scholarly journals Partial Methylation with Diazomethane of the Sugar Moiety of Some C- and O-D-Glucopyranosides

1970 ◽  
Vol 18 (4) ◽  
pp. 677-686 ◽  
Author(s):  
MASAKAZU ARITOMI ◽  
TOSHIO KAWASAKI
1977 ◽  
Vol 42 (11) ◽  
pp. 3180-3185 ◽  
Author(s):  
K. Kefurt ◽  
Z. Kefurtová ◽  
V. Ineman ◽  
J. Jarý
Keyword(s):  

1979 ◽  
Vol 44 (2) ◽  
pp. 613-625 ◽  
Author(s):  
Valentina I. Gulyaeva ◽  
Antonín Holý

The present paper studies the effect of the modification of heterocyclic base, sugar moiety and the presence of phosphate group on the nucleoside acceptors in the synthesis of dinucleoside phosphates from adenosine 2',3'-cyclic phosphate as donor, catalyzed by nonspecific acidic extracellular and intracellular ribonucleases from Penicillium claviforme. The enzyme binds specifically the acceptor molecule, preferring cytosine nucleosides. It requires the presence of the whole sugar moiety, an exact mutual orientation of the heterocyclic base and the reaction center (5'-hydroxy group), and a suitable conformation of the acceptor molecule. The enzyme-acceptor bond is homochiral and the presence of the N3-H group in the pyrimidine ring is important. The reaction between the donor and the acceptor is bimolecular and is competitively inhibited by some purine nucleosides.


1980 ◽  
Vol 45 (12) ◽  
pp. 3571-3582 ◽  
Author(s):  
Jiří Jarý ◽  
Miroslav Marek

Methyl α- and β-D-threofuranosides (I and II) and methyl α- and β-D-erythrofuranosides (VII and VIII) were prepared in a modified manner. For the preparation of monomethyl ethers of compounds I and II 1,2-O-isopropylidene-β-D-threofuranose (IV) was prepared as the starting compound. For the synthesis of monomethyl ethers of compounds VII and VIII partial methylation of these diols was made use of.


1984 ◽  
Vol 49 (12) ◽  
pp. 2922-2931 ◽  
Author(s):  
Jan Staněk ◽  
Jana Jeřábková ◽  
Jiří Jarý

The preparative advantages of partial methylation with subsequent separation of isomers over standard syntheses of individual derivatives are presented on the case of the methylation of methyl β-D-xylopyranoside (I). All seven possible methyl ethers were isolated in reasonable yields from a single reaction. Literature data concerning methyl 2,3-di-O-methyl-β-D-xylopyranoside (V) and methyl 2,4-di-O-methyl-β-D-xylopyranoside (VI) have been revised.


Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 719
Author(s):  
Meri Yulvianti ◽  
Christian Zidorn

Cyanogenic glycosides are an important and widespread class of plant natural products, which are however structurally less diverse than many other classes of natural products. So far, 112 naturally occurring cyanogenic glycosides have been described in the phytochemical literature. Currently, these unique compounds have been reported from more than 2500 plant species. Natural cyanogenic glycosides show variations regarding both the aglycone and the sugar part of the molecules. The predominant sugar moiety is glucose but many substitution patterns of this glucose moiety exist in nature. Regarding the aglycone moiety, four different basic classes can be distinguished, aliphatic, cyclic, aromatic, and heterocyclic aglycones. Our overview covers all cyanogenic glycosides isolated from plants and includes 33 compounds with a non-cyclic aglycone, 20 cyclopentane derivatives, 55 natural products with an aromatic aglycone, and four dihydropyridone derivatives. In the following sections, we will provide an overview about the chemical diversity known so far and mention the first source from which the respective compounds had been isolated. This review will serve as a first reference for researchers trying to find new cyanogenic glycosides and highlights some gaps in the knowledge about the exact structures of already described compounds.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3461
Author(s):  
Vasiliki Daikopoulou ◽  
Panagiotis Apostolou ◽  
Sofia Mourati ◽  
Ioanna Vlachou ◽  
Maria Gougousi ◽  
...  

Despite the fact that COVID-19 vaccines are already available on the market, there have not been any effective FDA-approved drugs to treat this disease. There are several already known drugs that through drug repositioning have shown an inhibitory activity against SARS-CoV-2 RNA-dependent RNA polymerase. These drugs are included in the family of nucleoside analogues. In our efforts, we synthesized a group of new nucleoside analogues, which are modified at the sugar moiety that is replaced by a quinazoline entity. Different nucleobase derivatives are used in order to increase the inhibition. Five new nucleoside analogues were evaluated with in vitro assays for targeting polymerase of SARS-CoV-2.


2005 ◽  
Vol 127 (37) ◽  
pp. 12758-12759 ◽  
Author(s):  
Ji-ang Liu ◽  
Christopher J. Petzold ◽  
Luis E. Ramirez-Arizmendi ◽  
James Perez ◽  
Hilkka Kenttämaa

2012 ◽  
Vol 68 (8) ◽  
pp. o283-o287 ◽  
Author(s):  
Vasily S. Minkov ◽  
Elena V. Boldyreva

N,N-Dimethylglycine, C4H9NO2, and its hemihydrate, C4H9NO2·0.5H2O, are discussed in order to follow the effect of the methylation of the glycine amino group (and thus its ability to form several hydrogen bonds) on crystal structure, in particular on the possibility of the formation of hydrogen-bonded `head-to-tail' chains, which are typical for the crystal structures of amino acids and essential for considering amino acid crystals as mimics of peptide chains. Both compounds crystallize in centrosymmetric space groups (PbcaandC2/c, respectively) and have twoN,N-dimethylglycine zwitterions in the asymmetric unit. In the anhydrous compound, there are no head-to-tail chains but the zwitterions formR44(20) ring motifs, which are not bonded to each other by any hydrogen bonds. In contrast, in the crystal structure ofN,N-dimethylglycinium hemihydrate, the zwitterions are linked to each other by N—H...O hydrogen bonds into infiniteC22(10) head-to-tail chains, while the water molecules outside the chains provide additional hydrogen bonds to the carboxylate groups.


Sign in / Sign up

Export Citation Format

Share Document