From structure to chemical shift and vice-versa

Hunter, Christopher A.; Packer, Martin J.; Zonta, Cristiano

doi:10.1016/j.pnmrs.2005.06.001

Cited by 42 publications

(20 citation statements)

References 145 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…. [40] We have measured the same previously unreported proton couplings of strychnine with our new pulse sequence obtaining similar but slightly higher values (see Supporting Information) together with an additional coupling constant, 5 J(H-15b,H-22), close to our experimental resolution of 1.0 Hz (calcd 0.7 Hz).…”

Section: Resultssupporting

confidence: 74%

“…[2] While automated routines, based on database queries or other predictor systems, [3][4][5] have become increasingly popular and successful, their scope is limited to structures similar to those for which the system has been validated, but "unusual" molecules (often a valuable asset in natural-product chemistry) may not be properly treated by using these approaches.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Toward the Complete Prediction of the ¹H and ¹³C NMR Spectra of Complex Organic Molecules by DFT Methods: Application to Natural Substances

Bagno

Rastrelli

Saielli

2006

Chemistry A European J

195

200

View full text Add to dashboard Cite

The NMR parameters (1H and 13C chemical shifts and coupling constants) for a series of naturally occurring molecules have been calculated mostly with DFT methods, and their spectra compared with available experimental ones. The comparison includes strychnine as a test case, as well as some examples of recently isolated natural products (corianlactone, daphnipaxinin, boletunone B) featuring unusual and/or crowded structures and, in the case of boletunone B, being the subject of a recent revision. Whenever experimental spectra were obtained in polar solvents, the calculation of NMR parameters was also carried out with the Integral Equation-Formalism Polarizable Continuum Model (IEF-PCM) continuum method. The computed results generally show a good agreement with experiment, as judged not only by statistical parameters but also by visual comparison of line spectra. The origin of the remaining discrepancies is attributed to the incomplete modeling of conformational and specific solvent effects.

show abstract

Section: Resultssupporting

confidence: 74%

Section: Introductionmentioning

confidence: 99%

Toward the Complete Prediction of the ¹H and ¹³C NMR Spectra of Complex Organic Molecules by DFT Methods: Application to Natural Substances

Bagno

Rastrelli

Saielli

2006

Chemistry A European J

195

200

View full text Add to dashboard Cite

show abstract

“…The first binding event is related to the formation of the ion‐pair, and the following complexation is associated with the formation of the ternary complex. As expected, the chemical shifts' variations observed are small for all the binding events 63, 64. As shown by the crystals, the aromatic rings of BTZ , which are the only functional groups owning a strong magnetic anisotropy, are distant from the protons of the amine.…”

Section: Resultssupporting

confidence: 77%

Regulation of Transcription by Synthetic DNA‐Bending Agents

Bednarski¹,

Firestine²

2006

ChemBioChem

View full text Add to dashboard Cite

Gene expression is regulated by a complex interplay between binding and the three-dimensional arrangement of transcription factors with RNA polymerase and DNA. Previous studies have supported a direct role for DNA bending and conformation in gene expression, which suggests that agents that induce bends in DNA might be able to control gene expression. To test this hypothesis, we examined the effect of triple-helix-forming oligonucleotide (TFO) bending agents on the transcription of luciferase in an in vitro transcriptional/translational system. We find that transcription is regulated only by a TFO that induces a bend in the DNA. Related TFOs that do not induce bends in DNA have no effect on transcription. Reporter expression can be increased by as much as 80 % or decreased by as much as 50 % depending on the phasing of the upstream bend relative to the promoter. We interpret the results as follows: when the bend is positioned such that the upstream DNA is curved toward the RNA polymerase on the same DNA face, transcription is enhanced. When the upstream DNA is curved away, transcription is attenuated. These results support the hypothesis that DNA-bending agents might have the capability to regulate gene expression, thereby opening up a previously undervalued avenue in research on the artificial control of gene expression.

show abstract

“…The methyl group is forced to the center of the aromatic shielding region of complex (R)-1c explaining the higher variation in chemical shifts observed. 28 The key role of p-p interactions is confirmed when an aliphatic sulfoxide was used. In the case of racemic n-octyl methyl sulfoxide, large variations of chemical shifts were observed (around 0.6 ppm) without any significant signal splitting.…”

Section: Resultsmentioning

confidence: 95%

Enantiopure Ti(IV) amino triphenolate complexes as NMR chiral solvating agents

et al. 2011

Self Cite

View full text Add to dashboard Cite

Enantiopure Ti(IV) complexes bearing pseudo-C(3) amino triphenolate ligands have been synthesized and characterized. The complexes bearing ortho phenyl groups act as (1)H NMR chiral solvating agent (CSA) for the stereochemical analysis of a series of sulfoxides. The coordination of a Lewis base coligand (sulfoxide) and the presence of aromatic rings are the key structural factors for the efficiency of the CSA.

show abstract

From structure to chemical shift and vice-versa

Cited by 42 publications

References 145 publications

Toward the Complete Prediction of the ¹H and ¹³C NMR Spectra of Complex Organic Molecules by DFT Methods: Application to Natural Substances

Toward the Complete Prediction of the ¹H and ¹³C NMR Spectra of Complex Organic Molecules by DFT Methods: Application to Natural Substances

Regulation of Transcription by Synthetic DNA‐Bending Agents

Enantiopure Ti(IV) amino triphenolate complexes as NMR chiral solvating agents

Contact Info

Product

Resources

About

From structure to chemical shift and vice-versa

Cited by 42 publications

References 145 publications

Toward the Complete Prediction of the 1H and 13C NMR Spectra of Complex Organic Molecules by DFT Methods: Application to Natural Substances

Toward the Complete Prediction of the 1H and 13C NMR Spectra of Complex Organic Molecules by DFT Methods: Application to Natural Substances

Regulation of Transcription by Synthetic DNA‐Bending Agents

Enantiopure Ti(IV) amino triphenolate complexes as NMR chiral solvating agents

Contact Info

Product

Resources

About

Toward the Complete Prediction of the ¹H and ¹³C NMR Spectra of Complex Organic Molecules by DFT Methods: Application to Natural Substances

Toward the Complete Prediction of the ¹H and ¹³C NMR Spectra of Complex Organic Molecules by DFT Methods: Application to Natural Substances