NMR two-dimensional exchange spectroscopy (EXSY) has been applied to measure the chemical exchange rate constants between water and hydroxyl protons in three natural organic compounds that contain four to eight hydroxyl groups. In data treatment, the simple geometric average (GA) method has been used. Application of the GA method to assumed exchange systems has indicated that the method is reliable.

A series of 1,3-oxazino[3,2-d] [1,5] benzodiazepine-1-one derivatives' stereochemistry was studied by ¹H NMR. During the ¹H NMR experiments, we found out their unique stereochemistry of seven-membered rings. All the discernible hydrogen's chemical shifts were assigned. Their distorted boat conformations were discovered by the related coupling constants and gNOESY results, which were compared with x-ray diffraction result and the conformation of analogous benzothioazepines.

A novel phenylpropanoid glycoside, named Martynoside, was isolated from cassiope selaginoids Hook. f.et T.Thoms. The structure of this glycoside was identified by spectral methods, including IR.MS. ¹H NMR, ¹³C NMR, DEPT, ORD, NOEDS and two dimensional Long-range coupling techniques.

By means of 2D NMR techniques, such as HMQC TOCSY,TOCSY,ROESY,HMQC,HMBC and COSY, the structures of chloromaloside A and B, two new C-27 steroidal saponins from Chlorophytum malayense were confirmed. Their complete assignment of ¹H and ¹³C NMR chemical shifts were also obtained.

The MDM2 oncoprotein is a cellular inhibitor of the P53 tumor suppressor in that it can bind the transactivation domain of P53 and downregulate its ability to activate transcription. In certain cancers, MDM2 amplification is a common event and contributes to the inactivation of P53. The crystal structure of the MDM2 bound to P53 has been analysised through x-ray crystallography. The crystal structure provides a framework for the discovery of compounds that may prevent the activation of the P53 tumor suppressor by the MDM2 oncogene in cancer. Inhibitors of the MDM2 oncogene have been synthesized on the base of this theory.
All assignments of inhibitors were obtained from ¹H、¹³C、¹H-¹H COSY、HMQC and HMBC spectra. With regarded to count space distance of two benzene rings, three-bond coupling constants were utilized to determine the structure of inhibitors. Sterostructures and relative configurations were discussed, and dominant energy was computed by using Sybyl software.

This paper reports some interesting prollemsion solution chemistry of V/S,V/Fe/S and Mn/O cluster compounds by their NMR studies.
The ¹H NMR spectrum of[V₄S₄(C₄H₈NCS₂)₆]^- shows three broad resonances at 4.77, 5.17 and 7.57ppm which were assigned to the α-H of C₄H₈NCS₂ ligands in terminal and bridged ligations. The signals of free C₄H₈NCS₂ are also observed, which occur from an exchange between the R₂NCS₂ ligand and the solvent molecules.
The ¹H NMR spectra of a series of[VFe₃S₄(R₂NCS₂)₄]^- were determined in DMSO-d₆, exhibiting two sets of signals assigned to the α-H of the R₂NCS₂ ligands linking to V and Fe sites, respectively. A broad peak centered at 19.6ppm for complex 2 or at 33ppm for 3 was found to grow up with time going on, indicating the formation of Fe₄S₄(R₂NCS₂)₄(R₂=OC₄H₈,Et₂). This assignment was identified by a dynamic tracing ¹H NMR experiment in which Fe₄S₄(R₂NCS₂)₄ was synthesized and its ¹H NMR signals were monitored. A possible metal exchange accompanying the formation of Fe₄S₄(R₂NCS₂)₄ in DMSO solution was suggested.
The ¹H NMR spectrum of mononuclear Mn bpy complex 4 containing H₂O and NO₃ ligands was determined, indicating the exchangeability of these monodentate ligands, which makes 4 become an inclusion compound including two mononuclear Mn molecules.

The egg yolk phosphatidylcholine(PC) liposomes loaded with bufalin(BF) were prepared so as to improve BF's therapeutic effect. The effects of BF on PC model membrane have been examined using the ³¹P NMR spectroscopy. The results show that the incorporation of BF into PC liposome can stabilize the lipid bilayer structure of PC, with the basal linewidth of the ³¹P spectrum increasing with increasing the content of BF in liposome. This may be related to the formation of hydrogen bonding between BF and polar headgroup of PC, or insertion of BF into PC by hydrophobic interaction. On the other hand, it was found for the first time that after exposure to ultrasonic waves, pure PC shows an additional narrow peak at the isotropic chemical shift (i.e., about 0.23ppm) in its ³¹P spectrum which corresponds to the mobile lipidic particles, e.g., micelles or small resicles, and furthermore, the addition of BF can significantly trigger such a transition from the phospholipid bilaryer to the micellar phase. This could be explained by the insertion of BF into the micellar phase or the formation of mobile BF-PC complexes. These studies demonstrate that the presence of BF has two-sided effect on the membrane structure of PC, depending on the preparation conditions of the liposome. Therefore, on preparing the BF-loaded liposome, partial attention should be paid to the potential influence of the preparation conditions on the structure and then physiochemical properties of the liposome, in addition to the effects of the medicine itself.

m1c8 and m4G3 are selenium-contaning abzymes with glutathione peroxidase activity and the two abzymes could scavenge free radicals.Their abilities to scavenge OH· were examined in iron containing Xanthine oxidase/hypoxathine system by using spin trapping method. It was found that the abilities of these two Se-abzymes to scavenge OH· did surpass the level of native glutathione peroxidase. m1c8 was the best one.

Diffusion weighted NMR spectroscopy was proposed and applied to the identification of the products of the chemical reaction. The method was demonstrated using a reaction of histidine and a poly-saccharide.

Through the study on longitudinal relaxation determination of the two-site fast exchange system of H₂O and Fe(H₂O)₆³⁺, it was found that under the condition of the experiment, the express forms of the observed longitudinal rates of weight average and relaxivity of Fe³⁺ were the same, then the relaxation rate of Fe(H₂O)₆³⁺ was obtained. It would be helpful in studying the complexes of ions and H₂O in water solution.

The maintenance of the concentration of intracellular Na⁺([Na⁺]_i) and the concentration gradient across plasma membrane plays critical roles in maintaining normal cell physiological function. The[Na⁺]_i of intact functioning biological samples can be measured by non invasive ²³Na NMR. The intra-and extracellular Na⁺ can be simultaneously quantified by using frequency chemical shift reagents (DyTTHA^3- and TmDOTP^5-), thereby permitting quantitative assessment of net Na⁺ movement. ²³Na NMR can be used to study Na⁺ changes in various physiological and pathological states and to diagnose disease. The information derived from ²³Na NMR help us to understand the mechanism of pathological changes such as ischemia and reperfusion injury, diabetes, osteoarthritis, liver dysfunction induced by burn trauma, and so on.

This paper reviewed structural and ¹H NMR spectroscopic characteristics of lignans from plants of Schisandraceae.