epimerization


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Related to epimerization: racemization, Mutarotation

epimerization

[‚e·pim·ə·rə′zā·shən]
(organic chemistry)
In an optically active compound that contains two or more asymmetric centers, a process in which only one of these centers is altered by some reaction to form an epimer.
References in periodicals archive ?
As seen with 25(OH)D, epimerization can lead to high concentrations of the C-3 epimer, 3-epi1,25[(OH).
Otoliths as recorders of palaeoenvironments: comparison of radiocarbon age and isoleucine epimerization in Pleistocene golden perch Macquaria ambigua otoliths from Willandra Lakes.
These solutions were stored at -20[degrees]C for several days without apparent loss of detectable alkaloids, other than the expected epimerization.
Epirubicin differs from adriamycin by the epimerization of the OH group in position 4' of the aminosugar moiety and has been shown to be less toxic during chemotherapeutic treatments against metastatic breast cancers (Ganzina 1983; reviewed by Hortabagyi 2000).
The epimerization strongly decreases the compound's biologic efficacy; the anabolic potency of TbOH-17[alpha] is only about 5% of that of TbOH-17[beta] (9), and the affinity to the recombinant human androgen receptor (rhAR) is reduced to about 4% (10).
D-chiro-inositol is an inositol isoform derived from myo-inositol through an epimerization process and this reaction is insulin dependent [1].
Several kinds of transformation have been documented for PSP toxins, such as epimerization, reduction, and hydrolysis (Cembella et al.
Until now, the following signature sequences could be observed: acyl carrier proteins, (ED)LGXDSL(DAT); ArCPs, (DN)LXXXGLDSXR [26]; PCPs preceding a C or Te domain, DXFFXXLGGHSLK; PCPs preceding an epimerization domain, DXFFXXLGGDSIK; and C- terminal PCPs, FF(ED)XGGNSLK.
Evidently, further investigations are needed to elucidate the biological significance of the 3-epi-25(OH)D metabolites, the conditions that favor C3 epimerization of 25(OH)D, and to what extent separate reporting of 3-epi-25(OH)[D.