title: Examination of the structure of an unknown green fluorescent compound, compound G2, accumulated in non-growing cells of Eremothecium ashbyii by the addition of dimeric diacetyl.
abstract: The addition of dimeric diacetyl to Eremothecium ashbyii caused simultaneous accumulation of two green fluorescent compounds with the inhibition of riboflavin formation in non-growing cells. One compound, referred to as Compound G1, was identified as 6, 7-dimethyl-8-ribityllumazine as reported previously and the other is referred to as Compound G2. The latter compound was considered to be 6-methyl-7-(2-hydroxy-2-methyl-3-oxobutyl)-8-ribityllumazine because a violet fluorescent compound, 6-methyl-7-hydroxy-8-ribityllumazine was derived from Compound G2 in the presence of p-quinone and because the known action mechanism of dimeric diacetyl as a trapping agent of possible intermediates in the biosynthetic pathway. The results indicate that an immediate intermediate to 6, 7-dimethyl-8-ribityllumazine in the biosynthetic pathway of riboflavin is 4-ribitylamino-5-amino-2, 6-dihydroxypyrimidine, whose pyrimidine portion is derived by the elimination of a dimeric diacetyl fragment from the molecule of the isolated lumazine.
mesh_terms: D001203:Ascomycota / Q000378:metabolism*; D002074:Butanones / Q000494:pharmacology*; D003931:Diacetyl / Q000494:pharmacology*; D005453:Fluorescence; D011621:Pteridines / Q000378:metabolism; D011743:Pyrimidines / Q000302:isolation & purification / Q000378:metabolism*; D012256:Riboflavin / Q000096:biosynthesis; D012266:Ribose / Q000031:analogs & derivatives / Q000378:metabolism; D004718:Saccharomycetales / Q000378:metabolism*; D013053:Spectrophotometry
chemical_list: D002074:Butanones; D011621:Pteridines; D011743:Pyrimidines; D012266:Ribose; D003931:Diacetyl; D012256:Riboflavin