Crystal structure of chartreusin derivative A132

The crystal structure of chartreusin derivative A132 (benzilidene chartreusin) has been determined by single-crystal X-ray diffraction. The space group is C2 with unit cell dimensions, a=18.482(4), b=8.749(3), c=43.906(2) Å, β=94.87(2)°, and the structure was refined to R-factors of 0.2365 (6585 all unique reflections) and 0.087 (2914 reflections with Fo>4σ(Fo)) by a full-matrix least-squares method. There are two molecules in an asymmetric unit. Both molecules have similar structures, which are favorable to bind with DNA in the minor groove. A modeling study of the A132–DNA complex based on the X-ray structures suggests that the sugar moiety of A132 may play an important role in recognizing the sequence of DNA base pairs.