Antibiotics amphotericin

Figure 10.9 NeuA catalyzed preparation of a synthetic precursor to the macrolide antibiotic amphotericin B.

Some substances form pores in the membrane that do not exhibit ion selectivity and permit flow of the solution through the membrane. These include the polyene antibiotics amphotericin B,... 

The mixing of nematogenic compounds with chiral solutes has been shown to lead to cholesteric phases without any chemical interactions.147 Milhaud and Michels describe the interactions of multilamellar vesicles formed from dilauryl-phosphotidylcholine (DLPC) with chiral polyene antibiotics amphotericin B (amB) and nystatin (Ny).148 Even at low concentrations of antibiotic (molar ratio of DLPC to antibiotic >130) twisted ribbons are seen to form just as the CD signals start to strengthen. The results support the concept that chiral solutes can induce chiral order in these lyotropic liquid crystalline systems and are consistent with the observations for thermotropic liquid crystal systems. Clearly the lipid membrane can be chirally influenced by the addition of appropriate solutes. 

Bolard J, Seigneuret M, Boudet G. Interaction between phospholipid bilayer membranes and the polyene antibiotic amphotericin B lipid state and cholesterol content dependence. Biochim Biophys Acta 1980 599 280. 

The polyene antibiotics, amphotericin B and nystatin, are of bacterial origin. They insert themselves into fun-LiJIlmann, Color Atlas of Pharmacology 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 

Antifungal antibiotics amphotericin B amphotericin B (lipid-based) griseofulvin... 

During synthetic work on the macrolide antibiotic amphotericin B, the diene 1 was required for preparation of an important building block. The key step to 1 featured diastereocontrol in the... 

Amphotericin B is available in the form of sterile lyophilized powder. Because it is insoluble in water, it is marketed with sodium deoxycholate for dispersal in sterile water and 5% dextrose. The polyene antibiotics — amphotericin B, nystatin, and candicidin — are all poorly absorbed from the gastrointestinal tract. In the plasma, amphotericin B binds to lipoproteins including cholesterol. It is extensively metabolized and the inactive metabolite, or metabolites, are slowly excreted in the urine. 

The limit test for amphotericin A (a tetraene, Amax 300 nm) in the antifungal antibiotic amphotericin (consisting primarily of amphotericin B, a hepta-ene, A 380 nm) is an example of such a two-component analysis (British Pharmacopoeia, 1980). 

Vertut-Croquin A, Bolard J, Chabbert M, Gary-Bobo C. Differences in the interaction of the polyene antibiotic amphotericin B with cholesterol- or ergosterol-containing phospholipid vesicles. A circular dichroism and permeability study. Biochemistry 1983 22(12) 2939 4. 

Bacillomycins (Fig. 8) were discovered as antifungal compounds by Peypoux et al. in 1980 and Eshita et al. in 1995 from B. subtilis K In bacillomycin L congeners, the antifungal activity increases directly with increases lipophilicity, and their antifungal activity is less potent than that of clinically available polyene antibiotics amphotericin B and nystatin ... 

Gutteridge et al. [20] investigated the autoxidation of four polyene antibiotics, amphotericin B, candicidin, natamycin and nystatin. The polyenes were treated in such a way that free radical damage occurred. This was done by autoxidation of 0.1% solutions of the polyenes in dimethyl sulphoxide ... 

H- and P- NMR studies on the methyl-ds amide derivative of the antibiotic amphotericin B incorporated into mechanically aligned bilayers of DPPC have been reported. Variations of the quadrupolar and dipolar splittings as a function of macroscopic sample orientation and temperature indicate that the amide derivative undergoes fast rotation about an axis parallel to the bilayer normal. 

Amphotericin B - Observations on the immunostimulant properties of the clinically used antifungal polyene antibiotic amphotericin B (AmB) and its methylester (AME) were extended. In mice, the drugs augmented antibody formation to TNP-HSA with pronounced enhancement of secondary IgG responses,... 

Lamy-Freund MT, Ferreira VFN, Schreier S. Mechanism of inactivation of the polyene antibiotic amphotericin B. J Antibiot (Tokyo) 1985 38 753-757. 

Alternate drugs that are suitable when the disease is not responsive to antimony include the antifungal antibiotic amphotericin B (Chapter 2) and diaminidines such as pentamidine (see later) (WHO, 1984). 

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