β-Selective xylulofuranosylation via a conformationally-restricted glycosyl donor

2020 ◽  
Vol 18 (12) ◽  
pp. 2264-2273 ◽  
Author(s):  
Bo-Shun Huang ◽  
Todd L. Lowary
Keyword(s):  
Conformationally Restricted ◽  
Stereoselective Method ◽  
Glycosyl Donor

Reported is the first stereoselective method for β-xylulofuranosylation, which employs 3,4-O-xylylene-protected thioglycoside donors.

Synthesis of N-substituted Five and Six-membered Iminocyclitols-bearing Sugar Moiety: Strategy Toward the Synthesis of Pseudodisaccharide

2018 ◽  
Vol 15 (6) ◽  
pp. 853-862
Author(s):  
Nader Al Bujuq ◽  
Manuel Angulo
Keyword(s):  
Molecular Modeling ◽  
Biologically Active Compounds ◽  
Biologically Active ◽  
Efficient Synthesis ◽  
Active Compounds ◽  
Sugar Moiety ◽  
Stereoselective Method ◽  
Glycosyl Donor ◽  
Derivatives Of ◽  
Glycosyl Donors

Aim and Objective: The efficient synthesis of disaccharide containing iminosugar moiety has a considerable interest in the field of glycoscience. In the present work, we describe a novel and applicable method for synthesis of five and six-membered N-substituted iminosugars attached with sugar moiety (pseudodisaccharides). Materials and Methods: The method of the glycosylation was based on the coupling of iminosugar thioglycoside (glycosyl donors) with partially protected sugars (glycosyl acceptors) in the presence of DMTST as a promoter. 2D COSY, HMQC, HMBC experiments were carried out to assist in NMR signal assignments. The pseudoanomeric configuration was established through NOE experiments and molecular modeling calculations. Results: Two classes of pseudodisaccharides were successfully obtained, five and six-membered N-substituted iminosugars glycosides. The six-membered pseudodisaccharides compounds were produced selectively with only β anomer. The corresponding five-membered pseudodisaccharides were achieved with moderate stereoselectivity. The yields obtained were good. These derivatives of iminocyclitols are thought to be precedents to develop various pseudodisaccharides, novel biologically active compounds, and new functional molecules. Conclusion: According to the results, utilizing iminosugar thioglycosides (1 and 2) as a glycosyl donor in glycosylation reactions is an efficient and highly stereoselective method to prepare (five- and six-membered) iminocyclitols (iminosugars) that bear a sugar moiety. The results will add to the synthesis of the iminosugars derivatives and contribute to make our approach among the few methods able to synthesize iminosugar glycosides.

scholarly journals A One-Pot Approach to Novel Pyridazine C-Nucleosides

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2341
Author(s):  
Flavio Cermola ◽  
Serena Vella ◽  
Marina DellaGreca ◽  
Angela Tuzi ◽  
Maria Rosaria Iesce
Keyword(s):  
Organic Chemistry ◽  
Research Field ◽  
Modified Nucleosides ◽  
Protecting Groups ◽  
Coupling Reactions ◽  
One Pot ◽  
Pharmacological Interest ◽  
Classical Methodology ◽  
Glycosyl Donor ◽  
Neutral Conditions

The synthesis of glycosides and modified nucleosides represents a wide research field in organic chemistry. The classical methodology is based on coupling reactions between a glycosyl donor and an acceptor. An alternative strategy for new C-nucleosides is used in this approach, which consists of modifying a pre-existent furyl aglycone. This approach is applied to obtain novel pyridazine C-nucleosides starting with 2- and 3-(ribofuranosyl)furans. It is based on singlet oxygen [4+2] cycloaddition followed by reduction and hydrazine cyclization under neutral conditions. The mild three-step one-pot procedure leads stereoselectively to novel pyridazine C-nucleosides of pharmacological interest. The use of acetyls as protecting groups provides an elegant direct route to a deprotected new pyridazine C-nucleoside.

