FORMATION OF GUANINE RIBONUCLEOTIDYL-(3'-5')-ADENOSINE IN A FLAVINOGENIC STRAIN OF EREMOTHECIUM ASHBYII

Abstract

The addition of caffeine caused the accumulation of a new nucleotide compound simultaneously with the rigid inhibition of ribo flavin production in non-growing cells of Eremothecium ashbyii. In the present study we tried to identify the structure of the nucleotide compound using non-growing cells of the mold.
1) It became possible to obtain a large amount of mycelia by massculti vation in a reagent tank.
2) A new nucleotide compound, referred to as compound A in the paper, was extracted with perchloric acid solution and purified by the following subsequent procedures: 1) Dowex 1×2 (HCOO^-) column, 2) charcoal treatment, 3) DEAE-Sephadex A25 (Cl^-) column, 4) Dowex 1×2 (Cl^-) column, and 5) DEAE-Sephadex A25 (HCO₃^-) column.
3) The structure of the new nucleotide compound was proved to be guanine ribonucleotidyl-(3'-5')-adenosine (G_pA) from the results of the following analyses: 1) alkaline degradation, 2) UV-spectra, IR-spectra and NMR-spectra, and 3) enzymatic treatments with RNase T2 and phosphodiesterase.
4) The roles of caffeine and guanine ribonucleotidyl-(3'-5')-adenosine in connection with flavinogenesis of this mold were discussed.