Perchlorate reductase

Bender KS, C Shang, R Chakraborty, SM Belchik, JD Coates, LA Achenvach (2005) Identification, characterization, and classification of genes encoding perchlorate reductase. J Bacterial 187 5090-5096. 

The standard assay contained retinal homogenate (0.2-3 mg protein), 0.05 mAf tyrosine, 1 mAf (6i ,S)-5,6,7,8-tetrahydro-L-biopterin, 3.5 mAf NADH, 0.02 unit of dihydroxypteridine reductase, 15 ng catalase, 40 mAf sodium acetate buffer (pH 6.0), and 0.1 mAf o-benzylhydroxylamine (inhibitor of Dopa decarboxylase) in a final volume of 100 fiL. After incubation of the mixture at 37°C for 5 to 20 minutes, the reaction as stopped by adding 100 fiL of 0.5 Af perchloric acid containing 0.4 mAf sodium metabisulfite and 0.1 mAf disodium EDTA. The supernate obtained after centrifugation was used for HPLC analysis. 

Inhibitors of the enzyme aldose reductase (which has a role in the development of cataract) have been synthesized from chromanones. Spirohydantoins and spiro-oxazolidines derived from chromanone are of interest, especially the (4S)(-)-enantiomer ( 102).106 107 Oxidation of chromanones in methanol-perchloric acid or trimethyl orthoformate has given moderately good yields of chromones together with minor amounts of 3-methoxychromanones.108 The 13C n.m.r spectrum of the benzochromanone fonsecin (103) has been analysed and its biosynthesis from a new type of polyketide chain folding demonstrated.109... 

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