H^EM ATO PORPH YRIN. 287 



In regard to the preparation and properties of the iodine-, bromine-, 

 and acetone-haemin we refer to the work of STRZYZOWSKI, MERUNOWICZ 

 and ZALESKi. 1 



By the action of acids upon haemochromogen, haematin, or haemin, a 

 new iron-free pigment, which was first closely studied by HOPPE-SEYLER 

 and called hcem,atoporphyrin, is produced. According to the method of 

 preparation haematoporphyrins having different solubilities, and whose 

 relation to each other is not perfectly clear, are produced, but all show 

 the same characteristic absorption-spectrum. The best-studied haema- 

 toporphyrin is the one obtained according to NENCKI and SIEBER'S 

 method, by the action of glacial acetic acid saturated with hydrobromic 

 acid upon haemin crystals, best at the temperature of the body (NENCKI 

 and ZALESKi 2 ). 



Haematoporphyrin, C 16 H 18 N2O3, or C34H 38 N 4 O 6 according to ZALESKI, S 

 is a pigment which according to MAcMuNN, 4 occurs as a physiological 

 pigment in certain animals. It occurs, as shown by GARROD and 

 SAILLET, as a normal constituent, although only as traces, in human 

 urine. It occurs in greater quantities in human urine after the use of 

 sulfonal (see Chapter XV). 



The formation of hsematoporphyrin from haematin can be expressed 

 by the following equation if we start with the above formula for haemin 

 and ZALESKI'S formula for haematoporphyriii : 



C 3 4H33N 4 04FeCl + 2HBr + 2H 2 O = C 3 4H38N 4 O 6 + FeBr 2 + HC1 . 



On heating haematoporphyrin it generates an odor of pyrrol. On oxida- 

 tion with bichromate and glacial acetic acid it yields hsematinic acid (see 

 page 283). A pigment closely allied to the urinary pigment, urobilin, 

 has been obtained by the action of reducing substances on haematopor- 

 phyrin (HOPPE-SEYLER, NENCKI and SIEBER, LE NOBEL, MACMUNN). 

 On the administration of hacmatoporphyrin to rabbits, NENCKI and 

 RoTSCHY 5 observed that a part was reduced to a substance similar to 

 urobilin. 



Of especial interest are the investigations of NENCKI, MARCHLEWSKI, 

 and ZALESKI 6 upon the reduction products of haematoporphyrin and 



1 Strzyzowski, Therap. Monatsh., 1901 and 1902; Merunowicz and Zaleski, Bull, 

 de 1'Acad. d. Scienc. de Cracovie, 1907. 



2 Hoppe-Seyler, Med.-chem. Untersuch., 528; Nencki and Sieber, Monatshefte f. 

 Chem., 9, and Arch. f. exp. Path. u. Pharm., 18, 20, and 24; Nencki and Zaleski, 

 Zeitschr. f. physiol. Chem., 30. 



3 Zeitschr. f. physiol. Chem., 37, 54. 



4 Journ. of Physiol., 7. 



5 Hoppe-Seyler, 1. c., 523; Le Nobel, Pfluger's Arch., 40; MacMunn, Proc. Roy. 

 Soc., 30, and Journ. of Physiol., 10; Nencki and Rotschy, Monatshefte f . Chem., 10. 



6 See footnote 1, page 269. 



