Microbial transformation of 18-hydroxy-9,13-epi-ent-pimara-7,15-diene by Gibberella fujikuroi

• Published in: Journal of natural products (Washington, D.C.) Vol. 66; no. 3; pp. 392 - 397
• Main Authors: Fraga, B.M, Gonzalez, P, Hernandez, M.G, Chamy, M.C, Garbarino, J.A
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 01.03.2003; Amer Chemical Soc
• Subjects: 18-hydroxy-9,13-epi-ent-pimara-7,15-diene; Biotransformation; chemical structure; Chemistry, Medicinal; Diterpenes - chemistry; Diterpenes - metabolism; diterpenoids; epoxidation; epoxides; Gibberella - chemistry; Gibberella - metabolism; Gibberella fujikuroi; Gibberellins - chemistry; Gibberellins - metabolism; hydroxylation; isomers; Life Sciences & Biomedicine; metabolites; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; oxidation; Oxidation-Reduction; Pharmacology & Pharmacy; Plant Sciences; Science & Technology; spectral analysis; stereochemistry; Stereoisomerism
• ISSN: 0163-3864; 1520-6025
• DOI: 10.1021/np020457h

The incubation of the diterpene 18-dihydroxy-9,13-epi-ent-pimara-7,15-diene (3) with the fungus Gibberella fujikuroi gave 14 metabolites, 4 and 6-18. The carbons functionalized were the C-20 methyl and all the secondaries, except C-12. The main reaction observed was the epoxidation of the 7,8-double bond, which rearranged to form 7-keto derivatives, such as 10-17, or the allylic alcohol 18. Compound 9 was the only one obtained in which the 7,8-double bond of the substrate remained unaltered. This work confirms that, in the feeding of this type of diterpene with this fungus, the oxidation at C-19, typical of the biosynthesis of gibberellins from ent-kaur-16-ene, is inhibited.