抄録
Lately, in Japan, “a crude ustilagic acid” was formed from glucose by Ustilago maydis, and the acid can be used as raw material for synthetic musk, exaltolide, or may be for synthetic polymers.
In this paper, authors have studied about the separation method of methylustilate A and B, obtained by methanolysis of “ustilagic acid”, and also about the quantitative analysis of ustilic acid A and B by potentiometric titration.
By means of column chromatography, using silica gel absorbed with 7% of water and methanolchloroform (5 : 95) solution as an eluent, good separation was achieved into three fractions, I, II and III. These were confirmed as that I is a mixture of lower fatty acid esters by gas-chromatography and IR-spectra and II (mp 8485°C, no lowering in melting point was seen by mixing with Lemiuexs' sample ; C 67.02%, H 11.41%, νc=0 1738 cm-1) is methylustilate A, and III (mp 73.575.0°C ; C 63.80%, H 10.71%, νcc=0 1714 cm-1 and the same IR-spectra was shown by Lemiuex) is methylustilate B. Ustilic acid A and B were derived and confirmed. Among them, methylustilate A alone showed the characteristic bands in its IR-spectra.
The mixture of ustilic acid A and B could be analysed quantitatively by potentiometric titration of pyridine or dimethylformamide solution of the acids, using tetra-n-butyl-ammoniumhydroxide in iso-propanol as a titrant and a combination electrode of the glass-electrode and saturated calomel reference electrode. In preparation of the sample for analysis, some care must be taken so as to remove lower fatty acids or their methylesters by steam distillation or washing with water. The ratio of ustilic acid A to B in “ustilagic acid” was measured to be 1.81.9.
