666 THE BIOCHEMISTRY OF B VITAMINS 



This is also indicated by the activity of the analogue in replacing the 

 vitamin in the nutrition of rats (Table 35). 



2-Methyl-3-hydroxy-4-ethoxymethyl-5-hydroxymethylpyridine is re- 

 ported to inhibit the growth of excised tomato roots. 24 



Other Analogues of Pyridoxine. Both 2-methyl-3-amino-4-hydroxy- 

 methyl-5-aminomethylpyridine and the corresponding 4-ethoxymethyl 

 analogue are inhibitory for Ceratostomella ulmi, and the toxicity is pre- 

 vented by sufficient pyridoxine. The inhibition indices are 250 and 2500, 

 respectively. 25 A homologue of the last compound, 2-ethyl-3-amino-4- 

 ethoxymethyl-5-aminomethylpyridine, prevents the stimulatory action of 

 pyridoxine for Saccharomyces cerevisiae. 70 For relatively high concentra- 

 tions the inhibitor appears to prevent the stimulatory action of an 

 equivalent amount of pyridoxine. Growth, however, is never completely 

 prevented by the analogue. 70 



Another inhibitory analogue of pyridoxine has been reported 70 to be 

 2-methyl-3-hydroxy-4-hydroxymethylpyridine ; however, this compound 

 is actually derived from 2-picoline by sulfonation, fusion of the sulfonate 

 with alkali, conversion to a dialkylaminomethyl derivative by the Man- 

 nich reaction and hydrolysis to a (hydroxymethyl)picolinol. The inter- 

 mediate hydroxypicoline has been shown to be 6-methyl-3-hydroxy- 

 pyridine. 78, 79 Consequently, this analogue probably is 6-methyl-3- 

 hydroxy-2(or 4) -hydroxymethylpyridine. The analogue prevents the 

 stimulatory action of pyridoxine on Saccharomyces cerevisiae at a molar 

 ratio of 250. 70 A similar revision of structure is necessary for a group of 

 (dialkylaminomethyl) picolinols prepared even earlier by analogous re- 

 actions. 80 



2-Methyl-3-hydroxy-5-hydroxymethylpyridine has been reported to 

 be slightly inhibitory. 81 - 82 Numerous other analogues have been pre- 

 pared 81, 82 including some pyrimidine analogues 83, 84 of pyridoxine, but 

 neither growth-promoting nor growth-inhibiting properties have been 

 reported for these compounds. 



Irradiation of pyridoxamine under aerobic or anaerobic conditions 

 produces a mixture with antibacterial properties. 85 The active principle 

 inhibits the growth of a wide variety of gram-negative organisms. The 

 effect of the vitamin B 6 group on the inhibition has not been determined. 85 



Bibliography 



1. Goldberger, J., and Lillie, R. D., U. S. Pub. Health Service Pub. Health Rept., 



41, 1025 (1926). 



2. Gyorgy, P., Nature, 133, 498 (1934); Biochem. J., 29,, 741, 760, 767 (1935). 



3. Kuhn, R., and Wendt, G., Ber., 71, 780, 1118 (1938). 



4. Lepkovsky, S., Science, 87, 169 (1938). 



