nystatin-a1 and Leishmaniasis

Several polyene macrolides are potent antifungal agents that have severe side effects. Increased glycosylation of these compounds can improve water solubility and reduce toxicity. Three extending glycosyltransferases are known to add hexoses to the mycosaminyl sugar residues of polyenes. The Actinoplanes caeruleus PegA enzyme catalyses attachment of a D-mannosyl residue in a β-1,4 linkage to the mycosamine of the aromatic heptaene 67-121A to form 67-121C. NppY from Pseudonocardia autotrophica adds an N-acetyl-D-glucosamine to the mycosamine of 10-deoxynystatin. NypY from Pseudonocardia sp. P1 adds an extra hexose to a nystatin, but the identity of the sugar is unknown. Here, we express the nypY gene in Streptomyces nodosus amphL and show that NypY modifies 8-deoxyamphotericins more efficiently than C-8 hydroxylated forms. The modified heptaene was purified and shown to be mannosyl-8-deoxyamphotericin B. This had the same antifungal activity as amphotericin B but was slightly less haemolytic. Chemical modification of this new disaccharide polyene could give better antifungal antibiotics.

Topics: Acetylglucosamine; Actinobacteria; Amphotericin B; Antifungal Agents; Candida albicans; Glycosyltransferases; Hexosamines; Leishmania; Leishmaniasis; Macrolides; Mycoses; Nystatin; Streptomyces

A series of new 3-[4-(1H-imidazol-1-yl) phenyl]prop-2-en-1-ones were synthesized by the condensation of various acetophenones with 4-(1H-imidazol-1-yl) benzaldehyde which was itself prepared by the N-arylation of imidazole using hexadecyltrimethylammonium bromide as catalyst for the first time. All the synthesized compounds were subjected to preliminary evaluation for their anti-leishmanial, anti-oxidant and anti-fungal activities. Few of the synthesized compounds showed significant activities.

Topics: Antifungal Agents; Antioxidants; Antiparasitic Agents; Chalcones; Crystallography, X-Ray; Fungi; Imidazoles; Leishmania; Leishmaniasis; Models, Molecular

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.

Topics: Amphotericin B; Animals; Anti-Bacterial Agents; Antiprotozoal Agents; Humans; In Vitro Techniques; Leishmania major; Leishmaniasis; Nystatin