Properties of unusual phospholipids IV: Chemoenzymatic synthesis of phospholipids bearing acetylenic fatty acids

Lipase‐catalyzed acidolysis and phospholipase D‐catalyzed transphosphatidylation of phosphocholine

“…Changes in phospholipid compositions during a reaction were quantitatively determined by TLC-FID analysis (Iatroscan, Iatron Laboratories, Tokyo, Japan) as described by Pisch et al [5]. To 60 mL sample, 0.3 mL Folsh's solution and 0.3 mL distilled water were added, followed by vigorous shaking for 30 s and centrifugation.…”

“…DLPC was synthesized according to the method of Pisch et al [5]. Briefly, 2.75 mmol fatty acid and 3 mmol 1,1'carbonyl diimidazol were dissolved in 20 mL dichloromethane (dried over 3Å molecular sieve at least 48 h prior to use) in a 50-mL round bottom flask.…”

“…According to the method of Pisch et al [5], 50 mg DLPC and 1.8 g ethanolamine were dissolved in 6 mL chloroform and incubated at 40 7C for 15 min in a screw-capped vial. The reaction was started by adding 9 mL PLD solution (0.05 mg/mL of 0.1 M sodium acetate buffer containing 0.1 M CaCl 2 , pH 5.6).…”

“…One alternative for the synthesis of phospholipids bearing different alcohols or nucleophiles, is PLD-catalyzed head group exchange. Since most PLD utilize alcohols rather than water, it is possible to accomplish transphosphatidylation reaction even in the presence of high amounts of water, such as in a biphasic (buffer/solvent) system [5]. However, the considerable amount of water present results in an undesirable hydrolytic side-reaction.…”

“…Synthesis of phospholipids is difficult by chemical means since control of regio-and also stereo-selectivity must be ensured. Phospholipids containing the same fatty acids at the sn1-and sn2-positions could be synthesized by chemical reaction [5]. However, biologically active polyunsaturated fatty acids (PUFA) are chemically unstable, which explains why chemical synthesis of phospholipids containing PUFA proceeds with low yield.…”