Yeast phenylalanine tRNA contains a fluorescent base adjacent to its anticodon. This base has attracted the interest of a great many workers in view of its significant role and fluorescence, but scarcity of material had prevented its structural elucidation. We have been able to propose a structure on the basis of spectroscopic properties obtained with ca. 300μg of material and model syntheses. The proposed structure has now received full support by a total synthesis of the racemic Y base. Moreover, the absolute configuration has been established by ozonolysis of a natural Y base to a compound which in turn has been prepared from S-(+)-glutamic acid. In addition, the rare hydroperoxide containing structure has been forwarded for a similar fluorescent base contained in livers of rat, calf, beef, chicken and in wheat germ. Presence of this hydroperoxy-Y also had already been noted by many workers, but nothing was known pertaining to its structure.
