DIFFERENCES IN PRODUCTS OF ACID AND ENZYMIC ACTION. 153 



cal with Fischer's isomaltose because Fischer's isomaltosc was not fermentable, while 

 tliis sugar is fermentable; and, moreover, Fischer's was Isevo-rotatory, while his was 

 dextro-rotatory. Diersscn goes on to state that from the results obtained no conclusions 

 can be drawn with regard to the course of the diastatic hydrolysis of starch, but the fact is 

 emphasized that the products in this case differ considerablj' from those yielded by acid 

 hydrolj^sis. Additional evidence is also afforded by the tendency of glucose to form 

 double compounils with other sugars, one molecule of the syruj)y isomaltose obtained by 

 Dierssen yiekUng crystalline double compounds with any number of molecules of glucose 

 from one upward. 



Griiters (Zeit. angew. Chem., 1904, xvii, 1169; Jour. Soc. Chem. Ind., 1904, xxiii, 

 875) also studied the final degradation products of the action of oxalic acid on starch. 

 He states that these substances include achroodextrin I and II, maltodextrin ;-, maltose, 

 glucose, and a small proportion of levulose. These he notes are the same as the products 

 yielded by diastatic action, except that in the latter case maltodextrin r is replaced by 

 maltodextrin /3, which exliibits different constants and also behaves differently towards 

 diastase. He beheves that both these dextrins occur simultaneously, but in varying pro- 

 portions, this view being supported by the fact that the conversion into maltose is some- 

 times veiy imperfect, and at other times almost complete. The divergent behavior of 

 various isomaltose preparations towards malt extract is also regarded as indicating that 

 the more resistant maltodextrin r occasionally preponderates as the lowest member of 

 the dextrin series. Like Lintner and Dierssen, he failed to isolate maltose in the pure 

 crystalline state from syrups; nor could he accomphsh this from mixtures of maltose and 

 dextrin, which, moreover, gave osazones resembling isomaltosazone. 



Differences in conditions under wliich hydi-olysis occm's may decidedly modify the 

 products, as shown by Ski'aup (Ber. d. d. chem. Gesellsch., 1899, xxxii, 241.3). He noted, 

 for instance, that usually, on acetylation of starch with mixtures of acetic and sulphuric 

 acid, products of gi-eater complexity are produced by little acid and low temperatures 

 than under opposite conditions. 



Of incidental interest in this connection, and in support of differences in the products 

 of acid and enzymic hydrolysis, are the results of the experiments of Tebb (Jour. Physi- 

 ology, 1897-8, XXII, 423) with glycogen, and of Loewi (^Vi-chiv f. exp. Path. u. Pharm., 

 1902, XLViii, 303), Henriques and Hansen (Zeit. f. physiol. Chemie, 1905, xliii, 417), 

 and Abderhalden and Rona (Zeit. f. physiol. Chemie, 1904, xlvii, 530 and 1905, xliv, 

 200) with proteins. Tebb foimd in the acid hydrolysis of glycogen that the products are 

 soluble glycogen, erythrodextrin, achroodextrin, and glucose, and that prolonged hydrol- 

 ysis by saliva, pancreatic extract, and malt extract the only dextrins that could be sepa- 

 rated in amount sufficient to work wath subsequently were of the achroodextrin variety, 

 although evidence of erythrodextrin was noted. By Uver enzyme the intermediate dextrins 

 resembled those produced by the amylolytic enzymes, except that a small amount of ery- 

 throdextrin is constantly found in the earlier stages of the hydrolysis of glycogen. The 

 reaction of liver enzyme differed from the other ezymes used in the nature of the final 

 product obtained, which is, cliiefly at least, glucose and not maltose. Loewi found that 

 an animal fed on the products of the prolonged self-digestion of pancreas may not only 

 thrive but gain in weight. Henderson and Dean fed a bitch on the non-protein products 

 of acid hydrolysis of lean beef together with lard and arrowroot, and record that their 

 numerical results are essentially similar to those obtained by Loewi. From the ninth to 

 the thu-teenth day of feeding, the animal was in nitrogenous cciuilibrium, and the body 

 weight was maintained. In opposition to the statements of Henderson and Dean, both 

 Henriques and Hansen and Abderhalden and Rona found that while animals may thrive 

 on the enzymic jiroducts of protein digestion they do not live longer on the products of 

 the acid hydrolysis of proteins than animals fed on a non-nitrogenous diet. 



