Naturally Occurring Coumarins and Related Physiological Activities

Photocontact allergy to 6-methylcoumarin

A proprietary sunscreen-induced photosensitivity reactions in a small number of users. Laboratory study revealed that the reactions were of the photoallergic type and were due to the presence of a synthetic fragrance, 6-methylcoumarin. By photomaximization testing 6-methylcoumarin was found to be a potent photocontact allergen.

Synthesis and blood pressure lowering activity of benzylic ethers of 2-diethylaminoethanol and a related diamine

Based upon the unpublished finding that 3'-hydroxy-4'-(beta-diethylaminoethoxy)-3',4'-dihydroseselin possessed a potent blood pressure lowering effect in the cat at a dose of 1 mg/kg, the present study examined the activities of several related compounds. These compounds were derived by dissection of the parent compound to give four benzylic ethers of 2-diethylaminoethanol and a diamine, derived by replacing the ether oxygen of the parent compound with an N--CH3 function. The simplest compounds were the benzyl and 2,6-dimethoxybenzyl ethers of the aminoalcohol. Closely related to the benzyl compound was a congener with a hydroxymethyl group on the benzylic carbon. The beta-diethylaminoethyl ether of 4-chromanol was the most complex of the ethers. The blood pressure measurements were carried out on male cats and compared to papaverine hydrochloride as a standard. In all cases, the most potent blood pressure lowering activity resided in the parent compound, which was not greatly superior to the diamine but substantially more active than the other compounds.

Coumarin and 4-methylcoumarin induced changes in the hepatic endoplasmic reticulum studied by quantitiative sterelogy

Coumarin and 4-methylcoumarin constitue chemicals widely available in foodstuffs and coumarin-induced hepatotoxicity has been characterized in laboratory animals. The present studies were undertaken to analyze the effects of these compounds on the structure of endoplasmic reticulum membranes. The liver of rats treated for seven days with 1 mmole/kg of either coumarin or 4-methylcoumarin were subjected to quantitative sterologic analysis and various morphometric parameters were determined. Coumarin induced cytoplasmic enlargement while 4-methylcoumarin produced changes in the endoplasmic reticulum and Golgi aratus (GOL) without altering cell size. Both compounds caused a significant overall reduction of smooth-surfaced (SER) membranes. Since 4-methylcoumarin stimulates drug metabolism, this indicates that conformational changes must have taken place in the membrane arrangement. On the other hand, the reduction of membranes by coumarin is accompanied by reduced enzyme activity and phospholipid metabolism, suggesting an impairment of membrane synthesis mircosopical examinations provides a useful and sensitive tool to study the effects of foreign compounds in the liver.