d-ビオチンの結晶多形について
1969 年 89 巻 4 号 p. 595-597
詳細
1969 年 89 巻 4 号 p. 595-597
The presence of a polymorphism phenomenon in a crystalline d-biotin was observed by infrared spectroscopy (IR) and X-ray diffractometry. By these measurements, d-biotin rectystallized from water (α type) and 80% ethanol (β type) revealed different IR spectra and diffraction powder patterns. These two kinds of crystals were different as for their crystalline form, and slightly as for their melting point. Elementary analysis showed the absence of water or solvent of crystallization in each type, respectively. It was found that d-biotin obtained by dissolution in methanol and evaporation of the solvent was a mixture of α and β type. The thermal conversion to a type isomorph was shown by heating the β type d-biotin at 200°, 1 hr.
