Wyniki wyszukiwania dla: antifungal activity
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Chemical and biological stability of polyene macrolides
PublikacjaThe polyene macrolide antibiotics have been used in an-tifungal therapy since first o f them were discovered in 1950's. Up to now, four polyene macrolides are being used in medical practice, namely amphotericin B, nystatin, candi-cidin and pimaricin.The antifungal activity and mode of ac-tion of polyene macrolides is determined by their structure, chemical and physical properties.The main fragment of polyene...
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Enhanced susceptibility to antifungal oligopeptides in yeast strains overexpressing ABC multidrug efflux pumps
PublikacjaPorównano podatność na działanie związków przeciwgrzybowych o strukturze oligopeptydowej oraz aminokwasowej szczepów Saccharomyces cerevisiae z usuniętymi genami kodującymi białka oporności wielolekowej oraz transformantów tych szczepów, zawierających geny CDR1, CDR2 lub MDR1, kodujące główne pompy wielolekowe Candida albicans. Rekombinowane szczepy nadprodukujące białka Cdr1p i Cdr2p wykazywały zwiększoną wrażliwość na wszystkie...
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Synthesis of 2-amino-2,6-dideoxy-D-glucitol-6-sulfonic acid as a potential antifungal agent.
PublikacjaGlucosamine-6P (GlcN-6P) synthase catalyzes the first committed step in the biosynthetic pathway leading to the formation of UDP-GlcNAc, a sugar nucleotide precursor providing D-glucosamine for the formation of chitin and manoproteins. 2-Amino-2,6-dideoxy-D-glucitol-6-sulfonic acid is an analog of 2-amino-2-deoxy-D-glucitol 6-phosphate (GlcN-ol-6-P), a known inhibitor of GlcN-6-P synthase, in which the phosphate group of the latter...
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Emerging anticancer activity of candidal glucoseamine-6-phosphate synthase inhibitors upon nanoparticle-mediated delivery
PublikacjaNumerous glutamine analogues have been reported as irreversible inhibitors of the glucosamine-6-phosphate (GlcN-6-P) synthase in pathogenic Candida albicans in the last 3.5 decades. Among the reported inhibitors, the most effective N3-(4-methoxyfumaroyl)-L-2,3- diaminopropanoic acid (FMDP) has been extensively studied in order to develop its more active analogues. Several peptide−FMDP conjugates were tested to deliver FMDP to its...
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The Substantial Improvement of Amphotericin B Selective Toxicity Upon Modification of Mycosamine with Bulky Substituents
PublikacjaAbstract: Background: It is assumed that the unfavorable selective toxicity of an antifungal drug Amphotericin B (AmB) can be improved upon chemical modification of the antibiotic molecule. Objective: The aim of this study was verification of the hypothesis that introduction of bulky substituents at the amino sugar moiety of the antibiotic may result in diminishment of mammalian vitro toxicity of thus prepared AmB derivatives. Methods:...
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Does the chemical modification of Nystatin A1 affect the drug's ability to overcome the multidrug resistance of fungi?
PublikacjaAlthough the contemporary medicine keeps moving forward, disseminated infections caused by fungal pathogens are an emerging challenge. The dramatic rise of fungal diseases, especially the most life-threatening systemic mycoses is associated with a permanently growing number of immunodeficient patients. Undoubted difficulties in the treatment of fungal infections are caused by lack of highly effective and selective antifungal drugs,...
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Review on Current Status of Echinocandins Use
PublikacjaFungal infections are rising all over the world every year. There are only five medical compound classes for treatment: triazoles, echinocandins, polyenes, flucytosine and allylamine. Currently, echinocandins are the most important compounds, because of their wide activity spectrum and much lower sides effects that may occur during therapy with other drugs. Echinocandins are secondary metabolites of fungi, which can inhibit the...
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Quest for the Molecular Basis of Improved Selective Toxicity of All-Trans Isomers of Aromatic Heptaene Macrolide Antifungal Antibiotics
PublikacjaThree aromatic heptaene macrolide antifungal antibiotics, Candicidin D, Partricin A (Gedamycin) and Partricin B (Vacidin) were subjected to controlled cis-trans to all trans photochemical isomerization. The obtained all-trans isomers demonstrated substantially improved in vitro selective toxicity in the Candida albicans cells: human erythrocytes model. This effect was mainly due to the diminished hemotoxicity. The molecular modeling...
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Intramolecular transformation of an antifungal antibiotic nystatin A1 into its isomer, iso-nystatin A1 - structural and molecular modeling studies
PublikacjaNystatin A1, a polyene macrolide antifungal antibiotic, in a slightly basic or acidic solution undergoes an intramolecular transformation, yielding a structural isomer, the translactonization product, iso-nystatin A1 with lactone ring diminished by two carbon atoms. Structural evidence is provided by advanced NMR and Mass Spectrometry (MS) studies. Molecular dynamics simulations and quantum mechanics calculations gave the insight...
