Homocystine

ChEBI: An organic disulfide obtained by oxidative dimerisation of homocysteine.

Solid

Homocystine is an organic disulfide obtained by oxidative dimerisation of homocysteine. It has a role as a human metabolite. It is a tautomer of a homocystine zwitterion.

D, L-Methionine (40 g; 0.268 mol) was placed in a 2-L Erlenmeyer flask, equipped with a Claisen adapter, a dry ice condenser, a glass coated magnetic bar, and potassium hydroxide tubes on both the inlet and outlet. At first, the apparatus was flushed with a vigorous stream of dry ammonia. After the condensation of approximately 1 L of ammonia, the gas-delivery tube was removed and replaced with a ground-glass stopper. Then, 3.1 equiv. of sodium (18.5 g; 0.8 mol) was added in small portions over 2 h until the dark blue color of the reaction mixture persisted for at least 20 min. The excess sodium was destroyed by adding a small amount of ammonium chloride, which resulted in decolorization of the solution. Stirring and cooling of the reaction mixture was stopped, and the ammonia was allowed to evaporate at rt overnight. The white solid with a typical homocysteine-like odor was dissolved in 400 mL of water, and the solution was acidified by the slow dropwise addition of HCl (2 M) until pH ~ 4-5 was reached. The flask was immersed in an ice bath, and 30percent H2O2 (28 mL) was added drop-wise under stirring. Precipitation of the product started a few minutes after all of the hydrogen peroxide was added. Stirring and cooling continued for 5 h. Then, the crystals were collected using a Büchner funnel, washed with 500mL of water, frozen at 80 °C and lyophilized. Yield: 29.6 g (82percent). White solid, m.p. 260-280 °C decay (lit. [53] 260-265 °C decay). Calculated for C8H16N2O4S (268.35): 35.81 percentC, 6.01percent H, 10.44percent N. Found: 35.84percent C, 6.14percent H, 10.18percent N. Rf = 0.40 (S5). 1H NMR (600 MHz, D2O + NaOD): δ = 3.33 (m, 2H, 2 N-CH-1): 3046 s (OH); 1659 s (C=O); 1600 vs, 1412 vs (COO-); 2609 m, 1573 s, 1531 m (NH+). HRMS (ESI) calc for C8H17O4N2S2 [M + H]+ 269.06242, found: 269.06247.EXAMPLE 3 Preparation of Homocysteine According to the Invention With the method of the invention, it is also possible to obtain the dimer of homocysteine (called homocystine). [0033] This example is carried out on a scale of 1 mmol of 2ABL in a pill box with magnetic stirring. The 2-ABL is placed in solution in 1.2 mL of NMP. CO

Molecular Weight:268.4
XLogP3:-5.6
Hydrogen Bond Donor Count:4
Hydrogen Bond Acceptor Count:8
Rotatable Bond Count:9
Exact Mass:268.05514934
Monoisotopic Mass:268.05514934
Topological Polar Surface Area:177
Heavy Atom Count:16
Complexity:216
Undefined Atom Stereocenter Count:2
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes