1,721,011 research outputs found
ENANTIOSELECTIVITY OF THE ENZYMATIC-HYDROLYSIS OF CYCLOHEXENE OXIDE AND (+/-)-1-METHYLCYCLOHEXENE OXIDE - A COMPARISON BETWEEN MICROSOMAL AND CYTOSOLIC EPOXIDE HYDROLASES
No full textENANTIOSELECTIVE HYDROLYSIS OF SUBSTITUTED PHENYLOXIRANES BY RABBIT LIVER MICROSOMAL EPOXIDE HYDROLASE
No full textThe rabbit liver epoxide hydrolase contained in the microsomal fraction (mEH) has been checked for its enantioselectivity towards several racemic ortho-, meta-, and para-substituted phenyloxiranes, benzyloxirane, and phenoxymethyloxirane. While for the last two substrates non-selective hydrolysis is observed, the orientation of substituents on the benzene ring is found to affect significantly the selective ring opening of phenyloxiranes
EVIDENCE FOR A REVERSIBLE ELECTROPHILIC STEP IN OLEFIN BROMINATION - THE CASE OF STILBENES
No full textCONCENTRATION-DEPENDENCE OF THE STERIC COURSE OF THE BROMINE ADDITION TO ARYLALKENES - THE CASE OF STILBENES
No full textREACTIVITY AND CRYSTAL-STRUCTURE OF 10,11-DIHYDRO-10,11-EPOXY-5H-DIBENZO[A,D]CYCLOHEPTENE - A COMPARISON WITH CIS-STILBENE OXIDE
No full textThe kinetics of product distributions for the HClO4 catalysed hydrolysis of 10,11-dihydro-10,11-epoxy 5H-dibenzo[a,d]cycloheptene 1 and of cis-stilbene oxide 6 in tetrahydrofuran-water (8:2), have been investigated by HPLC. The former epoxide gives 9,10-dihydroanthracene-9-carbaldehyde 4 and the trans- and cis-10,11-dihydro-5H-dibenzo[a,d]cycloheptene-10,11-diols, 2 and 3, in the (+/-)-1,2-diphenylethane-1,2-diol. These differences can be explained by the crystal structure of 1, which shows considerable ring strain due to the enlargement of the bond angles at C(10) and C(11). This structure also suggests an explanation for the much lower rate of the microsomal epoxide hydrolase catalysed hydration of 1 relative to 6
Determinazione della melatonina in Achillea millefolium fresca pretrattata con triptofano
No full textPRODUCT ENANTIOSELECTIVITY OF THE MICROSOMAL AND CYTOSOLIC EPOXIDE HYDROLASE CATALYZED-HYDROLYSIS OF MESO EPOXIDES
No full textTHE METABOLISM OF CARBAMAZEPINE IN HUMANS - STERIC COURSE OF THE ENZYMATIC-HYDROLYSIS OF THE 10,11-EPOXIDE
No full textSUBSTRATE ENANTIOSELECTIVITY IN THE RABBIT LIVER MICROSOMAL EPOXIDE HYDROLASE CATALYZED-HYDROLYSIS OF TRANS AND CIS 1-PHENYLPROPENE OXIDES - A COMPARISON WITH STYRENE OXIDE
No full textA preferential consumption of the (IS,2S) enantiomer of (+/-)-trans-1-phenylpropene oxide (3) and of the (1R,2S) enantiomer of cis-1-phenylpropene oxide (5) is observed during the rabbit liver mEH catalyzed hydrolysis of these epoxides. This preference is, respectively, much lower and much higher than that found for the consumption of the (R) enantiomer in the hydrolysis of (+/-)-styrene oxide. These results are rationalized in terms of the K(M) and V(max) of the respective reactions
ENANTIOSELECTIVITY IN THE RABBIT LIVER MICROSOMAL BIOTRANSFORMATION OF STYRENE AND PHENYLPROPENES
No full textThe rabbit liver microsomal P-450 catalyzed oxidation of styrene (1a) and isomeric phenylpropenes, trans-1-phenylpropene (1b), cis-1-phenylpropene (1c) and 3-phenylpropene (1d), was investigated and the enantioselectivity of the epoxidation of the olefinic double bond was determined by checking the enantiomeric excesses of the corresponding first formed epoxides (2). These enantiomeric excesses were always modest, ranging between 7% of (1S,2S)-(2b) and 22% of (1R,2R)-(2c). In the case of (1d) a non-enantioselective hydroxylation at the benzylic-allylic C(3) was also observed. The ratio between this hydroxylation and olefin epoxidation of (1d) was 1:2
- …
