Structures of Gibberellins A₃₉, A₄₈, A₄₉ and a New Kaurenolide in Cucurbita pepo L.

Abstract

The structures of three new gibberellins A₃₉, A₄₈ and A₄₉, and a new kaurenolide, isolated from seeds of Cucurbita pepo L., were elucidated. The structures of GA₃₉, GA₄₈ and GA₄₉ were shown to be ent-3α, 12β-dihydroxygibberell-16-ene-7, 19, 20-trioic acid (1), ent-2α, 3α, 10, 12α-tetrahydroxy-20-norgibberell-16-ene-7, 19-dioic acid 19, 10-lactone (5) and the epimer at C-12 of GA₄₈ (8), respectively. The kaurenolide was shown to have the structure: ent-6β, 7α, 12β-trihydroxykaur-16-en-19-oic acid 19, 6-lactone (14).