Studies On The Cyclosporin Minor Components Produced By Fusarium Solani

Three minor components in cyclosporin A mother liquor were separated and purified by combination of macroporous adsorptive resin and high speed countercurrent chromatography (HSCCC). By these methods, three first reported cyclosporins produced by Fusarium solani were purified.Electrospray ionization mass spectrometry (ESI-MS) was adopted for the analysis of amino acid residues after intensive acid hydrolysis of the minor components, especially the unique amino acid in the position 1. The fragment ions and fragmentation pathways of the three cyclosporins in ESI-MSn were analyzed. By this way,the sequences of amino acids in them can be deduced, which provide a fast and accurate method for the structural characterization of cyclosporins. Also other modern spectrometric methods were applied in the structural determination of the three first reported cyclosporins produced by Fusarium solani. Among them, one was identified as cyclosporin E, another two had a molecular weight of 1188. Preliminary experimentals showed that the two"new"compounds could be demethylated cyclosporin A or demethylated cyclosporin H respectively in position 3 or 4, the exact chemical structure studies is underway.Immunosuppressive and antifungal activities of the cyclosporins, which were purified as monocomponents, were tested and the experimental results were discussed.