Biotransformation of 7-oxo-ent-kaur-16-ene derivatives by Gibberella fujikuroi

Fraga, Braulio M.; González, Pedro; Hernández, Melchor G.; Suárez, S.

doi:10.1016/j.tet.2005.03.089

Cited by 23 publications

(34 citation statements)

References 19 publications

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“…The formation of a 1-oxo-2-hydroxy group in the biotransformation of 5 is very interesting, being similar to that produced in the incubation of some 7-oxo-ent-kaur-16-ene derivatives to give the corresponding 7-oxo-6 -hydroxy derivatives. 9 We have indicated in previous work the similar results obtained in the biotransformation of 7-oxo-ent-kaur-16-ene derivatives and 3-oxo-13-epient-manoyl oxide (ribenone) by G. fujkuroi giving seco-acids in rings B and A, respectively. 10 Now, a comparable equivalence of both rings is also observed between the ent-kaur-16-ene and 13-epi-ent-pimara-9 (11),15-diene skeletons, which can be explained considering the similarity of the ent-pimaradiene and ent-manoyl oxide carbon frameworks.…”

Section: Resultssupporting

confidence: 77%

Biotransformation of Two ent-Pimara-9(11),15-diene Derivatives by Gibberella fujikuroi

et al. 2009

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The incubation of 19-hydroxy-13-epi-ent-pimara-9(11),15-diene (4) with Gibberella fujikuroi gave 8 alpha,19-dihydroxy-9 alpha,11alpha-epoxy-13-epi-ent-pimara-15-ene (6), 7-oxo-11 alpha,19-dihydroxy-13-epi-ent-pimara-8(9),15-diene (7), 7-oxo-11beta,19-dihydroxy-13-epi-ent-pimara-8(9),15-diene (9), and 8 alpha,19-dihydroxy-9 alpha,11 alpha:15,16-diepoxy-13-epi-ent-pimarane (11), while the feeding of 13-epi-ent-pimara-9(11),15-diene-19-oic acid (5) with this fungus afforded 1-oxo-2 alpha,9 alpha-dihydroxy-13-epi-ent-pimara-11,15-dien-19-oic acid (13), 1-oxo-2 beta,9 alpha-dihydroxy-13-epi-ent-pimara-11,15-dien-19-oic acid (14), 13-epi-ent-pimara-9(11),15-dien-1,19-dioic acid 1,2-lactone (15), and 1-oxo-12 beta-hydroxy-13-epi-ent-pimara-9(11),15-dien-19-oic acid (16). In both biotransformations, the main reaction was the epoxidation of the 9(11)-double bond, followed by rearrangement to afford allylic alcohols. The formation of lactone 15 represents the first time that a Baeyer-Villiger oxidation has been observed in a microbiological transformation with this fungus.

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Section: Resultssupporting

confidence: 77%

Biotransformation of Two ent-Pimara-9(11),15-diene Derivatives by Gibberella fujikuroi

et al. 2009

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“…Similar results were also obtained in kauranes having the ent-16β,17-diol [94], ent-15α-hydroxyl or 15-oxo [95] groups. Besides, an ent-11α-hydroxylation seems to be directed by the presence of a 7-oxo group [96]. The non-oxidation of C-19 by this microorganism was also observed in kauranes having one ent-3β-hydroxyl or one carbonyl at C-3 [75,95].…”

Section: Microbiological Methodsmentioning

confidence: 64%

Occurrence, Biological Activities and Synthesis of Kaurane Diterpenes and their Glycosides

2007

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This paper presents a review on kaurane diterpenes and their glycoside derivatives, covering aspects of their occurrence, biological activities and the synthesis of these natural products and their analogues. First, it shows and classifies diterpenes, in accordance with the already established structural criteria in the literature. Then, kaurane diterpenes are presented, focusing on their chemical structures, occurrence in the plant kingdom and their main, recently described, biological activities. Moreover, the most significant works, published between 1964 and November 2006, which describe the total synthesis or structural transformations of some kaurane diterpenes, including either semisynthetic and/or microbiological methodologies, are consisely reviewed. At this point, some general considerations on glycosides are introduced, and kaurane glycosides are presented and discussed on the basis of their toxic importance and occurrence in the plant kingdom, having focused on related aspects of their biological activities and the relationships between these activities and the structural factors of their molecules. Finally, the principal methods of glycosidation by enzymatic and chemical processes are both presented, and a few papers on the synthesis of kaurane glycosides are succinctly discussed. Molecules 2007, 12 456

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“…[23] This structure was later confirmed by 13 C-NMR and HMBC NMR experiments. [25][26][27] It is widely distributed in different botanical families [15] while the isolation of the (À )-7oxo-regioisomer ( Figure 2B) is rarely reported. It was firstly obtained by partial synthesis in 1966, from 7hydroxykaurenolide ( Figure 2C), an intermediate in the Chem.…”

Section: Resultsmentioning

confidence: 99%

A Comprehensive View on (−)‐7‐Oxo‐ent‐kaur‐16‐en‐19‐oic Acid, the Major Constituent of Xylopia sericea Leaves Extract: Complete NMR Assignments, X‐Ray Crystallographic Structure, in Vitro Antimalarial Activity and Cytotoxicity

Gontijo

Nascimento

Borgati

et al. 2019

Chemistry & Biodiversity

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Bioguided fractionation of Xylopia sericea antiplasmodial dichloromethane leaves extract led to the isolation of (−)‐7‐oxo‐ent‐kaur‐16‐en‐19‐oic acid (C20H28O3) that was identified by a combination of 1D and 2D NMR experiments (COSY, HMBC, HSQC, HSQC‐TOCSY, HSQC‐NOESY and NOESY) and by X‐ray crystallography. A feature to be pointed out is its (4R) configuration that was inferred from the NOE experiments (HSQC‐NOESY and NOESY) and X‐ray crystallography. In vitro evaluation of this rare diterpene acid against the chloroquine‐resistant strain Plasmodium falciparum W2 by the PfLDH method showed it disclosed a low antiplasmodial activity and was not cytotoxic to HepG2 cells (CC50 862.6±6.7 μm) by the MTT assay. The unequivocal NMR signals assignments, the X‐ray crystallographic structure, the assessment to the bioactivities and the occurrence this diterpene in X. sericea are reported here for the first time.

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Biotransformation of 7-oxo-ent-kaur-16-ene derivatives by Gibberella fujikuroi

Cited by 23 publications

References 19 publications

Biotransformation of Two ent-Pimara-9(11),15-diene Derivatives by Gibberella fujikuroi

Biotransformation of Two ent-Pimara-9(11),15-diene Derivatives by Gibberella fujikuroi

Occurrence, Biological Activities and Synthesis of Kaurane Diterpenes and their Glycosides

A Comprehensive View on (−)‐7‐Oxo‐ent‐kaur‐16‐en‐19‐oic Acid, the Major Constituent of Xylopia sericea Leaves Extract: Complete NMR Assignments, X‐Ray Crystallographic Structure, in Vitro Antimalarial Activity and Cytotoxicity

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