H组氨酸的咪唑鏈在全pH值下為芳香環的形式。 其含有六個pi电子,其中四個電子來自兩個双键,另外兩個來自氮原子的孤对电子。並且可以形成 pi stacking 的交互作用,[2],可是帶正電荷會使此種情形更複雜化[3]。在兩種情形下都不會吸收280nm波長的光譜,可是卻比一些其他的胺基酸於紫外光譜下落在更低的吸收區間。[4][5]
^IUPAC-IUBMB Joint Commission on Biochemical Nomenclature. Nomenclature and Symbolism for Amino Acids and Peptides. Recommendations on Organic & Biochemical Nomenclature, Symbols & Terminology etc. [2007-05-17]. (原始内容存档于2011-08-21).
^Lijun Wang,, Na Sun,, Simon Terzyan,, Xuejun Zhang, and, David R. Benson. A Histidine/Tryptophan π-Stacking Interaction Stabilizes the Heme-Independent Folding Core of Microsomal Apocytochrome b5 Relative to that of Mitochondrial Apocytochrome b5. Biochemistry 2006 45 (46), 13750-13759
^Robert H. Blessing, Edward L. McGandy. Base stacking and hydrogen bonding in crystals of imidazolium dihydrogen orthophosphate. Journal of the American Chemical Society 1972 94 (11), 4034-4035.
^ Katoh R. Absorption Spectra of Imidazolium Ionic Liquids. Chemistry Letters. Vol. 36 (2007) , No. 10 p.1256.
^ AR Goldfarb, LJ Saidel, E Mosovich. THE ULTRAVIOLET ABSORPTION SPECTRA OF PROTEINS. Journal of Biological Chemistry, 1951, p.397-404.
^Freeman, Rm; Taylor, Pr. Influence of histidine administration on zinc metabolism in the rat. (Free full text). The American journal of clinical nutrition. Apr 1977, 30 (4): 523–7. ISSN 0002-9165. PMID 851080.
^Wensink, J; Van, Den, Hamer, Cj. Effect of excess dietary histidine on rate of turnover of 65Zn in brain of rat.. Biological trace element research. Jul 1988, 16 (2): 137–50. PMID 2484542. doi:10.1007/BF02797098.