Effects of Various Pregnanes and Two 23-Nor-5-cholenic Acids on Cardenolide Accumulation in Cell and Organ Cultures of<i>Digitalis lanata</i>

Haussmann, Werner; Kreis, Wolfgang; Stuhlemmer, Ursel; Reinhard, E.

doi:10.1055/s-2006-957731

Cited by 23 publications

(15 citation statements)

References 6 publications

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“…Proton chemical shifts of compound 2 were generally consistent with those of digitoxigenin (1), the major In a similar way, 13 C NMR spectrum of product 3 revealed the signals of two olefinic non-hydrogenated carbons at 129.7 and 138.3, respectively assigned to C-8 and C-14, which allowed identifying the other dehydration derivative as [8][9][10][11][12][13][14] -digitoxigenin (3).…”

Section: Resultssupporting

confidence: 63%

“…Digitoxigenin (1), employed as substrate for biotransformation in the present work, was obtained by the acid hydrolysis of digitoxin under previously described conditions, 8 with some modifications ( Figure 2). The temperature of the hydrolysis reaction was held at 55 °C, for 35 min, to minimize the formation of the side product digitoxigenin-monodigitoxoside.…”

Section: Resultsmentioning

confidence: 99%

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Biotransformation of digitoxigenin by Fusarium ciliatum

Pádua¹,

Oliveira²,

Filho³

et al. 2005

J. Braz. Chem. Soc.

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A biotransformação da digitoxigenina (1) por Fusarium ciliatum foi investigada. O cardenolídeo 1 foi obtido a partir da hidrólise ácida da digitoxina e a reação também forneceu os produtos secundários 14-15 -digitoxigenina (2) e 8-14 -digitoxigenina (3). A reação de biotransformação foi realizada em um período de 5 dias e três produtos foram isolados e identificados a partir de análises espectrométricas: digoxigenina (4), digoxigenona (5) e digitoxigenona (6). A obtenção dos dois últimos cardenolídeos nas condições empregadas é inédita. A investigação da cinética da reação de biotransformação indicou 6 como o primeiro produto a ser formado, seguido dos derivados hidroxilados 4 e 5, sugerindo o envolvimento de enzima distintas na hiroxilação em 12 e na oxidação em C-3 da digitoxigenina (1). A reação de biotransformação também foi realizada com a digitoxina, mas F. ciliatum se mostrou incapaz de promover sua hidroxilação.The biotransformation of digitoxigenin (1) by Fusarium ciliatum was investigated. The cardenolide 1 was obtained by the acid hydrolysis of digitoxin and the reaction also afforded two side products, identified as [14][15] -digitoxigenin (2) and 8-14 -digitoxigenin (3) by spectroscopic analysis. The biotransformation reaction was carried out in a 5 days process and three products were isolated and had their structures elucidated as digoxigenin (4), digoxigenone (5) and digitoxigenone (6). The investigation of the biotransformation kinetics disclosed 6 as the first derivative to be formed, followed by the more polar hydroxylated products 4 and 5, suggesting the involvement of different enzymes in 12 hydroxylation and C-3 oxydation of digitoxigenin (1). The production of 5 and 6 under the employed conditions has never been reported. The biotransformation reaction was also undertaken with digitoxin, but F. ciliatum has been unable to promote its hydroxylation.

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Section: Resultssupporting

confidence: 63%

Section: Resultsmentioning

confidence: 99%

Biotransformation of digitoxigenin by Fusarium ciliatum

Pádua¹,

Oliveira²,

Filho³

et al. 2005

J. Braz. Chem. Soc.

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“…This observation fits well with the results of a previous study in which various pregnane precursors were fed to D. lanata shoot cultures. Only some of them led to the formation of both digitoxose-type and fucose-type cardenolides, whereas fucose-type cardenolides were formed from any of the precursors (12). It was thus supposed that at least two cardenolide pathways exist side by side in D. lanata.…”

Section: Discussionmentioning

confidence: 99%

“…Authentic 3-epidigitoxigenin (3a-digitoxigenin) (2) and digitoxigen-3-one (3) used as a substrate and reference standard for HPLC and TLC were obtained by chemical synthesis, starting with digitoxin. Digitoxigenin (1) was prepared from digitoxin as described previously (12). Compound 1 was then oxidized with Kiliani solution (Cr03 in sulphuric acid) according to Sawlewicz et al (13).…”

Section: Synthesis Of 3-epidigitoxigenin and Digitoxigen-3 -Onementioning

confidence: 99%

Effects of Digitoxigenin, Digoxigenin, and Various Cardiac Glycosides on Cardenolide Accumulation in Shoot Cultures ofDigitalis lanata

Theurer

Kreis²,

Reinhard³

1998

Planta Med

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Various cardenolide genins and cardenolide glycosides were administered to light-grown and dark-grown Digitalis lanata shoot cultures to investigate conversion reactions related to the formation and rearrangement of the sugar side chain of Digitalis glycosides. Digitoxigenin was converted to digitoxigen-3-one, 3-epidigitoxigenin, and digoxigenin. In addition, various cardiac glycosides were formed, including mono-glycosides with glucose, glucomethylose, fucose, and digitalose, as well as the corresponding diglycosides, all containing a terminal glucose. Digitoxosylated cardenolides were not formed, although the light-grown shoot cultures were capable of producing these compounds. Exogenous cardenolide fucosides were not converted into cardenolide digitoxosides. Administration of evatromonoside (digitoxigenin monodigitoxoside) did not force the formation of cardenolide di- or tridigitoxosides. Our results support the hypothesis that cardenolide fucosides and digitoxosides are formed via different biosynthetic routes and that cardenolide genins can be fucosylated but not digitoxosylated, indicating that digitoxosylation may only occur at an earlier stage in the cardenolide pathway.

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“…Actually, synthetic 23-nor-5-cholenic acids, not containing these hydroxyl groups, have been shown to be precursors of cardenolides and it was discussed that the condensation reaction may be an earlier event and 14b-hydroxylation a later event in cardenolide biosynthesis than previously assumed. 3,4 Alternatively, it was postulated that a pregnane 21-O-malonyl hemiester is formed prior to an intramolecular ester condensation ('pregnane-21-O-malonyl hemiester pathway'). Subsequent decarboxylation and dehydration then yields the butenolide ring.…”

Section: Introductionmentioning

confidence: 99%