Solubility and Specific Rotatory Power of Carbohydrates and Certain Organic Acids and Bases in Pyridine and Other Solvents
The Journal of Physical Chemistry
The term carbohydrate is applied to a large class of organic substances closely related to each other. The majority of these compounds are soluble in water, though those of the class (C8Hlo05)z, of which starch and inulin are types are, as a rule, insoluble, The range of solubility of the carbohydrates in solvents other than water is very limited, only bodies like the sugars have been found to dissolve in liquids such as methyl and ethyl alcohols, acetone and pyridine, and then only to a slight
... extent. But little work has been done in determining the solubilities of these compounds in various solvents. At the suggestion of Prof. Kahlenberg, I have investigated the solubility and rotatory power of these substances with the hope of ascertaining the effect of the solvent upon the dissolved substance and the influence of the solvent on the specific rotation of the solute. In some recent investigations carried on in this laboratory by Prof. Kahlenberg, it was found that cane-sugar was soluble in pyridine. Later investigation by G. M. Wilcox'has shown the extent of this solubility and also the influence of the pyridine upon the rotatory power of the cane-sugar. The following work represents a further study of the sugars and other carbohydrates with pyridine as a solvent. Milk-sugar . The first substance used was milk-sugar. This was one of Schuchardt's preparations and labeled chemically pure. T h e samples used were first carefully dried at about 1 0 0 ' to expel moisture. It was The substance then corresponds to C"H"O".H,O. The pyridine used was purchased from Kahlbaum. Jour. Phys. Chem., 5 , 587 (1901).