Nomenclature
CAS number: 66-02-4
3,5-Diiodo-4-hydroxy-β-phenylalanine; iodogorgoic acid; Agontan (Knoll).
C
9H
9I
2NO
3; mol wt 432.98.
C 24.97%, H 2.10%, I 58.62%, N 3.23%, O 11.09%.
Description and references
Found in the skeletal proteins of corals, sponges,
and other marine organisms. Isoln from Gorgonia cavollini as the dl acid: Drechsel, Z. Biol. 33, 99; Jahresber. Tierchemie 1896, 574; Henze, Z. Physiol.
Chem. 38, 71 (1903); isoln from the common
sponge: Wheeler, Mendel, J. Biol. Chem. 7, 1 (1909-10); Low, J. Mar.
Res. 10, 239 (1951); from marine algae: Coulson, Chem. Ind. (London) 1953, 997;
prepn from l- or dl-tyrosine: Henze, Z. Physiol. Chem. 51, 67 (1907);
Borrows et al., J. Chem. Soc. 1949, Suppl. Issue no. 1, S185; Jurd, J. Am. Chem. Soc. 77, 5747 (1955);
Boyle, Zlatkis, US 2835700 (1958 to Basic, Inc.).
Derivative
l-Form.
Properties
Bunches of needles from water or 70% alcohol,
dec 213°. [α]D20 +2.89° (0.246 g in 5 g 4% HCl); [α]D20 +2.27° (0.227 g in 5 g 25% NH3). pK1 2.12; pK2 6.48; pK3 7.82. Soly in water (g/l): at 0° = 0.204; at 25° = 0.617; at 50°
= 1.862; at 75° = 5.62; at 100° = 17.00. On boiling with dil alc
the crystals swell, and after prolonged boiling a gelatinous precipitate
is formed.Derivative
dl-Form.
Properties
Double wedge crystals from 70% alc, rectangular
plates from water. Dec about 200°. Soly in water (g/l): at 0° =
0.149; at 25° = 0.340; at 50° = 0.773. On cooling a boiled hydroalcoholic
soln, no gelatinous precip is formed.Thyroid inhibitor.