June, 1943
COMMUNICATIONS TO THE
EDITOR
1247
presented later, together with a discussion of the lytic agent for digestion of the starch of wheat or molecular structure. rye or of their flours may be of pronounced phyDEPARTMENT OF CHEMISTRY LESTERGUTTMAN siological significance. As far as starch is conL TOF CALIFORNIA ~ EDGAR ~ F. WESTRUM, ~ JR. ~ ~ the recognized ~ ~ ~ ~ and cerned, high nutritive value I ~ E R K E L E Y ,CALIFORNIA KENNETHS. PITZER digestibility of these cereals must be attributed to RECEIVED OCTOBER19. 1942 actions in regions of the digestive tract other than the mouth. The finding likewise has industrial AN AMYLASE INHIBITOR FROM CERTAIN CEREALS significance, since bacterial amylases may be used Sir : as “pre-malting” agents in the current expansion In the course of an investigation of the action of of alcohol production from grain. lndications salivary amylase on native wheat starch granules, are that a t least certain bacterial amylase preparai t was observed that starch degradation did not tions, while entirely satisfactory for pre-malting occur when the wheat berry was crushed in a corn, would not be as applicable in the liquefacsolution of human saliva. Degradation was rapid tion of unautoclaved wheat mashes. Experimental data relative to the above diswhen starch prepared from similar grain was thus treated, but it again was inhibited by adding to it cussion are being prepared for publication and the wash liquid obtained during starch extraction. work in progress is designed to provide additional Further studies indicated that wheat grain con- information relative to the nature and mode of tains a water-soluble, protein-like substance which action of the inhibiting substance. OF AGRICULTURAL CHEMISTRY has a powerful inhibitory action on salivary, pan- DEPARTMENT UNIVERSITY OF NEBRASKA ERICKNEEN creatic, and most bacterial amylases. The sub- LINCOLN, NEBRASKA R. M. SANDSTEDT stance inhibits the action of these enzymes both RECEIVED MAY10, 1943 on gelatinized and native (raw) starch. No inhibition was observed with two commercial amylSTEROLS. CLIV. SAPOGENINS. LXVI. THE ase preparations, supposedly of bacterial origin, SAPOGENIN OF TRIGONELLA FOENUMnor with fungal nor cereal malt amylases. The GR AE C U M sensitive amylases varied in their response; under Sir : comparable conditions equal amounts of the inIn the course of our plant studies during the hibitor gave reductions in starch dextrinization past year we have found two hundred new sources rates of S2Y0 for salivary amylase, 48% for bac- for steroidal sapogenins. Among the plants interial amylase, and 23Y0 for pancreatic amylase. vestigated was Foenugreek seed, Trigonella FoeThe inhibiting substance is soluble in water num-Graecum. Recently, Soliman and Mustafa and in dilute salt and dilute ethanol solutions but [Nature,151, 196 (1943)l have reported that the insoluble in petroleum ether. High levels of am- sapogenin fraction from this plant contains an monium sulfate or of ethanol give precipitates that unknown sapogenin, m. p. 198”, of thecomposition are active when redissolved in water. The subC27H4203, having one free hydroxyl group and two stance is retained by a cellophane dialysis mem- inert oxygen atoms. These authors state the sapobrane. In water solution i t is quite thermostable, genin “belongs to the sarsasapogenin group of sapobeing little affected by temperatures up to 90’. genins and its structure is now the subject of study.” However, autoclaving for thirty minutes a t 15 We wish to report that we have identified the lb. pressure causes complete loss of inhibiting sapogenin of Trigonella Foenum-Graecum as diosproperties. genin, m. p. and mixed m. p. 202” (Anal. Calcd. Reaction of the inhibitor with the amylase is for C2,H4203: C, 78.2; H, 10.2. Found: C, 78.3; reversible ; differential alcohol solubilities have H, 10.1). Acetylation with boiling acetic anhybeen utilized to separate a combination of the two dride gave diosgenin acetate, m. p. and mixed m. p. into active inhibitor and active amylase. 199” (Anal. Calcd. for C29H4404: C, 76.3; H. The inhibitor was found in all samples of wheat 9.7. Found: C, 76.2; H, 9.5). and rye tested and one of similar properties in RUSSELLE. MARKER certain of the sorghums. Amylase inhibitors could SCHOOL OF CHEMISTRY AND PHYSICS R. B. WAGNER STATE PAULR. ULSHAFER not be detected in barley, oats, maize, rice, or most THEPENNSYLVANIA COLLEGE DALEP. J. GOLDSMITH of the sorghums. STATECOLLEGE, PENNA. CLARENCE H. RUOF The inefficiency of human saliva as a hydroRECEIVED APRIL12, 1943
