Use of a compound of formula I ##STR1## wherein R.sub.1 is an optionally substituted straight- or branched carbon chain having 12 to 22 carbon atoms which may be optionally interrupted by an optionally substituted phenylene, and each of R.sub.2, R.sub.3, R.sub.4 and R.sub.5, independently, is H or lower alkyl, in free form or in pharmaceutically acceptable salt form, in the prevention or treatment of chronic rejection in a recipient of organ or tissue allo- or xenotransplant, or of acute rejecti...

Use of a compound of formula (I) wherein R.sub.1 is an optionally substituted straight- or branched carbon chain having 12 to 22 carbon atoms which may be optionally interrupted by an optionally substituted phenylene, and each of R.sub.2, R.sub.3, R.sub.4 and R.sub.5, independently, is H or lower alkyl, in free form or in pharmaceutically acceptable salt form, in the prevention or treatment of chronic rejection in a recipient of organ or tissue allo- or xenotransplant, or of acute rejection in a...