Hydrolysis of 2-diethylaminoethyl p-nitrobenzoate in liposomal suspension
Yotsuyanagi, T.; Hamada, T.; Tomida, H.; Ikeda, K.
Acta Pharmaceutica Suecica 16(5): 325-332
1979
ISSN/ISBN: 0001-6675 PMID: 44071 Document Number: 145396
The hydrolysis of 2-diethylaminoethyl p-nitrobenzoate in liposomal suspension was examined and compared with the spontaneous hydrolysis in aqueous solution. The analysis was based on the partition model. Unlike the procaine case, the protonated form of 2-diethylaminoethyl p-nitrobenzoate interacted with the lipid bilayer and its hydrolysis was enhanced. This was attributed to the ion-ion and ion-dipole interactions between the protonated form and the lipid head group, which put the molecule in a favorable position on the membrane surface for OH- attack. The hydrolysis of the free base was retarded. Probably the free base partitioned into the hydrophobic interior due to the loss of electrostatic interaction and was more protected from a close approach of OH-.