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Biotransformation reaction of digitoxigenin (1) by Fusarium ciliatum: production of digoxigenin (4), digoxigenone (5) and digitoxigenone (6).
Source publication
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 D14-15-digitoxigenina (2) e D8-14-digitoxigenina (3). A reação de biotransformação foi realizada em um período de 5 dias e três produtos foram isolad...
Contexts in source publication
Context 1
... compounds were isolated from the biotrans- formation of digitoxigenin by Fusarium ciliatum ( Figure 3). Structure elucidation was accomplished by 1D and 2D NMR techniques, using digitoxigenin (1) as model compound and also by comparison with spectral data reported for other cardenolides. ...
Context 2
... biotransformation of digitoxigenin (1) by F. ciliatum has been previously carried out on a 11 days process and afforded 100% yield of digoxigenone (5). 6,7 In the present work, shortening of the biotransformation reaction time to 5 days afforded the products digoxigenin (4), digoxigenone (5) and digitoxigenone (6) (Figure 3). In order to explain these results, we decided to investigate the biotransformation kinetics of the reaction. ...
Citations
... Compounds A series of 65 CDs was employed in this study; they were obtained from Digitalis lanata leaves [40,41] [42] or by semisynthesis. [43 -45] The purity of the tested compounds was checked by HPLC and NMR analyses (at least 95 % purity; data not shown). ...
There is growing interest in exploring Digitalis cardenolides as potential antiviral agents. Hence, we herein investigated the influence of structural features and lipophilicity on the antiherpes activity of 65 natural and semisynthetic cardenolides assayed in vitro against HSV‐1. The presence of an α,β‐unsaturated lactone ring at C‐17, a β‐hydroxyl group at C‐14 and C‐3β‐OR substituents were considered essential requirements for this biological activity. Glycosides were more active than their genins, especially monoglycosides containing a rhamnose residue. The activity enhanced in derivatives bearing an aldehyde group at C‐19 instead of a methyl group, whereas inserting a C‐5β‐OH improved the antiherpes effect significantly. The cardenolides lipophilicity was accessed by measuring experimentally their log P values ( n ‐octanol‐water partition coefficient) and disclosed a range of lipophilicity (log P 0.75 ± 0.25) associated with the optimal antiherpes activity. In silico studies were carried out and resulted in the establishment of two predictive models potentially useful to identify and/or optimize novel antiherpes cardenolides. The effectiveness of the models was confirmed by retrospective analysis of the studied compounds. This is the first SAR study addressing the antiherpes activity of cardenolides. The developed computational models were able to predict the active cardenolides and their log P values.
... DIGI was obtained according to the method reported by Pádua et al. (2005), with few modifications. Briefly, a methanolic extract from Digitalis lanata leaves (kindly donated by Prof. Wolfgang Kreis, University of Erlangen-Nuremberg, Germany), which is an industrial refuse resulting from the extraction of digoxin, was resuspended (17 g) in 200 mL acetone and sonicated for 30 min at room temperature. ...
Treatment for visceral leishmaniasis (VL) is hampered mainly by drug toxicity, their high cost, and parasite resistance. Drug
development is a long and pricey process, and therefore, drug repositioning may be an alternative worth pursuing. Cardenolides
are used to treat cardiac diseases, especially those obtained from Digitalis species. In the present study, cardenolide digitoxigenin
(DIGI) obtained from a methanolic extract of Digitalis lanata leaves was tested for its antileishmanial activity against Leishmania
infantum species. Results showed that 50% Leishmania and murine macrophage inhibitory concentrations (IC50 and CC50,
respectively) were of 6.9 ± 1.5 and 295.3 ± 14.5 μg/mL, respectively. With amphotericin B (AmpB) deoxycholate, used as a
control drug, values of 0.13 ± 0.02 and 0.79 ± 0.12 μg/mL, respectively, were observed. Selectivity index (SI) values were of 42.8
and 6.1 for DIGI and AmpB, respectively. Preliminary studies suggested that the mechanism of action for DIGI is to cause
alterations in the mitochondrial membrane potential, to increase the levels of reactive oxygen species and induce accumulation of
lipid bodies in the parasites. DIGI was incorporated into Pluronic® F127-based polymeric micelles, and the formula (DIGI/Mic)
was used to treat L. infantum–infected mice. Miltefosine was used as a control drug. Results showed that animals treated with
either miltefosine, DIGI, or DIGI/Mic presented significant reductions in the parasite load in their spleens, livers, bone marrows,
and draining lymph nodes, as well as the development of a specific Th1-type response, when compared with the controls. Results
obtained 1 day after treatment were corroborated with data corresponding to 15 days after therapy. Importantly, treatment with
DIGI/Mic induced better parasitological and immunological responses when compared with miltefosine- and DIGI-treated mice.
