COMMUNICAT~ONS TO THE EDITOR
2824
VOl. 60
This difference is not certain, however, since the correspopding acids mel&at the same point. C It has been generally accepted since the work Sir: sf Tschesche and Bohle [Ber. 69,2497’ (1936)1that We have recently described [THISJOURNAL, 60, digoxig&n and sarmentogenin differ only in the 1493, 2566 (1938)] a series of etiio-cholanic acids confimration at (2-9. Inasmuch as some of the and esters with oxygen atoms a t C-3 and C-12. adrenal steroids contain an oxygen atom which Steiger and Reichstein [Helv. Chim.Acta, 21, 828 corresponds in almost all respects with the inert (1938)] have prepared from digoxigenin a similar oxygen atom of sarmentogenin, it has been asseries of acids which were thought to have oxygen sumed [Marker, THIS JOURNAL, 60, 1725 (1938)] atoms at C-3 and C-IL. Since the S,r-diketo-$- that they had a configuration a t C-9 like that of etio-cholenic acids derived from digoxigenin and sarmentogenin which was supposed to have a cis from corticosterone proved to be different, they linkage of rings B and C instead of the normal or considered it doubtful that a n oxygen atom oc- trans linkage. Marker [THISJOURNAL, 60, 1061 cupied C-11in the acids derived from digoxigenin. (1938)l has made the same assumption €or his Through the courtesy of Professor Reichstein we urane compounds. There is now no need to ashave been able to compare directly the methyl sume such a configuration at 6-9 for sarmentodiketo-etio-cholanates and the methyl diketo-4- genin to explain its difference from digoxigenin, etio-cholenates from the two sources. The re- although such a possibility is by no means exsults given in the table show that the properties cluded. Consequently, such an assumption for of the esters from the two sources are identical. the adrenal compounds has no basis. Indeed, We conclude that Keichstein’s acids are identical all the evidence [Reichstein, Helv. Chim. Acta, 19, with those derived from desoxycholic acid and 402 (1936); 20,978 (1937); 21,161 (193831 points that the inert oxygen atom of digoxigenin, which to a normal steroid skeleton with an oxygen atom was assigned to C-11 by ‘Tschesche and Hohle a t C-11. (Bey. 69, 793 (1936) 1, is actually at C-12. DEFARTXENT OF BIOCE~EMISTRY H. L. MASON
TEZ
GOXI
THEMAYOFOUNDATION
Acid or ester 1 Methyl diketoefio-cholanate 2 Methyl diketo-4elro-cholenate 3 Diketo-eho-cholank acid 4 Dihydroxy - elrocholanic acid 5 Methyl &hydroxycfio-cholanate
From digoxi enin
M. p ,
‘c.
L]lb
171-17Za
138 3 = 2
236-23Sb
163
*2
From desoxycholic acid ?r% P I ‘C [U]zsD 169-170”
162
*3
L36-23ab
100
6
W. M. HOE” ROCHESTER, MINNESOTA RECEIVED OCTOBER22, 1938
ABSENCE OF COMBINED FATTY ACID IN CEREAL, STARCHES
I70
178
Sir:
280-286
283-288
180-183
145-146
The common cereal starches contain fatty material which cannot be extracted by solvents such as petroleum ether, ethyl ether or carbop tetrachloride. From this behavior, T. C. Taylor and his co-workers assumed that the fatty acid must be present as an ester of the carbohydrate substance. His later work indicated that the cyamylose fraction of the starch was characterized by-and owed its insolubility to-this esterification with fatty acid, Recent investigations in these Laboratories show that the fatty acids in corn, wheat and rice starches can be removed completely by Soxhlet extraction with certain water-miscible fat solvents, particularly methanol, the cellosolves, and SOTo dioxane. The de-fatted starch retains its characteristic granule structure and optical birefringence, and gelatinizes in hot water to give a paste of normal high viscosity. By treatment
Mixtures melted at 169-170“. b Mixtures melted a t 236-237’.
4
The other comparisons of the table are less satisfactory since the specific rotations of these compounds of Reichstein were not known and specimens were not available for mixed point determinations. The melting points of the diketo-etio-cholanic aeids are in reasonable agreement, since we have found, as bas Reichstein, that the acid is very difficult to purify. The metbyl dihydroxy-etio-cholanatesappear to be m e r e n t dince the melting point of our ester was sharp and could not be raised by distillation or rccrystadlization. Accepting this difference, epimerism at C-12 is indicated since the configuration of both esters at C-3 is a (no precipitation with digitonin).
