Leucomycin A6

Aim: To identify the components of acetylleucomycin and its hydrolytic products by LC-MS. Methods: Acetylleucomycin was separated on a Diamonsil C18 column with 0.1 mol x L(-1) ammonium acetate-acetontrile (35 : 65) as mobile phase. The LC-MS was equipped with an electorspray ion source (ESI), which was set at the positive ion mode, and the mass spectra of each component in chromatogram were obtained with difference cone voltage. Results: The components of acetylleucomycin and its hydrolytic products can be separated by HPLC. The components were identified according to the molecular weight and its major mass fragment ions. The major components identified in domastic acetylleucomycin were acetylleucomycin A4, A5; acetylleucomycin A1, A3; acetylleucomycin A6, A7, and acetylleucomycin A13. The hydrolytic products of acetylleucomycin were not kitasamycin, but some non-complete hydrolytic product. Conclusion: The method is rapid, sensitive and specific. It' s suitable to application in the fields of multi-components antibiotics analysis.

A reversed phase high performance liquid chromatographic method for the assay of midecamycin was developed. The method used a Hitachi Gel 3050 column at 50 degrees C and a mobile phase of methanol--0.01 mol/L phosphate buffer solution at pH 5.8 (45:55). The column effluent was monitored Z at 231 nm. SF-837A1, leucomycin A6 and minor components could be separated in less than 15 min. The retention times of SF-837A1 and leucomycin A6 are 7 and 10 min respectively. The method is very simple and rapid.