“…Liquori et al [1967] suggested that SPE binds to DNA in the minor groove of the double helix, while Feurstein et al [ 19861 proposed an interaction of the compound in the major groove. SPE was one of the first antimutagens detected, reducing the spontaneous and induced mutability of several prokaryotic test systems [Johnson and Bach, 1966;Clarke, 1972; Clarke and Shankel, 1977; Gridley and McDougall, 19791. It prevents the N-methylnitrosourea-induced methylation of DNA at the N7 or O6 positions of guanine and the N3 position of adenine [Rajalakshmi et al, 19781. SPE did not have a clear antimutagenic effect on induced forward mutation in Schizosaccharomyces pombe, and indeed, in some cases, it increased the mutation frequency [McDougall and Lemontt, 19791. It failed to decrease the mutation induced by UV in Schizosaccharomyces pombe [Prendergast et al, 19841, but it reduced the micronuclei formation in bone marrow cells and the incidence of abnormal sperm head morphologies in mice treated with gamma radiation [Nandan, 19901. Moreover, SPE drastically reduced SCE formation induced by psoralen in Chinese hamster ovary cells (CHO) [Cozzi et al, 19911. 0 1994 Wiley-Liss, Inc.…”