Polyene macrolide antibiotic is composed of 25 to 37 carbons with conjugated polyene fragment, substituted by hydroxyl and glycosidation of aminopolysaccharide. It has the characteristics of light unstability, wide antifungal spectrum, low toxicity by intravenous injection, high toxicity by oral administration. In this paper, it was reported that the idntification and detailed assignment of Lucensomycin, antifungal active substance produced from actinomycetes-1356, by means of UV, IR, MS, 1D and 2D NMR technology. Furthermore, the deficiency of 13C NMR data for olefinic carbons reported in literature was also corrected and the regularity for NMR data of polyene macrolide was summarized.

The correlation time, τ_c, and the nuclear quadrupolar coupling constant (NQCC) of I>1/2 nuclei are important parameters for characterizing local and microdynamic structures of molecules. However, it is often difficult to determine those constants in solution. In this study, τc and NQCC of the ⁵⁹Co nuclei were determined for a series of supercomplexes [12] aneN₄[Co(CN)₆], [18]aneN₆[Co(CN)₆], [24]aneN₈[Co(CN)₆], [16]aneN₄[CoCN)₆], [24]aneN₆[Co(CN)₆] and [32]aneN₈[Co(CN)₆] in dilute solution. The Dynamic Laser Light Scattering (DLLS) method, which is now widely used in macromolecule research, was first applied to determine the hydrodynamic radii (0.4～0.6 nm) of these molecules. Based on the Stokes-Einstein-Debye equation and the measured hydrodynamic radii, the rotational reorientation correlation times τ_c were calculated. τ_c obtained in this study had a range of 3.8～9.5×10^-11s, which arefairly reasonable for molecules with molecular  weights of about 300～500. Finally, NQCC of the ⁵⁹Co nuclei in the supercomplexes were determined by combining the τ_c values calculated and the experimentally measured longitudinal relaxation times, T₁, of the ₅₉Co nuclei. The NQCC values obtained ranged from 0.5 to 2.2 MHz, which are considerably lower than those extracted from solid static NMR lineshape (5 to 7 MHz). The difference is probabl
y due to the structural effects originating from the anisotropy of local electric gradient around ⁵⁹Co nucleus in solid.

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¹H spin-spin (T₂) relaxation times of sodium 4-decyl naphthalene sulfonate (SDNS) protons at different concentrations of 0.82 and 2.59 mmol/L were meas
ured at 298, 303 and 313 K. These T₂ values give the information about the dynamic characteristic of SDNS molecules in their monomeric and micellar states. The decrease in the T₂ values of a part of SDNS micellar protons, which participate in the formation of the palisade layer, with the increase in temperature suggests that the palisade layer becomes more tightly compact with the increase in temperature in order to prevent water penetration into the hydrophobic micellar core. While the reverse effect of the other protons in the T₂ values with the temperature up to 313 K shows that their motion of those protons is enhanced.

The intrinsic point defects of GaP nanocrystals were investigated by electron paramagnetic resonance (EPR). The g value of GaP nanocrystals EPR si
gnal observed was 2.0027±0.0004, suggesting the existence of Ga self-interstitial defect. Collapse of hyperfine splitting and narrowing of peak-to-peak linewidth (ΔH_PP) were observed, probably resulting from interface disorders and rapid electron exchange between the defect atoms and the interface atoms. In lower measuring temperature range, increase of temperature led to occurrence of grain boundary relaxation of GaP nanocrystals. The value of both ΔH_PP and concentration of dangling bound decrease as the measuring temperature increased from 100 K to 423 K.

Poly(aryl-ether-ether-ketone)copolymers containing 1,5-Naphthalene moieties have been heated at 340 ℃ in air for different time, and it has been sho
wn that crosslinks are formed under oxidative condition, causing a reduction in the crystallizability of the material. Using ESR spectroscopy, we investigated t
he radicals generated from P(EEK-co-20 mol% ENEK) random copolymers heated at 340 ℃ in air and in nitrogen in this study. The ESR spectra obtained in the process of thermal treatment were originated from two species of free radicals, namely the RO[KG-*2]\5free radicals (R\-1)  and the naphthalene free radicals (R\-2). Based on the above experimental observations, it can be concluded that both free radical species take part in the crosslinking reaction, but  R\-1 plays a more important role.

The design of a pulsed field gradient unit for uses on NMR spectrometers is discussed. The main features of the present design are simplicity, high pe
rformance and economy. This unit is capable of generating arbitrary waveforms with only two external trigger lines. It is convenient to integrate this unit into
different types of NMR spectrometers.

