0.22 g (0.887 millimoles) of palmitic acid are dissolved in 15 ml of methanol and so much water is added dropwise to the solution that the palmitic acid should not precipitate. To the solution thus obtained 2.51 ml of a saturated barium hydroxide solution are added. The precipitated barium salt is filtered and added to a suspension of of 1.0 g (0.887 millimoles) of primycin sulfate and 120 ml of methanol. The reaction mixture is heated to boiling for an hour whereby the barium palmitate is dissolved and the insoluble barium sulfate is precipitated. The hot reaction mixtures is filtered over Celite. The filtrate is evaporate in vacuo. The residue is treated with ether and filtered again. The solid is washed on the filter with a 2:1 mixture of acetone and water and dried until constant weight. Thus 0.98 g of primycin palmitate are obtained, yield 82.2%. Mp.: 180-181° C., /α/D25 +30.
