| Abstract: | Summary 1. Seven different derivatives of the polypeptide antibiotic A-128-OP at its  -amino group have been obtained for the first time, and their physicochemical and antibiotic properties have been studied.2. It has been shown that modification of the amino group lowers the antibacterial activity of the antibiotic. Derivatives with an additional acid grouping have one fifth to one seventh of the biological activity of derivatives of the antibiotic with voluminous hydrophobic substituents.M. V. Lomonosov Moscow State University. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 632–636, September–October, 1974. |
