THE CONVERSION OF C14-LABELED SUGARS TO l-ASCORBIC ACID IN RIPENING STRAWBERRIES

Abstract

The labeling patterns exhibited by n-ascorbic acid,l free glucose, sucrosederived glucose, and free xylose from detached ripening strawberries administered glucose-1-CY4, glucose-2-C14, or galactose-l-Cl4 have been reported in previous papers (1, 2).The present report communicates the patterns found in ascorbic acid and other carbohydrate components of detached ripening strawberries that had been stem-fed arabinose-l-Cl4 or xylose-1-CY4. MaterialsArabinose-1-CY4, 1.7 PC. per mg., and xylose-1-CY4, 1.2 PC. per mg.2 were obtained from Dr. H. S. Isbell, National Bureau of Standards.The strawberries used in these experiments were obtained from the Gill Tract of the University of California through the kindness of Professor S. Wilheim.Analytical grade reagents were employed throughout these experiments. MethodsIncorporation of Cl4 Sugars into Strawberries---The method employed in labeling the strawberries has already been described (1).In Experiment 16 a green berry weighing 11.4 gm. was stem-fed 10.3 PC. of arabinose-l-Cl4 over a 24 hour period, followed by an additional 24 hours of respiration with the stem in distilled water.At the end of this time it had gained 0.5 gm. and was uniformly pink in color.