A similar increase in DNA-cleavage activity of a related sulfone with an extra conjugation was also observed for the Z isomer Q as compared to the E analogue P (Scheme 103).

Scheme 103. Synthesis of unsaturated bispropargyl sulfones.

Dai et al. have earlier reported efficient photo-inducible DNA-cleaving ability of propargylic sulfone conjugated to the anthraquinone moiety (Scheme 104). From DNA-cleavage studies using different anthraquinone-based sulfones, it was concluded that appropriate spatial arrangement between the activated allenic sulfone and nucleobase, which is derived from an efficient intercalation, leads to a substantial amount of DNA cleavage via alkylation of the nucleobase and photo-induced one-electron oxidation of guanine bases.

Scheme 104. Anthraquinone-based propargyl sulfone.