Molecular Formula: C₁₉H₂₅BN₄O₄ 

Synonyms: Pyz-Phe-boroLeu; Boronic acid, [(1(R)-3-methyl-1-[[(2S)-1-oxo-3-phenyl-2-[(pyrazinylcarbonyl)amino]propyl]amino]butyl]-; Boronic acid, [1-[[1-oxo-3-phenyl-2-[(2-pyrazinylcarbonyl) amino]propyl]amino]-3-methylbutyl]-, L-(S)-; [(1R)-3-methyl-1-[[(2S)-3-phenyl-2-(pyrazine-2-carbonylamino)propanoyl]amino]butyl]boronic acid; PS 341 (pharmaceutical); 

Appearance: yellow solid 

Molecular Weight: 384.24 

Density: 1.214 

Melting Point: 122-124℃ 

Refractive index: 1.564 

Solubility: In water, 3.3 to 3.8 mg/mL in a pH range of 2 to 6.5 (as the monomeric boronic acid)In water, 76 mg/L at 25 deg C (est) 

Usage: It is used as a medicine to treat some refractory disease, for example relapsed multiple myeloma and mantle cell lymphoma.