UV-A Photolysis of Khellin: Products and Reaction Mechanism

Article abstract of DOI:10.1021/jo00077a026

Photolysis at 365 nm of khellin in various solvents was studied: the degradation rate strongly depends on solvent but not on polarity, since it is related to the singlet oxygen lifetime in each solvent.Eight products were isolated and characterized, some of which had previously been described as coming from chemical oxidation of khellin.Both facts support an oxic pathway for photolysis involving singlet oxygen and leading to unstable intermediates.These are rapidly decomposed by nucleophiles, suggesting possible interference - if they are also formed in vivo - with physiological processes during photochemotherapeutic treatment with khellin.