Contributions to the Study of Marine Products. XLVI. Phospholipids of a

In connection with our comparative studies on the composition and evolution of the lipids of marine invertebrates, we have investigated the phospho- l...
0 downloads 0 Views 590KB Size
SEPTEMBER

1938

MARINE PRODUCTS. XLVI

[CONTRIBUTIOS No. 1486 FROM

THE

1241

STERLING CHEMISTRY LABORATORY, AND THE BINGHAM OCEANOGRAPHIC LABORATORY, YALE UNIVERSITY]

Contributions to the Study of Marine Products. XLVI. Phospholipids of a Sea Anemonel Received February 17,1958 WERPiER BERGMANN

AND

ROBERT A. LBNDOWNE

The phospholipids of the sea anemone, Anthopleura elegantissima, have been isolated and analyzed. The principal, if not the only, representatives were sphingomyelin and plasmalogen in a ratio of twenty to one. The sphingomyelin consisted mainly of the X-palinityl type. The plasmalogen fraction was obtained in a high state of uniformity. Its rather small degree of unsaturation, its infrared spectrum, and the presence of only one chain of methylene groups showed the acetal attachment of the aldehyde moiety in agreement with Feulgen's original formulation.

In connection with our comparative studies on the composition and evolution of the lipids of marine invertebrates, we have investigated the phospholipids of the common sea anemone of the West Coast, Antlioptettra elegantissima.2 The composition of the phospholipid mixture was of an exceptional simplicity .ivhich made possible a relatively facile isolation in a pure state of its only representatives, sphingomyelin and plasmalogen. They occurred in a ratio of ahout twenty to one, and plasmalogen, the minor component, constituted about 0.1 per cent of the (drym-eight of the anemone. The sphingomyelin, a colorless powder, map. 181.5-183" (dec.) appeared to be free of other phospholipids when subjected t o paper strip chromatography. Its elementary analysis indicated that it waf; a sphingomyelin with an N-palmityl group (I). In accordance with this structure the

ester mixture contained small amounts of esters of acids of the order Clzt o Cz0.The low iodine number of the ester mixture indicated unsaturation not exceeding 0.1 double bond per mole. Similar results were obtained by means of gas chromatography of the brominated esters, and catalytic hydrogenation of spingomyelin. I n the latter only 0.1 mole of hydrogen was consumed in addition to the one mole required to saturate the double bond in the sphingosine moiety. The infrared spectrum of the dihydrosphingomyelin differed from the unsaturated material only in the diminution of the absorption band a t 10.3 microns, which is attributable t o the disappearance of the trans-substituted double bond. The simplicity of the phospholipid mixture made possible the isolation of the plasmalogen fraction without taking recourse to hydrolyses. Only selective treatments with organic solvents at room temperature were required, ensuring the isolation of an unaltered plasmalogen fraction. The material thus obtained appeared t o be of a uniformity rarely if ever equaled before. It was a white wax, which upon heating decomposed above 200". I t s optical activity, ,I].[ -7.85", agreed in direction and magnitude with that of Rapport's plasmalogen f r a ~ t i o nbut ,~ not with that of Thannhauser's sample; [CY], +6.25°.6 The plasmalogen rapidly gave a positive Schiff's aldehyde test. I t s elementary analysis, and sphingomyelin upon hydrolysis afforded choline, the quantitative determinations of choline and sphingosine, and palmitic acid. The choline was isolated as its reineckate, and the sphingosine was glycerol showed that the aldehyde group constituted cha,racteriaed as its triacetyl derivative, m.p. 97" ; the only long methylene chain in the molecule. [CY], -18.2'. The palmitic acid was isolated as its Hydrolysis afforded a mixture of aldehydes in a methyl ester and determined by means of gas yield of nearly ninety per cent. The aldehydes chromatography. Besides methyl palmitate the showed the well-known tendency to polymerize, and some crystalline polymeric product was obtained. The unpolymeriaed material was converted to the ( 1 ) This investigation waa supported by a research grant, 2,4-dinit,rophenylhydrazones, whose elementary Nonr 253(00)from the Office of Naval Research. (2) The authors express their gratitude to Dr. E. C. Dougherty of the University of California School of Medicine for a generous supply of this anemone. (3) The authors are greatly indebted to Dr. S. R. Lipsky of the Yale University School of Medicine for his help in performing the gas chromatographic analyses.

(4)M. M. Rapport, B. Lerner, N. Alonso, and R. E. Franzl, J. Biol. Chem., 225, 859 (1957). ( 5 ) S. J. Thannhauser, N. F. Boncoddo, and 0. Schmidt, J . Biol. Chem., 188, 417 (1951).

1242

BERGMANN AND L A S D O I V N E

VOL.

23

I'lasmalogen,

%

TABLE I COMPARISON

OF

CEREBROSIDE A S D

PIIOSPI1OLIPID CONTESTS

Anemone

Cerebroside, %

Lecithin, %

Cephalin, %

Sphingomyelin, %

Anthopleura Cyrostoma