GA12-aldehyde obtained from mevalonate via ent-kaurene, ent-kaurenol, ent-kaurenoic acid and ent-7α-hydroxykaurenoic acid in a cell-free system from immature seeds of Cucurbita maxima was converted to GA12by the same system. When Mn2+was omitted from the system GA12-aldehyde and GA12were converted further to several products. Among these GA15, GA24, GA36and GA37were conclusively identified by GC-MS. With the exception of GA37these GAs have not previously been found in higher plants. Another biosynthetic pathway led from ent-7α-hydroxykaurenoic acid to very polar products via what was tentatively identified as ent-6α, 7α-dihydroxykaurenoic acid. An unidentified component with an MS resembling that of a dihydroxykaurenolide was also obtained from incubations with mevalonate. © 1974.
Graebe, J. E., Hedden, P., Gaskin, P., & MacMillan, J. (1974). Biosynthesis of gibberellins A12, A15, A24, A36, and A37by a cell-free system from Cucurbita maxima. Phytochemistry, 13(8), 1433–1440. https://doi.org/10.1016/0031-9422(74)80304-3