. Author manuscript; available in PMC: 2009 May 21.

Published in final edited form as: J Am Chem Soc. 2008 Apr 24;130(20):6381–6387. doi: 10.1021/ja0780277

Table 1.

ESR HFCs of l-tryptophan and related cation free radicals^a

Cation radical	a_N-1	a^HN-1	a^H_β(1)	a^H_β(2)	a^H_C-4^b	a^H_C-2^b	a^H_C-6^b	a^H_C-5^b	a^H_C-7^b
l-tryptophan	0.20	0.35	0.71	1.07	0.54	0.51	0.42	0.13	0.06
l-[¹⁵N₂]tryptophan	0.28^c	0.35	0.71	1.08	0.54	0.51	0.42	0.12	0.06
l-[indole N-²H]- tryptophan	0.19	0.05^d	0.70	1.08	0.56	0.52	0.42	0.14	0.05
l-[2,4,5,6,7-²H₅]- tryptophan	0.19	0.37	0.69	1.05	0.08^d	0.08 ^d	0.07 ^d	0.02 ^d	0.01 ^d
tryptamine	0.21	0.37	1.04	1.04	0.54	0.50	0.42	0.11	0.07
3-methylindole	0.23	0.39	1.42^e	---	0.46	0.46	0.45	0.10	0.05

Hyperfine coupling values are in mT

HFC assignments are based on theoretical spin density calculations⁴,⁹.

¹⁵N HFC

²H HFC

HFC for three equivalent methyl hydrogens