?Bortezomib (CAS NO.179324-69-7), its Synonyms are ((1R)-3-Methyl-1-(((2S)-3-phenyl-2-((pyrazinylcarbonyl)amino)propanoyl)amino)butyl)boronic acid ; Boronic acid, ((1R)-3-methyl-1-(((2S)-1-oxo-3-phenyl-2-((pyrazinylcarbonyl)amino)propyl)amino)butyl)- ; N-((1S)-1-Benzyl-2-(((1R)-1-(dihydroxyboranyl)-3-methylbutyl)amino)-2-oxoethyl)pyrazinecarboxamide ; Velcade . It is yellow solid.