DZ-Methionine

Methionine sulfoxide [454-41-1, 62697-73-8] M 165.2, m >240 (dec). Likely impurities are dl-methionine sulfone and dZ-methionine. Crystd from water by adding EtOH in excess. 

Liquid Dosage Forms Sodium nitropruside in aqueous solution for injection will remain stable for up to one year if protected from light however, its shelf life is about 4h when exposed to normal room light [35]. It has been reported that uric acid increases the photostability of sulfathiazole sodium in solutions [36]. Further dZ-methionine increased the photostability of ascorbic acid in solution [37]. The... 

Likely impurities are dZ-methionine sulfone and dZ-methionine. CrystalUse the sulfoxide by dissolving it in hot H2O and adding excess EtOH. [Lepp Dunn Biochemical Preparations 4 SO 1955, Micheel Schmitz Chem Ber 72 518 1939, Beilstein 4 III 1650, 4 IV 3192.]... 

The formation of thiosulfate after injection of dZ-methionine has been observed in rabbits (49) which were kept on an extremely low sulfur diet. Of the 378 mg. of methionine sulfur introduced, 0.6%. was recovered from the urine after a 48-hour interval. This amount, though very small, is nevertheless significant. It bears out the fact that thiosulfate forms an intermediary compound in the oxidation of sulfur to sulfate, as we shall see on page 400. 

The oxidation of methionine sulfur to sulfate in humans, after ingestion of the Z-form was observed for the first time by Mueller (88). It has since been encountered in a number of other cases in rabbits, after ingestion or subcutaneous or intravenous injection of the [Pg.372]

Regarding the oxidation of methionine sulfur to taurine, the results of the experiments by Virtue and Doster-Virtue (134) with dogs have shown the existence of the oxidation reaction to be highly probable. The animals were first given a diet to deplete their taurine reserves a bile fistula operation was performed then ingestion of dZ-methiouine and cholic acid simultaneously was forced. This ingestion produces a decided increase in the quantity of excreted taurocholic acid. The absolute proof of the oxidation of sulfur of methionine to taurine has been furnished by Tarver and Schmidt... 

This specific oxidation of d-methionine by d-amino acid oxidase has been utilized by Duschinsky and Jeannerat (37) for the preparation of Z-methi-onine from the dZ-derivative. 

---