Warfarin

Structure

• Warfarin Chemical Structure – C19H16O4

Structure-Activity Relationship (SAR) of Warfarin

• Warfarin is an anticoagulant medication used to prevent blood clots. It functions as a vitamin K antagonist. The SAR of warfarin includes:

1. Coumarin Structure:

• The core structure of warfarin is a coumarin derivative.

• Coumarin's lactone ring is essential for anticoagulant activity.

2. Substituents at the 3-Position:

• Substitution at the 3-position of the coumarin ring is crucial for biological activity.

• In warfarin, this is typically a phenyl group.

3. Substituents at the 4-Position:

• The presence of a ketone group at the 4-position is necessary for activity.

4. Stereoisomerism:

• Warfarin exists as two stereoisomers (R and S forms).

• The S-isomer is more potent than the R-isomer due to better binding affinity with the target enzyme, vitamin K epoxide reductase.

5. Hydrophobic Side Chain:

• The hydrophobic side chain at the 3-position affects the drug's distribution and binding to plasma proteins.

Structure-Activity Relationship (SAR) of Warfarin

Synthesis of Warfarin

• The synthesis of Warfarin can be illustrated through the following key chemical reaction:

• Condensation of 4-Hydroxycoumarin with Benzalacetone: 

• 4C9​H6​O3 ​+ C10​H10​O → C19​H16​O4​

• In this reaction, 4-hydroxycoumarin (C9H6O3) is condensed with benzalacetone (C10H10O). The reaction typically involves a base catalyst and leads to the formation of warfarin (C19H16O4).

• This synthesis route highlights the formation of warfarin's coumarin structure and the introduction of key substituents that are critical for its anticoagulant activity. The specifics of the synthesis, such as the reaction conditions and purification steps, can vary based on the desired scale of production and purity requirements.

Mode of action

• By inhibiting vitamin K reductase, it interacts with the vitamin K-dependent synthesis of clotting factors II, VII, IX, and X in the liver. which further prevent blood clotting.

Uses

• The drug warfarin is used to stop blood clots in your blood and blood vessels from forming or spreading.

• It is used to treat thromboembolism, pulmonary embolism, and venous thromboembolism.