title: The microbiological transformation of two ent-16 beta,17-epoxykaurane derivatives by Gibberella fujikuroi.
abstract: The biotransformation of ent-16beta-17-epoxy-7 alpha-hydroxykaurane by Gibberella fujikuroi affords ent-7 alpha,11 alpha,16 beta,17-tetrahydroxykaurane and ent-7 alpha, 9 alpha, 16 beta, 17-tetrahydroxykaurane. These results indicated that the presence of the 16 alpha, 17-diol group, into which the 16 alpha, 17-epoxy is transformed in the medium, inhibits oxidation at C-19 and favours hydroxylation at C-11(beta). Incubation of ent-16 beta, 17-epoxykauran-19-oic acid, via the 16 alpha, 17-diol, gave the 7-aldehyde of 16 alpha, 17-dihydroxy-GA12.
authors.affiliation: Instituto de Productos Naturales y Agrobiología, La Laguna, Canary Islands, Spain.
authors.forename: B M
authors.initials: BM
authors.lastname: Fraga
authors.forename: P
authors.initials: P
authors.lastname: González
authors.forename: R
authors.initials: R
authors.lastname: Guillermo
authors.forename: J R
authors.initials: JR
authors.lastname: Hanson
authors.forename: M G
authors.initials: MG
authors.lastname: Hernández
authors.forename: J A
authors.initials: JA
authors.lastname: Takahashi
mesh_terms: D001711:Biotransformation; D004224:Diterpenes / Q000378:metabolism*; D045786:Diterpenes, Kaurane; D005874:Gibberella / Q000378:metabolism*; D005875:Gibberellins / Q000096:biosynthesis; D009682:Magnetic Resonance Spectroscopy
chemical_list: C091396:7,11,16,17-tetrahydroxykaurane; C091397:7,9,16,17-tetrahydroxykaurane; D004224:Diterpenes; D045786:Diterpenes, Kaurane; D005875:Gibberellins; C007842:gibberellic acid