SYNTHESIS AND NMR IDENTIFICATION OF ISOBUTYL ANALOGS OF PHOSPHOLIPIDSDESIGNED FOR THE MODELING OF BIOMEMBRANE FRAGMENTS

Three isobutyl analogs of phospholipids - isobutyl phosphoric acid (IP A), analog of phosphatidic acid; isobutyl phosphoethanolamine (IPE), a nalog of phosphatidylethanolamine; and isobutyl phosphocholine (IPCh), analog of phosphatidylcholine - were synthesized for use in mixed cry stals as initial material for modeling biomembrane fragments. Isobutyl oxophosphodichloride served as a common precursor yielding IPA when h ydrolyzed. Cyclic compounds of the former with ethanolamine and ethyle ne glycol were used re synthesize IPE and IPCh. The structure of the o btained compounds was identified by means of NMR. For all three compou nds the following signals were registered (ppm): 0.9, d, 6H, (CH3)(2)C H-; 1.9, m, 1H, (CH3)(2)CH-; 3.7, t, 2H, -P-O-CH2-CH(CH3)(2); which ca n be attributed to the isobutyl radical. In addition, the following si gnals were registered for IPE: 3.3, 2H, -P-O-CH2-CH2-NH2; 4.1, m: 2H, -P-O-CH2-CH2NH2; and for IPCh: 3.2, s, 9H, -CH2-CH2-N+(CH3)(3); 4.2, m , 2H, -P-O-CH2-CH2-N+(CH3)(3). X-ray analysis of the crystals is in pr ogress as part of model studies of the biomembrane organization.