Electron spin resonance spectrometrical study of the melanins in the wool of some North European sheep in relation to their color inheritance

Abstract

Additional peaks that were known on the esr-spectrograms of red human and reddish-brown Karakul hair to be diagnostic traits of phaeomelanin esr-signal also were found on esr-spectrograms of the tan, but not of black or chocolate brown wool from Icelandic sheep. This tan color is thought to depend on the presence of phaeomelanin and is due to the top dominant allele at the A locus. The two methods of distinguishing between eu- and phaeomelanin-dependent brown colors--esr-spectrometrical and genetical--are in agreement for European as well as for Asiatic breeds. Both light and dark brown Soay fleece samples lacked the additional peaks and are interpreted as eumelanin pigmentation.

Electron spin resonance (ESR/EPR) of free radicals observed in human red hair: a new, simple empirical method of determination of pheomelanin/eumelanin ratio in hair

“…). Figure (a) shows an asymmetric singlet with an additional peak in a low field . The second type of ESR spectrum represents a highly asymmetric singlet with additional splitting in a HF (Fig.…”

Pigment Types of Various Color Genotypes of Horses

“…The two types, eumelanin and pheomelanin, can sometimes be confused phenotypically. The other common method of determining melanin content rests on the detection of pheomelanin by an electron spin resonance spectroscopy technique (Sealy et al, 1982;Vsevolodov et. al., 1987).…”

Comparative Analysis of Hair Melanins by Chemical and Electron Spin Resonance Methods

“…However, it becomes clear now that the alternative character of eumelanin or pheomelanin biosynthesis is not a common rule. There exist intermediate types of melanin in hair (Prota, 1980;Sealy et al, 1982a;Jimbow et al, 1983;Burchill et al, 1986;Vsevolodov et al, 1987;Sponenberg et al, 1988a,b).…”

“…One of the chemical methods depends on the destruction of both types of melanins followed by the estimation of concentration of characteristic "fragments" produced from melanin molecules (Jimbow et al, 1983;Ito and Fujita, 1985;Burchill et al, 1986;Sponenberg et al, 1988a,b). One of the physical nondestructive methods is based on the estimation of free radicals, present in rather high but variable concen-trations, by electron spin resonance (ESR) spectrometry (Sealy et al, 1982a,b;Vsevolodov et al, 1987).…”