Phenyl Phosphates

Phosphatase Test. The phosphatase [9001-78-9] test is a chemical method for measuring the efficiency of pasteurization. AH raw milk contains phosphatase and the thermal resistance of this enzyme is greater than that of pathogens over the range of time and temperature of heat treatments recognized for proper pasteurization. Phosphatase tests are based on the principle that alkaline phosphatase is able, under proper conditions of temperature and pH, to Hberate phenol [108-95-2] from a disodium phenyl phosphate substrate. The amount of Hberated phenol, which is proportional to the amount of enzyme present, is determined by the reaction of Hberated phenol with 2,6-dichloroquinone chloroimide and colorimetric measurement of the indophenol blue formed. Under-pasteurization as well as contamination of a properly pasteurized product with raw milk can be detected by this test. 

Biological activities also may correlate with electronic substituent factors alone, eg, the inhibition of acetylcholinesterase by six diethyl phenyl phosphates (36) gave r = 0.95 for... 

Fig. 3. Infrared absorption data for the four tricresyl phosphate isomers present in hydrauHc oil. a, Trimetacresyl phosphate b, metametaparacresyl phosphate c, metaparaparacresyl phosphate d, triparacresyl phosphate. The P=0 stretch between 1300 and 1350 cm is marked as is the phenyl—phosphate vibration around 965 cm . Also included are the metacresyl (875 cm ) and paracresyl (820 cm ) frequencies.

Bis-(2-chlorophenyl) phenyl phosphate [597-80-8] M 395, b 254"/4mm, n 1.5767. Same as for 2-biphenylyl diphenyl phosphate above. 

N-Dibutylami no-ethanol Dibutyl phenyl phosphate Dibutyl phosphate Dibutyl phthalate 6,6 -Di-tert-butyl-4-4 -... 

Et4N F , CH3CN, 48 h, reflux. TMSF and allene are formed in the cleavage reaction. These conditions are not compatible with phenyl phosphates, which are cleaved preferentially with fluoride.Cleavage of a bis TMSP phosphate results in the cleavage of only one of the TMSP groups. 

Pt02 (stoichiometric), TEA, AcOH, H2, 91% yield. This method cannot be used in substrates that contain a tyrosine, because tyrosine is easily reduced in the acidic medium. Neutral conditions fail to cleave phenyl phosphates. ... 

Pyr, i-BuNH2, H2O. Cleavage occurs in the presence of the 2,6-dichloro-phenyl phosphate." ... 

When phenyl phosphate is the substrate, the released phenol is conveniently measured using the reaction described by Powell and Rind and Ring based on 4-amino antipyrine (4-AAP) and ferri-cyanide. It is possible to incorporate the 4-AAP directly into the buffered substrate mixture, so that color can be developed... 

Acid phosphatase catalyzes the dephosphorylation of an artificial organic substrate, such as B-glycerophosphate, phenyl-phosphate or thymolphthalein monophosphate. The analyst may measure either the phosphate or the organic radical liberated. 

The substrate phenyl phosphate, which is hydrolyzed by the serum acid phosphatases originating from many tissues, has been used in most of the published studies. Total serum acid phenylphos-phatase is elevated in diseases of the liver, disease of bone such as Paget s disease, and several blood dyscrasias, especially those involving platelets (99>100). 

The anaerobic degradation of phenol proceeds by carboxylation of phenyl phosphate, followed by dehydroxylation, and fission of the ring after partial reduction (Brackmann and Fuchs 1993). 

A competitive electrochemical enzyme immunoassay has been demonstrated for digoxin Alkaline phosphatase, which catalyzes the hydrolysis of phenyl phosphate... 

A sandwich electrochemical enzyme immunoassay has been described for IgG Alkaline phosphatase was again used as the enzyme label with the conversion of phenyl phosphate to phenol being determined electrochemically by LCEC. A detection limit of 10 pg/mL was reported. 

Phenols with an appropriate leaving group in the benzylic position such as fluoride may form QMs by spontaneous hydrolysis, possibly catalyzed by a basic amino acid residue as shown in Scheme 10.2c. Evidence for this process was obtained with 4-(fluoromethyl)phenyl phosphate involving initial enzymatic hydrolysis of the phosphate followed by nonenzymatic formation of a QM.11 Similarly, several lines of evidence demonstrate nonenzymatic QM formation from 4-trifluoromethylphenol under physiologic conditions.12... 

Successful combination of a chromatographic procedure for separating and isolating additive components with an on-line method for obtaining the IR spectrum enables detailed compositional and structural information to be obtained in a relatively short time frame, as shown in the case of additives in PP [501], and of a plasticiser (DEHP) and an aromatic phenyl phosphate flame retardant in a PVC fabric [502], RPLC-TSP-FTIR with diffuse reflectance detection has been used for dye analysis [512], The HPLC-separated components were deposited as a series of concentrated spots on a moving tape. HPLC-TSP-FTIR has analysed polystyrene samples [513,514], The LC Transform has also been employed for the identification of a stain in carpet yarn [515] and a contaminant in a multiwire cable [516], HPLC-FTIR can be used to maintain consistency of raw materials or to characterise a performance difference. 

Schrader prepared the ester (38) in 60% yield by reaction of sodium p-nitrophenate with diethyl chlorophosphate, using xylene as solvent for the reaction. He made it, but in lower yields, from p-nitrophenol and diethyl chlorophosphate, using, respectively, pyridine and sodium cyanide as acceptors for hydrogen chloride. Schrader also prepared it in 96% yield by nitrating diethyl phenyl phosphate at 0° C. or below. Under the conditions he used, Schrader claims that the nitro group is directed to the para position. No yield is given for the diethyl phenyl phosphate, which he presumably made from sodium phenate and diethyl chlorophosphate. Diethyl chlorophosphate may be prepared in high yield (30) from diethyl phosphite and chlorine. 

AChE = acetylcholinesterase Bd Wt = body weight BTP = butylated triphenyl phospate BUN = blood urea nitrogen (C) = capsule Cardio = cardiovascular d = day(s) deer. = decreased DBPP = dibutylated phenyl phosphate 2EDP = 2-ethylhexyl diphenyl phosphate Endocr = endocrine F = female (G) = gavage Gastro = gastrointestinal ... 

With acute-duration exposure to tricresyl phosphate and dibutyl phenyl phosphate, decreased litter size and pup survivability were found at 400 mg/kg/day (Carleton et al. 1987) and 50 mg/kg/day (Healy et al. 

Johannsen and colleagues (1977) report dermal LD50 values for rabbits at levels of >3,700 mg/kg for a group of triaryl phosphates, >5,000 mg/kg for dibutyl phenyl phosphate, 5,000 mg/kg for both asymmetrical and symmetrical triaryls, and >3,100 mg/kg for tributyl phosphate. This study looked at structural activity relationships for the organophosphate esters. 

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