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Content with tag raman spectroscopy .

Impairment of mixed melanin-based pigmentation in parrots

Parrots and allies (Order Psittaciformes) have evolved an exclusive capacity to synthesize polyene pigments called psittacofulvins at feather follicles, which allows them to produce a striking diversity of pigmentation phenotypes. Melanins are polymers constituting the most abundant pigments in animals, and the sulphurated form (pheomelanin) produces colors that are similar to those produced by psittacofulvins. However, the differential contribution of these pigments to psittaciform...

Molecular vibration as a novel explanatory mechanism for the expression of animal colouration

Animal colouration is characterized by the concentration of pigments in integumentary structures and by the nanoscale arrangement of constitutive elements. However, the influence of molecular vibration on colour expression has been overlooked in biology. Molecular vibration occurs in the infrared spectral region, but vibrational and electronic properties can influence each other. Thus, the vibration of pigment molecules may also affect their absorption properties and the resulting colours....

Raman spectroscopy quantification of eumelanin subunits in natural unaltered pigments

Eumelanins are large polymers composed of 5,6-dihydroxyindole (DHI) and 5,6-dihydroxyindole-2-carboxylic acid (DHICA). ROS generation is higher during the synthesis of DHI than during the synthesis of DHICA, thus the production of eumelanins with high relative DHI contents may compromise the viability of cells and organisms. Here it is shown that dispersive Raman spectroscopy allows a non-invasive direct detection and quantification of DHI and DHICA in unaltered eumelanins that can be applied...

Identification and quantification of melanin types by Raman spectroscopy

Melanins are the most prevalent pigments in animals and are involved in visual communication by producing colored traits that often evolve as intraspecific signals of quality. Identifying and quantifying melanins are therefore essential to understand the function and evolution of melanin-based signals.