DL-Norvaline

DL-Norvaline (2-aminopentanoic acid). Prepare as for valine, using 2-bromo-pentanoic acid (Expt 5.164) m.p. c. 300 °C (decomp.). 

C8H16N203 DL-alanyl-DL-norvaline 2325-18-0 25.00 1.0877 2 15454 C8H180 2-ethyl-1-hexanol 104-76-7 ... 

Itoh et al. (1969) have measured the far-infrared spectra (700 to 60 cm ) of the x-helix structures of poly(L-a-amino-n-butyric acid), poly-L-norvaline, poly-L-nor-leucine, and poly-L-leucine, as well as the spectra of the ) -form structures of poly(L-a-amino-n-butyric acid), poly-L-valine, poly(DL-a-amino-n-butyric acid), poly-DL-norvaline, and poly-DL-norleucine. The a-helix has characteristic bands near 690, 650, 610, 380, 150, and 100cm . The -form has characteristic bands near 700, 240, and 120 cm . The vibrations of the main chain are strongly coupled with the deformation vibrations of the side chains. An earlier study (Itoh et al., 1968) involved various polyalanines and correlations of spectra with a- and j8-structures. 

The adsorptiop of four apliphatic a-amino acids, DL-norleucine (NL), DL-norvaline (NV), DL-a-amino-n-butyric acid (ABA) and DL-a-alanine (AL), at the mercury-neutral aqueous solution interface has been studied by means of double-layer capacitance, potential of zero charge, and surface tension measurements [96]. The adsorption of NL, NV, and ABA obeys the Frumkin isotherm. The interaction parameter and the potential dependence of the adsorption energy were determined [96]. The shifts of p.z.c. with surface coverage are negative for AL and positive for ABA, NV, and NL, which can be explained by assuming the existence of a small dipole component perpendicular to the mercury surface. 

DL-Norvaline-3-C on administration to rats or on incubation with rat liver homogenates yielded radioactive a-ketovaleric acid, butyric acid, acetic acid, acetoacetate, and 3-hydroxybutyric acid HI). These compounds were isolated by column cluomatography and their identity established. Degradation of the butyric acid demonstrated that only C-2 was significantly labeled. This established that the butyrate was formed by a direct pathway from norvaline and not by the subsequent condoisation of two-carbon fragments. 

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