Gibberellins in immature seed of Prunus cerasus: Structure determination and synthesis of gibberellin, GA 95 (1,2-Didehydro-GA 20)

Abstract

Ten C-13-hydroxylated gibberellins (GA 3, GA 17, GA 19, GA 20, GA 32, GA 44, GA 86, GA 87, GA 95 and GA 95 isolactone) and two C-13-deoxy-GAs (GA 25 and GA 30) were identified in immature seeds of sour cherry ( Prunus cerasus L. cv. Montmorency) by GC-mass spectrometry. GA 95 is a new GA whose structure was determined to be 1,2-didehydroGA 20 by GC-mass spectral comparison with an authentic sample, synthesized from GA 3. In addition, six unknown GA-like compounds were detected by GC-mass spectrometry. It remains unclear whether GA 95 isolactone was an artefact. On the basis of the structures of the endogenous GAs and the absence of GA 5, the sequence of GA 20 → GA 95 → GA 3 → GA 87 → GA 32 could be conceived of as a possible biosynthetic pathway.