Further Studies on the Relation between Metals and Natural Pigments

Abstract

search Laboratories were used. Infrared spectra were obtained on a Perkin-Elmer model 21, double-beam instrument; a barium fluoride cell (0.052 mm) and a transmittance screen in the reference beam (3) were used. The spectrum of water has been published (3), and our spectrum for water corresponds to it.A 20 percent (weight by volume) solution of CDMT was prepared and scanned as soon as possible after dilution to the mark, scanned again 5 minutes after dilution, and then scanned every 30 minutes thereafter for a total elapsed time of 6 hours. The scanning rate was approximately 30 sec/u. Due to crowding of the curves during the run, only the initial and final curves are shown (Fig. 1), although the pen tracings during the experiment definitely showed progressive differences with time.Examination of the spectra in Figs. 1 and 2 shows that CDMT has a slight resemblance to both cysteine hydrochloride and acetone. The spectrum of the solution of hydrolysis products (see Fig. 1, curve 2) closely resembles the spectrum obtained for a synthetic mixture prepared in the stoichiometric proportions expected for total hydrolysis (see Fig. 2, curve 3). The curve obtained (Fig. 1, curve 2) indicates that at the end of the 6-hour period the system is at equilibrium and that the point of equilibrium lies very close to total hydrolysis (2).These data indicate that it is possible, by means of infrared spectrophotometric techniques, to follow the changes which small molecules undergo in aqueous solution if the concentrations of reactants and products are high enough and if their absorption spectra are sufficiently different. Similar experiments along these lines are being pursued.

On the Reaction of Sex Hormones and Related Compounds With Metals in Ethanolic Solutions by Spectrophotometry

“…On the brown leghorn, Goodale (1913), Domm( 1927) and Juhn andGustanson (1930, 1932) found that the structure and the color of feathers were due to the presence of estrogens.Namely,it was found that female feathers changes by ovariectomy to the male-like and that male given estrogen becomes the female type. Kikkawa and Ogita (1955a, b )and Kikkawa et al(1958) suggested that there is a certain relationship between metals and colors of the fur of guinea pigs. Albert (1950a, b, c and d) confirmed that active substances such as riboflavin, folic acid, amino acids and peptides could chelate with copper in vivo.…”