辽东楤木叶中皂苷Congmuyenoside B(2)的分离与鉴定

本研究实现了对辽东楤木叶中Congmuyenoside B(2)的分离与鉴定。研究中采用大孔吸附树脂提取法和硅胶柱层析法对其分离,应用HPLC色谱法和薄层色谱法对纯度进行分析,利用电喷雾多级串联质谱结合核磁共振和红外光谱对该化合物的结构进行分析鉴定。本提取分离法操作简便,提高了分离化合物的纯度。HPLC色谱法灵敏度高,结果准确、减少了质谱及其它色谱中的杂质峰对化合物鉴定的干扰,结构准确,可靠。     

Identification of 5-(3,4-Dihydroxyphenyl)-5-Phenylhydantoin: A Metabolite of 5,5-Diphenylhydantdin (Dilantin1) in Rat Urine

Abstract

Using radioisotope tracer technics and GC-mass spectrometry, a new metabolite of 5,5^?diphenylhydantoin present in rat urine has been dentified as 5-(3,k-dihydroxyphenyI)-5-phenylhydantoin. This catechol represented about 2% of the total metabolites excreted in rat urine folowing administration of diphenylhydantoin in the diet for over two weeks     

珠兰花香味成份的分离和鉴定

用石油醚回流蒸馏法抽取新鲜珠兰花的挥发性香味成份，经旋转蒸发器浓缩，通过气相色谱质谱联用仪鉴定出６０余种组份，包括脂肪烃，芳香烃，醚，醇，醛酮，羧酸和脂等，主要组分是４－羟基－β－紫罗酮（２０％）表茉莉酮酸甲脂（６％）和茉莉酮酸甲脂（４％）。     

八极杆碰撞/反应池(ORS)-电感耦合等离子体质谱(ICP-MS)法测定复杂矿物中的稀土元素

对未知复杂矿物样品采用扫描电子显微镜-能谱法解析样品,确定基本成分后选择合适的样品前处理方法。实验中采用过氧化钠熔融法熔解样品,用水浸出,硝酸酸化后制备待测样品溶液。以Rh为内标,用八极杆碰撞/反应池(ORS)-电感耦合等离子体质谱(ICP-MS)法测定了复杂样品中的稀土元素。多次测定同一混合标准溶液结果的相对标准偏差(RSD,n=11)小于4%,加标回收率为90%~110%。方法适用于未知复杂矿物中稀土元素的测定。     

Identification and Quantitative Determination of 5-(Hydroxymethyl)furfural in Sugar Color

The possibility was examined for quantitative determination of 5-(hydroxymethyl)furfural without reference samples by chromatographic analysis with several internal references whose molar extinction coefficients are known.     

IR and Raman characterization of the zincocenes (eta(5)-C5Me5)2Zn2 and (eta(5)-C5Me5)(eta(1)-C5Me5)Zn

The measured Raman and IR spectra of solid, polycrystalline bis(pentamethylcyclopentadienyl)dizinc, (eta(5)-C5Me5)2Zn2, 1, and bis(pentamethylcyclopentadienyl)monozinc, (eta(5)-C5Me5)(eta(1)-C5Me5)Zn, 8, are reported in some detail. The IR spectra of the vapors of 1 and 8 each trapped in a solid Ar matrix at 12 K confirm the essentially molecular character of the solids. The experimental results have been interpreted with particular reference (i) to the corresponding spectra of (68)Zn-enriched samples of the compounds, and (ii) to the spectra simulated by density functional theory (DFT) calculations at the B3LYP level. The marked differences of structure of 1 and 8 contrast with the relatively close similarity of their vibrational spectra, disparities being revealed only on detailed scrutiny, including the effects of (68)Zn enrichment, and primarily at wavenumbers below 1000 cm(-1). The Zn-Zn stretching motion of 1 features not as a single, well-defined mode identifiable with intense Raman scattering but in several normal modes which respond in varying degrees to (68)Zn substitution. A stretching force constant of 1.42 mdyne A(-1) has been estimated for the Zn-Zn bond of 1.     

