298 THE BLOOD. 



ing oxime of methylethylmaleic imide. The third pyrrol found by 

 WILLSTATTER, which he calls phyllopyrrol, is a tetra-substituted pyrrol, 



H 3 C.C- -C,C 2 H 5 

 namely, 2, 3, 5 trimethyl-4-ethylpyrrol = 



H 3 C.C-NH-C.CH 3 



The statement that the hsemopyrrol of WILLSTATTER is in part derived 

 from cryptopyrrol is not correct, and must be changed because of the 

 investigations of PILOTY and STOCK, who find that the hsemopyrrol of 

 WILLSTATTER (and ASAHINA) undoubtedly contains cryptopyrrol, but 

 consists chiefly of the B-hsemopyrrol, consequently isohsemopyrrol. Ac- 

 cording to more recent investigations of PILOTY and STOCK 1 the hsemo- 

 pyrrol question is even more complicated than was expected. 



In the crude pyrrol obtained by the reduction of the blood pigments 

 several other pyrrol bodies have been found, for example the phonopyrrol 

 of PILOTY which has not been sufficiently explained. According to 

 GRABOWSKI and MARCHLEWSKi 2 as well as to PILOTY and STOCK, the 

 crude hsemopyrrol contains also disubstituted pyrrol, namely, 1, /3-methyl- 

 ethylpyrrol. On fusing haematoporphyrin or hsematopyrrolidinic acid 

 (see below) with caustic alkali we obtain, according to PILOTY, a mixture 

 of pyrrols among which we will mention 2, 3-dimethylpyrrol 

 HC C.CH 3 



, which has been studied by PILOTY and WILKE. S 

 HC-NH-C.CHs 



By the reduction of hsematoporphyrin and hsemin by various methods, 

 PILOTY and co-workers have obtained, besides hsemopyrrol, several 

 acids namely hsematopyrrolidinic acid, phonopyrrolcarboxylic acid 

 (isophonopyrrolcarboxylic acid) and xanthopyrrolcarboxylic acid. The 

 hsematopyrrolidinic acid seems from the most recent investigations 

 not to be a unit substance. PILOTY obtained from it phonopyrrolcar- 



H 3 C.C -C.CH 2 .CH 2 .COOH 

 boxylic add, CgHi3NO 2 = which on 



H 3 C.C NH CH 

 treatment with nitrous acid lost a methyl group and was converted into 



H 3 C.C==C.CH 2 CH 2 .COOH. 

 the oxime of hsematinic acid, The acid 



HONG NH CO 



received this name because, according to PILOTY, it yields a special 

 dimethylethylpyrrol, called phonopyrrol by him. The question as to the 

 nature of xanthopyrrolcarboxylic acid and its occurrence has not been 



1 Piloty and Stock, Annal. d. Chem. u. Pharm., 392 and Ber. d. d. chem. Gesellsch., 

 46, 1008. 



2 Grabowski and Marchlewski, Zeitschr. f. physiol. Chem., 81. 



3 Piloty and Wilke, Ber. d. d. chern. Gesellsch., 45. 



