1. The use of a compound of formula I to destroy, inhibit or prevent the growth of microbial biofilms where X, X, Xi are independently (ie, the same or different) hydrogen atom, lipophilic residue, phenyl group, lower alkyl, alkaryl or aralkyl group or cationic a group of the following formula； wherein L is a linking group or is absent； R is lower alkylene, lower alkenylene or lower alkynylene, which is optionally substituted with one or more substituents people selected from lower alkyl, lower alkylene (optionally including oxygen), fluorine, OR, C (O) R, C (O) OR, C (O) NRR, NRR and NRRR； and R, R and R are independently (i.e., the same or different) H, aryl, lower alkyl, lower alkenyl or lower alkynyl, the last three of which are optionally substituted with one or more substituents selected from lower alkyl, lower alkylene (optionally including oxygen), aryl, OR, C (O) R, C (O) OR, C (O) NRR, NRR, and NRRR； Z is —CH or N； Y, Y, Y, and Y are absent or independently represent aryl, lower alkyl , lower alkenyl or lower alkynyl, the last three of which are optionally substituted with one or more substituents selected from lower alkyl, lower alkylene (optionally including oxygen), aryl, OR, C (O) R, C (O) OR, C (O) NRR, NRR and NRRR； or being conjugated to the pyrrole ring to which they are attached, may form a cyclic group； and R, R, R, R, R, R, R, R, R, and R independently represent H or lower alkyl, provided that at least X, X, Xi X is a cationic group as described above, and at least one of X, X, X�1. Применение соединения формулы I для уничтожения, ингибирования или предотвращения роста микробных биопленокгдеX, Х, Хи Хнезависимо представляют собой (т.е. являются одинаковыми или различными) атом водорода, липофильный остаток, фенильную группу, низшую алкильную, алкарильную или аралкильную группу или катионную группу следующей формулы；гдеL представляет собой связывающую группу или она отсутствует；Rпредставляет собой низший алкилен, низший алкенилен или низший алкин
