GIBBERELLINS IN IMMATURE SEED OF PRUNUS-CERASUS - STRUCTURE DETERMINATION AND SYNTHESIS OF GIBBERELLIN, GA(95) (1,2-DIDEHYDRO-GA(20))

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-1 3-deoxy-GAs (GA(25) and GA(30)) were identified in immature seeds of s our cherry (Prunus cerasus L. cv. Montmorency) by GC-mass spectrometry . GA(95) is a new GA whose structure was determined to be 1,2-didehydr oGA(20) by GC-mass spectral comparison with an authentic sample, synth esized from GA(3). In addition, six unknown GA-like compounds were det ected by GC-mass spectrometry. Tt remains unclear whether GA(95) isola ctone was an artefact. On the basis of the structures of the endogenou s 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 biosyn thetic pathway.