Hughes R A, Toth I, Ward P, Ireland S J, Gibbons W A
Department of Pharmaceutical Chemistry, School of Pharmacy, University of London, U.K.
J Pharm Sci. 1991 Dec;80(12):1103-5. doi: 10.1002/jps.2600801202.
A series of lipidic morphine esters 1b-1f with enhanced membrane-like character were synthesized by coupling the lipidic amino acids 2a-2e to the phenolic hydroxyl group of the opioid analgesic morphine (1a). The antinocioceptive activity of the esters 1b-1f was determined in vivo following both iv and oral dosing. After iv administration, four of the conjugates, 1b, 1c, 1d, and 1f, exhibited antinocioceptive activity in the mouse abdominal constriction test, with a potency similar to that of the parent compound 1a. Conjugate 1b showed activity following oral administration.
