Abstract
(1) The alkali- and thermo-stablesubstance indicating vitamin B12 -activity in plant kingdom was confirmed to be a porphyrin-derivative containing Cobalt by paper partition chromatography and bioautography.
(2) Culture experiments on Euglena and Lactobacillus leichmannii with Go-porphyrin-derivative prepared from radish-leaves were always successful by vitamin B12-free basal medium when sup-plemented with 1, 2-diamino-4, 5-dime-thyl-benzene or 5, 6-dimethyl-benzimidazole.
(3) From these results, the physiologi-cal role of Co-porphyrin-derivative as one of the active components effecting on the intermediary motabolism of vitamin B12 seems to be established.
