SYNTHESIS OF LYSINE-VALINOMYCIN BY SOLID-PHASE SEGMENT CONDENSATION

In order to obtain a readily derivatized analog of the ionophore antibiotic valinomycin, [1‐lysine]valinomycin (Lys‐VAL) was synthesized. The compound was built up on a polystyrene support by stepwise segment condensation and was cyclized in solution. The segments used were didepsipeptides protected by the t‐butyloxycarbonyl and p‐nitrobenzyloxycarbonyl groups. Derivatives prepared by acylation of the e‐amino group of Lys‐VAL included [14C]acetyl‐Lys‐VAL, dansyl‐Lys‐VAL, palmitoyl‐Lys‐VAL and dithiodiglycoyl‐bis‐Lys‐VAL. These derivatives had a high potassium binding capacity but were in general much less active than VAL in mediating ion transport in membranes. © 1979 Munksgaard, Copenhagen