ISOMALTOSE, MALTOSE. GLUCOSE, SACCHAROSE, ETC. 145 



and isomaltose is not the same as the invertase wliich is also found in yeast, as it is less 

 soluble than invertase and more nearly resembles glucase. 



Certain statements of Fischer, and of Lintner and Diill, were opposed by Ost (Cliemi- 

 ker Zeit., 1895, xix, 1501, 1727). Ost investigated Fischer's isomaltosazone and concluded 

 that it is a maltosazone, and he belie\-es that maltose and not isomaltose is formed l)y hydro- 

 chloric acid, as in Fischer's experiments. He followed Lintner and Diill's method for obtain- 

 ing and purifying isomaltose, and concluded that the substance was not homogeneous and 

 that it is the nature of an impure maltose. Ost determined the rotatory power of maltose to 

 be (a)D = +136.95° at 20°. He notes that this value differs from those of Meissl, Brown 

 and Heron, Effront, and Herzfeld, Ixit agrees with that of Parcus and Tollens. Ulrich 

 (Chemiker Zeit., 1895, xix, 1523), under Ost's direction, arrived at the same conclusion as 

 Ost regarding the conversion of starch into maltose and not into isomaltose; and he also 

 states that the melting-point of the maltosazone is modified by the method of preparation. 



Ling and Baker (Proc. Chem. Soc. Trans., 1895, xlvii, 702, 739) also investigated 

 Lintner's isomaltose, and obtained a substance yielding crystals resembling those of mal- 

 tose and having properties resembling those of Lintner's isomaltose. The rotatory power 

 was found to be +142.0° to +143.8°, and the reducing power 81.52 to 81.81 per cent of 

 that of maltose. The melting-point of the osazone was 160° to 170°. In another instance 

 an alcoholic extract of the products of diastatic digestion at 70°, upon treatment with 

 phenylhydrazine, yielded a small quantity of glucosazone, and also an osazone that had 

 the properties of Lintner's isomaltosazone. The latter osazone had a melting-point of 151°. 

 They thought at first that this osazone was derived from a hexatriose, but in their second 

 paper they withdraw this suggestion. 



Brown and Morris (Proc. Chem. Soc. Trans., 1895, lxvii, 709) agree with Ling and 

 Baker that lintner's isomaltose is not a chemical individual. They state, moreover, that 

 Lintner gives no evidence in any of his pubhcations that the isomaltose prepared by him 

 is identical with that of Fischer. They hold that Lintner's isomaltose can he split by 

 fractionation with alcohol, or by fermentation, in such a manner as to indicate a mixture 

 of maltose and dextrinous compounds of the maltodextrin or amyloin class; that the isomal- 

 tosazone prepared by Lintner, upon which mainly he based his belief in the existence of 

 isomaltose, is nothing but maltosazone modified by the presence of small but \-arying 

 quantities of another substance, such as dextrinous compounds; and that the only product 

 of diastatic digestion capable of yielding an osazone is maltose. 



Jalowetz (Chemiker Zeit., 1895, xix, 2003) confirmed the statement of Brown and 

 Morris that by mixing variable pro])ortions of dextrin with maltose, maltosazones can 

 he obtained which differ in melting-point, crystalline form, and general characteristics. 



In comparative studies of the actions of salivary, pancreatic, and intestinal enzymes, 

 Hamburger (Archiv f. ges. Physiologie, 1895, lx, 543) showed that under certain condi- 

 tions each will produce isomaltose, maltose, and glucose. He here found that two enzymes, 

 diastase and glucase, are present in different proportions in the salivary, pancreatic, and 

 intestinal secretions, and also in the blood. More diastase and glucase are found in the 

 pancreatic juice than in the saliva, and less glucase than in the blood. In the saliva more 

 diastase is found than in the blood and intestinal ferment, but less than in the pancreatic 

 juice. Glucase predominates in the blood ferment, and therefore larger amounts of glucose 

 than isomaltose and maltose are obtained by saccharification (see page 141). By the action 

 of extract of pancreas on starch-paste, Chlodounsky and Sulz (Sitz. d. k. bohm Gesellsch. 

 d. Wissensch., 1896; Jahr. u. d. Fort. d. Thierchemie, 1896, xxvi, 67) found that a sugar 

 was formed which yielded an osazone that was identified with glucosazone. 



In three contributions during this and the following year. Brown, Morris ami Millar 

 (Proc. Chem. Soc. Trans., 1896, xlviii, 242, 243; 1897, xlix, 4) take up a technical study 

 of the specific rotatory and reducing powers of glucose, maltose, levulose, and invert sugar. 



10 



