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Structural studies on aqueous and hydroalcoholic solutions of a polyene antibiotic: Amphotericin B
Author(s) -
Rinnert Hubert,
Thirion Christian,
Dupont Gaston,
Lematre Jean
Publication year - 1977
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1977.360161107
Subject(s) - chemistry , aqueous solution , amphotericin b , polyene , circular dichroism , absorption (acoustics) , absorption spectroscopy , alcohol , analytical chemistry (journal) , crystallography , organic chemistry , antifungal , optics , medicine , physics , dermatology
Circular dichroism and absorption and light scattering have been used to study the effect of ethyl alcohol on an aqueous solution of Amphotericin B (“Fungizone”), which is an antifungal heptene. In aqueous solution, light‐scattering studies show that Amphotericin B exists in an aggregated form. The estimated mass of these aggregates is about 2 × 10 6 daltons, representing about 2000 molecules. Since the aggregated form is high molecular weight and scattering, the CD involves probably the differential scattering of right and left polarized light. In aqueous solution, Amphotericin B exhibits a strong dissymetric couplet in CD at the wavelength of the absorption maximum (328 nm). This latter maximum presents a blue shift when compared with the normal absorption in polar organic solvents. In hydroalcoholic solutions, for alcohol concentrations below 35%, the molecular weight of the aggregates is unchanged, while the absorption and CD spectra are modified. For alcohol concentrations greater than 35%, the aggregates mass decreases quickly and becomes undetectable at 50% ethyl alcohol concentration. For these solutions, the CD and absorption spectra are practically constant and characteristic of unaggregated Amphotericin B form.