Geoffrey Bodenhausen

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Procedures are described for automated anal. of two-dimensional NMR spectra correlating the chem. shifts of carbon-13 with the shifts of neighbor protons that are directly attached to the carbon-13 nuclei and with remote protons that have scalar couplings to the neighbor protons. The anal. yields connectivity matrixes with quality factors that provide a measure for the reliability of the evidence. The connectivity matrixes can be represented graphically either by drawing the paths of magnetization transfer

In NMR of spins with I = 1/2 in an isotropic phase, it is demonstrated by simulation and expt. that virtually unlimited bandwidths can be decoupled effectively by using chirp pulses with linear frequency modulation for adiabatic inversion combined with phase-cycles and supercycles similar to those used in composite pulse decoupling. The av. radio-frequency amplitude required is modest compared to other techniques. In applications with inhomogeneous radio-frequency fields, as in magnetic resonance imaging an

Two methods, based on the phase modulation of spin-echo signals due to J-coupling, of selective simplification of coupled homonuclear spectra are described. Both pulse methods employ a 90 Deg-t-180 Deg-t spin-echo sequence to prep. suitable phases of the magnetization in the rotating frame. For t = (4J)-1, all doublet magnetization vectors have opposite phases, parallel to the phase of the initial pulse. The 1st method uses a single 45 Deg pulse, with a phase F alternating between +y and -y and addn. of the

A method is described to det. long-range cross-correlations between the modulations of an anisotropic chem. shift (e.g., of a C' carbonyl carbon in a protein) and the fluctuations of a weak long-range dipolar interaction (e.g., in cross-correlation between the same C' carbonyl and the HN proton of the neighboring amide group). Such long-range correlations are difficult to measure because the corresponding long-range scalar couplings are so small that Redfield's secular approxn. is often violated. The method

A fully analytical description of the control of the cross-correlated cross relaxation of multiple-quantum coherences in the presence of local dynamics under heteronuclear double-resonance radio-frequency (RF) irradiation is presented. The contribution of chemical exchange to relaxation can be partly or fully quenched by RF fields. We assume a correlated two-site chemical exchange model with arbitrary populations, and show that in the limit of fast exchange the dependence of the effective multiple-quantum c

New schemes are introduced that allow one to improve the resolution in the indirect dimension of single-scan 'ultrafast' two-dimensional NMR spectra. The methods combine undersampling with band-selective pulses to recover signals that lie outside the detec ...

We show that dynamic nuclear polarization (DNP) can be used to enhance NMR signals of C-13 and Si-29 nuclei located in mesoporous organic/inorganic hybrid materials, at several hundreds of nanometers from stable radicals (TOTAPOL) trapped in the surroundin ...

Relaxation processes induced by the antisymmetric part of the chemical shift anisotropy tensor (henceforth called anti-CSA) are usually neglected in NMR relaxation studies. It is shown here that anti-CSA components contribute to longitudinal relaxation rates of the indole N-15 nucleus in tryptophan in solution at different magnetic fields and temperatures. To determine the parameters of several models for rotational diffusion and internal dynamics, we measured the longitudinal relaxation rates R-1=1/T-1 of

A new expression for the spectral d. function of cross-correlated dipole-dipole interference is proposed. It allows one to assess to what extent anisotropic rotational diffusion results in complications in the interpretation of cross-correlation rates. The 13Ca-1Ha vectors undergoing significant local motion were detd. The importance of rotational anisotropy for human ubiquitin was evaluated. The comparison between cross-correlation rates predicted for a set of hydrodynamic parameters with exptl. rates and

In a preliminary communication (B. Baishya, T. F. Segawa, G. Bodenhausen, J. Am. Chem. Soc. 2009, 131, 17538–17539), we recently demonstrated that it is possible to obtain clean echo decays of protons in biomolecules despite the presence of homonuclear scalar couplings. These unmodulated decays allow one to determine apparent transverse relaxation rates R2app of individual protons. Herein, we report the observation of R2app for three methyl protons, four amide HN protons, and all 11 backbone Hα protons in c

Transverse and longitudinal relaxation times (T11 and T1) have been widely exploited in NMR to probe the binding of ligands and putative drugs to target proteins. We have shown recently that long-lived states (LLS) can be more sensitive to ligand binding. ...

The populations of long-lived spin states, in particular, populations of singlet states that are comprised of antisymmetric combinations of product states, ∣αIβS⟩−∣βIαS⟩, are characterized by very long lifetimes because the dipole-dipole interaction betwee ...

Hyperpolarization by dissolution dynamic nuclear polarization (DNP) enhances Y-89 spin magnetization by 3 to 4 orders of magnitude and provides a way to monitor yttrium-ligand complexation "on the fly" by means of Y-89 NMR. In this communication, we show a ...

