Fragment Is at Least as Good as Whole

The structure shown—a fragment of the thiopeptide antibiotic thiostrepton—exhibits biological activity comparable with, and sometimes even better than, that of the complex natural product, a new study shows (J. Am. Chem. Soc. 2005, 127, 15042).

Thiostrepton also has promising antimalarial and anticancer activity. Its total synthesis last year, by K. C. Nicolaou and coworkers at Scripps Research Institute and the University of California, San Diego, allowed access to various fragments and structural motifs.

Now, Nicolaou and coworkers report that the fragment shown, called the dehydropiperidine core, possesses significant activity against antibiotic-resistant bacteria and is 30 times more active against bacterial cells than against human red blood cells. Furthermore, the fragment’s potency against various cancer cell lines is higher than that of thiostrepton.