A Crystalline Factor Functionally Related to Folic Acid

Abstract

Communications to the Editor 2299 (m. p. 135°) and a dipicrate (m. p. 206-207°) of ¿¿-sparteine, which they obtained from naturally occurring ¿¿-lupanine. As a further proof of identity, our ¿¿-sparteine was converted to dloxysparteine, m. p. 110-111°, by treatment with alkaline potassium ferricyanide. The melting point of ¿¿-oxysparteine has been reported as 110-111°,6 112-113°,4 1130.7 Finally, the infrared absorption spectra of our synthetic ¿¿-sparteine dipicrate and an authentic sample of ¿-sparteine dipicrate (m. p. 208°) were found to be identical in solution.8We are aware of the desirability of resolving dlsparteine and of isolating the other two racemates of I. We also foresee the applicability of our method to the synthesis of other bases related to sparteine.(8) The authors are indebted to Mrs. James L. Johnson for determination of the infrared absorption spectra.

Anti-B-Vitamins

“…The work of Lampen & Jones (1946 and of Woods (1948) points in the same direction. The observation of Shive et al (1948) that thymidine may be the end product of this reaction further confirms this hypothesis. Thymidine is required by a number of lactobacilli which formerly could not be grown on simple synthetic media (Snell, Kitay & McNutt, 1948).…”

“…T h e action of methylfolic acid was counteracted by thymidine, the desoxyriboside of thymine. This led Shive, Eakin, Harding, Ravel & Sutherland (1948) to suggest that thymidine is the end substrate in the synthesis of which PGA is concerned as part of an enzyme system.…”

Differential Reversal of Inhibitory Effects of Folic Acid Analogues on Growth, Division, and Deoxyribonucleic Acid Synthesis of Microorganisms

“…The fact that thymine is more effective than thymidine in overcoming the inhibitory effects of aminopterin and amino-an-fol on the growth and division of E. coli (strain B) is of interest. The nucleoside is usually considered to be more effective than the free pyrimidine base in counteracting the effects of folic acid deficiency and in reversing the effects of the analogues on bacterial growth (Shive et al, 1948;Martin, 1951). Indeed, Franklin et al (1949) found that thymine had no effect upon the growth-inhibitory action of aminopterin on their strain of E. coli, whereas reversal was obtained with thymidine.…”

The Folic Acid and Serine Nutrition of Leuconostoc mesenteroides P60 (Streptococcus equinus P60)

“…Thymine or thymidine has frequently been found to be a component of mixtures which will support the growth of organisms requiring members of the folic acid group in the absence of these factors. Shive, Eakin, Harding, Ravel & Sutherland (1948) found the inhibition of growth of a strain of Ln. mesenteroides by a methylpteroylglutamic acid to be overcome by thymidine, but not thymine, as well as by ptero ylglut amic acid.…”