Question

Which of the following anticoagulant is a sulfated polysachharide?

• A. Heparin
• B. Warfarin
• C. phenindione
• D. Dicoumarol

Hint:

Heparin is a highly sulfated polymeric carbohydrate (polysaccharide), which gives it a strong negative charge. This charge can be neutralized in cases of overdose using the highly positively charged antidote, Protamine Sulfate.

Answer 1

The Correct Option is A

Understanding the Concept: Anticoagulants are therapeutic agents that disrupt the coagulation cascade to prevent or treat thromboembolic disorders. They are broadly categorized into parenteral agents (administered via injection) and oral agents. This question asks us to identify an anticoagulant based on its chemical polymer composition. Let us evaluate the chemical nature of each option:
• Option (A) Heparin: Heparin is a naturally occurring anticoagulant found in mast cells and basophils. Chemically, it is a glycosaminoglycan, which is a type of polysaccharide composed of repeating disaccharide units (glucosamine and uronic acid). It stands out because it is highly sulfated, giving it the highest negative charge density of any known biological macromolecule. This high negative charge allows it to bind to antithrombin III, accelerating the inactivation of thrombin (Factor IIa) and Factor Xa.
• Option (B) Warfarin: Warfarin is a synthetic oral anticoagulant. Chemically, it is a small, crystalline monocyclic organic molecule belonging to the coumarin class (specifically, 4-hydroxycoumarin). It is not a carbohydrate or a polysaccharide.
• Option (C) phenindione: Phenindione is an oral anticoagulant belonging to the indandione chemical class. Like warfarin, it acts as a Vitamin K antagonist but is structurally distinct from sugars and polysaccharides.
• Option (D) Dicoumarol: Dicoumarol is a naturally occurring derivative of coumarin consisting of two coumarin rings linked by a methylene bridge. It served as the structural prototype for the synthesis of warfarin and is not a polysaccharide. Conclusion: Heparin is the only anticoagulant listed that is a highly sulfated polysaccharide macromolecule.