Energy transport in carbohydrates. Part VI. Energy transfer in amylose complexes and derivatives

Abstract

γ-Irradiation of wheat and corn amylose in the solid state leads to the formation of reducing products and an exponential decrease in chain length. The effects of γ-irradiation on solid channel inclusion complexes of amylose have been examined. Chemical protection of the amylose, and modification in form and intensity of the e.s.r. spectrum of the irradiated complex from that of amylose irradiated alone, indicate that energy transfer from the amylose to the included molecule occurs. Maximum transfer and chemical protection are observed when the first singlet excited level (E₁) of the included molecule is ca. 4 eV. Evidence is presented that intermolecular transfer occurs through singlet states, as was found ¹ during γ-irradiation of cycloamylose complexes. Protection of amylose by direct substitution has been examined using amylose tosylates and carbanilates with various degrees of substitution. The results indicate approximate limits of energy transfer in these molecules.