Partial methylation of methyl 4,6-dideoxy-α-D-arabino-hexopyranoside

1977 ◽  
Vol 42 (11) ◽  
pp. 3180-3185 ◽  
Author(s):  
K. Kefurt ◽  
Z. Kefurtová ◽  
V. Ineman ◽  
J. Jarý
Keyword(s):  
Partial Methylation

The synthesis of methyl tetrosides and their methyl ethers

1980 ◽  
Vol 45 (12) ◽  
pp. 3571-3582 ◽  
Author(s):  
Jiří Jarý ◽  
Miroslav Marek
Keyword(s):  
Partial Methylation ◽  
Starting Compound

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.

Monomethyl and dimethyl ethers of methyl β-D-xylopyranoside

1984 ◽  
Vol 49 (12) ◽  
pp. 2922-2931 ◽  
Author(s):  
Jan Staněk ◽  
Jana Jeřábková ◽  
Jiří Jarý
Keyword(s):  
Partial Methylation ◽  
Separation Of Isomers ◽  
Subsequent Separation ◽  
Single Reaction

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.

The effect of partial methylation of the glycine amino group on crystal structure inN,N-dimethylglycine and its hemihydrate

2012 ◽  
Vol 68 (8) ◽  
pp. o283-o287 ◽  
Author(s):  
Vasily S. Minkov ◽  
Elena V. Boldyreva
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Water Molecules ◽  
Amino Group ◽  
Asymmetric Unit ◽  
Partial Methylation ◽  
Space Groups ◽  
Carboxylate Groups ◽  
Anhydrous Compound ◽  
Additional Hydrogen

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.

Strain-specific transgene methylation occurs early in mouse development and can be recapitulated in embryonic stem cells

Development ◽  
1995 ◽  
Vol 121 (9) ◽  
pp. 2853-2859 ◽  
Author(s):  
A. Weng ◽  
T. Magnuson ◽  
U. Storb
Keyword(s):  
De Novo ◽  
Es Cells ◽  
Embryonic Stem ◽  
Dependent Manner ◽  
Mouse Development ◽  
Partial Methylation ◽  
Distal Chromosome ◽  
Before And After ◽  
Endogenous Genes ◽  
De Novo Methylation

A murine transgene, HRD, is methylated only when carried in certain inbred strain backgrounds. A locus on distal chromosome 4, Ssm1 (strain-specific modifier), controls this phenomenon. In order to characterize the activity of Ssm1, we have investigated developmental acquisition of methylation over the transgene. Analysis of postimplantation embryos revealed that strain-specific methylation is initiated prior to embryonic day (E) 6.5. Strain-specific transgene methylation is all-or-none in pattern and occurs exclusively in the primitive ectoderm lineage. A strain-independent pattern of partial methylation occurs in the primitive endoderm and trophectoderm lineages. To examine earlier stages, embryonic stem (ES) cells were derived from E3.5 blastocysts and examined for transgene methylation before and after differentiation. Though the transgene had already acquired some methylation in undifferentiated ES cells, differentiation induced further, de novo methylation in a strain-dependent manner. Analysis of methylation in ES cultures suggests that the transgene and endogenous genes (such as immunoglobulin genes) are synchronously methylated during early development. These results are interpreted in the context of a model in which Ssm1-like modifier genes produce alterations in chromatin structure during and/or shortly after implantation, thereby marking target loci for de novo methylation with the rest of the genome during gastrulation.

scholarly journals Partial Methylation Studies on Methyl beta-D-Glucopyranoside and some Derivatives.

1962 ◽  
Vol 16 ◽  
pp. 2005-2009 ◽  
Author(s):  
A. N. de Belder ◽  
Bengt Lindberg ◽  
Olof Theander
Keyword(s):  
Partial Methylation

scholarly journals Preliminary Analysis of Within-Sample Co-methylation Patterns in Normal and Cancerous Breast Samples

2019 ◽  
Vol 18 ◽  
pp. 117693511988051
Author(s):  
Lillian Sun ◽  
Surya Namboodiri ◽  
Emily Chen ◽  
Shuying Sun
Keyword(s):  
Deep Understanding ◽  
Physical Distance ◽  
Normal Breast ◽  
Breast Cancer Cell Lines ◽  
Partial Methylation ◽  
Methylation State ◽  
New Methods ◽  
Novel Biomarkers ◽  
Methylation Patterns ◽  
Breast Tissues

DNA methylation plays a significant role in regulating the expression of certain genes in both cancerous and normal breast tissues. It is therefore important to study within-sample co-methylation, ie, methylation patterns between consecutive sites in a chromosome. In this article, we develop 2 new methods to compare co-methylation patterns between normal and cancerous breast samples. In particular, we investigate the co-methylation patterns of 4 different methylation states/levels separately. Using these 2 methods, we focus on addressing the following questions: How often does 1 methylation state change to other methylation states and how is this change dependent on chromosome distance? What co-methylation patterns do normal and cancerous breast samples have? Do genomic sites with different methylation states/levels have different co-methylation patterns? Our results show that cancerous and normal co-methylation patterns are significantly different. We find that this difference exists even when the physical distance of 2 sites are less than 50 bases. Breast cancer cell lines tend to remain in the same methylation state more often than normal samples, especially for the no/low or high/full methylation states. We also find that the co-methylation region lengths for various methylation states (no/low, partial, and high/full methylation states) are very different. For example, the co-methylation region lengths for partial methylation regions are shorter than the unmethylated or fully methylated regions. Our research may provide a deep understanding of co-methylation patterns. These co-methylation patterns will aid in discovering and understanding new methylation events that may be related to novel biomarkers.

Partial methylation of methyl glycosides: A source of samples for analysis of methylation of carbohydrate-containing compounds

1975 ◽  
Vol 68 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Yu.N. Elkin ◽  
N.I. Shulga ◽  
T.I. Vakorina ◽  
A.K. Dzizenko
Keyword(s):  
Partial Methylation
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