INCORPORATION OF GLUCOSE-U-C14, GLUCOSE-1-C14, AND GLUCOSE-6-C14 IN VITRO INTO THE PROTEIN-BOUND AMINO ACIDS OF ONE DAY-OLD MOUSE BRAIN

The incorporation of formate-C14, glycine-2-C14, adenine-4, 6-C14, and phosphate-P32 into nucleic acids.

nine labeled either with C'4 or N'5. Considerable controversy has developed as to which one of these tracer compounds gives an accurate measurement of the “relativeturnover-rate― of the nucleic acids. In order to determine the “absolute turnover rate― of the nucleic acids, it is necessary to know the specific activity of the immediate precursor of the nucleic acids. Since even the ident...

Synthesis of D-Glucose-1-C14 and D-Mannose-1-C14

Heretofore, radiochemical yields of sugars position-labeled with carbon-14 have been only 5 to 10 percent. This paper reports an improved cyanohydrin synthesis, and the preparation of D-glucose-1-C and D-mannose-1-C from D-arabinose in yields of about 50 percent. Low yields in prior syntheses appear to have been due to several inefficient steps, and to the fact that extension of the carbon chai...

Conversion of glucose-1-C14 to pectin in the boysenberry.

Many authorities believe that pectins play a dominant r&e in the changes in texture of fruits during the ripening process, although the origin and fate of pectic substances in plant tissues are unknown ((1) p. 273). There is no evidence that in nature pectic substances are formed directly from galactose or galactan ((1) p. 277). To obtain some insight into the mechanism of pectin formation, glu...

The biosynthesis of glucuronic acid from 1-C14-glucose.

Although many classes of substances found in the animal organism have been suggested as possible biological precursors of glucuronic acid (l), recent research has narrowed the number of these possibilities to two, namely hexoses (2,3) and trioses (4, 5). Various experimental techniques, including isotopic tracers, have been used in the effort to choose between these alternatives, but invariably...

Conversion of DL-lactate-2-C14 or -3-C14 or pyruvate-2-C14 to blood glucose in humans: effects of diabetes, insulin, tolbutamide, and glucose load.