L-ascorbic acid biosynthesis in higher plants from L-gulono-1, 4-lactone and L-galactono-1, 4-lactone.
Detached bean (Phaseolus vulgaris) and strawberry (Fragaria) fruits fed l-gulono-1,4-lactone or l-galactono-1,4-lactone convert this compound, in part, to l-ascorbic acid. When l-galactono-1,4-lactone is given as a 0.25% solution to detached bean shoots, the ascorbic acid content is tripled in less than 10 hours. l-Gulono-1,4-lactone is only 5 to 10% as effective as its epimer. Experiments with specifically labeled l-gulono-1,4-lactone and l-galactono-1,4-lactone prove that conversion is direct. Ascorbic acid is labeled at the same carbon as its precursor.A method is described for preparation of l-galactono-1,4-lactone-2-(14)C from myo-inositol-2-(14)C. This method can be extended to the preparation of l-ascorbic acid-2-(14)C on the basis of results obtained in the present study.
D001205:Ascorbic Acid / Q000096:biosynthesis*; D002247:Carbon Isotopes; D005638:Fruit; D007783:Lactones / Q000378:metabolism; D010945:Plants, Edible / Q000378:metabolism*; D014574:Uronic Acids / Q000378:metabolism*
D002247:Carbon Isotopes; D007783:Lactones; D014574:Uronic Acids; D001205:Ascorbic Acid