21. Coumarin was first synthesized in 1868.22. It is an isomer of coumarin . 23. Under his later testimony he would repeatedly classify coumarin as a " lung-specific carcinogen ". 24. Chemically, it can be considered a methoxy derivative of coumarin or a methyl derivative of umbelliferone. 25. It is a derivative of coumarin , a natural product and precursor for the widely used Coumadin. 26. Tonka beans contain coumarin , a substance known to cause liver and other organ damage in test animals. 27. Levels of the blood-thinning agent coumarin in Ceylon cinnamon are much lower than those in cassia. 28. Anticoagulant effect Coumarin compounds in chamomile such as herniarin and umbelliferone may have blood-thinning properties. 29. Coumarin is still used as a legal flavorant in the tobacco industry, particularly for sweet pipe tobacco.30. He conducted extensive research and development of dicumarol, an anti-coagulant that is produced from coumarin .
