the invention relates to a novel acylate which is the reaction product of a substance which is selected from the group consisting of naturally occuring alpha - aminocarboxylic acids , neurotransmitters other than such acids , and central or peripheral nervous system pharmacologically active compounds , and containing a functional group including an acylatable hydrogen atom , or a reactive derivative thereof ; and an essential fatty acid or a reactive derivative thereof ; and including the pharmaceutically acceptable salts of such acylates possessing a basic and acidic function ; and to their functional derivatives . the acylates and their functional derivatives may be used for treatment of a disease or condition related to a neurotransmitter defector deficiency , or to another central or peripheral nervous system defect or deficiency , and in particular parkinson &# 39 ; s disease .