Synthesis and antimicrobial activity of sperabillin derivatives.

Modification of sperabillins was carried out. The 2-amidinoethylamino moiety was removed by brief acidic hydrolysis. The 2,4-hexadienoyl moiety was hydrogenated to the hexanoyl moiety and this was cleaved by an enzymatic reaction using the cells of Pseudomonas acidovorans IFO 13582. The 2-amidinoethylamino and the 2,4-hexadienoyl moieties were replaced with other groups. The derivative which was prepared by condensation of two molar amounts of dehexadienoylsperabillin A with (E,E)-muconic acid showed better protective effects than sperabillin A against Gram-negative bacteria.