Collisional spectroscopy in structural characterization of melanins. 2--Laser desorption experiments on bio- and synthetic tryptophan melanins.
Melanins are naturally occurring macromolecules whose structural complexity appeared evident from the first researches of Quilico. Their structural characterization remains a difficult problem, mainly due to the physico-chemical properties of such compounds. Melanins are insoluble in organic solvents as well as aqueous solutions and are infusible. Consequently the traditional chemical degradation and physicochemical methods such as ultraviolet, infrared, 1H and 13C nuclear magnetic resonance, ESR (electron spin resonance), XPS (X-rays photoelectron spectroscopy) and X-ray diffraction have led, until now, to limited information on melanin chemical structure.
Allegri
G
G
Dipartimento di Scienze Farmaceutiche dell'Università degli Studi di Padova, Italy.
Biasiolo
M
M
Frison
G
G
Pelli
B
B
Traldi
P
P
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D007834:Lasers; D013058:Mass Spectrometry; D008543:Melanins / Q000032:analysis*; D013053:Spectrophotometry; D014364:Tryptophan / Q000032:analysis; D014961:X-Ray Diffraction
D008543:Melanins; D014364:Tryptophan