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Coumarins photosensitization

Dimerizations of oc,/ -unsaturated carbonyl compounds are perhaps the most interesting reactions, and certainly are the subjects of the most wide-spread investigations. Many are photosensitized, including that of coumarin, Eq. 50. 123> Other reactions of simple enones also involve... [Pg.167]

Other coumarin-related compounds include furans, found in moldy sweet potatoes, and the furan coumarin complexes (furanocoumarins) found in parsnip leaves (psoralens). They are photoreactive compounds (primary photosensitizers) that exacerbate sunburn to psoralen exposed skin. [Pg.54]

Unlike coumarin, chromone (206) undergoes efficient unsensitized photoaddition to tetramethylethylene, cyclopentene, ketene dimethyl acetal, and but-2-yne.180 The major product of such an addition to tetramethylene is the cis-fused cyclobutane derivative (207) the formation of the two minor products (208 and 209) is easily rationalized. Added benzophenone has no visible effect on this cycloaddition, which is therefore believed to involve the attack of triplet chromone on the ground-state alkene. Photoaddition to furo-chromones has also been studied,179 and the photosensitized cyclo-... [Pg.51]

Wang, B. and Zheng, A. (1997) A photosensitive protecting group for amines based on coumarin chemistry. Chemical et Pharmaceutical Bulletin, 45, 715-718. [Pg.446]

As shown in Scheme 55, the photosensitized cycloaddition of coumarin (106a) to olefins 290a-c (tetramethylethylene 290a, cyclopentene 290b, and 1,1-diethoxyethylene 290c in dioxane in the presence of benzophenone... [Pg.325]

Photochemically induced arylations and heteroarylations of coumarin and of 7-aroinocoumarins ° have been described, and replacement of thymine by 5-bromouracil in DNA enhances photosensitivity. [Pg.390]

Clinical uses and toxicity The drug is indicated for severe dermatophytoses of the skin, hair, and nails. Adverse effects include headaches, mental confusion, gastrointestinal irritation, photosensitivity, and changes in liver function. A drug interaction may enhance coumarin metabolism, resulting in decreased anticoagulant effect. [Pg.422]

The mode of photosensitizing action of coumarins has been studied before [192]. An important mechanism in this action is coupling of the compounds to thymine of DNA [188]. Some plant cells especially the... [Pg.361]

Lavender oil Used in doses of 0.1 mL as a canninative. Contains trace amounts of coumarin (see p 378). May cause photosensitization. [Pg.147]

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See also in sourсe #XX -- [ Pg.137 ]



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