The electronic structure of a Lindqvist type [Mo7O24]6- anion with 5 different types of counterion (K+, Na+, NH4+, [NH3Pr]+ and [NH3Pri]+) was calculated by using the Discrete Variational Method coupled with Density Functional Theory (DFT-DVM). It could be concluded through variance analysis to the calculated results that the type of counterion does not influence remarkably the electronic structure of [Mo7O24]6- anions. Perhaps it can be used to explain the experiment fact that the polyoxomolybdate structure of the Mo7O24 framework is apparently of critical significance to antitumor action. On these grounds we forecast that two other lindqvist type heptamolybadates(their counterions are Na+ and [NH3Pr]+ respectively) may also exhibit antitumor activities.
Antineoplastic Agents ; chemistry ; Ions ; chemistry ; Molybdenum ; chemistry

OBJECTIVETo study the Cupric ion release characteristics of different copper raw materials in intrauterine device in vitro by ICP. Reveal the relationship between purity and shape of Cu-IUD copper and copper ion release.

METHODSAccording to a certain proportion, the copper raw materials were 100 times diluted into the simulated uterine solution at 37 +/- 0.5 degrees C. Replaced medium at certain time points and collected soaking liquid. Using ICP analyzed the concentration of copper ion released.

RESULTSThe largest daily release of copper ions was in the first 7 days. There was no statistically significant difference between the copper ion release amount of 99.99% and 99.95% purity copper wire (P > 0.05). The release of copper ion of the copper wire was far greater than that of the copper pipe in early stage (P < 0.01). The release amount decreased and stabilized at 56 day.

CONCLUSIONRelease characteristics of copper ion could effectively analysis by ICP. And in the same area, the release amount of copper ions of copper wire was greater than that of copper pipe.

Stereoselective transformation of Baylis-Hillman acetates 1 into corresponding (Z)-allyl iodides 2 has been achieved by treatment of 1 with samarium triiodide in THF. Remarkable rate acceleration of samarium triiodide-mediated iodination of 1 was found when ionic liquid 1-n-butyl-3-methyl-imidazolium tetrafluroborate ([bmim]BF(4)) was used as reaction media in stead of THF. This novel approach proceeds readily at 50 degrees C within a few minutes to afford (Z)-allyl iodides 2 in excellent yields. A mechanism involving stereoselective iodination of the acetates of Baylis-Hillman adducts by samarium triiodide is described, in which a six-membered ring transition state played a key role in the stereoselective formation of 2.
Acetates ; chemistry ; Iodides ; chemical synthesis ; Ions ; Kinetics ; Samarium ; chemistry ; Solutions

Two kinds of Cu-containing intrauterine contraceptive device (Cu-IUD) has been evaluated through the study on the release of copper ion and corrosion of copper surface in artificially formulated fluid. The result showed that the copper ions were released profusely from the stainless steel stents Cu-IUD in the first week of soak (25-12 microg/d), and then it became slowly and steady. The release of the copper ions from the titanium nickel shape memory alloy stents Cu-IUD were always slowly and steady in two months (0.5-5 microg/d). It obviously shows that the corrosion on copper surface of stainless steel stents Cu-IUD were more serious than titanium nickel shape memory alloy stents Cu-IUD by using 200 times microscope testing before and after soaking in formulated fluid.
Copper ; chemistry ; Corrosion ; Intrauterine Devices ; Ions ; chemistry ; Stents

Objective To establish an ion chromatography method for the salt form determination of new psychoactive substances （NPS）. Methods The method of conducting qualitative and quantitative analysis of six types of organic acid ions （acetate ion, tartrate ion, maleate ion, oxalate ion, fumarate ion, citrate ion） and five types of inorganic anions （fluoride ion, chloride ion, nitrate ion, sulfate ion, phosphate ion） in NPS sample by ion chromatography was developed. The salt forms of 222 seized NPS samples （103 samples with synthetic cannabinoids, 81 samples with cathinones, 44 samples with phenylethylamines, 12 samples with tryptamines, 7 samples with phencyclidines, 6 samples with piperazines, 2 samples with aminoindenes, 26 samples with fentanyls and 43 samples with other types of NPS） were analyzed by this method. Results Each anion had good linearity in the corresponding linear range, the correlation coefficients （r） were greater than 0.999, the limits of detection were 0.01-0.05 mg/L, and the limits of quantitative were 0.1-0.5 mg/L. Except that 5F-BEPIRAPIM was hydrochloride, the salt forms of the other 102 synthetic cannabinoids were all base. The salt form of 81 cathinone samples, 44 phenylethylamine samples, 7 phencyclidine samples and 2 aminoindene samples were all hydrochloride. The salt forms of tryptamine samples included base, hydrochloride, fumarate and oxalate. The salt forms of piperazine samples included base and hydrochloride. The salt forms of fentanyl samples and samples of other types included base, hydrochloride and citrate. Conclusion Ion chromatography is a simple, accurate and efficient method for determining the salt form of NPS samples, which makes the qualitative and quantitative conclusions of NPS more scientific and rigorous.
Chromatography, Liquid ; Gas Chromatography-Mass Spectrometry ; Ions ; Psychotropic Drugs/chemistry*

