Formation of β-Galactosyl Compounds of Arabinosylcytosine in Growing Culture of Sporobolomyces singularis

Abstract

Two new compounds of 1-β-D-arabinofuranosylcytosine (ara-C) were found to be produced in a high yield in a culture filtrate of Sporobolomyces singularis, when grown on a medium containing lactose and ara-C. The compounds I and II were obtained as white needle crystals from the culture filtrate by preparative paper chromatography, gel-filtration on Sephadex G-10 and Toyopearl HW-40S, lyophilization, and ethanol treatment. The compounds I and II were identified as 3'-O-(β-D-galactopyranosyl)-ara-C and 3'-O-[β-D-galactopyranosyl-(1→4)-O-β-D-galactopyranosyl]-ara-C, respectively, on the basis of the various experimental results, viz., elementary analyses, UV, IR, 1^H-, and <13>^C-NMR spectra, and products by hydrolysis with α- and β-galactosidases. Also, the yeast produced a large amount of 3'-O-β-galactosyl compounds of adenosine and inosine in the culture filtrate when grown on a medium containing lactose and their ribonucleosides.