| 摘要 |
Alkali metal polyphosphate complexes of alpha -6-deoxy-5-hydroxytetracycline are prepared which have the formula (C22H24N2O8)z . (MePO3)x . (HPO3 )y in which Me is sodium or potassium, z = 1 to 5, x = 1 to 5, y = 1 to 5, x + y </= 6 and z </= y. The compounds are obtained by reacting metaphosphoric acid in an organic medium which is inert to the reaction with 1 to 5 mol of alpha -6-deoxy-5-hydroxytetracycline. The remaining free acid groups of the metaphosphoric acid are then neutralised with a methanolic or ethanolic solution of sodium hydroxide or potassium hydroxide in the stoichiometric quantity. The complex formed in this process is then precipitated by addition of a non-solvent which is inert to the reaction. Preferred compounds are the ethanol/water solvate of the complex of the formula C22H24N2O8 . NaPO3 . (HPO3)5 and C22H24N2O8 . (NaPO3)2 . (HPO3)4. The said compounds have an antibiotic activity, and they are very highly tolerable. |
