利用LC-MS-MS等方法分析确定黄连总碱提取物中微量未知物的结构

中药黄连中所含的多种生物碱中主要成分是小檗碱、棕榈碱、药根碱和黄连碱等,为了分析鉴定黄连总碱中微量生物碱,运用ESI-MS-MS,FaB-MS-MS以及LC-MS-MS等多种质谱方法对由甲醇提取的总碱部分提取物进行了分析研究,并结合LC-NMR对其中1种未知物的结构给予了确认.     

Studies on the Constituents of Camptotheca Acuminata Decne,II. The Constituents of Fresh Fruits,

Camptothecin, ethyl caffeate, ursolic acid, betulinic acid, and inositol have been isolated and characterized from fresh fruits of Camptotheca acuminata Decne (Nyssacese).     

Alkaloids of Aconitum coreanum VI. Structure of acoridine

The new C₂₀-diterpene alkaloid acoridine has been isolated from the epigeal part ofAconitum coreanum (Levl.) Rapaics, and the structure of 14-hydroxy-2-propionylhetisine has been established for it on the basis of spectral characteristics. Acoridine is the first diterpene alkaloid esterified by propionic acid.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 91–93, January–February, 1991.     

Crystal Structure and Characterisation of Mercury(II) Dichromate(VI)

Summary. Dark-red single crystals of HgCr₂O₇ were grown by reacting HgO and CrO₃ in excess at 200°C for four days. The crystal structure (space group P3₂, Z = 3, a = 7.2389(10), c = 9.461(2) ?, 1363 structure factors, 57 parameters, R[F ²>2σ(F ²)] = 0.0369, wR(F ² all) = 0.0693) was determined from a crystal twinned by merohedry according to (110). It consists of nearly linear HgO₂ units ( (Hg–O) = 2.02 ?) and dichromate units that are linked into infinite chains ‘O₃Cr–O–CrO₃–Hg–O₃Cr–O–CrO₃’ running parallel to the c-axis. Six additional Hg–O contacts between 2.73 and 2.96 ? stabilise the structural arrangement. The dichromate anion exhibits a staggered conformation with a bent Cr–O–Cr bridging angle of 140.7(6)°. Upon heating above 300°C, HgCr₂O₇ decomposes in a two-step mechanism to Cr₂O₃. The title compound was additionally characterised by vibrational spectroscopy.     

Crystal Structure and Characterisation of Mercury(II) Dichromate(VI)

Dark-red single crystals of HgCr₂O₇ were grown by reacting HgO and CrO₃ in excess at 200°C for four days. The crystal structure (space group P3₂, Z = 3, a = 7.2389(10), c = 9.461(2) ?, 1363 structure factors, 57 parameters, R[F ²>2σ(F ²)] = 0.0369, wR(F ² all) = 0.0693) was determined from a crystal twinned by merohedry according to (110). It consists of nearly linear HgO₂ units ( [`(d)]{\bar {d}} (Hg–O) = 2.02 ?) and dichromate units that are linked into infinite chains ‘O₃Cr–O–CrO₃–Hg–O₃Cr–O–CrO₃’ running parallel to the c-axis. Six additional Hg–O contacts between 2.73 and 2.96 ? stabilise the structural arrangement. The dichromate anion exhibits a staggered conformation with a bent Cr–O–Cr bridging angle of 140.7(6)°. Upon heating above 300°C, HgCr₂O₇ decomposes in a two-step mechanism to Cr₂O₃. The title compound was additionally characterised by vibrational spectroscopy.     

两头尖的化学成分研究(Ⅰ)

采用硅胶柱色谱和高效液相色谱等方法,对两头尖的化学成分进行了研究,从中分离得到两个化合物,经化学及IR,ESI-MS,^1H NMR,^13C NMR,DEPT,HMQC,HMBC,GCOSY,TOCSY等谱学分析鉴定其结构分别为：3-O-α-Larabinopyranosyl(1→3)-α-L-dmmnopyranosyl(1→2)[β-D-glucopymnosyl(1→4)]-α-L-arabinopyranosyl oleanolic acid 28-O-α-L-rhamnopyranosyl(1→4)-β-D-glucopyranosyl(1→6)-β-D-glucopyranoside(1),3-O-β-D-glucopyranosyl(1→4)-β-D-glucopymnosyl(1→3)-α-L-rhammnopyranosyl(1→2)-α-L-arabinopyranosyl oleanolic acid 28-O-α-L-rhammnopymnosyl(1→4)-β-D-glucopyranosyl(1→6)-β-glucopymmside(2),该两个化合物为新化合物,分别命名为：多被银莲花皂苷16(Raddeanoside 16)和多被银莲花皂苷17(Baddeanoside 17)．     

Preparation,Thermal Behaviour and Crystal Structure of the Basic Mercury(II) Tetraoxotellurate(VI), Hg2TeO5, and Redetermination of the Crystal Structure of Mercury(II) Orthotellurate(VI), Hg3TeO6

