“…For Tyr, our data (g max = g 270 = 0.0002) is in agreement with the g factor (g 266 = 0.000176) estimated by Nikogosyan et al using the % ee of Tyr generated by CPL irradiation using laser irradiation. 41 For histidine (His) and tryptophan (Trp) the chromophores are the common amine and carboxy groups, with a further imidazolyl and indolyl group, respectively, as the third chromophores. The pK a1 , pK a2 and pK a3 values are pK a1 : His 1.77, Trp 2.38, pK a2 : His 6.10, Trp 9.39, pK a3 : His 9.18.…”