mutarotation

(redirected from birotation)
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mu·ta·ro·ta·tion

(myū'tă-rō-tā'shŭn),
The process of changing specific rotation at a given wavelength; for example, a solution of α-d-glucose recrystallized from its solution in acetic acid and freshly dissolved in water gives a rotation of [α] 20D = +112.2°, but when recrystallized from a boiling aqueous solution (as the β-form) it shows an initial rotation of [α] 20D = +18.7°; either solution, on standing, slowly changes its specific rotation to a value of [α] 20D = +52.7°, indicating a mixture of the two anomeric forms of d-glucose.

mutarotation

/mu·ta·ro·ta·tion/ (-ro-ta´shun) a change in optical activity of a freshly prepared solution of a pure compound, occurring because of the formation of diastereoisomers having different optical activity.