87190-67-8Relevant academic research and scientific papers
Asymmetric Total Synthesis of Brasilicardins
Yoshimura, Fumihiko,Itoh, Ryusei,Torizuka, Makoto,Mori, Genki,Tanino, Keiji
, p. 17161 - 17167 (2018/12/11)
Brasilicardins, bacterial diterpenoid natural products that display highly potent immunosuppressive activity, are promising immunosuppressant drug candidates. Structurally, they can be described as hybrids of terpenoids, amino acids, and saccharides, and share a characteristic highly strained anti-syn-anti-fused perhydrophenanthrene terpenoid scaffold (ABC-ring system) with two quaternary asymmetric carbon atoms. A unified and stereoselective total synthesis of all four brasilicardins has been designed based on the strategic use of an intramolecular conjugate addition. The ABC-ring system was initially constructed with high stereocontrol by novel intramolecular conjugate additions of Weinreb amides and in situ generated (Z)-vinyl copper species. The late-stage common intermediate was subjected to stereoselective installation of the amino acid component, followed by introduction of the saccharide unit via glycosylation to accomplish the total synthesis of brasilicardins A–D. Our synthesis offers opportunities to synthesize various brasilicardin analogues for biological and pharmacological investigations.
An efficient synthesis of the protected carbohydrate moiety of Brasilicardin A
Jung, Michael E.,Koch, Pierre
, p. 3710 - 3713 (2011/09/14)
A synthesis of the protected carbohydrate moiety 2 of Brasilicardin A starting from l-rhamnose and d-glucosamine is described. The disaccharide was synthesized using a TMSOTf-mediated glycosylation of the 2-phthalimido-2- deoxyglucose donor 5 and the 3-hydroxyl group of the protected l-rhamnose derivative 4, which already bears the 3-hydroxybenzoate unit. The imidate 2 was coupled via TMSOTf-mediated glycosidation with cholesterol as a model aglycone followed by the selective cleavage of all the acetate groups to give the Brasilicardin A analogue 16.
Solid-phase synthesis of thioether-linked glycopeptide mimics for application to glycoprotein semisynthesis.
Macmillan, Derek,Daines, Alison M,Bayrhuber, Monika,Flitsch, Sabine L
, p. 1467 - 1470 (2007/10/03)
[reaction: see text]. Glycoproteins are particularly suited to protein semisynthesis since homogeneous samples for biological analyses are not readily available using traditional recombinant techniques. Here we apply glycosyl iodoacetamides, normally used for the modification of bacterially derived proteins, to solid-phase glycopeptide synthesis. This provides access to glycopeptide alpha-thioesters, which may lend themselves to the semisynthesis of homogeneous N-linked glycoprotein mimics and novel glycopeptide libraries.
Large scale synthesis of linker-modified sialyl Lewis(X), Lewis(X) and N-acetyllactosamine
Kretzschmar, Gerhard,Stahl, Wilhelm
, p. 6341 - 6358 (2007/10/03)
The synthesis of sialyl-Lewis(X) (1b), Lewis(X) (2) and N- acetyllactosamine (3), each being attached to the 1β-O-(6-amino)hexyl handle, were scaled up to gram amounts to obtain sufficient material for thorough pharmaceutical evaluations and for derivatisations aiming at more potent selectin antagonists. The disaccharide 3 was synthesised from inexpensive lactose to provide a versatile building block, either to be used for alternative approaches to the Lewis type oligosaccharides, or to prepare polyvalent LacNAc templates to be further elaborated by glycosyltransferase reactions. All syntheses were directed to reasonable large scale procedures, especially by minimising the number of steps and the use of heavy metal salts in glycosylations.
