Figure 1.

Chemical structure of bortezomib. Bortezomib ([(1R)-3-methyl-1-({(2S)-3-phenyl-2-[(pyrazin-2-ylcarbonyl)amino]propanoyl}amino)butyl]boronic acid) is marketed as Velcade^® by Millennium Pharmaceuticals and currently used to treat people with multiple myeloma.