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.

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    fatty acid and differing from one another only in the nature of these fatty acids. There is some evidence also for the existence of lecithins derived from /5-glycerophosphoric acid in which the phosphoric radicle is attached to the central C atom of glycerol (Bailly, 1915). Sphingomyelin, which occurs in brain, in red blood corpuscles, and many other tissues, also belongs to this class of ether-soluble compounds, the phospholipins or phosphatides. It contains no glycerol; but, according to Levene (1916), the phosphoric acid is joined by ester linkages with choline and with another hydroxy- base, sphingosine, while lignoceric or another fatty acid is attached to the sphingosine through the amino group. Levene’s formula for sphingomyelin is here shown with the composition of sphingosine altered from C17 to Cig in accordance with the recent work of Klenk (1929). Sphingosine Lignoceric acid O • C18H33OH • NH • CO C23H47 / O—P—OH \ OCH2CH2N(CH3)3OH The phospholipins of plant tissues have been less thoroughly investigated than those derived from animal sources, but there is evidence that both lecithins and kephalins are synthesised by plants (Levene and Rolf, 1925, 1926; Daubney and Smedley- MacLean, 1927). Chibnall and Channon (1927) have isolated from cabbage a phospholipin, which resembles lecithin in con- taining fatty acids joined to a-glycerophosphoric acid but con- tains no choline or other base. This ester, named phosphatidic acid, occurs in the form of its calcium salt which is soluble in ether. CHrOOCRi I choocr2 o / \ CH2-0—P=0 Ca \ / o