compound of formula (i)for use in the prevention or treatment of a bacterial infection, where RP1 represents methyl, ethyl, \u0438\u0437\u043e\u043f\u0440\u043e\u043f\u0438\u043b, \u0446\u0438\u043a\u043b\u043e\u0433\u0435\u043a\u0441\u0438\u043b or \u0444\u0435\u043d\u0438\u043b RP2 selected from bromide, ethyl and, \u0438\u0437\u043e\u043f\u0440\u043e\u043f\u0438\u043b\u0430, \u0446\u0438\u043a\u043b\u043e\u0433\u0435\u043a\u0441\u0438\u043b\u0430 and phenyl RP3 represents an ethyl, \u0438\u0437\u043e\u043f\u0440\u043e\u043f\u0438\u043b, \u0446\u0438\u043a\u043b\u043e\u0433\u0435\u043a\u0441\u0438\u043b, \u0444\u0435\u043d\u0438\u043b or \u043f\u0438\u0440\u0438\u0434\u0438\u043b and constitutes a or s, or se ra is selected from:where each of y1, Y2, Y3, Y4 and Y9 independently selected from sn or n, and at least three of y1, Y2, Y3, Y4 and Y9 represents sn, v is selected from oh, ch - ORO1, n - co2 - rc1 or n - RN2 one of the Y5, Y6, Y7 and y8 selected from sn, and n, and the other represents sn x is selected from nh.s or o rc1 is selected from o - RO2 or NHRN1 RO1 selected from h or c1 - 3 \u043d\u0435\u0440\u0430\u0437\u0432\u0435\u0442\u0432\u043b\u0435\u043d\u043d\u043e\u0433\u043e \u0430\u043b\u043a\u0438\u043b\u0430 RO2 represents c1 - 3 \u043d\u0435\u0440\u0430\u0437\u0432\u0435\u0442\u0432\u043b\u0435\u043d\u043d\u044b\u0439 \u0430\u043b\u043a\u0438\u043b RN1 selected from h or c1 - 3 \u043d\u0435\u0440\u0430\u0437\u0432\u0435\u0442\u0432\u043b\u0435\u043d\u043d\u043e\u0433\u043e \u0430\u043b\u043a\u0438\u043b a RN2 represents c1 - 3 \u043d\u0435\u0440\u0430\u0437\u0432\u0435\u0442\u0432\u043b\u0435\u043d\u043d\u044b\u0439 \u0430\u043b\u043a\u0438\u043b rc1 represents c1 - 3 \u043d\u0435\u0440\u0430\u0437\u0432\u0435\u0442\u0432\u043b\u0435\u043d\u043d\u044b\u0439 \u0430\u043b\u043a\u0438\u043b or c3 4 elaborate \u0430\u043b\u043a\u0438\u043b RC3 selected from c1 to 3 \u043d\u0435\u0440\u0430\u0437\u0432\u0435\u0442\u0432\u043b\u0435\u043d\u043d\u043e\u04