Syntheses of the linkage isomers (H2O)5CrNCCo(CN)5 and (H2O)5CrCNCo(CN)5

The slow reaction of Cr(H₂O)₆³⁺ with Co(CN)₆³⁻ produces (H₂O)CrNCCo(CN)₅. The rapid reaction of Co(CN)₅N₃³⁻ with nitrious acid in the presence of Cr)OH₂)₅CN²⁺ produces (H₂O)₅CrCNCo(CN)₅. The two binuclear complexes were separated and purified by cation and anion exchange procedures. The orientation of the bridging cyanide in the isomeric complexes was determined by a spectroscopic technique. For (H₂O)₅CrNCCo(CN)₅ the ⁴A_2g → ⁴T_2g and ⁴A_2g → ⁴T_1g of the chromium moiety are at 560 and 401 nm, respectively, and the ¹A_1g → ¹T_1g of the cobalt moiety is at 310 nm. For (H₂O)₅CrCNCo(CN)₅ the ⁴A_2g → ⁴T_2g band is at 552 nm, but the ⁴A_2g → ⁴T_1g absorption of the chromium is obscured by the ¹A_1g → ¹T_1g transition of the cobalt at 347 nm. The base hydrolysis of (H₂O)₅CNCCo(CN)₅ produces Co(CN)₆³⁻ and “chromite” quantitatively. The vase hydrolysis of (H₂O)₅CrCNCo(CN)₅ produces chromite and an unidentified cobalt(III) species that absorbs at 345–347 nm.     

New route to (3RS) (5R) (5-2H)- and (3RS) (5S) (5-2H)-mevalonolactones

The synthesis of mevalonolactone stereospecifically labeled at carbon 5 is described combining chemical reactions with an enzymatic reduction step.     

Coordination properties of 4(5)-hydroxymethylimidazole and 4(5)-hydroxymethyl-5(4)-methylimidazole towards cobalt(II) ions

Two new complexes of imidazole alcohols, 4-hydroxymethylimidazole (4-CH₂OHim) and 4-hydroxymethyl-5-methylimidazole (4-CH₂OH-5-CH₃im), with cobalt(II) of formula [CoL₂(H₂O)₂](NO₃)₂ were obtained. These compounds were described through single X-ray diffraction studies, spectroscopic (Ir. Far-IR, UV-Vis-NIR) and magnetic measurements. In the present complexes imidazole ligands are bidentate coordinating the heterocyclic ring through pyridine-like nitrogen and the oxygen atom of the hydroxymethyl group (chromophore CoN₂O₄). The shape of Co(II) coordination polyhedra is that of a distorted octahedron, with the equatorial plane defined by the 4-CH₂OHim (or 4-CH₂OH-5-CH₃im) bidentate ligands and two water molecules occupying axial positions (i.e. trans to each other). Formation of successive cobalt(II) complexes with 4-CH₂OH-5-CH₃im in aqueous solution was followed quantitatively by potentiometry.     

X-ray crystal structure of (eta(5)-pentaphenylcyclopentadienyl)[1-(eta(5/6)-phenyl)-2,3,4,5-tetraphenylcyclopentadienyl]iron(II), [Fe(eta(5)-C(5)Ph(5))[(eta(5/6)-C(6)H(5))C(5)Ph(4)]], a linkage isomer of decaphenylferrocene

Very dark blue prismatic crystals of [Fe(eta(5)-C(5)Ph(5))[(eta(5/6)-C(6)H(5))(C(5)Ph(4))]], the linkage isomer of decaphenylferrocene, were grown from (3:1 v/v) hexane/ethyl acetate and characterized by single-crystal X-ray diffraction (space group P2(1)/n, R1(F) 0.0404). The iron atom is coordinated to two C(5)Ph(5) ligands: one with an eta(5)-C(5)-configuration and the other with a coordinated arene configuration. The phenyl groups of the (eta(5)-C(5)Ph(5)) ligand are oriented in a "paddle-wheel" arrangement about the C(5) ring, with which four of them make an average angle of approximately 53 degrees, the other, an angle of approximately 42 degrees. The coordinated C(6)H(5) ring of the other ligand is inclined at only approximately 5 degrees to the uncoordinated C(5) ring, with which three of the other four phenyl rings make an average angle of approximately 64 degrees, and the other (opposite the coordinated arene ring), an angle of 38 degrees.     

Thermische disproportionierung von (η5-C5H5)2V2(CO)5. Tetrakis[carbonyl(η5-cyclopentadienyl)vanadium], (η5-C5H5)4V4(CO)4

The novel vanadium cluster tetrakis[carbonyl(η⁵-cyclopentadienyl)- vanadium has been prepared in 32% yield by thermal disproportionation of μ-dicarbonyltricarbonylbis(η⁵-cyclopentadienylvanadium) (V-V) in boiling tetrahydrofuran.     

Reactions of (η5-C5H5)Fe(CO)2(η1-C5H5) with phosphorus donor ligands

The course of the reaction of (η⁵-C₅H₅)Fe(CO)₂(η¹-C₅H₅) with phosphorus donor ligands depends strongly on the nature of the ligand; products derived from an Arbuzov-like rearrangement or from reduction have been found as well as the expected simple substitution product. The dynamic PMR behavior of (η⁵-C₅H₅)Fe(CO) (P(OPh)₃) (η¹-C₅H₅) has been examined.