An NMR Study of the Bortezomib Degradation under Clinical Use Conditions

Table 1

Molecular weight, mass peak, and elemental analysis of BTZ, BTZ1, and BTZ2.

Comp.			Elemental analysis
	MW	Mass peak m/z	C		H		N
			calcd	found	calcd	found	calcd	found
BTZ	C19H25BN4O4	[M+H−H2O]^+	59.39	59.48	6.56	6.58	14.58	14.61
	384	367
BTZ1	C19H24N4O3	[M+H−H2O]^+	64.03	64.12	6.79	6.81	15.72	15.70
	356	339
BTZ2	C19H22N4O3	[M+H]^+	64.39	64.32	6.26	6.30	15.81	15.78
	354	355