Antimycin A produced by Streptomyces species is active against fungi, insects and mammals and, moreover, is extremely toxic to fish, so it has been used for many years as a piscicide in fishery management. It is an inhibitor of cell respiration.
Antimycin A was isolated by Dunshee et al. ' in 1949 and Watanabe et al2 as blastmycin (1957), and later its complexity was also revealed3-5. It is a complex of four major components designated as Al, A2, A3 (blastmycin), Aq and six minor ones. The sum of the minor components is usually less than lo%, mostly not more than 1% of the complex 6. The antimycins are nine-membered ring dilactonic compounds with different alkyl substituents and acyloxy groups on the 7 and/or 8 side chain4.5.7.8
The ultraviolet (Uv) spectra of the components in ethanolic solution show two bands, with absorption maxima at 227 and 320 nm and are practically identical. The antimycins exhibit fluorescence, with a peak at 420 nm, activated by a wavelength of 350 nm. A spectrofluorimetric assay has been developed by Sehgal et aLgJO for the determination of the sum of the compounds.
Lockwood et aL3 and Liu and Strong5 demonstrated by paper chromatography that antimycin A contains at least four different active substances. Paper chromatography has been used for the detection of the components. The components Ai, A2, A3 can be well separated, but Ah only slightly. The method is time-consuming (analysis time about 24 h). The substances were detected microbiologically.
The components can also be separated by countercurrent distribution", but only partially.
Gas-liquid chromatography (GLC) of antimycin A antibiotics and their degradation products was investigated12 and after pyrolysis, GLC of the pyrolyzate was used for the analysis of the antimycin components4. Straight GLC was not applicable because of the thermal instability of the antimycin A molecules.
Abidi13 detected and determined the antimycin A components by high-performance liquid chromatography (HPLC) using electrochemical, fluorescence and UV detectors.
We have used reversed-phase thin-layer chromatography @P-TLC) for the separation of the antimycin A components.