Phospholipide antithromboplastin. II. Preparation and properties

• 1.1. The preparation of the phospholipide fractions found to be active as in vivo anticoagulants (1) is described.
• 2.2. The active material is probably an unsaturated phosphatidylserine. The most important evidence of this was obtained by a paper Chromatographic study of the composition of the active fractions and by deamination with pyridoxal producing inactivation. Of the contaminating substances, inositol phosphatide and acetal phosphatide were shown to be inactive. Only phosphatidylserine and lysophosphatidylserine remain.
• 3.3. The activity of the anticoagulant is destroyed or decreased by deamination, acylation, hydrolysis, bromination, diazomethanolysis, reduction with lithium aluminum hydride, reduction of unsaturation by catalytic hydrogenation, and epoxide formation.