In conclusion, DIGI/Mic has the potential to be used as a therapeutic agent to protect against L. infantum infection, and it is
therefore worth of consideration in future studies addressing VL treatment.
... Inti dari senyawa steroid glikosida tipe C berbeda dari glikosida A hanya pada posisi C-12β yaitu terdapat gugus hidroksil (OH) pada glikosida tipe C (Tabel 1). Lanatoside C dan digoksin turunannya secara industri diperoleh dari daun Digitalis lanata dan lanatosida A merupakan hasil produk samping (Padua et al., 2005). ...
Digoksin merupakan glikosida kardioaktif, salah satu senyawa yang penting dalam terapi yang saat ini tersedia sebagai obat untuk pengobatan penyakit jantung. Penggunaan obat ini meningkat sejalan dengan bertambahnya penderita penyakit jantung. Oleh karena itu, perlu dilakukan penelitian dan monitoring penggunaan obat ini pada penderita penyakit jantung dalam proses terapi kesembuhan. Tujuan dari penelitian ini adalah untuk mengetahui metode analisis digoksin dengan menggunakan alat Ultra Performance Liquid Chromatography (UPLC). Digoksin yang digunakan adalah Fargoksin (Injection 0,25 mg/mL, ampoule/berbentuk cairan). Pengenceran digoksin dilakukan dengan penambahan pelarut metanol. Kolom yang digunakan adalah kolom BEH C18. Optimasi metode analisis yang dilakukan meliputi perbandingan pelarut yang digunakan, suhu kolom, dan laju alir. Setelah melakukan optimasi, diperoleh kondisi fasa gerak yang optimum adalah larutan air-asetonitril (72:28%), laju alir 0,3 mL/menit, waktu selama ± 6 menit, suhu kolom off, dan detektor yang digunakan adalah spektrofotometer UV dengan panjang gelombang 218 nm. Pengulangan analisis dengan menggunakan hasil yang diperoleh secara optimum dilakukan sebanyak sepuluh kali. Berdasarkan data tersebut, proses analisis dengan menggunakan UPLC dapat berlangsung lebih cepat dibandingkan dengan menggunakan HPLC.
... So we switched to a different procedure that also used acid catalyzed hydrolysis, but under different reaction conditions allowing for the synthesis of 2 in several hours instead of 10 to 14 days. 17 The synthesis of 2 is important because it results in an analog that is identical to digitoxin, minus the sugar moiety. Including this analog in the wound closure assay (Chapter Three) provides valuable information about the way in which cardiac glycosides inhibit cell migration. ...
... This accounted for the downstream 13 C signals indicating the presence of alkenes. Upon comparison of the 1 H and the 13 C data to the data published by Pádua et al., 17 we were sure that the reaction product we had isolated from the reaction products was a mixture of 4a and 4b. ...
... It was not until reading the Pádua et al. study on the biotransformation of digitoxigenin17 ...
The focus of this research is on cell migration and how it can be better understood through the use of small molecules that modulate cell migratory activity. The results have particular relevance in the realm of cancer pharmacology. Cardiac glycosides, which are known inhibitors of the eukaryotic Na+/K+-ATPase, have been determined to have antimigratory activities through the screening of several small molecule libraries. Here we investigate the antimigratory activities of the cardiac glycoside digitoxin as well as its analogs that we synthesized. Antimigratory activity was determined by conducting a wound closure assay with MDA-MB-231 human breast carcinoma cells. This antimigratory activity was compared to the inhibitory activity when Na+/K+-ATPase was treated with digitoxin and its analogs in a Na+/K+-ATPase assay. A coloration between wound closure activity Na+/K+-ATPase inhibitory activity provides evidence that cardiac glycosides inhibit cell migration through their interaction with the Na+/K+-ATPase protein. This research will provide the grounds to study the specific pathways in which Na+/K+-ATPase is linked to the regulation of cell migration.
