence of filipin in the OBS resulted in an activation of the transepithelial K+ transport and in an inhibition of the active Na+ transport. This is in agreement with the notion that Ba++ decreases the passive K+ permeability of the inward facing membrane. In the presence of amiloride (which blocks the specific Na permeability of the outward facing membrane) and Ba++ there was a good correlation between the active Na+ and K+ transport. It is concluded that the active transepithelial K+ transport is carried out by a coupled electrogenic Na-K pump, and it is suggested that the pump ratio (Na/K) is 1.5.

Amiloride↗
PubMed1978

Effect of the polyene antibiotic filipin and the calcium ionophore A23187 on sodium transport in isolated frog skin (Rana temporaria).

Addition of filipin (50 micrometer) to the inside bathing solution of the frog skin resulted in a transient increase in the active sodium transport [measured as short-circuit current (SCC)]. The filipin-induced increase in the SCC required the presence of calcium. The calcium ionophore A23187 (4 micrometer) also induced a transient increase in the SCC. After the activation of the SCC by A23187, the SCC could not be activated by filipin. This indicates that the polyene antibiotic filipin acts as a calcium ionophore. Higher concentrations (40 micrometer) of A23187 resulted in a shrinking of the cells in the transporting cell layer. A23187 also increased the potassium-42 exchange in the isolated epithelium. It is suggested that calcium ionophores enhanced the intracellular calcium concentration; this increase in the calcium concentration resulted in an increase in the potassium permeability of the inward-facing membrane. The increase in the potassium permeability might explain the observed increase in the SCC.

Action Potentials↗
PubMed1978

Properties of morphologically variant haploid frog cells formed by combined treatment with Mengo virus and the polyene antibiotic mediocidin.

Comparisons have been made of cell surface glycoproteins, concanavalin A agglutinability, and cloning efficiencies in liquid media of ICR 2A (haploid frog cells), ICR 2A M (three cloned populations of haploid frog cells resistant to 5 microgram per ml of the polyene antibiotic mediocidin), and ICR 2A M/MV cells (five cloned populations of morphologically variant haploid frog cells produced by exposure of the parental cells to the combined effects of mediocidin and an RNA mammalian virus, Mengo virus). Independently isolated ICR 2A M/MV clones exhibited altered cell surface glycoproteins, increased concanavalin A agglutinability, and enhanced cloning efficiency in liquid media when compared with ICR 2A parental cells. In contrast, ICR 2A M cells had properties similar to ICR 2A cells, with the exception of the former's increased resistance to mediocidin. The differences in properties between ICR 2A M/MV and ICR 2A cells suggest that alterations resembling transformation have occurred in ICR 2A M/MV cells as a consequence of combined treatment with mediocidin and Mengo virus.

Agglutination↗
PubMed1982

A new streptomycete and a new polyene antibiotic, acmycin.

A new antifungal antibiotic named acmycin was isolated from a soil streptomycete. Detailed comparative taxonomic studies showed that the organism differed from three related species of streptomycetes. The organism was referred to as Streptomyces sp. AC2. The isolated antibiotic appears to be of polyene nature.

Antifungal Agents↗
PubMed1983

Biological properties of acmycin, a new polyene antibiotic.

Acmycin, a new polyene antibiotic, was fungistatic at low and fungicidal at high concentrations. It produced malformations in conidia of Helminthosporium oryzae and Curvularia lunata and caused leakage of yeast cells. Acmycin was fairly nontoxic to germinating seeds. The intravenous LD50 was 300-400 and intraperitoneal maximum tolerated dose 100-500 mg/kg body mass of mice.

Animals↗
PubMed2004

Topical polyene antifungals in hematopoietic cell transplant patients: tolerability and efficacy.

PURPOSE: The effectiveness of amphotericin B oral suspension versus nystatin oral suspension for the prevention of oral colonization by Candida in hematopoietic cell transplant (HCT) patients was examined. METHODS: Prior to hematopoietic cell infusion, 40 patients receiving systemic fluconazole for prophylaxis were randomized to receive either amphotericin B oral suspension or nystatin oral suspension, q.i.d. The study continued to day 21 or until the patient was discharge from the hospital or withdrawn from the study. Oral examinations were conducted twice weekly, and adverse events and compliance were recorded. Cultures were taken for quantitative counts and species identification. Candida isolates were assessed for resistance to the oral antifungal agents. Blood was collected for assessment of amphotericin B levels. RESULTS AND DISCUSSION: Ulcerative mucositis occurred in 84.6% of patients undergoing HCT, and no correlation was observed between the severity of mucositis and the presence of oral Candida and the severity of mucositis. Systemic and topical antifungal treatment resulted in a decrease in the number of colonized patients (54.8% before treatment; 23.1% during treatment); however, oral colonization was not eliminated. Tolerability of the oral rinse products was limited, with greater noncompliance in the amphotericin B than the nystatin group. Reports of altered taste appeared to be greater in the amphotericin B group. Minimal absorption of amphotericin B was seen following oral rinsing (serum levels 0.12-0.50 microg/ml), and no consistent changes in organism susceptibility to polyenes were seen. The results suggest that topical antifungal rinses may further control oropharyngeal colonization by Candida in patients on systemic antifungals receiving HCT, but the effect is limited by tolerability and reformulation and should be considered in order to increase compliance.

