The significance of phosphoric esters in metabolism / by Robert Robinson.

  • Robison, Robert, 1883-1941.
Date:
1932
Catalogue details

Licence: In copyright

Credit: The significance of phosphoric esters in metabolism / by Robert Robinson. Source: Wellcome Collection.

    15/136 (page 3)
    I THE OCCURRENCE OF PHOSPHORIC ESTERS IN NATURE THE occurrence of phosphoric esters among the products of metabolism was recognised as early as 1850, when Gobley demonstrated the presence of glycerophosphoric acid in a substance which he had isolated from egg yolk (1846, 1847) and had named lecithin. He showed that this substance also contained fatty acids and a nitrogenous constituent which was later identified by Strecker (1868) as the base choline. Strecker held that the fatty acids are joined to the glycerol, and choline to the phosphoric acid, by ester linkages; and this view has become generally accepted. Compounds of this type were discovered to be most widely dis- tributed in animal tissues; but for many years the chemistry of this group was in great confusion, from which it emerged largely through the investigations of H. MacLean and of Levene and his colleagues. Besides lecithin itself a second compound, kephalin, occurs with it in all tissues. It contains the base aminoethyl alcohol in place of choline, but in other respects its structure is probably similar to that of lecithin although this is not yet beyond dispute. Lecithin CHrOOCRi ch-oocr2 OH / CHi-O—P=0 \ OCH2CH2N(CH,)i,OH Kephalin CH2-OOCRi I ch-oocr2 OH / ch2-o—p=o \ OCH2CH2NH2 It is probable that various lecithins and kephalins exist, each containing one radicle of a saturated and one of an unsaturated