"j^) Intracellular Lipins [Sept. 



thus becomes evident. This circumstance shows one o£ the many 

 important reasons for understanding the way in which " lipins " are 

 held and coordinated in cellular material. 



In this discussion of the lipins that occur in cellular material, 

 mention will also be made of certain products of a synthetic nature 

 that bear on intracellular problems. 



Compounds of lipins with inorganic substances and tissue 

 metabolites. It has long been known that the complex lipin§ con- 

 tain inorganic Clements, but at present it is not always possible to 

 say whether such Clements are held in mechanical mixtures, or by 

 true chemical unions, or as adsorption associates. The importance 

 of such relationships in intracellular phenomena may be very great, 

 whether they are adsorption unions or true chemical combinations. 

 Koch has lately determined the characters and proportions of the 

 inorganic Clements in various preparations of lecithin and kephalin. 

 He found considerable potassium in kephalin and thinks that the 

 abundance of potassium in cells is due to the affinity of potassium 

 for kephalin. Koch has also shown that hypoxanthin, creatin, 

 Creatinin, adrenalin, and ammonium salts combine with lecithin. 

 Winternitz has found calcium to the amount of 6.7 per cent. in a 

 vegetable phospholipin. Lecithans unite chemically with both acids 

 and bases. 



Compounds of lipins with amino-acids. Abderhalden and his 

 co-workers have prepared Compounds of glycin, alanin, and ty- 

 rosin with Stearin and with palmitin; also Compounds of glycerol 

 with tyrosin, and glycerol with palmitin and tyrosin. They have 

 also described Compounds of cholesterol with amino-acids and with 

 fatty acids. That similar Compounds occur in protoplasm is very 

 probable. 



Compounds of lipins with proteins. The substances of this 

 nature which have received most study are the " lecithalbumin " 

 of Liebermann and the " ovovitellin " of Hoppe-Seyler. Lieber- 

 mann obtained protein products containing lecithin as an insoluble 

 residue after peptic digestion of the mucous membrane of the stom- 

 ach, liver, kidneys, lungs, and spieen. He considered these residues 

 to be true Compounds of protein and lecithin. It is impossible to 

 remove the lecithin from this combination with ether or cold alco- 



