S-(-)-Warfarin Sodium Description Optical Rotation: [a]D23 = -95(c = 3.2, ethanol) Optically active S enantiomer of Warfarin Sodium. Used for preventing thrombosis and embolism. A synthetic derivative of coumarin. Decreases blood coagulation by inhibiting vitamin K epoxide reductase. Specifications Product ID W0274 Product Name S-(-)-Warfarin Sodium Formula Wt. 330.31 Purity ≥98% Store Temp +4°C Ship Temp Ambient