[CONTRIBUTION FROM THE STERLING CHEMISTRY
LABORATORY, YALE
UNIVERSITY]
CONTRIBUTIONS TO THE STUDY OF MARINE PRODUCTS. XIV. ASTROL WERNER BERGMANN
AND
HARRY A. STANSBURY,
JR.
Received March IS, 19.48
The name astrol was assigned in 1915 by Kossel and Edlbacher (1) to an alcohol of m.p. 71" and probable formula C2a&80s, which occurs together with the as yet ill-defined stellasterol in the unsaponifiable fraction of the fat of the starfish Asterias rubens. Page (2), in 1923 announced the presence of a sterollike compound of m.p. 71" in Asterias forbesi, the common starfish of the New England coast. Believing this compound to be different from previously described sterols, the author named it asteriasterol. As has already been pointed out in a previous communication (3), however, asteriasterol is not a single compound, but a mixture of one or more sterols of the type of stellasterol and an alcohol similar to or identical with astrol. h comparison of the properties and the molecular formula of astrol with those of the naturally occurring glyceryl ethers at once suggested to the present authors the identity of astrol with either batyl alcohol or the as yet unknown cu-eicosylglyceryl ether. An opportunity to investigate this question presented itself when, during a study of the starfish sterols, there became available several grams of a non-steroid alcohol which showed close similarity to astrol and batyl alcohol. The compound melted at 70-71", analyzed for C21H~Oa, and showed a slight positive optical rotation, the magnitude of which was significantly influenced by the concentration of the solution. The identity of this substance with batyl alcohol was demonstrated by its behavior towards lead tetraacetate (4), its conversion to the bis-phenylurethan of m.p. 1OO.5-10lo, and by direct comparison with the synthetic d-a-(n-octadecy1)glycerol ether1 of Baer and Fischer (5). While it is true that the results of Kossel's analyses of astrol are in closer agreerather than one of C21H~03, there exists a strong ment with a formula C28H4803 possibility that the higher carbon values were caused by the presence of some sterol, which was indicated by a slight reaction of astrol with digitonin. The present investigation leaves little doubt as to the identity of astrol and batyl alcohol, the presence of which in marine invertebrates has already been indicated in a previous communication (6). It is of interest to note in this connection that Kossel ,and Edlbacher must be regarded as the discoverers of this interesting compound, since their description of astrol predates by seven years the report of Tsuji.moto and Toyama (7) on the isolation of batyl alcohol from sharkliver oil. 1 The authors express their gratitude to Drs. H . 0. L . Fisher and E . Baer for a sample of synthetic batyl alcohol.
283
284
WERNER BERGMANN AND H. A. STANSBURY, JR. EXPERIMENTAL
All melting points are corrected. The unsaponifiable matter of the oil from the starfish Asterias jorbesia was dissolved in the minimum amount of hot methanol, and the sterols which separated on cooling were removed by filtration. The mother liquor was evaporated to dryness in BUCUO, and the residue again dissolved in hot methanol. After several repetitions of this process the bulk of the sterols had been removed from the unsaponifiable matter. The remaining material was then dissolved in the minimum amount of hot benzene. Upon cooling, a copious precipitate of small needles separated. It was recrystallized three times from ethyl acetate and once from dilute acetone. It melted at 70-70.5'; when mixed with synthetic d-a(n-octadecy1)glycerol ether of m.p. 71-71.5" i t melted at 70.5-71". Rotation: 30.6, 110.3 and 254.4 mg. dissolved in chloroform and made up to 3 cc. gave rotations in a 2 dm. tube of +0.08", 0.16", and 0.13";hence [a]E 3.9", 2.2", and 0.8". The values given by Baer and Fischer (5)for corresponding concentrations of synthetic material were [alD 4.0", 1.70", and $0.8" respectively. Titration with lead tetraacetate. Samples weighing 56.0 and 49.0 mg. were treated with an excess of 0.1 N lead tetraacetate solution for 24 hours a t room temperature. Titration of the solution indicated a consumption of 1.06 and 1.04 moles of lead tetraacetate per mole of alcohol. Anal. Calc'd for CtlHtaOI: C, 73.25; H, 12.8. Found: C, 73.5; H, 13.0. Octadecyl iodide. A 100-mg. sample of the alcohol was converted into octadecyl iodide by the method previously described (6). The iodide melted a t 32.5", and when mixed with an authentic sample of octadecyl iodide a t 32.5-33.5'. Anal. Calc'd for Ci8H3,1: C, 56.8; H, 9.8. Found: C, 57.0; H, 9.6. Batyl bis-phenylurethan. This derivative was prepared as previously reported. It melted a t 100.5-101", and gave no depression of the melting point with authentic batyl bisphenylurethan.
+
+
+
CONCLUSIONS
It has been demonstrated that the alcohol astrol, first isolated by Kossel and Edlbacher from the starfish A S ~ T ~rubens C L S is identical with batyl alcohol. K'EW HAVEN,CONN.
(1) (2) (3) (4) (5) (6) (7)
REFERENCES KOSSELAND EDLBACHER, 2. physiol. Chem., 94,277 (1915). PAGE,J . Biol. Chem., 67, 471 (1923). BERGMANN, J. Biol. Chem., 117, 777 (1937). DAVIES,HEILBRON, AND JONES, J. Chem. soc., 166 (1933). BAERAND FISCHER, J. Biol. Chem., 140, 397 (1941). KINDAND BERGMANN, J . Org. Chem., 7, 424 (1942). TSUIJIMOTO AND TOYAMA, Chem. Umschau, 29,27,35,43 (1922).
2 The authors are greatly indebted to Mr. Chas. F. Lee, Fish and Wildlife Service, College Park, Md. for his generous gift of a large quantity of starfish oil.
