Gooseberry Varieties Research Articles

Occurrence of Shikimic Acid in Gooseberry Fruits

IN a recent survey of the organic acids of fruits, shikimic acid has heen found in considerable amount in each of the varieties of gooseberry examined. Aqueous extracts of unripe fruits of the varieties Leveller, Careless and Whinham's Industry, after precipitation of pectin with 60 per cent acetone, were investigated by paper chromatography using the following three solvents: (1) benzyl alcohol–iso-propyl alcohol – tert.-butyl alcohol – water – formic acid (3:1:1:1:2 per cent)1, (2) n-propyl alcohol – cone. ammonia (70:30)2, (3) phenol – water – formic acid (3:1:1 per cent)1. In addition to malic and citric acid spots, a third spot (A) was observed with RF values in solvents (2) and (3), 0.17 and 0.58 respectively, identical with those of shikimic acid; citric acid and shikimic acid do not separate in solvent (1). Spot A separated from quinic and dihydroshikimic acids in solvent (3)3, RF values 0.58, 0.50 and 0.66 respectively, and rapidly gave a greenish-yellow colour at room temperature on spraying with sodium metaperiodate followed by sodium nitroprusside and piperazine4. This reagent is so far only known to give a reaction with quinic, shikimic and dihydroshikimic acids3. It has now been found that shikimic acid reacts at room temperature within a few minutes, while the other acids react more slowly. This observation is an additional aid to identification.