Abstract
(1) Besides rubiginol, two substances of positive ferric chloride reaction were isolated from the culture liquid of Glu-conoacetobacter liquefaciens with a medium of 0.8% yeaet extract water containing 9.3% glucose and 2.5% calcium carbonate.
(2) One of them was found to be a new γ-pyrone derivative and was named rubiginic acid. It was isolated in the shape of prismatic needles and decomposes at 230°C. It gives a reddish violet color reaction with ferric chloride solution and reduces Fehling's and ammoniacal silver nitrate solution weakly, and decolorizes bromine water and potassium permanganate solution. Its molecular formula is. C6H4O6 and one mole rubi-ginic acid decomposed to one mole rubiginol with the liberation of one mole carbon dioxide by heating at 230°C or boiling with conc. hydrochloric acid. The composition of rubiginic acid was concluded to be 3, 5-dihydroxy-1, 4-pyrone-2-carboxylic acid.
(3) Another substance of positive ferric chloride reaction was identified as comenic acid.
(4) The quantities of these substances formed were very little. From 140g of glucose, about 1.2g of rubliginol, 0.6g of rubiginic acid, and 0.5g of comenic acid were obtained.
