Syntheses of new bacteriochlorins and their antitumor activity

Purpurin-18 methyl ester 1a was converted into a series of new bacteriochlorins 2b, 2c, 2f and 4b. These stable bacteriochlorins have strong long wavelength absorptions in the range of 760 to 816 nm, and were tested for in vivo photosensitizing activity using the standard screening system of DBA/2 mice bearing transplanted SMT/F tumors. In preliminary screening, among the photosensitizers tested so far, bacteriochlorins 2f and 4b have shown promising anti-tumor activity.