Methanol → Pantoic acid

Participants

Reaction Conditions

Reaction Steps

A liquid medium (pH 6.5) consisting of 1% glucose, 0.5% peptone, 0.5% yeast extract and 0.5% corn steep liquor was dispensed in 5 ml portions into test tubes, and then heat-sterilized by autoclaving at 121° C. for 20 minutes. The various strains mentioned in Table 1 were each inoculated from slants into the medium in the test tubes, and subjected to aerobic shake culture at 28° C. for 5 days. After the cultivation, cells were collected by filtration. Into containers each containing different collected cells was dispensed a 2% D,L-pantolactone solution in Tris-HCl buffer (pH 7.5) in 2 ml portions, and the containers were shaken overnight at 28° C. After the reaction, cells were removed by filtration, and each reaction liquid was subjected to HPLC (Nucleosil 5C18 φ 4.6×l 150 mm; eluent 10% methanol; rate of flow 1 ml/min; wavelength for detection 230 nm) to determine the decrease in pantolactone and the amount of pantoic acid formed. Unreacted pantolactone in the reaction liquid is separated by extraction with ethyl acetate, and pantoic acid remaining in the reaction liquid is then heated under acidification with hydrochloric acid for lactonization. The resultant D-pantolactone was extracted with ethyl acetate. The optical purity of the D-pantolactone thus obtained from the pantoic acid was measured by GLC (Analytical Biochemistry 112, 9-19 (1981)). The results are as shown in Table 1.

Provenance & Evidence