The mobility of 15N labeled proteins can be characterized by measuring the cross-correlation rates dN,NI that govern the conversion of Zeeman order Nz of an amide 15N nucleus into longitudinal two-spin order 2NzIz involving the amide 15N and 1H nuclei. This represents an alternative to the measurement of 15N self-relaxation rates 1/T1 and 1/T2 or 1/T1r. The rate of interconversion between Nz and 2NzIz is due to cross-correlation between fluctuations of different interactions and is not affected by a variety

New NMR techniques are described for transferring transverse magnetization between scalar-coupled nuclei in the rotating frame. The methods involve simultaneous spin-locking of two selected spins A and X, using cosinusoidal modulation of the radio frequency (rf) carrier. If transverse magnetization of spin A is excited selectively before spin-locking, for example with a self-refocusing 270 Deg Gaussian pulse, in-phase magnetization will be transferred from spin A to spin X, and in-phase multiplets are obtai

Phase-modulated spin echoes were generated by a 90-180 Deg pulse sequence applied to some strongly coupled proton spin systems (AB, ABX, and ABC), and the modulation was analyzed by 2-dimensional Fourier transformation. Projection of the resulting 2-dimensional spectra onto the F1 axis leads to a J spectrum, whereas projection onto the F2 axis gives the conventional NMR spectrum. Anal. solns. are presented which correctly predict the shape of the AB and ABX J-spectra, and an iterative numerical anal. were u

In scalar-coupled spin systems where in-phase and antiphase coherences have different lifetimes, the envelopes of spin echoes may feature modulations that are induced by relaxation. These modulations are most pronounced when the couplings that lead to the interconversion of in-phase and antiphase coherences are too small to provide an effective mechanism for averaging. The modulations occur even if the scalar coupling term is formally eliminated from the av. Hamiltonian that describes the evolution between

In order to achieve selective inversion of a chosen family of sidebands in NMR spectra of solids rotating at the magic angle (MAS spectra), a sequence of so-called DANTE pulses can be applied in synchronization with the sample rotation period. It is shown by simulation and expt. that the profiles of the offset dependence can be greatly improved by varying the amplitudes of the DANTE pulses, so that the envelope corresponds to that of a G3 Gaussian cascade. Alternatively, the DANTE pulses may be replaced by

Trains of short pulses in the manner of `delays alternating with nutations for tailored excitation' (DANTE) have been applied to the Pake patterns of protons of water molecules trapped in a static powdered sample of barium chlorate monohydrate. The spin dy ...

A new NMR method has been designed for the measurement of the longitudinal relaxation rates of both donor and acceptor nitrogen-15 nuclei in Watson-Crick base pairs in 15N-enriched nucleic acids. The expt. was applied to a 22-nucleotide RNA hairpin. The lengths of four hydrogen bonds could be estd. from the longitudinal relaxation rates. [on SciFinder (R)]

Geoffrey Bodenhausen

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Analysis of two-dimensional nuclear magnetic resonance spectra with relayed proton-proton-carbon magnetization transfer: a step toward automated structure elucidation

Broadband decoupling in NMR with frequency-modulated 'chirp' pulses

Selective removal of magnetization in coupled NMR spectra

Measurement of long-range cross-correlation rates using a combination of single- and multiple-quantum NMR spectroscopy in one experiment

Control of Cross Relaxation of Multiple-Quantum Coherences Induced by Fast Chemical Exchange under Heteronuclear Double-Resonance Irradiation

Improving resolution in single-scan 2D spectroscopy

Mesoporous Silica Nanoparticles Loaded with Surfactant: Low Temperature Magic Angle Spinning C-13 and Si-29 NMR Enhanced by Dynamic Nuclear Polarization

Determination of the antisymmetric part of the chemical shift anisotropy tensor via spin relaxation in nuclear magnetic resonance

Anisotropy of rotational diffusion, dipole-dipole cross-correlated NMR relaxation and angles between bond vectors in proteins

Transverse Relaxation of Scalar-Coupled Protons

Drug Screening Boosted by Hyperpolarized Long-Lived States in NMR

Molecular Properties Determined from Relaxation of Long-Lived Spin States

Kinetics of Yttrium-Ligand Complexation Monitored Using Hyperpolarized 89Y as a Model for Gadolinium in Contrast Agents

Local mobility of 15N labeled biomolecules characterized through cross-correlation rates: applications to paramagnetic proteins

Coherence transfer in nuclear magnetic resonance by selective homonuclear Hartmann-Hahn correlation spectroscopy

NMR spectra of some simple spin systems studied by two-dimensional Fourier transformation of spin echoes

Relaxation-induced oscillations of spin-echo envelopes

Shaped pulses for selective inversion of magnetization in solids spinning at the magic angle

Exciting Wide NMR Spectra of Static Solid Samples with Weak Radiofrequency Fields

Hydrogen bonds lengths in nucleic acids estimated from longitudinal nitrogen-15 relaxation