... The 65 tested cardenolide derivatives were obtained from plants (Braga et al., 1996;Braga et al., 1997), by synthesis (Extrasynthèse, Genay, France; Merck, Darmstadt, Germany; Boehringer, Mannheim, Germany; Carl Roth, Karlsruhe, Germany), or by fungi biotransformation (Pádua et al., 2005;Pádua et al., 2007). Acyclovir, digoxin, dextran sulfate and furosemide were obtained from Sigma (St. Louis, MO, USA). ...
Cardiac glycosides, known ligands of the sodium pump, are widely used in the treatment of heart failure, such as digoxin and digitoxin. Besides this important activity, other biological activities, such as the antiviral activity, have been described for this group. HSV are responsible for many infections of oral, ocular and genital regions. Treatment with nucleoside analogs such as acyclovir is effective in most cases; however drug-resistance may arise due to prolonged treatment mainly in immunocompromised individuals. In this study, an antiherpes screening was performed with 65 cardenolide derivatives obtained from different sources, and one natural cardenolide, glucoevatromonoside, inhibited HSV-1 and HSV-2 replication at very low concentrations. This cardenolide showed viral inhibitory effects if added up to 12h p.i. and these effects appear to take place by the inhibition of viral proteins synthesis (ICP27, U(L)42, gB, gD), the blockage of virus release and the reduction of viral cell-to-cell spread. This compound also showed synergistic antiviral effects with acyclovir and anti-Na(+)K(+)ATPase activity, suggesting that cellular electrochemical gradient alterations might be involved in the mechanism of viral inhibition. These results suggest that cardenolides might be promising for future antiviral drug design.
... The low therapeutic index of DT (Tanaka et al. 1990 ) which made DG clinically preferable has motivated several researchers to find a way of transforming DT into DG with sustaining the pharmacologic activity and high yield under mild fermentation conditions (Volkov 1994).Therefore, microbial biotransformation of DT-containing wastes, under optimized conditions, into their corresponding DGs is still a reasonable approach to achieve this goal. Members of the cardiac glycosides are either transformed into cardioactive derivatives not known to occur in nature (Padua et al. 2005 ), or to valuable products in high yields (Alonso et al. 2009). Therefore, application of microorganisms to induce stereo-specific structural modifications of cardenolides is still a promising approach for economic production of commercially required drugs. ...
The biotransformation of digitoxin and some of its derivatives extracted from Digitalis lanata by Streptomyces isolated species was investigated. Cultures of a Streptomyces strain designated EUSA2003B, isolated from an Egyptian soil sample, efficiently induced selective 12beta-hydroxylation of the steroid aglycone of digitoxin (DT) and its alpha-acetyl and beta-methyl derivatives. The transformation reaction was performed within a 5-day fermentation process, products were isolated and their aglycone moiety was obtained by acid hydrolysis and their structures were elucidated by 13C and 1H NMR. The biotransformation resulted mainly digoxin (DG, approximately 87%), meanwhile, digoxigenone (DGON, approximately 7.0%) was also afforded as a side product. The present study revealed that: 1-Streptomyces isolate EUSA2003B harbors its specific 12beta-hydroxlase and has the capability to transform DT and it's alpha-acetyl and beta-methyl derivatives into their corresponding digoxins at reasonable yields. 2-The minor structural differences in the trisaccharide side chain seemed ineffective on the transformational capability of this organism. 3-The Streptomyces might also possess a specific glycosidase that splits the saccharidic side chain beside another dehydrogenase that oxidizes C3 at the steroid nucleus into its ketone form (DGON).
... Compound I was identified as thevetin B (Fig. 1) by comparing its spectroscopic measurements with that published with Rodrigo et al. (2005). Its FAB-MS (positive mode) spectrum showed a molecular ion peak at m/z 858 (calcd. ...
... Compound II was identified as digitoxigenin (Fig. 1) by comparing its spectroscopic measurements with that published with Rodrigo et al. (2005). Its FAB-MS (positive mode) showed a fragment ion peak at m/z 374.25 (calcd 374.51), which is corresponding to the molecular formula C 23 H 34 O 3 . ...
