NATURAL WAXES 



353 



into the hormone, progesterone, offers further proof of the postulated 

 structure."^^^"^''^ 



Stigmasterol was first isolated as a component of the non-saponifiable 

 fraction of the oil of the deadly calabar bean'^* {Physostigma venenosum). 

 It is also a prominent component in the oil of the kidney bean (Phaseolus 

 vulgaris) y"^^^ as well as of corn, coconut, rapeseed, rice bran, and soybean oils. 

 The properties of some of its estei's and their derivatives are included in 

 Table 7. 



Table 7 

 Properties of Some Stigmasterol Derivatives 



Stigmasteryl 



ester Formula M.p., °C. Remarks 



-acetate 

 -acetate- 

 dibromide 



C29H470-OCCH3 



C29H47Br20-OCCH3 



-acetate- CssHitBi-jO • OCCH3 

 tetrabromide 



-benzoate C29H47O • OCCeHj 



-palmitate C29H4rO-OC(CH2)uCH3 



-stearate C29H470-OC(CH2)i6CH3 



-oleate C29H470-OC(CH2)7- 

 CH:CH(CH2)7CH3 



144.0-144.6 

 132-135 



205 



160 



99 



101 



44 



White (Schaffer) 



White needles, more readily sol. 



than acetate. From acetate 



in CHCI3 .sol. with Br in cold 



Produced from acetate in acetic 



acid ether sol. with Br 



From CHCI3 



Difficultly sol. in ethanol 



Difficultly sol. in ethanol 



c'. Brassicasterol : Brassicasterol is a doubly unsaturated sterol first 

 isolated from oil of turnip (Brassica rapa) by Windaus and Welsch,"^ 



CH-CH = CH-C — CH — CHj 



I 

 H 



Brassicasterol 



which was first thought to be isomeric with stigmasterol,^"* even though 

 the brassicastanol differs from stigmastanol.^^* However, Fernholz and 

 Stavely'-'*^ later reformulated the structure to the C28 order (C28H46O) and 



2" E. Fernholz and P. N. Chakravortv, Bei., 67, 2021-2026 (1934). 



"2 A. Butenandt, U. Westphal, and H. Cobler, Ber., 67, 1611-1616 (1934). 



2" E. Fernholz, Ber., 67, 2027-2031 (1934). 



2-^ A. Windaus and A. Wel.sch, Ber., 42, 612-616 (1909). 



2" IC. Fernholz and H. E. Stavely, J. Am. Chem. Soc, 61, 142-143 (1939). 



2'6 E. Fernholz and H. E. Stavelv, J. Am. Chem. Soc, 62, 428-430, 1875-1877 (1940). 



