Patent ID: 6852725

Claim:
A compound of the formula the racemic-diastereomeric mixtures and optical isomers of said compound or a pharmaceutically acceptable salt thereof, wherein R 3 is —(CH 2 ) m —E—(CH 2 ) m —Z 2 ; E is O, S, —C(O)—, —C(O)—O—, —NH—C(O)—O—, —N—(C 1 -C 6 )alkyl-C(O)—O— or a bond; Z 2 is H, (C 1 -C 12 )alkyl, amino, (C 1 -C 12 )alkylamino, N,N-di-(C 1 -C 12 )alkylamino, (C 1 -C 12 )alkylguanidino, or an unsubstituted or substituted moiety selected from the group consisting of phenyl, indolyl, imidazolyl, thiophene, benzothiophene, pyridinyl and naphthyl; Z 3 is X 1 is —(CH 2 ) 2 —N(CH 3 ) 2 and X 2 is benzyl; or X 1 and X 2 are taken together with the nitrogen atom to which they are attached, to form