Correlation between the NMR Chemical Shifts and Thiolate Protonation Constants of Cysteamine, Homocysteine, and Penicillamine

Table 3

The regression statistics of the cysteamine, cystamine, homocysteine, homocystine, penicillamine, and penicillamine disulfide chemical shift data.

			Slope	Std. err	Intercept	Std. err	Adj R^2	p value
Cysteamine	1H	α	−0.33	—	5.85	—	—	—
		β	−0.16	—	4.09	—	—	—
	13C	α	1.44	—	34.88	—	—	—
		β	3.95	—	−7.66	—	—	—
Cystamine	1H	α	−0.37	—	6.50	—	—	—
		β	−0.17	—	4.43	—	—	—
	1H	α	−0.57	0.02	8.92	0.21	0.9951	0.0016
		βa	−0.26	0.06	4.24	0.57	0.8415	0.0543
		βb	−0.26	0.02	4.36	0.20	0.9783	0.0073
Homocysteine	13C	γ	−0.09	0.01	3.34	0.10	0.9619	0.0128
		α	4.98	0.82	10.0	7.5	0.9228	0.0261
		β	0.42	0.05	19.58	0.46	0.9585	0.0139
		γ	1.58	0.12	29.5	1.1	0.9821	0.0060
		α	−0.57	0.03	9.01	0.31	0.9898	0.0034
Homocystine	1H	βa	−0.21	0.08	4.13	0.69	0.6941	0.1078
		βb	−0.32	0.00	5.09	0.04	0.9994	0.0002
Panicillamine	1H	γ	−0.07	0.03	3.47	0.24	0.6550	0.1225
		α	−0.28	0.06	5.64	0.52	0.8613	0.0473
		CH3a	−0.07	0.01	1.84	0.08	0.9382	0.0208
		CH3b	−0.06	0.02	1.97	0.13	0.7782	0.0769
	13C	α	1.89	0.10	54.23	0.86	0.9909	0.0031
		β	0.83	0.37	41.7	3.0	0.5747	0.1536
		CH3a	−2.01	1.28	49.5	10.5	0.3255	0.2581
		CH3b	2.61	1.38	12.8	11.3	0.4643	0.1982
Penicillamine disulfide	1H	α	−0.25	0.01	6.02	0.11	0.9915	0.0028
		CH3a	−0.09	0.03	2.12	0.25	0.7183	0.0988
		CH3b	−0.07	0.01	2.00	0.07	0.9574	0.0143