DNA damage by MoCH3(P>3-allyl)(CO)2(phen) complexes has been shown to occur by two mechanisms:by backbone cleavage via the abstraction of H1' and/or H5' from the deoxyribose moiety and by basemodification, resulting in G-specific cleavage via the formation of base-labile residues methylguanine,methoxyguanine, and 8-oxo-G.