IDENTIFICATION OF MYOINOSITOL AS A MAJOR CARBOHYDRATE IN KIWIFRUIT, ACTINIDIA-DELICIOSA

Kiwifruit plants contain unusually high levels of inositol at 20% of t otal soluble carbohydrate in the leaves through the season, and up to 40% of total soluble carbohydrate in parts of the fruit during mid-dev elopment. Fruit inositol content falls to 1-2% at full ripeness, mainl y through large increases in the sugars rather than inositol utilisati on. Kiwifruit inositol was purified by Ca++-complexation chromatograph y and was obtained as a crystalline product. It was optically inactive , gave a C-13 NMR pattern identical to authentic inositol, and the sam e reaction rates as myo-inositol (but not other isomers) with myo-inos itol dehydrogenase. We conclude that inositol is present in kiwifruit as the myo-isomer, and discuss its possible significance in kiwifruit physiology. (C) 1997 Elsevier Science Ltd. All rights reserved.