PHOTOBIOLOGICAL ACTIVITIES OF 5-A-LKOXYPSORALENS WITH RESPECT TO THE ACTION ON Escherichia coli

Abstract— Near-UV induced activities of a series of 5-a-lkoxypsoralen derivatives (C₁ to C₈) and 5-h-ydroxypsoralen were compared with respect to lethal, mutagenic and prophage inducing effects on E. coli . Although 5-a-lkoxypsoralen derivatives having an alkoxyl chain longer than C₂ were slightly soluble, their saturated solutions containing their insoluble portion showed the significant photolethal effect on E. coli . 5-E-thoxypsoralen was less photoactive in inducing phenotypic reversion of the arginine auxotrophy than 5-m-ethoxypsoralen but it photoinduced prophage lambda from the lysogenic bacteria as well as 5-m-ethoxypsoralen. Photomutagenesis by the derivatives of C₃ to C₈ could not be detected but ca . 10% of the lysogenic bacteria photoinduced prophage in the presence of the derivatives at the maximum induction.