The impact of metal ions on the phase behavior of phosphatidylcholine (PC) was investigated at the air/water interface by surface pressure-area (pi-A) isotherm measurements. The analysis of the pi-A isotherms showed that with the metal ionic radius decreasing, the concentration of the metal ions C increasing, and the valence of metal ions Q increasing, the amount of the corresponding curves of A0 decreases, the phase transition point would change more apparently, the collapse pressure would become larger subsequently, and the curve would be extended outside. The phenomenon could be approached when the metal ion concentration C became great enough. These experiments were identified with the rules on Langmuir films, by a variety of properties of metal ions (ion radius, ion concentration, ion valence, etc.). Among all the factors, the ionic valence showed the greatest impact on the phase changes, followed by the ion concentration, while the ionic radius influences were less on the phase-change characteristics.
Air ; Ions ; chemistry ; Membranes, Artificial ; Metals ; chemistry ; Phase Transition ; Phosphatidylcholines ; chemistry ; Surface Properties ; Water ; chemistry

Decoction is one of the most commonly used dosage forms of traditional Chinese medicine. The stability of chemical constituents in decoction is closely related to the clinical efficacy and safety. There were few reports about the influence of metal ions in the stability of chemical constituents in traditional Chinese medicine. However, there is no evidence that metal ions in decoction water need to be controlled. In this study, 2,3,5,4'-tetrahydroxy stilbene-2-O-β-D-glucoside (THSG), one of the main constituents in Polygoni Multiflori Radix was studied. Ordinary tap water, deionized water, and water containing different metal ions were used to investigate and compare the influence on THSG. The results showed that after storage in a dark place at the room temperature for 10 days, the degradation of THSG was 7% in deionized water, while undetectable in tap water. The content of THSG could be decreased by different kinds of metal ions, and the effect was concentration-dependent. Moreover, Fe3+ and Fe2+ showed the greatest influence at the same concentration; and our study has shown that THSG decreased more than 98% in Fe and Fe2+ solutions at 500 ppm concentration. In the same time we found out p-hydroxybenzaldehyde (molecular weight: 122.036 7) and 2,3,5-trihydroxybenzaldehyde-2-O-glycoside (molecular weight: 316.079 4) were the main degradation products of THSG in tap water and water containing Cu2+, Ca2+, Zn2+, Mg2+ and Al3+. The product of THSG dimer with a water molecule was found in water containing Fe3+ and Fe2+. The above results showed that the metal ions in water could significantly influence the stability of THSG in water, indicating that the clinical efficacy and safety of decoction would be affected if the metal ions in water were not under control. It's suggested that deionized water should be used in the preparation of decoction containing Polygoni Multiflori Radix in the clinic to avoid degradation of THSG. Meanwhile, decoction prepared by tap water should be taken by patients in a short time. Our investigation provides important information and reference about the influence of metal ions on the stability of decoctions in other traditional Chinese medicine that have unstable groups such as hydroxyls and unsaturated bonds, etc.
Drugs, Chinese Herbal ; chemistry ; Glucosides ; chemistry ; Ions ; chemistry ; Metals ; chemistry ; Plant Roots ; chemistry ; Polygonaceae ; chemistry ; Stilbenes ; chemistry

