Abstract
Slices of unripe avocado fruit placed in 2H2O (45 atom %) synthesized abscisic acid enriched 18.7% with 2H at C-5′. 500 MHz 1H NMR showed that the signal of the axial, 5′-pro-S H atom was decreased by 20%. The signal of the uncoupled, equatorial H atom was 9 Hz upfield owing to shielding from its geminal 2H partner, the reciprocal shielding was 8.9 Hz. The H+ added during cyclization, therefore, is at the C-5′-pro-S position of ABA. Unlabelled ABA leaked into the medium, the newly synthesized, 2H labelled ABA was retained in the tissue.
Original language | English |
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Pages (from-to) | 2641-2642 |
Number of pages | 2 |
Journal | Phytochemistry |
Volume | 28 |
Issue number | 10 |
DOIs | |
Publication status | Published - 1989 |
Externally published | Yes |
Keywords
- H shielding
- abscisic acid
- Avocado
- biosynthesis
- cyclization
- NMR.