Abstract
This experiment is a preliminary work to explore the organic acid metabolism of paddy rice plant. Leaf blades (50 g) of paddy rice in a head sprouting period were sampled on a fine day morning. These leaves were instantly homogenized by Waring Blender and mortar, then filtered through cheese-cloth. The filtrate was centrifuged at 3000 r.p.m. for 30 minutes. Sediments were dealt with cation exchanger, and then centrifuged. Both supernatants of centrifugations above mentioned were put together, then dealt with anion exchanger under an analogous method to that of BRYANT et al. Acid fraction thus obtained (3.17 m eq.) was exactly neutralized and concentrated under reduced pressure. Half of this acid mixture was chromatographed on a silica gel in the BULEN et al's method. Obtained chromatogram is shown in Fig. 3. The other half of the acid fraction was chromatographed on another column of silica gel containing no sulfuric acid. This chromatogram is shown in Fig. 4. Fig. 1 is a typical chromatogram obtained with a mixture of several pure acids and Fig. 2 is that of BULEN et al. By comparing with Fig. 1 and 2,each fraction of Fig. 3 and 4 may be roughly identified, however, this estimation cannot be conclusive. Then the authors undertook the procedure of paper chromatography to verify the estimation. Table 1,2,and 3 show the results of such paperchromatography. From these experiments, it is conceived that the following organic acid are conclusively contained in leaf-blade of matured rice-plant. 1) Lactic acid 2) Oxalic acid 3) Succinic acid 4) Fumaric acid 5) Malic acid 6) Citric acid.
