The capacity of various furocoumarins to generate singlet oxygen in aqueous solution has been determined. The antiproliferative and the skin-photosensitizing activities of the same furocoumarins did not show any correlation with the capacity to generate the singlet oxygen, while these photobiological properties could be correlated with the capacity of furocoumarins to induce photolesions to the...

BACKGROUND Photocontact dermatitis to Ficus carica is induced by furocoumarins present in sap. These substances are generally considered to cause phototoxic reactions. OBJECTIVES We conducted a patch test and histopathological study of patients with phytophoto contact dermatitis from the fig tree to evaluate the mechanism underlying the photoreaction. PATIENTS AND METHODS Patch and photopat...

Many furocoumarins and their analogs possess a prominent photobiological activity. Some of them are successfully used as drugs in phototherapy of skin diseases. Fries rearrangement of acyloxyheteroarenes, condensation of acylhydroxyheteroarenes with alpha-carbonyl compounds under base catalysis and transformations of dihydrofurocoumarinones are new trends in synthesis of furocoumarins and their...

The photoreaction at 3655 Ä between skin-photosensitizing furocoumarins and DNA leads to a photo-C4-cyclo-addition reaction in which the 5 — 6 double bond of the pyrimidine bases and the 3 — 4 or the 4' —5' double bond of the furocoumarins are involved. In continuing the research in this field, the authors have investigated the photoreactions (3655 A) of psoralen, xanthotoxin (8-methoxy-psorale...

We have synthesized a new series of coumarins and furocoumarins and evaluated their vasorelaxant activity in rat aorta rings pre-contracted with noradrenaline or by depolarisation with high KCl. The new furocoumarins relax smooth vascular muscle with a profile similar to that of khellin (a furochromone that directly relaxes smooth muscle) and at a greater potency, suggesting that these compound...

The Authors have studied the biosynthesis of some furocoumarins contained in Ruta graveolens. Labeled 5,7and 7,8-dihydroxycoumarins have been administered to the herb, however practically no incorporation of radioactivity was observed in the isolated furocoumarins. Moreover, with the aim to study in a more detailed way the role of rutaretin and marmesin, trapping experiments have been performed...