Phenyl acid phosphate reagent

Other reagents that open the epoxide ring with substitution, to give the useful derivatives indicated in parentheses, include phenols (phenyl ethers) (81) y carboxylic acids (esters) (8 ), hydrogen sulfide in the presence of barium hydroxide (thiols) (82), sodium methyl mercaptide (methyl thio-ethers) (83), dipotassium hydrogen phosphate or dibenzylphosphoric acid (phosphate esters) (84), alkyl or aryl magnesium halides (halodeoxysugars)... 

Because of the results found with p-(chloromercuri)benzoate and because /3-galactosidase is believed to be a sulfhydryl enzyme, it seemed advisable to investigate the effects of other sulfhydryl reagents. Virtually no inhibition of /3-galactosidase was found in the presence of iodoacetam-ide (9 X 10 M) over a period of 7 hours. A -Phenylmaleimide, at concentrations as high as 8.7 X 10 M, produced less than 10 % inhibition over a 20-hour period. However, when the concentration of V-phenyl-maleimide was raised to 9.1 X 10 M, assay of the incubation mixture revealed that 50% inhibition of /3-galactosidase occurred within a 2-hour period when the experiment was performed in 2-amino-2-(hydroxymethyl)-1,3-propanediol— acetic acid buffer, pH 8.0. Virtually no activity was lost when the latter experiment was repeated in phosphate buffer (Na salts) at the same pH. 

Semen is generally detected by identifying acid phosphatase or choline. The suspected stain is cut and incubated for 30 min at 37°C with two drops of a 0.1% aqueous solution of disodium phenyl-phosphate the phenol resulting from the enzyme-catalyzed hydrolysis can be detected with the Folin-Ciocalteu reagent. Phenol forms molybdenum blue on reaction with the molybdophosphate or tungstophosphate incorporated in this reagent. 

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