alpha-Methyldopa sesquihydrate

White Solid

Potent inhibitor of invertase and glucosidase inhibitor with a different specificity of action to DNJ and castanospermine. Inhibits glucosidase I.

Antihypertensive agent.

l-(-)-α-methyldopa (hydrate) is an alpha-adrenergic agonist (selective for α2-adrenergic receptors) psychoactive drug used as a sympatholytic or antihypertensive.

Recrystallise methyldopa from H2O. [Reinhold et al. J Org Chem 33 1209 1968.] The L-isomer forms a sesquihydrate from H2O m 302-304o (dec), and the anhydrous crystals are hygroscopic,[] 23D -4.0o (c 1, 0.1N HCl), []546 +154.5o (c 5, CuSO4 solution). It has max at 281nm ( 2780). Its solubility in H2O at 25o is ~10mg/mL and the pH of an aqueous solution is ~5.0. It is insoluble in most organic solvents. [Stein et al. J Am Chem Soc 77 700 1955, Beilstein 4 IV 2505.]