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COMMUNICATIONS TO THE EDITOR
Vol. 68
difficulty soluble in water. In contrast the barium salt of the unoxidized starting material is extraordinarily soluble. The methoxyl content of the unoxidized barium salt was 10.4% with a barium content of 12.5y0. The barium salt of the oxidized material has a methoxyl content of 6.4V0 with barium content of 17.2y0. This indicates the cleavage from the anion of a methbxylcontaining fragment during periodate oxidation. From the oxidized material an oxime has been prepared containing 2.7% nitrogen. Complete accounts of these experiments and other studjes now in progress on the periodate oxidation of lignin sulfonic acids and other lignins will be given in future communications.
The ratio of the values of vitamin Bc to the conjugate was determined as 2.72: 1 . With the molecular formula of vitamin Bc established as C19H1906NT (mol. wt. 441.4)5 the above ratio suggests a minimum molecular weight for the conjugate of 1200 (found by diffusion 1400).6 A molecule consisting of one molecule of the vitamin in peptide linkage with a peptide chain consisting of six 1(+)-glutainic acid residues would have the molecular formula C49H~1024N~~ (1216.1). This formulation is in agreement with elementary analytical findings some of which have been reported.' That the conjugate is not a mixture of peptides with an average of 7 glutamic acid residues is evidenced by its homogeneous behavior on PCLPMILLSRESEARCH PROJECT electrophoresis.6 Following the suggested nomenUNIVERSITYOF WASHINGTON DERROLPENNINCTON clature of Angier, et al.,7 vitamin Bc cmjugate SEATTLE 5, WASHINGTON D. M. RITTER may be designated pteroylhexaglutamylglutaniic RECEIVED JUNE 10, 1946 acid. The conjugate is essentially inactive microbioON THE PEPTIDE NATURE OF VITAMIN BC CON- logically, whereas the fermentation L.casei factor TUGATE FROM YEAST reported by Angier, et al.,? to yield 3 moles of Sirs: glutamic acid has high microbiological activity. Demonstration of the peptide nature of the Evidence has been presented to support the view that vitamin Bc conjugate consists of vitamin conjugate identifies the conjugase enzymes* which Rc linked to an ultraviolet-transparent nitro- split the microbiologically active compound from geneous moiety. The non-vitamin Rc portion the conjugate as peptidases. Since conjugases of the molecule has been found to consist of six do not liberate vitainin Bc from the conjugate molecules of 1(+)-glutamic acid in peptide link- methyl ester1 they can be further classified as carboxypeptidases. age. Following hydrolysis ( lSyohydrochlofic acid for J . J . I'FIFFNliR 1). C . CALKINS sixteen hours a t 100") 59.6Y0 of the total N rc- K l i S E A R C l l r2Al10RATORIES E. s.UI,OOM acted as a-amino acid N,2which was accounted for I'ARKli, I)AVIS A N D COMPANY B. L. O'DtiLL as glutamic acid nitrogen by microbiological as- I)ETK(JIT, MICHICAN J U N E 20, 1946 ~ a y . ~From , ~ 298 mg. of conjugate methyl ester -~ RECEIVED 220 mg. of 1(+)-glutamic acid hydrochloride was Our analytical d a t a allowed a choice between C1aIIwOsNr and isolated. [ a I z 4 D +25.4" (5.1% solution in 1 N CxH?aOQNaas the probable molecular formula while our degradation hydrochloric acid; C, 32.75; H, 5 . 6 ; N , 7.8, 7..(biologic:il determinations.
(l~l43)) (6) \Ve wish t o thnnk Dr. J . M. Vandenbelt for the ultraviolet a h s r p t i i m diffusion and electrophoresis determinations. ( 7 ) Angier, et al., S c i e n c e , 113, 667 (1046). (81Uird, Binkley, Llloom, b m m s t t and Phffner, J . B i d . Cheirz.. 157, 413 11345).