The fragmentation pathways of five estrogens (estradiol, estrone, equilin sulfate, 17 a-dihydroequilin sulfate and equilenin sulfate) have been studied with high resolution and high mass accuracy using electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-Q-TOF/MS) in the negative ion mode. Molecular weights were obtained from [M-H](-) ions in the product ion spectra. The results indicate that the five structurally similar estrogens have similar fragmentation pathways. Using their stable isotope forms as internal reference compounds, the accurate mass and composition of the fragment ions were determined. During collision-induced dissociation (CID), cleavage is initiated by loss of oxygen atoms from carbon-17, after which D and C rings cleave sequentially and rearrange to finally form stable conjugate structures with highly abundant characteristic fragment ions at m/z 183 (accompanied by m/z 181), m/z 169 and m/z 145 (accompanied by m/z 143). Understanding these characteristic fragmentation pathways of estrogens will be helpful in identifying the structures of steroid hormones in general.
Chemical Fractionation ; methods ; Equilenin ; chemistry ; Equilin ; analogs & derivatives ; chemistry ; Estradiol ; chemistry ; Estrogens ; chemistry ; Estrone ; chemistry ; Ions ; Spectrometry, Mass, Electrospray Ionization

The tandem mass spectrum of apigenin-6,8-C-di-glucoside( 1) and apigenin-6-C-glucose-8-C-rhamnoside( 2) were obtained by high resolution electrospray ionization mass spectrometry( HR-ESI-MS/MS) in both positive and negative ion modes. The elemental composition of each ion was determined according to its accurate mass-to-charge,hence,the fragmentation pathways of each compound were proposed in both negative and positive ion modes. Comprehensive analysis of each ion and its proposed fragmentation pathways of the two compounds was initially conducted in both negative and positive ion mode HR-ESI-MS/MS to explore the diagnostic ions for flavone-6,8-C-di-glycosides and the characteristic ions for each compound and their cleavage rules. The results showed that a family of fragmentation ions with m/z 353,325,311,297 in ESI(-)-MS and m/z 355,325,307,295 in ESI( +)-MS could be the diagnostic ions of flavone-6,8-C-di-glycoside,and characteristic neutral loss could be assigned to glycosyl substitution,for example,neutral losses of C_4H_8O_4( 120),C_3H_6O_3( 90),C_2H_4O_2( 60) for glucoside substitution while neutral losses of C_4H_8O_3(104),C_3H_6O_2( 74),C_2H_4O( 44) for rhamnoside substitution. Furthermore,only one H_2O loss from mother ion( [M-H]-) was observed for 1 & 2 in ESI(-)-MS while five to six H2 O loss from mother ion( [M+H]+) was observed for 1 & 2 in ESI( +)-MS to produce a family of ions by subsequent loss of H_2O,which could be applied for glucosyl difference. The flavone-6,8-C-di-glycosides in both ESI( +)-MS and ESI(-)-MS showed the cleavage similarity at sugar substitutions. However,there were much more differences by the fragmentation pathways and neutral losses between ESI( +)-MS and ESI(-)-MS as following,hyperconjugation ions by subsequent loss of H_2O from precursor ions of flavone-6,8-C-di-glycosides in ESI( +)-MS were not observed in ESI(-)-MS; the subsequent neutral loss of CH_2O in ESI( +)-MS were rarely observed in ESI(-)-MS; the loss of CO only happen at C-ring of flavone ESI( +)-MS other than glycosyl position in ESI(-)-MS; the C4-chain neutral loss of flavone-6,8-C-di-glycosides happened at 8-C-glycosyl position other than at 6-C-glycosyl position. The above cleavage rules and diagnostic ions of ESI( +)-MS were successfully applied for the structure identification of 4 flavone-6 C,8 C-diglycosides from the stem extract of Dendrobium officinale as vicenin Ⅱ,vicenin Ⅰ,isoschaftoside,schaftoside as well as one flavone-O-glysoside named rutin,which were supported by ESI(-)-MS data as well.
Flavones/chemistry* ; Glycosides/chemistry* ; Ions ; Spectrometry, Mass, Electrospray Ionization ; Tandem Mass Spectrometry

Ion beam enhanced deposition (IBED) has been applied to prepare titanium oxide layer on titanium alloy (Ti6A14V) in order to improve its biocompatibility. The layer on titanium alloy is even, and the elements Al and V in substrate are not detected. The layer is composed of TiO containing nitrogen oriented along (111) plane. The critical load of the layer in scratch test is 16.8 N. Morphological observation reveals the layer ends in a failure caused by plastic deformation.
Biocompatible Materials ; chemistry ; Coated Materials, Biocompatible ; chemistry ; Ions ; chemistry ; Surface Properties ; radiation effects ; Titanium ; chemistry ; X-Ray Diffraction