New reagent for oxidative phenol coupling. The transformation of the monocyclic spermine base (S)-dihydroxyverbacine to the bicyclic alkaloid (S,S,S)-aphelandrine by cell free extract of barley seedlings

Nezbedová, Lenka; Hesse, Manfred; Drandarov, Konstantin; Werner, Christa

doi:10.1016/s0040-4039(01)00670-0

Cited by 5 publications

(1 citation statement)

References 18 publications

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“…A dihydrobenzofuran unit constitutes the central substructure of the bicyclic Spm alkaloid ( S , S , S )-aphelandrine ( 194 ) which is present in Aphelandra plants (Acanthaceae). Nezbedovà and coworkers has obtained this alkaloid in preparative yield through a stereoselective intramolecular POC of the Spm-CouA hybrid ( S )-dihydroxyverbacine ( 193 ) in the presence of the soluble protein fraction of barley seedlings ( Hordeum vulgare , Gramineae) as catalyst and O 2 as oxidant (Scheme 65) [91]. The PA alkaloid (+)-hordatine A ( 196 ), isolated from barley ( Hordeum vulgare L.), has a similar benzofuranoid substructure.…”

Section: Neolignan Skeleton Assemblymentioning

confidence: 99%

Bioinspired Syntheses of Dimeric Hydroxycinnamic Acids (Lignans) and Hybrids, Using Phenol Oxidative Coupling as Key Reaction, and Medicinal Significance Thereof

Magoulas

Papaioannou

2014

Molecules

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Lignans are mainly dimers of 4-hydroxycinnamic acids (HCAs) and reduced analogs thereof which are produced in Nature through phenol oxidative coupling (POC) as the primary C-C or C-O bond-forming reaction under the action of the enzymes peroxidases and laccases. They present a large structural variety and particularly interesting biological activities, therefore, significant efforts has been devoted to the development of efficient methodologies for the synthesis of lignans isolated from natural sources, analogs and hybrids with other biologically interesting small molecules. We summarize in the present review those methods which mimic Nature for the assembly of the most common lignan skeleta by using either enzymes or one-electron inorganic oxidants to effect POC of HCAs and derivatives, such as esters and amides, or cross-POC of pairs of HCAs or HCAs with 4-hydrocycinnamyl alcohols. We, furthermore, provide outlines of mechanistic schemes accounting for the formation of the coupled products and, where applicable, indicate their potential application in medicine.

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Section: Neolignan Skeleton Assemblymentioning

confidence: 99%

Bioinspired Syntheses of Dimeric Hydroxycinnamic Acids (Lignans) and Hybrids, Using Phenol Oxidative Coupling as Key Reaction, and Medicinal Significance Thereof

Magoulas

Papaioannou

2014

Molecules

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Dibenzotetraazamacroheterocycles: Synthesis and properties. (Review)

Kulikov

Pavlovsky

Андронати

2005

Chem Heterocycl Compd

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Data on the synthesis, complexing ability, practical applications, and biological activity of dibenzotetraazamacroheterocycles of the azacrown ether, amide, and azomethinedibenzotetraazacycloalkane types and also dibenzotetraazamacroheterocycles containing amide and azomethine fragments are classified and analyzed.At present the chemistry of nitrogen macrocycles is developing at a very high rate. Many of the compounds are highly effective extractants for metal ions [1-3], find widespread use as contrast agents for magnetic resonance imaging [4][5][6][7][8], and can also be used as precursors in the biosynthesis of certain types of alkaloids [9] and also as ion-selective [10] and fluorescent [11] receptors and as agents for the transport of ions through a liquid membrane in dialysis and electrodialysis [12,13]. Chiral macrocyclic tetraamides are used as stationary phase in liquid chromatography [14]. The potentialities of nitrogen macrocycles in theoretical and practical respects have not been exhausted, and further research in the field is promising.In the last 15 years there have been a fairly large number of monographs and reviews in which aspects of the synthesis, properties, and applications of azamacroheterocycles and their metal complexes have been touched upon [15][16][17][18][19][20][21][22][23][24][25][26]. However, there have been significantly fewer publications devoted to the various classes of dibenzotetraazamacroheterocycles (e.g., dibenzotetraaza [14]annulenes [27][28][29], macrocyclic Schiff bases based on 2,6-diformylphenols [30]). Dibenzotetraazamacroheterocycles have found use as effective extractants for metal ions and as spectrophotometric agents [31][32][33], are used in the design of new magnetic materials [34], etc. To fill the gap we considered it desirable to analyze existing published material on the synthesis, complexation, and practical applications of dibenzotetraazamacrocycles of the azacrown ether, amide, azomethine, and dibenzotetraazacycloalkane types and also dibenzotetraazamacrocycles containing amide and azomethine fragments.

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