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Heptaene macrolides biosynthesis by Streptomyces species
PublikacjaPolyene macrolides are one of the groups of secondary metabolites, generated by microorganisms belonging to the Streptomyces genus. These compounds, containing 3 - 7 conjugated double bonds systems in their molecules exhibit high antifungal activity against a broad spectrum of fungal pathogens with heptaenes demonstrating the highest antifungal potential. At the large extent, efficiency of biosynthesis of these natural products...
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Sporothrix schenckii: purification and partial biochemical characterisation of glucosamine-6-phosphate synthase, a potential antifungal target
PublikacjaW artykule opisano izolację i charakterystykę właściwości natywnego enzymu, syntazy GlcN-6-P z komórek dimorficznego grzyba patogennego Sporothrix schenckii. Masę cząsteczkową enzymu natywnego określono na 350 kDa, a enzymu zdenaturowanego na około 79 kDa, co sugeruje homotetrameryczną strukturę białka. Wartość punktu izoelektrycznego wyniosła 6,26; wyznaczono także parametry kinetyczne katalizowanej reakcji. Aktywność enzymu była...
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A Central Composite Design in increasing the quercetin content in the aqueous onion waste isolates with antifungal and antioxidant properties
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Inhibitory Effect of Eugenol and trans‐Anethole Alone and in Combination with Antifungal Medicines on Candida albicans Clinical Isolates
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Amphotericin B and Its New Derivatives - Mode of Action
PublikacjaAmphotericin B (AmB) is a well known antifungal and antiprotozoal antibiotic used in the clinic for several decades. Clinicalapplications of AmB, however, are limited by its nephrotoxicity and many other acute side effects which are not acceptable by patientswhen their life is not threaten. In order to improve the therapeutic index of this drug, lipid formulations have been introduced and manyefforts have been made to obtain less...
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Molecular organization of antifungal antibiotic amphotericin B in lipid monolayers studied by means of Fluorescence Lifetime Imaging Microscopy
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Essential Oils, Silver Nanoparticles and Propolis as Alternative Agents Against Fluconazole Resistant Candida albicans, Candida glabrata and Candida krusei Clinical Isolates
PublikacjaDevelopment of effective and safe therapeutic treatment of fungal infections remains one of the major challenge for modern medicine. The aim of presented investigation was to analyze the in vitro antifungal activity of selected essential oils, ethanolic extracts of propolis and silver nanoparticles dropped on TiO2 against azole-resistant C. albicans (n = 20), C. glabrata (n = 14) and C. krusei (n = 10) clinical isolates. Among...
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Amphotericin B derivatives: novel strategy for the development of non-toxic, broad spectrum, fungicidal and overcoming multidrug resistance antifungal agents.
PublikacjaZaprezentowano porównawczą charakterystykę działania amfoterycyny B (AmB) oraz jej pochodnych o różnym stopniu selektywnej toksyczności na szczepy grzybów reperezentujących różne mechanizmy oporności. Były to mutanty C. albicans posiadające defekt w szlaku biosyntezy ergosterolu oraz wielolekooporne szczepy S. cerevisiae wyposażone w pompy eksportujące typu ABC i MFS. Badania obejmowały: 1)porównanie aktywności przeciwgrzybowej...
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Sławomir Milewski prof. dr hab. inż.
OsobySławomir Milewski, urodzony w 1955 r. w Pucku (woj. pomorskie), ukończył w 1979 r. studia magisterskie na kierunku Chemia, w specjalności Chemia i Technologia Organiczna, na Wydziale Chemicznym PG. Po ukończeniu Studium Doktoranckiego w 1984 r., został zatrudniony na macierzystym wydziale w Katedrze Technologii Leków i Biochemii, początkowo na stanowisku naukowo-technicznym, a od r. 1986 jako nauczyciel akademicki. W 1985 r. uzyskał...
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Iso-Partricin, an Aromatic Analogue of Amphotericin B: How Shining Light on Old Drugs Might Help Create New Ones
PublikacjaPartricin is a heptaene macrolide antibiotic complex that exhibits exceptional antifungal activity, yet poor selective toxicity, in the pathogen/host system. It consists of two compounds, namely partricin A and B, and both of these molecules incorporate two cis-type bonds within their heptaenic chromophores: 28Z and 30Z. In this contribution, we have proven that partricins are susceptible to a chromophore-straightening photoisomerization...
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Amino Acid Based Antimicrobial Agents – Synthesis and Properties
PublikacjaStructures of several dozen of known antibacterial, antifungal or antiprotozoal agents are based on the amino acid scaffold. In most of them, the amino acid skeleton is of a crucial importance for their antimicrobial activity, since very often they are structural analogs of amino acid intermediates of different microbial biosynthetic pathways. Particularly, some aminophosphonate or aminoboronate analogs of protein amino acids are...