Alfalfa Saponin1

cooperative experiments10 the feeding of alfalfa saponin to ruminants caused typical symptoms of bloat. Recovery of the mixed saponins from the plant ...
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April 20, 1954 Anal. Calcd. for CzdHz1N: C, 89.2; H , 0 .SO. C, 89.0; H, 6.40. CANCER RESEARCH LABORATORY UNIVERSITY O F FLORIDA FLA. GAINESVILLE,

Found:

Alfalfa Saponin' AND BY E D. %'ALTER,G R . I-AN ATTA,C R . THOMPSON lV, D. MACLAY RECEIVED DECEMBER 7, 1953

Investigation of the water-soluble fraction of alfalfa (hfedicago satiaa), undertaken to test the hypotheses that it contains saponin capable of inhibiting grow,th of chicks2 and contributing to ruminant bloat3e4confirmed earlier reports of the presence of a t least two Mixed saponins were recovered from dried alfalfa and have since been shown in a cooperative study by Heywangg to be inhibitory to the growth of chicks. In other recent cooperative experiments'O the feeding of alfalfa saponin to ruminants caused typical symptoms of bloat. Recovery of the mixed saponins from the plant material was effected through formation of their water-insoluble cholesterides. Because the cholesterides are split by alcohol^,^^* it was necessary to form them by heating aqueous plant extract solutions containing an excess of cholesterol in suspension. Partial resolution of the mixed saponins gave two fractions which differed from each other in optical rotation and mobility on paper and which by acid hydrolysis were also found to differ significantly from one another in both their sugar and aglycone components. One of the sapogenins, its diacetate and diacetate dimethyl ester were prepared in crystalline form. Its dimethyl ester and monobromolactone were obtained as non-crystalline products. Properties of the sapogenin and its derivatives indicate that it is a monounsaturated dihydroxy dicarboxylic acid having the molecular formula Cs&&O6. The specific rotation of the sapogenin, +111", and of its diacetate, +87", suggests a triterpenoid, since the steroid-sapogenin side chain usually confers pronounced levorotation.I1 The acidic character of the sapogenin and the fact that i t contains 30 carbon atoms further support the idea that it belongs to the triterpenoid rather than the steroid class.I2 h search of the literature disclosed no description of a sapogenin coinciding in all respects with that of the present substance. Castanogenin, a dihy(1) Presented a t ACS meeting in Kansas City, Mo., 1954,

(2) D. U'. Peterson, J . Biol. Chem., 183, 647 (1950). ( 3 ) H . H . Cole, C. F. H u f f m a n , M. Kleiher, T. h l . Olson and A . F. Schalk J . 4tziinat S c i . , 4 , 183 (1945). (4) AI. Henrici, Ondersfepoovl J . V e t . Research, 26, 4 5 (1952). (3) C. A . Jacobson, THISJ O U R N A L , 4 1 , 640 (1919). (6) F.Boas and R. Steude, Angew. Botoitik, 18, 16 (1936). ( 7 ) R . Jaretzky a n d W . Lindner, A v i h . Pitarm.. 277, 4.5 (1939). (8) R.Jaretzky, Annrro. R o l n n i k , 22, 147 ({(NO) (9) Burt U' Heywang. P o i ~ l l r ? ,. C c i . , in / , r e s . (IO) I. 1.. 1.indnlil. 4 C C o o k , 11. I < . D a v i s ;ind W. 1). Al:iclay, . S f i u i ? r u , 1 1 9 , 157 (1934), (11) D. 11. I