Single crystals of Hg₂TeO₅ were obtained as dark‐red parallelepipeds by reacting stoichiometric amounts of Hg(NO₃)₂ · H₂O and H₆TeO₆ under hydrothermal conditions (250 °C, 10d). The crystal structure (space group Pna2₁, Z = 4, a = 7.3462(16), b = 5.8635(12), c = 9.969(2)Å, 1261 structure factors, 50 parameters, R[F² > 2σ(F²)] = 0.0295) is characterized by corner‐sharing [TeO₆] octahedra forming isolated chains [TeO_4/1O_2/2] which extend parallel to [100]. The two crystallographically independent Hg atoms are located in‐between the chains and interconnect the chains via common oxygen atoms. Amber coloured single crystals of Hg₃TeO₆ were prepared by heating a mixture of Hg, HgO and TeO₃ together with small amounts of HgCl₂ as mineralizer in an evacuated and sealed silica glass tube (520 °C). The previously reported crystal structure has been re‐investigated by means of single crystal X‐ray data which reveal a symmetry reduction from Ia3¯d to Ia3¯ (Z = 16, a = 13.3808(6) Å, 609 structure factors, 33 parameters, R[F² > 2σ(F²)] = 0.0221). The crystal structure is made up of a body‐centred packing of [TeO₆] octahedra with the Hg atoms situated in the interstices of this arrangement. Upon heating, both title compounds decompose in a one‐step mechanism under formation of TeO₂ and loss of the appropriate amounts of elementary mercury and oxygen.     

Triterpene glycosides ofAcanthophllum gypsophiloides VI. Structure of acanthophylloside D

Summary A new triterpene glycoside — acanthophylloside D — has been isolated from the roots ofAcanthophyllum gypsophiloides Rgl. It is a decaoside of quillaic acid containing O-glycosidic and O-acylosidic carbohydrate chains identical in structure with the analogous fragments of acanthophylloside B.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 176–180, March–April, 1979.     

Thermal studies of lead(II) salts,VI

The kinetics and mechanisms of the thermal decomposition of lead(II) carbonate and lead(II) hydroxide carbonate have been studied over a range of temperatures and partial pressures of carbon dioxide using both isothermal and programmed heating. All stages in each decomposition are diffusion controlled and Arrhenius parameters have been determined. These values for loss of carbon dioxide are all extremely high for a diffusion process, but show a compensation effect, following the equation: logA=–5.02+0.067E The compensation effect is discussed and comparisons with other systems showing such effects are made.

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Zusammenfassung Kinetik und Mechanismus der thermischen Zersetzung von Blei(II)carbonat und Blei(II)hydroxycarbonat wurden bei verschiedenen Temperaturen und CO₂-Partialdrücken sowohl isotherm als auch unter den Bedingungen der programmierten Aufheizung untersucht. Bei allen Zersetzungsschritten ist die Diffusion der geschwindingkeitsbestimmende Schritt; die Arrhenius-Parameter wurden bestimmt. Für einen Diffusionsprozess sind diese Werte extrem hoch, sie zeigen aber einen durch die Gleichung logA=–5.02+0.067E zu beschreibenden Kompensationseffekt, der diskutiert wird. Durch Vergleich mit anderen Systemen wird gezeigt, wie solche Effekte zustande kommen.

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- - , . - - . , , - : log=– 5.02 + 0.067. K .

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We wish to record our thanks to Dr. A. K. Galwey for his interest and the considerable time he has spent discussing the general and particular problems of the compensation effect.     

Thyrocalcitonin. II. Structure of alpha-thyrocalcitonin

The highly active peptide hormones isolated from pig thyroids – i.e. α-thyrocalcitonin and its sulfoxide, containing 32 amino acid residues – were subjected to sequence studies using chemical and enzymatic methods. On the basis of these studies the following structure was derived for α-thyrocalcitonin: In the α-thyrocalcitonin sulfoxide (designated formerly as β-thyrocalcitonin) the methionine residue is replaced by methionine sulfoxide.     

Triterpene saponins from Thalictrum minus. VI. Structure of thalicoside C

From the epigeal part ofThalictrum minus L. (Ranuncluaceae) we have isolated a minor cycloartane trisdesmoside — thalicoside C — 3,16,22(S),29-tetrahydroxy-9,19-cyclo-20(S)-lanost-24-ene 3-O--galactopyranoside 22,29-di-O--D-glucopyranoside. Its structure was established from the results of chemical transformations and of FAB-mass and NMR spectroscopies (¹H₁,¹³C,¹H-¹H₁, and¹³C-¹H).Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated from Khimiya Prirodnykh Soedeninii, No. 1, pp. 103–109, January–February, 1993.     

Constituents of tabebuia guayacan—II : The structure of guayin

A unique oxalactone dibenzxanthone, guayin, has been isolated from the heartwood of T. guayacan and structurally identified. A biomimetic synthesis of the dihydro derivative of guayin, based upon the probable biosynthetic origin of guayin from the dibenzxanthene guayacanin, has been successfully achieved.