Conformationally Constrained Analogues of Diacylglycerol. 18. The Incorporation of a Hydroxamate Moiety into Diacylglycerol-Lactones Reduces Lipophilicity and Helps Discriminate between sn-1 and sn-2 Binding Modes to Protein Kinase C (PK-C). Implications for Isozyme Specificity

An approach to reduce the log P in a series of diacylglycerol (DAG)-lactones known for their high binding affinity for protein kinase C (PK-C) is presented. Branched alkyl groups with reduced lipophilicity were selected and combined with the replacement of the ester or lactone oxygens by NH or NOH groups. Compound 6a with an isosteric N-hydroxyl amide arm represents the most potent and least lipophilic DAG analogue known to date.