[CONTRIBUTION FROM THE DEPARTMENT O F CHEIIISTRY OF COLUMBIA UriIVERSITY]
INVESTIGATIOYS ON LOCO WEEDS. 11. T H E ISOLATION O F d-PINITE FROM ASTRAGALUS EARLEI AND FROM OXYTROPIS LAMBERTII DONALD C. PEASE,' MALCOLM J. REIDER,
AND
ROBERT C. ELDERFIELD
Received October 28, 1939
In the preceding paper (1) the isolation of two organic bases from Astragalus earlei, or Big Bend loco weed, was described. At the same time considerable quantities of d-pinite mere encountered in the weed. In addition, we have commenced a preliminary study of the constituents of Oxytropis lambertii, or white loco weed, which had previously been investigated incompletely by Couch (2). Inasmuch as the same sugar has been isolated from both weeds in approximately the same amounts, we are taking this opportunity to record our observations. d-Pinite, the monomethyl ether of inosite, has been obtained chiefly from the sap of Pinus lambertiana Dougl. (3), and as a by-product in the preparation of coniferin (4). Griffin and Selson ( 5 ) later made a somewhat more detailed study of the sugar and prepared a number of derivatives. The substance isolated by us from both varieties of loco weed is identical in every respect with the material of Griffin and Nelson. We were fortunate in having available samples of the original compounds prepared by Griffin and Nelson. EXPERIMENTAL
For the isolation of d-pinite from AstragaEus earlei in best yield, the procedure is slightly different from that given in the preceding paper. The extraction of the ground weed, clarification of the extract with basic lead acetate, and concentration to a resin were carried out as for the isolation of the nitrogenous components. The resin was then extracted several times with boiling commercial absolute alcohol, rather than a t 55'. The combined alcoholic extracts were clarified by liberal use of Norit and diatomaceous earth. On standing in the refrigerator, with occasional scratching, the pinite gradually crystallized. The yield was about 10 g. per kilo of dried weed. More of the sugar may be obtained by concentrating the mother liquors, as well as by further extraction of the original resin. d-Pinite, as thus obtained, melted a t 188", after recrystallization four times from alcohol. A sample of Griffin and ic'elson's (5) pinite melted a t 186", and mixtures of varying amounts of the two showed no depression. The specific rotation was [a] $65" (c = 2.480 in water); Griffin and Nelson report [ C Y ] ; + 6 5 O for d-pinite.
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1
DuPont fellow in chemistry 1938-1930. 198
PINITE FROM LOCO WEED
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A n d . Calc'd for C7HlaO6:C, 43.3; H, 7.2; OCH3, 15.7. Found: C, 43.3; H, 7.5; OCH8, 16.0. Acetyl pinite prepared from our sugar melted a t 98". Griffin and Nelson's material melted a t 98", and a mixture of the two showed no depression. For our acetyl derivative, [a]'," $8.6" ( c = 1.970 in alcohol); for Griffin and Nelson's acetyl derivative, [a]: $8.7" ( c = 1.960 in alcohol). A n d . Calc'd for C17H2401~:C, 50.5; H, 5.9. Found: C, 50.7; H, 6.2. Sub&antially the same procedure was used in isolating pinite from Ozytropis Zambertii in about the same yield. The sugar was identical in all respects with pinite from the other two sources. The acetyl derivatives were also identical. The micro-analyses here reported were performed by Mr. Saul Gottlieb of these laboratories. NEWYORK,N. Y. REFERENCES (1) PEASE AND ELDERFIELD, J. Org. Chern., 6 , 192 (1940). (2) COUCH,J . Pharmacol., 36, 55 (1929). (3) BERTHELOT, Ann. Chim., [3], 46, 76 (1856); JOHNSON, Am. J . Sci., [2], 22, 7 (1856); WILEY, J. Am. Chem. SOC.,13, 228 (1891). (4) TIEMANN A N D HAARMANN, Ber., 7, 608 (1874). (5) GRIFFIN AKD NELSON,J . Am. Chem. SOC.,37, 1552 (1915).
