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‘COMMUNICATIONS TO THE EDITOR
VOl. 72
111, R = H IV, R = C&CO--
C, 77.81; H, 7.67). The smooth nitration furnished VII, identical with the product from I (pale yellow prisms, m. p. 142’. Anal. Calcd. for CBH1403N1:C, 63.41; H, 5.7. Found: C, 63.57; H,5.96). Further reactions and rearrangements in this series will be reported shortly.
present finding would favor the latter view. Since the folic acid antagonist leads to the accumulation of the same imidazole as do the $-aminobenzoic acid antimetabolites, the latter presumably act by creating a ddciency of folic acid, which in turn is responsible for the failure in purine formation. The demonstration was conducted as follows: E . coli was grown in the manner of Stetten and CONVERSE MEMORIAL LABORATORY HARVARD UNIVERSITY J. B. PATRICK* Fox’ except that sulfadiazine was omitted and 0.2 CAMBRIDGE, MASSACHUSETTS BERNHARD WITKOP$ mg. per cc. of 4-aminopteroylglutamic acida was RECEIVED NOVEMBER 13, 1949. added. Judged colorimetrically, about the same amount of diazotizable amine accumulated as * Harvard University Graduate School. when sulfadiazine was the inhibitor. Isolation of $ Harvard University Faculty 194%. the base was accomplished as in1 except that 2.5 times as much mercury salt was used and the FORMATION OF 4-AMINO-5-CARBOXAMIDOIMI- ether extraction was omitted. Final separation DAZOLR DURING GROWTHOF ESCHERICHIA COLI was made on paper strips with butanol-diethylene IN THE -PRESENCE OF 4-AMINOPTEROYL__ ~-~ glycol-water solvent, in an atmosphere containing GLUTAMICACID ammonia,’ in which the imidazole showed Rp of sir: 0.5. Identity of the isolated substance with synWhen Escherichia coli is grown in the presence thetic 4-amino-5-carboxamidoimidazole8was esof amounts of 4-aminoptero~flglutamicacid just tablished by comparison of (a) the Rp in the sold c i e n t to inhibit multiplication slightly, 4- vent just mentioned, (b) the absorption spectra amino-5-carboxamidoimidazoleaccumulates in the in the ultraviolet region a t pH 2.0 and 11.0, and medium, and has been isolated from it. This is the (c) the melting points (with decomposition) of the same substance which was found by Stetten and picrate. In every case the behavior of the known Fox1 when this and other bacteria were grown in and the unknown was the same. the presence of sulfadiazine or sulfapyridine. It THEROCKEFELLER INSTITUTE D. W. WOOLLEY was identified by Shive, et a1.,2and recognized as FOR MEDICAL RESEARCH R. B. PRINGLEg N. Y . the probable precursor in the biosynthesis of hy- NEWYORK, poxanthine. RECEIVED DECEMBER 7.1949 The accumulation of the imidazole through the (6) Kindly made available by Dr. T H. Jukes of Lederle Laboraintervention of the antimetabolite of folic acid is tories. (7) E. Vischer and E. Chargaff, J . Bioi. Chcm., 176, 703 (1948) of importance in consideration of the mode of ( 8 ) E. Shaw and D. W. Woolley, ibid., 181, 89 (1849). action of sulfonamide drugs and of folic acid. (9) Fellow of the National Institutes of Health Thus, inhibition analysis has led to the conclusion that p-aminobenzoic acid participates in several reactions, of which the first to be affected by SPECIFICITY OF UREASE ACTION sulfanilamide derivatives is the formation of Sir: methionine, the next is concerned with purine Urease has been repeatedly cited’ as a strictly formation,* and less sensitive processes, presumspecific enzyme which hydrolyzes only urea. In ably the synthesis of folic acid,4 are then retarded. the course experiments with substances related On the other hand, Woods6 has concluded that to urea weofhave hydrolysis of biuret the primary action of the sulfonamides is the in- HP,N-C-NH-C-NHZobservedbya urease preparations. hibition of folic acid formation, and that syntheIt 11 sis of purines and of methionine are secondary 0 0 events in which that vitamin participates. The As much as 33% of nitrogen initially contained (1) M. R. Stetten and C. L. Fox, J . Bioi. Chcm., 161, 333 (1948). in solutions of biuret was identified as ammonia (2) W. Shive, W. W. Ackermann, M. Gordon and M. E. Get(by Nessler technique2) after prolonged enzycendaner, Tms JOURNAL, 69,725 (1947). (3) W. Shive and E. C. Roberts, J . Bioi. Chcm., 182, 462 (1946). (4) K. C Winlder and P. G. de Haan, Arch Biochcm.. 18, 97 (1948). (8) D.D.wwdr, ~ u l la. ~ cbim. . bid., ao, 730 ( l o w .
(1) Sumner and Sommas, “Enzymes,” Academic Press, New York, N. Y., p. 156. (9) Ambrose, P;istt.korrkr and Kridl. Tnri JOUBNAL, 99, a17
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