متماثل بورتيزوميب R,R و S,S

[(1R)-3-methyl-1-[[(2R)-3-phenyl-2-(pyrazine-2-carbonylamino)propanoyl]amino]butyl]boronic acid;[(1S)-3-methyl-1-[[(2S)-3-phenyl-2-(pyrazine-2-carbonylamino)propanoyl]amino]butyl]boronic acid; ((R)-3-Methyl-1-((R)-3-phenyl-2-(pyrazine-2-carboxamido)propanamido)butyl)boronic acid compound with ((S)-3-methyl-1-((S)-3-phenyl-2-(pyrazine-2-carboxamido)propanamido)butyl)boronic acid (1:1); Bortezomib R,R and S,S Diastereomer impurities