| abstract |
This invention relates to compounds of the formula <IMAGE> I or an optical isomer thereof wherein R1 and R2 are the same or different and are an alkyl or alkenyl group of 6 to 24 carbon atoms; R3, R4 and R5 are the same or different and are alkyl of 1 to 8 carbon atoms, aryl, aralkyl of 7 to 11 carbon atoms, or when two or three of R3, R4, and R5 are taken together to form quinuclidino, piperidino, pyrrolidino, or morpholino, n is 1 to 8; and X is a pharmaceutically acceptable anion. |