Phase-sensitive heteronuclear multiple-bond correlation in the presence of modest homonuclear coupling. Application to distamycin A

1989 ◽  
Vol 82 (3) ◽  
pp. 605-612 ◽  
Author(s):  
D.S Williamson ◽  
R.A Smith ◽  
D.L Nagel ◽  
S.M Cohen
Keyword(s):  
Multiple Bond ◽  
Heteronuclear Multiple Bond Correlation ◽  
Distamycin A ◽  
Phase Sensitive

Gradient-Enhanced Inverse-Detected NMR Techniquesfor Determination of 1H-15N Coupling Constants in 2,2-Dimethylpenta-3,4-dienal Derivatives

1997 ◽  
Vol 62 (11) ◽  
pp. 1747-1753 ◽  
Author(s):  
Radek Marek
Keyword(s):  
Double Bond ◽  
Chemical Shifts ◽  
Multiple Bond ◽  
Coupling Constants ◽  
Single Quantum ◽  
Nmr Techniques ◽  
Phase Sensitive ◽  
Heteronuclear Coupling

Determination of 15N chemical shifts and heteronuclear coupling constants of substituted 2,2-dimethylpenta-3,4-dienal hydrazones is presented. The chemical shifts were determined by gradient-enhanced inverse-detected NMR techniques and 1H-15N coupling constants were extracted from phase-sensitive gradient-enhanced single-quantum multiple bond correlation experiments. Stereospecific behaviour of the coupling constants 2J(1H,15N) and 1J(1H,13C) has been used to determine the configuration on a C=N double bond. The above-mentioned compounds exist predominantly as E isomers in deuteriochloroform.

High-quality oligo-RNA synthesis using the new 2′-O-TEM protecting group by selectively quenching the addition of p-tolyl vinyl sulphone to exocyclic amino functions

2007 ◽  
Vol 85 (4) ◽  
pp. 293-301 ◽  
Author(s):  
Chuanzheng Zhou ◽  
Wimal Pathmasiri ◽  
Dmytro Honcharenko ◽  
Subhrangsu Chatterjee ◽  
Jharna Barman ◽  
...  
Keyword(s):  
Michael Addition ◽  
Chemical Biology ◽  
Rna Synthesis ◽  
Spectroscopic Analysis ◽  
Multiple Bond ◽  
Protecting Group ◽  
High Quality ◽  
Heteronuclear Multiple Bond Correlation ◽  
Michael Adducts

During the F–-promoted deprotection of the oligo–RNA, synthesized using our 2′-O-(4-tolylsulfonyl)ethoxymethyl (2′-O-TEM) group [Org. Biomol. Chem. 5, 333 (2007)], p-tolyl vinyl sulphone (TVS) is formed as a by-product. The TVS formed has been shown to react with the exocyclic amino functions of adenosine (A), guanosine (G), and cytidine (C) of the fully deprotected oligo–RNA to give undesirable adducts, which are then purified by HPLC and unambiguously characterized by 1H, 13C Heteronuclear Multiple Bond Correlation (HMBC) NMR and mass spectroscopic analysis. The relative nucleophilic reactivities of the nucleobases toward TVS have been found to be the following: N6–A > N4–C > N2–G > > N3–U. This reactivity of TVS toward RNA nucleobases to give various Michael adducts could, however, be suppressed by using various amines as scavengers. Among all these amines, morpholine and piperidine are the most efficient scavenger for TVS, which gave highly pure oligo–RNA even in the crude form and can be used directly in RNA chemical biology studies.Key words: RNA synthesis, RNA alkylation, p-tolyl vinyl sulphone, Michael addition.

scholarly journals Chemical Constituents of Tagetes patula and Their Neuroprotecting Action

2020 ◽  
Vol 15 (11) ◽  
pp. 1934578X2097450
Author(s):  
Linlin Liu ◽  
Simin Luo ◽  
Miao Yu ◽  
Ahmed M. Metwaly ◽  
Xiaoku Ran ◽  
...  
Keyword(s):  
High Performance ◽  
Chemical Constituents ◽  
Multiple Bond ◽  
Tagetes Patula ◽  
Chemical Methods ◽  
Heteronuclear Multiple Bond Correlation ◽  
Flight Mass Spectrometry ◽  
Whole Plant ◽  
Heteronuclear Single Quantum Correlation ◽  
Neuroprotective Action

Two novel flavonoids (1, 2) and 3 known compounds (3-5) were isolated from the flowers and whole plant of Tagetes patula L., and their structures were elucidated by means of ultra-high performance liquid chromatography with electrospray ionization, coupled to quadrupole-time-of-flight/mass spectrometry, 1H and 13C-nuclear magnetic resonance (NMR), as well as 2-dimensional-NMR (heteronuclear single quantum correlation and heteronuclear multiple bond correlation) and chemical methods. In addition, all the compounds were examined for their neuroprotective action on the injury of SH-SY5Y cells induced by glutamate, indicating that the protective effect of these compounds on glutamate-induced SH-SY5Y cell was marigold biflavone > patuletin > quercetin > kaempferol-3- O-β-d-glucoside > patuletin-3- O-α-l-arabinopyranoside. Thus, it could be concluded that flavonoids played a key role in the neuroprotective action of T. patula.

scholarly journals 5-(6-Hydroxy-6-methyl-5-oxoheptan-2-yl)-2-methyl Phenyl Acetate

Molbank ◽  
10.3390/m1041 ◽  
2018 ◽  
Vol 2019 (1) ◽  
pp. M1041
Author(s):  
Maya Rahayu ◽  
Susi Kusumaningrum ◽  
Hayun Hayun
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Fourier Transform ◽  
Mass Spectra ◽  
Multiple Bond ◽  
Phenyl Acetate ◽  
Two Dimensional ◽  
Heteronuclear Multiple Bond Correlation ◽  
1H Nuclear Magnetic Resonance ◽  
Resolution Mass ◽  
Methyl Phenyl

We synthesized a novel compound, 5-(6-hydroxy-6-methyl-5-oxoheptan-2-yl)-2-methylphenyl acetate, in a good yield by oxidation of 1-O-acetyl-xanthorrizol using potassium permanganate in acidic condition. The structure was elucidated by Fourier Transform Infrared (FTIR), 1H-Nuclear Magnetic Resonance (NMR) and 13C-NMR, two-dimensional (2D)-HSQC, Distortionless Enhancement by Polarization Transfer (DEPT), 2D-Heteronuclear Multiple Bond Correlation (HMBC), and High-Resolution Mass Spectra (HRMS) spectral data.

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