In vivo and in vitro extracted cardiac glycosides of immature seeds (IS) cultures of Thevetia neriifolia Jussieu. and T. thevetioides Kunth. were chemically identified. Calli were grown on modified Murashige & Skoog (MS) medium supplemented with 1mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) +3mg/l kinetin (Kin). The content of cardiac glycosides in IS cultures of T. neriifolia and T. thevetioides were monitored by HPLC. Two major compounds were detected and isolated from IS extracts i.e. digitoxigenin and thevetin B. The different structures of the in vivo and in vitro isolated compounds were verified by means of MS and NMR spectral analysis, as well as those compounds were identified and determined using HPLC technique
... 81 Other steroids have recently been biotransformed using fungi. [82][83][84][85][86][87][88][89][90][91] The 11b hydroxylation is a key structural factor for the bioactivity of steroidal drugs. This reaction has been achieved in the biotransformation of different steroidal substrates by some fungi. ...
The development of novel biocatalytic methods is a continuously growing area of chemistry, microbiology, and genetic engineering due to the fact that biocatalysts are selective, easy-to-handle, and environmentally friendly. A wide range of reactions are catalyzed by microorganisms. Fungi can be considered as a promising source of new biocatalysts, mainly for chiral reactions. Chemo-, regio-, and stereoselective processes are very important in the synthesis of many chemical, pharmaceutical, and agrochemical intermediates; active pharmaceuticals; and food ingredients. This report reviews stereoselective reactions mediated by fungi, such as stereoselective hydroxylation, sulfoxidation, epoxidation, Baeyer–Villiger oxidation, deracemization, and stereo- and enantioselective reduction of ketones, published between 2000 and 2007.
Phytochemical investigations on the fruits of Cascabela thevetia (L.) Lippold led to obtain three new cardenolides (1–3) and five known analogues (4–7). Their structures were elucidated by means of UV, IR, HR-ESI-MS, 1D and 2D NMR spectroscopic data analysis. Compounds 1 and 2 represent the first examples of naturally occurring cardenolides with 19-nor-5(10)-ene group and α-l-3-demethyl-thevetose, respectively. Compound 3 is a rare C-nor-D-homocardenolide in nature. All isolated cardenolides (1–7) were evaluated for their cytotoxic activities against four human cancer cell lines (MCF-7, HCT-116, HeLa and HepG2), and the results indicated the compounds with sugar units (1, 2, 4, and 5) exhibited stronger cytotoxic activities with IC50 values ranging between 0.022 and 0.308 μM.
In recent years, new therapeutic possibilities were proposed for cardiac glycosides traditionally used to treat heart diseases, such as anticancer and antiviral activities. In this sense, this work aimed to synthesize the readily accessible 3β-azido-3-deoxydigitoxigenin (5) from digitoxigenin (1). Two new series of compounds were obtained from derivative (5): (i) O-glycosyl trizols through click chemistry with propargyl glycosides; and (ii) compounds substituted in the alpha carbonyl position with different residues linked via an amino-group. All obtained derivatives have their chemical structures confirmed, and their anti-herpes (against HSV-types 1 and 2 replication) and cytotoxic (against PC3, A549, HCT-8 and LNCaP cell lines) activities evaluated. Compounds 10 and 11 exhibited the most promising results against HSV-1 (KOS and 29-R strains) and HSV-2 (333 strain) replication with SI values > 1000. Both compounds were also the most cytotoxic for the human cancer cell lines tested with IC 50 values similar to those of paclitaxel. They also presented reduced toxicity toward non-cancerous cell lines (MRC-5 and HGF cells). Promising compounds were tested in regard to their ability to inhibit Na ⁺ /K ⁺ -ATPase. The inhibition rate correlates suitably with the bioactivity demonstrated by those both compounds against the different human cancer cells tested as well as against HSV replication. Moreover, the results showed that specific chemical features of compound 10 and 11 influenced the bioactivities tested. In summary, it was possible to obtain novel digitoxigenin-derivatives with remarkable cytotoxic and anti-herpes activities as well as low toxicity and high selectivity. In this way, they could be considered potential molecules for the development of new drugs.
