English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Radical formation during autooxidation of the polyene antibiotic amphotericin B was monitored by following the kinetics of decay of the ESR signal of a stable nitroxide. The kinetics were seen to depend both on antibiotic and on nitroxide concentration. The radicals formed were studied by spin trapping. Three preparations--clinical Fungizone, amphotericin B suspended in buffer, and amphotericin B in buffer - 10% dimethyl sulfoxide--yielded spin adducts of different nature and/or concentrations. In the absence of dimethyl sulfoxide, amphotericin B yielded at least two carbon-centered radicals whose spectra indicated restricted mobility. This suggests that the radicals arise from the whole amphotericin B molecule located in molecular aggregates present in the preparations, and not from smaller and possibly more water-soluble fragments of the antibiotic. In the presence of dimethyl sulfoxide the spin adducts derived from secondary carbon radicals originated from this solvent. Their spectra were indicative of fast tumbling. Direct evidence for autooxidation was obtained by measuring oxygen consumption. All processes examined occurred at the same time scale observed for drug inactivation, in agreement with the idea that loss of activity is due to antibiotic autooxidation.

Mechanism of inactivation of the polyene antibiotic amphotericin B. Evidence for radical formation in the process of autooxidation.