The microbiological transformation of two ent-16β,17-epoxykaurane derivatives by Gibberella fujikuroi

Fraga, Braulio M.; González, Pedro; Guillermo, Ricardo; Hanson, James R.; Hernández, Melchor G.; Takahashi, Jacqueline A.

doi:10.1016/s0031-9422(00)90345-5

Cited by 19 publications

(25 citation statements)

References 18 publications

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“…Fraga and co-workers [75,93] showed that the biotransformation of ent-15β,16β-dihydroxy-or ent-15β,16β-epoxy-kauranes by Gibberella fujikuroi produced selective hydroxylation at the ent-7β and ent-11α positions, and inhibited the oxidation of C-19. 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].…”

Section: Microbiological Methodssupporting

confidence: 82%

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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Section: Microbiological Methodssupporting

confidence: 82%

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

2007

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“…6 Kaurenoic acid (1), along with several related kauranes, 7 exhibits a wide variety of biological activities such as antimicrobial, anti-inflammatory, anti-fertility, cytotoxic, and trypanocidal. [8][9][10][11][12][13][14][15][16] The relatively high natural abundance of kaurenoic acid (1) and the inexistence of a general method for the synthesis of alkyl kaurenoates by esterification of 1 provides further motivation to investigate its chemical modification 17 in order to obtain derivatives and test their pharmacological activity. 18 This paper describes a general synthesis of kaurenoic esters and derivatives as well as their antifungal activity, evaluated against a panel of human opportunistic pathogenic fungi including yeasts, hialohyphomycetes and dermatophytes.…”

Section: Introductionmentioning

confidence: 99%

A simple synthesis of kaurenoic esters and other derivatives and evaluation of their antifungal activity

Boeck

Sá

Souza

et al. 2005

J. Braz. Chem. Soc.

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Este trabalho descreve a preparação de ésteres e amidas derivados do ácido caurenóico e a avaliação da atividade antifúngica frente a cepas padronizadas de fungos patogênicos. Ésteres alquílicos e benzílicos foram obtidos com bons rendimentos, sob condições brandas, a partir da esterificação do ácido caurenóico com haletos de alquila em KOH-acetona. Todos os compostos sintetizados foram submetidos aos testes de inibição contra leveduras, hifomicetos e dermatófitos, mas somente o ácido caurenóico e os derivados contendo um grupo carboxilato livre apresentaram atividade moderada frente a dermatófitos.Representative esters derived from kaurenoic acid were prepared in order to evaluate their antifungal properties. Alkyl and substituted benzyl esters were obtained in good yield under mild conditions by esterification of kaurenoic acid with the corresponding alkyl halide in KOH-acetone. All synthesized compounds were tested for antifungal properties against pathogenic yeasts, hialohyphomycetes and dermatophytes. Kaurenoic acid and derivatives containing a free carboxyl group were moderately active against dermatophytes.

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“…No entanto, as análises espectroscópicas de RMN (Hou et al, 2000;Parker et al, 1989) e espectrométricas (He Zhyong et al, 2009;Sannomiya et al, 2005) (Holland e Weber, 2000). Além disso, é reportado a biotransformação do epóxido de ácido caurenóico resultando no ácido 16α,17-diidroxi-ent-cauran-19-oico e A 12 -7-aldeido 16α,17-diidroxigiberelin por Gibberella fujikuroi (Fraga et al, 1994). Outro fato observado foi a formação somente o diol α como produto de biotransformação, contudo esses dados condizem com a literatura, pois sabe-se que na hidrólise do epóxido, micro-organismos são capazes de abrir o epóxido de forma estéreo-seletiva que dão origem a dióis opticamente puros (Swaving e Bont, 1998 De acordo com Besson (1997), a inflamação aguda ou crônica é um modelo de nocicepção e pesquisas sobre dor inflamatória têm mostrado que mediadores inflamatórios podem gerar impulsos nociceptivos.…”

Section: Discussionunclassified

“…O epóxido do ácido caurenóico (7) foi preparado a partir da epoxidação do composto ácido caurenóico (5) (Fraga et al, 1994). Para tanto, 300 mg do ácido ent-caur-16-en-19-oico foram dissolvidos em CH 2 Cl 2 (8 mL), sendo adicionados 300 mg do ácido 3-cloroperbenzóico (Aldrich, lote 273031) e foi mantido em refluxo por 2 h em temperatura ambiente.…”

Section: Obtenção Do Epoxido De áCido Caurenóicounclassified

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Caracterização fitoquímica, avaliação das atividades analgésica e anti-inflamatória e biotransformação de um composto isolado das folhas de Copaifera langsdorffii

Furtado¹

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The microbiological transformation of two ent-16β,17-epoxykaurane derivatives by Gibberella fujikuroi

Cited by 19 publications

References 18 publications

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

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

A simple synthesis of kaurenoic esters and other derivatives and evaluation of their antifungal activity

Caracterização fitoquímica, avaliação das atividades analgésica e anti-inflamatória e biotransformação de um composto isolado das folhas de Copaifera langsdorffii

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