Abstract: There are disclosed novel compounds of formula (Ia) or (Ib) wherein R1, R2, R3, R4, X and Y are as defined in the specification, and pharmaceutically acceptable salts thereof; together with processes for their preparation, compositions containing them and their use in therapy. The compounds are inhibitors of the enzyme MPO and are thereby particularly useful in the treatment or prophylaxis of neuroinflammatory disorders.

Abstract: The invention is an assay for detecting inhibitors of the enzyme myeloperoxdase The assay method comprises reacting myeloperoxdase with hydrogen peroxide and a chloride source to generate hypochlorous acid in the presence of a potential inhibitor of said myeloperoxidase; reacting any formed hypochlorous acid with an amine to form the corresponding chloramino; optionally removing any unreacted hydrogen peroxide; reacting any for-med chloramine with a detector compound in the presence of iodide to form oxidized detector compound; determining the amount of formed oxidized detector compound by measuring the absorbents or fluorescence at a suitable wavelength; and identifying as inhibitors of myeloperoxidase those compounds which cause the amount of formed oxidized detector compound to be decreased The assay is useful in diagnostic tests for myeloperoxidase activity.

Abstract: An assay for detecting inhibitors of the enzyme myeloperoxidase said method comprising: reacting myeloperoxidase with hydrogen peroxide and a chloride source to generate hypochlorus acid in the presence of a potential inhibitor of said myeloperoxidase; reacting any formed hypochlorous acid with a suitable amine to form the corresponding chloramine; Optionally removing any unreacted hydrogen peroxide; reacting any formed chloramine with a suitable detector molecule in the presence of iodide to form oxidised detector molecule; determining the amount of formed oxidised detector molecule by measuring the absorbance or fluorescence at a suitable wavelength; Identifying as inhibitors of myeloperoxidase those compounds which cause the amount of formed oxidised detector molecule to be decreased. And for use in diagnostic tests for myeloperoxidase activity is disclosed.