Administration, Oral↗
PubMed1988

Interaction of the polyene antibiotic filipin with model and natural membranes containing plant sterols.

The interaction of the polyene antibiotic, filipin, with individual or mixed plant sterols (stigmasterol, sitosterol, campesterol and 24-methylpollinastanol) incorporated into large unilamellar vesicles (LUV) of soybean phosphatidylcholine (PC) as well as the filipin interaction with purified membrane fractions from maize roots containing these sterols was investigated by ultraviolet (UV) absorption and and circular dichroism (CD) spectroscopy. With both types of membrane preparation, dramatic changes in the UV absorption and CD spectra of the antibiotic were evidenced. When LUV containing stigmasterol, sitosterol and/or campesterol were incubated with low filipin concentrations (i.e., for filipin/sterol molar ratios (rst) lower than 1), CD signal characteristic of the formation of filipin-sterol complexes were observed. At higher rst values, the filipin-sterol interaction was shown to be in competition with a filipin-phospholipid interaction. With 24-methylpollinastanol-containing LUV, the filipin-phospholipid interaction was detected even at rst values lower than 1, which suggests a lower affinity of filipin for this sterol and emphasizes the structural differences between delta 5-sterols and 9 beta,19-cyclopropylsterols. With sterol-free soybean PC LUV, a filipin-phospholipid interaction could also be evidenced. With maize root cell membranes containing either delta 5-sterols or 9 beta,19-cyclopropylsterols, CD spectra similar to those obtained in the presence of LUV having these sterols as components were observed. Thus, the protein component of the membranes does not appear to be an important feature.

Cell Membrane↗
PubMed1995

Identification of the structural elements of amphotericin B and other polyene macrolide antibiotics of the hepteane group influencing the ionic selectivity of the permeability pathways formed in the red cell membrane.

The selectivity of the transmembrane permeability induced by polyene antibiotics was studied in human erythrocytes and related to the hemolytic potency of the drugs. The selectivity induced was differently, dependent on the antibiotic structure in aromatic (vacidin A, gedamycin) and nonaromatic heptaenes (amphotericin B, candidin). Aromatic heptaenes were more effective than nonaromatic in inducing permeability to K+. For both groups of antibiotics, permeability to K+ was not affected by substitution at the carboxyl group but important differences in the induction of permeability to H+, OH- and Cl- were found. The strongly hemolytic aromatic heptaenes vacidin A and gedamycin exhibited much higher protonophoric activity than the nonaromatic ones: amphotericin B, and candidin. The protonophoric properties of aromatic heptaenes were related to the presence of a free carboxyl group in the antibiotic molecule. Indeed the esterification or amidation of the carboxyl group of vacidin A or gedamycin eliminated the ability of the antibiotic to increase H+ conductance and consequently diminished their hemolytic activity to an important extent. Both groups of antibiotics differed also in the efficiency of anion permeability induction. Only unsubstituted aromatic heptaenes, at high concentration, induced Cl-/OH- exchange and conductive flux of Cl- in a concentration-dependent manner. Substitution at the carboxyl group of vacidin A or gedamycin eliminated this property. Amphotericin B as well as its carboxyl-substituted derivatives formed a pathway characterized by low K+ over Cl- selectivity, whatever the concentration. The hemolytic activity, related to K+ permeability increased by heptaenes was dependent on simultaneous increase of the permeability to anions, and net KCl influx. Carboxyl-substituted derivatives of aromatic heptaenes presenting a remarkably high selectivity for K+, had consequently a very poor hemolytic activity.

Amphotericin B↗
PubMed1986

Structure-activity relationships of retinoids in developmental toxicology. II. Influence of the polyene chain of the vitamin A molecule.

The comparative teratogenic potencies of 7,8-dihydroretinoic acid, 7,8-dehydroretinoic acid, 9,10-dihydroretinoic acid, 9-cis-retinal, hydroxenin, oxenin, the C15 analog of all-trans-retinoic acid, abscissic acid, beta-C14 aldehyde, beta-ionone, and psuedoionone were determined in golden Syrian hamsters and compared with that of all-trans-retinoic acid. A single oral dose of each retinoid on Day 8 of gestation failed to induce signs of retinoid intoxication in the dams and the maternal weight gain was not affected significantly, except after treatment with beta-C14 aldehyde, pseudoionone, and the lowest dose of 9-cis-retinal, where maternal weight was depressed. A significant teratogenic response was observed after intubation of 7,8-dihydroretinoic acid, 7,8-dehydroretinoic acid, or 9-cis-retinal. The highest dose of hydroxenin (equivalent to nearly seven times an equimolar teratogenic dose of all-trans-retinoic acid) showed a limited teratogenic response. None of the remaining retinoids induced terata. The results suggest that the side chain plays an important role in retinoid embryotoxicity and that even minor structural alterations of retinoids at the side chain can abolish teratogenic activity. The present results indicate that a polyene chain of greater than five carbon atoms was necessary for retinoid teratogenic activity and that the presence of the ring, the nine-carbon side chain, and the acidic polar terminus was insufficient to ensure teratogenic activity. Retinoid teratogenicity in hamsters required the hydrophobic ring, a terminal polar group with an acidic pKa, and the hydrophobic, curved plane of the tetraene chain.

Animals↗