4,6,1′,6′-tetrachloro-4,6,1′,6′-tetradeoxygalactosucrose and its two monoacetyl derivatives were synthesized. The structures of the compounds were elucidated by using ¹H NMR, ¹³C NMR, MS and 2D NMR.

Two styrene/maleic anhydride copolymers (St/MAh), H10 and UV4, were prepared by controlled polymerization at 110 ℃, using 1-(ethoxycarbonyl)-prop-1-yl dithiobenzoate (EPDTB) as a chain transfer agent and AIBN as an initiator, and by copolymerization in THF with EPDTB as an initiator under UV irradiation at
room temperature respectively. Normal ¹³C NMR spectra and DEPT135 spectra were measured for both copolymers. All carbon chemical shifts in St/MAh copolymers were assigned. As a comparison, chemical shifts of the main chain carbons were calculated based on the substitution constants for phenyl group of St unit: α=16, β=6, γ=-2, and for anhydride group of MAh: α=13.5, β=2.5, γ=-2. The molar ratio of St to MAh, (F_S/F_M), alternation degree, number-average sequence length of St block, molar ratio of cis- to trans-configuration of MAh ring and numberaverage molecular weight for the samples H10 and UV4 were calculated using integral values of the corresponding peaks. The copolymer UV4 had much higher alternating degree than that of H10, indicating a big influence of polymerization temperature on the formation of alternating structure in the copolymerization of St and MAh.

Three tautomers of gossypol, aldehyde (I), lacto (II) and ketal (III), exist in CDCl\-3, and are in equilibrium. ¹H NMR spectra of the three tautomers were assigned by means of 1D and 2D NMR techniques including ¹H-¹H COSY, DEPT, HMQC (¹H Detected Heteronuclear Multiple Quantum Coherence) and HMBC (¹H Detected Heteronuclear Multiple Bond Connectivity) experiments.

We report a methodology that allows identification of natural mixtures, using difference spectra of several NMR spectra. During the study on natural products from marine sponge Hymeniacidon perleve we obtained the consecutive elutates by column chromatography with the eluent(the value of ε₀ from 0.2～0.3) then NMR and GC-MS were used to determine the composition of the elutates. By comparing the spectra of the elutates we could classify the peaks into several groups and assign the partial peaks to identify the compounds. In the process we obtained the relationship between elutates and ε₀. 

Manumycin produced by Streptomyces Parvulus (strain Tu 64) was extracted from the mycelium with acetone. The ¹H and ¹³C NMR chemical shifts of this compound were assigned using 1D and 2D NMR techniques such as gCOSY, gNOESY, gHSQC and gHMBC.

The structures of several drugs, namely Lorartadine, Etodolac, Formoterol Fumarate and Zaleplon, were elucidated by 1D NMR and 2D NMR techniques (gCOSY, gNOESY, gHSQC, gNMBC). The ¹H and ¹³C NMR chemical shifts of these compounds were assigned.

Realoxifen hydrochloride is a new drug that can be used for the prevention and treatment of osteoporosis and other diseases caused by osteoporosis. In
 this study, NMR techniques, including DEPT, two-dimensional ¹H-¹H COSY, HMQC and HMBC, were used for the elucidation of its structure.

Gardenia yellow is a physiologically active and edible nature pigment. Its usage, however, is limited due to its instable property. An inclusion complex of Gardenia yellow pigment with β-cyclodextrin was synthesized. UV, IR, fluorescence and NMR spectroscopy was used to confirm the formation of the inclusion complex and to determine the composition and the formation constant of the inclusion complex. The results show that β-cyclodextrin and Gardenia yellow pigment form a 1∶1 inclusion complex. This experiment will provide reference frame for the application of Gardenia yellow pigment.

In this paper an improved method for calculating the ¹⁷O NMR chemical shift of hydroxyl group in carboxylic acids, including saturated and unsaturated fatty acids, benzyl acids, benzyl acetic acids, benzyl propenoic acids and amino acids, was discussed. A new parameter, Δα, was proposed for calculation.

Some common malfunctions found on a  Bruker AC-80 NMR spectrometer are analyzed and summarized, and for which the possible solutions are proposed. On one hand, one can save valuable time for research if the malfunctions are repaired rapidly. On the other hand, it's important for researchers to grasp the frequently used techniques in dealing with and preventing malfunctions, and in designing and modifying commercial NMR spectrometers in order to meet the needs of the innovated experiments.

The availability of liquid chromatography-ultraviolet-nuclear magnetic resonance-mass spectrometry (LC-UV-NMR-MS)integrated systems is providing greater information content and confidence for a variety of sample types, such asdrug metabolites, natural products, impurities, and degradants. A wide range of experimental strategies can be pur-sued, highlighting the flexibility and performance possible with this multihyphenated technique.