Apparent proton transverse relaxation times of the hydrophilic group (N-CH₃) were measured in aqueous solution of surfactant CTAB with different concentrations using the CPMG pulse sequence, and found to be dependent on the interpulse delay between the refocusing pulses (τcp). This indicates that diffusion and/or chemical exchange contribute to the transverse relaxation process of the N-CH₃ protons. It was observed that the apparent transverse relaxation time has a linear relationship with τ²_cp when τ_cp≤1 ms, but becomes independent on τ_cp when τ_cp≥4.6 ms. Using the Luz-Meiboom two-site chemical exchange model, the chemical exchange rates of the N-CH₃ protons at different concentrations were calculated and found to change from 1.57 ms^-1 to 1.15 ms^-1 at the critical micelle concentration (CMC), behaving similarly as the intrinsic transverse relaxation time and selfdiffusion coefficient D. Change of the chemical exchange rate at CMC is probably a reflection of alteration of the exchange dynamics of adjacent CTAB molecules when micelles are formed.

A composite of poly (ethylene oxide) (PEO) and fullerene (C₆₀) was prepared by lyophilization, and studied by high-resolution solid-state NMR spectroscopy. The ¹H spin-spin relaxation time  (T₂) of the composite was measured by ¹H-¹³C cross-polarization experiments with different contact times. It was found that the choice of contact time influence the results of intermolecular cross-polarization experiments, implying that extra care should be taken to select appropriate contact time when applying the intermolecular crosspolarization method to study the phase structures of composites. On the other hand, variation of contact time may provide a new dimension for experimental design and be used to gain information that is not obtainable in conventional experiments with fixed contact time. For example, the results of our experiments showed that in the PEO/C₆₀ composite not all the fullerene molecules are confined in the noncrystalline region of PEO, at least a portion of the C₆₀ molecules are located close to the crystalline region.

The dynamic behaviors of the lamellar and hexagonal liquid crystalline phases of PEO-PPO-PEO/D₂O/p-xylene composite were studied by ²H NMR spectroscopy. ²H powder spectra and ²H spin-lattice and spinspin relaxation times were measured in two samples with different compositions. All spectra showed powder lineshape with quadrupole splitting and a reversed peak at the center when β_LD=54.7°, indicating that the dominant dynamic process that modulates the quadrupole interaction is in the extreme narrowing region. Dynamic parameters of the studied systems were obtained by fitting the experimentally measured ²H spectra, spin-lattice and spin-spin relaxation times and the intensity of the reversed peak to a theoretical NMR relaxation model.

Forming performances of Sm\-2O\-3 doped BaO-B₂O₃-Al₂O₃-SiO₂-Sm₂O₃ (BBASS) glass systems have been assessed in previous studies. In this study, magic angle spinning (MAS) NMR spectroscopy and differential thermal analysis (DTA) test were employed to characterize glass structure and to study the factors affecting glass structure, such as glass composition and conditions for heat-treatment, in such glass systems. In BBAS glass without rare earth doping, the boron coordination were mainly [BO₃] and [BO₄] and the aluminum coordination were mainly[AlO₄], [AlO₅] and [AlO₆]. It was found that, with the increase of BaO content in the BBAS glass, [BO₃] gradually became [BO₄], and [AlO₅]/[AlO₆] gradually changed to [AlO₄]. Sm³⁺ could accumulate in the glass with large amount, facilitating [BO₄] to form a large network. It was also found that heat-treatment had little or no effect on the boron and aluminum coordination in the glass structure.

Linear models are often used to describe the relationship between nuclear spin-spin coupling constant and structural parameters, despite it has been shown that calculation using these models often result in large errors. Based on the results of previous works, a non-linear model was proposed in this study to describe the relationship between the spin-spin coupling constants of the C-F bonds and the chemical environment they are in. Back propagation (BP) neural network analysis was used to fit the experimental data to the model. The accuracy of the model proposed was tested in four compounds, and it was shown that the non-linear model fitted by BP neural network analysis provides much better predictions than the commonly used linear models. Calculation errors for the four test compounds were less than 0.4% when the nonlinear model was used.

An amino alcohol and its hydrolysate, which are potential glycosidase inhibitors, were synthesized from C10 higher carbon sugar. The structures of these novel higher carbon sugar-derived compounds were elucidated by NMR. The ¹H and ¹³C chemical shifts of the hydrolysate of the amino alcohol were completely assigned by 2D NMR techniques including ¹H-¹H COSY, HMQC and HMBC.

This paper provided an equation: δ_cal=δ_0n+C×Δα for calculating the ¹⁷O chemical shifts of carbonyl groups in aliphatic ketones and acyl halides. Twenty two substituent parameters for the equation were obtained with least\|square linear regression. Experimentally measured ¹⁷O chemical shifts from 61 aliphatic ketones and acyl halides were used as the test set to examine the accuracy of the calculated results. The confidence limit was found to be 99.5% and the calculating errors for about 90% of the compounds were less than 10.0 (relative errors 1.0%).

An equation: δ_cal=550.0+Δo+Δm+Δp for calculating the ¹⁷O NMR chemical shifts of the carbonyl groups in substituted acetophenones was provided. Twelve substituent parameters for the equation were obtained with least-square linear regression. Experimentally measured ¹⁷O chemical shifts from 44 substituted acetophenones were used as the test set to examine the accuracy of the calculated results. The confidence limit was found to be 99.5% and the calculating errors for about 90% of the compounds were less than 5.0 (relative errors 0.5%).

A new isoflavone and two compounds with similar structures, namely 5, 7, 3′-trihydroxy-6, 2′, 5′-trimethoxyisoflavone, 5, 7, 3′-trihydroxy-6, 4′, 5′-trimethoxyisoflavone (irigenin) and its glucoside (iridin), were isolated from Belamcanda chinensis. The structures of these compounds were determined by ¹H  and ¹³C NMR spectroscopy. The structure of the new isoflavone was further verified by combined use of mass spectroscopy and 2D NMR techniques including HMBC, HSQC and NOESY.

Valacyclovir hydrochloride, 2-[(2-amino-1，6-dihydro-6-oxo- 9H-purine-9-yl)methoxy] ethyl-L-valinate  hydrochloride, was synthesized from purine through acetylation, hydrolysis, condensation and deprotection reactions. The structure of the target compound was elucidated by combined use of mass spectroscopy and 1D/2D NMR techniques including ¹H  and ¹³C NMR, DEPT, ¹H-¹H COSY, HMQC and HMBC. The ¹H and ¹³C chemical shifts of the compound were completely assigned.

Two limonoid compounds, xyloccensin K and 6-acetoxycedrodrorin, were isolated from the fruit of xylocarpus granatum. Their structures were elucidated by 1D and 2D NMR spectroscopy. It was shown that previous chemical shift assignment for some of the ¹H and ¹³C signals of xyloccensin K is incorrect. Correction was made for the incorrect assignment.

Protein-ligand interaction studies play an important role in understanding of biological science, drug screening and drug design, thus have both scientific and economic meanings. In this review, NMR techniques that are being widely employed to study protein-ligand interaction are summarized. The important parameters used to characterize the intermolecular interaction are introduced firstly, followed by descriptions of the approaches for identifying interaction regions and how to extract valuable information related to intermolecular interaction. Finally, the NMR techniques that have been applied to map protein-ligand interaction are introduced with application examples.