Dimethylzinc-mediated enantioselective addition of terminal alkynes to 1,2-diketones using perhydro-1,3-benzoxazines as ligands

2021 ◽  
Author(s):  
Elena Prieto ◽  
Rebeca Infante ◽  
Javier Nieto ◽  
Celia Andres
Keyword(s):  
Chiral Ligand ◽  
Terminal Alkynes ◽  
Conformationally Restricted ◽  
Enantioselective Addition

A conformationally restricted perhydro-1,3-benzoxazine derived from (-)-8-aminomenthol behaves as a good chiral ligand in the dimethylzinc-mediated enantioselective monoaddition of aromatic and aliphatic terminal alkynes to 1,2-diketones. The corresponding α-hydroxyketones were...

scholarly journals Cold-Active β-Galactosidases: Insight into Cold Adaption Mechanisms and Biotechnological Exploitation

Marine Drugs ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 43
Author(s):  
Marco Mangiagalli ◽  
Marina Lotti
Keyword(s):  
Low Temperature ◽  
Molecular Mechanisms ◽  
Building Blocks ◽  
Cold Active ◽  
Cold Adaption ◽  
Glycosyl Donor ◽  
Pharmaceutical Industries ◽  
Biotechnological Processes ◽  
Hydrolysis Of ◽  
Insight Into

β-galactosidases (EC 3.2.1.23) catalyze the hydrolysis of β-galactosidic bonds in oligosaccharides and, under certain conditions, transfer a sugar moiety from a glycosyl donor to an acceptor. Cold-active β-galactosidases are identified in microorganisms endemic to permanently low-temperature environments. While mesophilic β-galactosidases are broadly studied and employed for biotechnological purposes, the cold-active enzymes are still scarcely explored, although they may prove very useful in biotechnological processes at low temperature. This review covers several issues related to cold-active β-galactosidases, including their classification, structure and molecular mechanisms of cold adaptation. Moreover, their applications are discussed, focusing on the production of lactose-free dairy products as well as on the valorization of cheese whey and the synthesis of glycosyl building blocks for the food, cosmetic and pharmaceutical industries.

Substituted benzamides with conformationally restricted side chains. 5. Azabicyclo[x.y.z] derivatives as 5-HT4 receptor agonists and gastric motility stimulants

1993 ◽  
Vol 36 (6) ◽  
pp. 683-689 ◽  
Author(s):  
Frank D. King ◽  
Michael S. Hadley ◽  
Karen T. Joiner ◽  
Roger T. Martin ◽  
Gareth J. Sanger ◽  
...  
Keyword(s):  
Gastric Motility ◽  
Side Chains ◽  
Receptor Agonists ◽  
Conformationally Restricted ◽  
Substituted Benzamides

A Double Diastereoselective Michael-Type Addition as an Entry to Conformationally Restricted Tn Antigen Mimics

2013 ◽  
Vol 78 (21) ◽  
pp. 10968-10977 ◽  
Author(s):  
Carlos Aydillo ◽  
Claudio D. Navo ◽  
Jesús H. Busto ◽  
Francisco Corzana ◽  
María M. Zurbano ◽  
...  
Keyword(s):  
Tn Antigen ◽  
Conformationally Restricted ◽  
Michael Type Addition

Conformationally restricted 2,5-diphenyloxazoles: failure of the electromer model for anomalous amplified spontaneous emission spikes

2006 ◽  
Vol 104 (5-7) ◽  
pp. 957-969 ◽  
Author(s):  
J. Saltiel ◽  
R. A. Ivanov ◽  
D. A. Gormin ◽  
T. S. R. Krishna ◽  
R. J. Clark
Keyword(s):  
Spontaneous Emission ◽  
Amplified Spontaneous Emission ◽  
Conformationally Restricted
Sign in / Sign up

Export Citation Format

Share Document