雷公藤碱乙、碱庚和碱己的结构

雷公藤(Tripterygium wilfordii Hook.f.)系卫矛科雷公藤属植物。前已报道了雷公藤次碱(wilforine,l)、雷公藤碱及新生物碱雷公藤碱戊的结构。本文报告雷公藤碱已(wilformine,2),雷公藤碱乙(wilforgine,3)及雷公藤碱庚(wilforzine,4)的结构,2为首次分得之新生物碱,3、4结构系首次报道。     

石杉碱O的结构鉴定

蛇足石杉[Huperziaserrata(Thunb.)Trev.]中,R~f与石杉碱甲相近部位分离得到一个新生物碱,经IR,MS,1D和2DNMR确定了其化学结构,为一个有内氢键烯醇型新的lycopodine类生物碱,命名为石杉碱O(HuperzineO)。     

新生物碱雷公藤碱戊的结构

雷公藤(Tripterygium wilfordii Hook.f.)系卫矛科雷公藤属植物.今分得五个生物碱,其中一个为新生物碱,命名为雷公藤碱戊(wilforidine,1);另外四个为已知化合物:雷公藤次碱(wilforine,2),雷公藤碱乙(wilforgine),雷公藤碱(wilfordine,3)及雷公藤碱丁(wilfortrine).     

黄草乌的生物碱研究——Ⅰ.黄草乌碱甲和碱丙的化学结构

黄草乌(Aconitum vilmorrianum Kom.)是云南的一种常用民间草药。朱元龙等曾从其根中分得三种生物碱,即黄草乌碱甲(vilmorrianine A)、碱乙(vilmorrianine B)和另一微量成分,均未确定化学结构。我们从这种植物的根中分得六个生物碱,本文报告其中三个乌头碱型二萜酯碱的结构鉴定。一个与黄草乌碱甲为同一化合物,另一个命名为黄草乌碱丙(vilmorrianine C),可能与朱元龙等分得的微量生物碱相同。通过红外光谱、紫外光谱、核磁共振谱和质谱测定以及化学工作,证明碱甲和碱丙的化学结构分别为2和3。第三个酯碱则鉴定为滇乌碱(yunaconitine)(1)。     

乌头碱水解产物的研究

乌头碱为C_(19)二萜类双酯型生物碱,是乌头类中药的主要毒性成分和活性成分,乌头碱具有很强的抗炎和镇痛活性~([1]),在临床上被用于抗肿瘤药物,由于其治疗剂量与中毒剂量接近,必须经炮制后使用.乌头碱水解产物已有报道,但主要集中在苯甲酰乌头原碱和乌头原碱上,焦乌头碱很少提及,本研究利用硅胶柱色谱法对乌头碱的水解产物进行了分离和纯化,利用质谱和核磁共振谱确定了3种主要产物的结构,为研究乌头碱类生物碱的水解产物提供了新的数据.     

原阿片碱盐酸盐的结构研究

十员环异喹啉生物碱在植物中广为存在,是一类具有药物学意义的生物碱.一些研究表明,这类生物碱分子的十员环内氮原子和14-(或13-)位羰基碳原子之间有一种类酰胺的相互作用,具有成环的趋向;但对成环的条件及成环后的稳定性均未最终证明.我们对这类生物碱中的原阿片碱(protopine,1)及其盐酸盐的结构进行了研究,并通过 UV、IR、1~(13)CNMR 以及 X 衍射分析,证明1成盐后这种跨环相互作用已使氮原子和14-C 原子间形成稳定的单键,致使十员环变成两个六员环,整个分子变成了氢化原小蘖碱类生物碱基本骨架;当生物碱盐转为游离碱时,分子骨架又变回原来的构型.这种作用推测对十员环异喹啉生物碱具有普遍的意义.     

自苦木中分离得到两个新的β-咔巴啉生物碱——-苦木碱辛和苦木碱壬

自苦木科植物苦木的木质部分离得到四个生物碱,经UV,IR,NMR和MS分析和物理化学常数测定,确定其中两个为新的β-咔巴啉生物碱,分别命名为苦木碱辛和苦木碱壬.苦木碱辛的结构为1-甲酰基-4-甲氧基-β-咔巴啉(1),苦木碱壬的结构为1-甲氧丙酰基-β-咔巴啉(2).另外两个为已知生物碱1-乙烯基-4-甲氧基-β-咔巴啉(3)和3-甲基铁屎米-2,6-二酮(4)     

草酸单乙酯三尖杉碱酯的合成及其在三尖杉酯类生物碱合成中的应用

用醇钠催化的酯交换方法合成了草酸单乙酯三尖杉碱酯(4),并用4和格氏试剂反应,得到合成三尖杉酯类生物碱的关键中间体α-酮酰基三尖杉碱(2),简化了已报道的一些三尖杉酯类生物碱的合成方法。     

乌头碱的LC-MS定量分析

乌头生物碱各成分毒性差异很大,其中乌头碱的毒性为其它成分的100-2000倍,是引起中毒和死亡的主要原因。乌头生物碱种类多,在煎煮或泡制过程中易水解产生不同水解产物,进入体内后代谢情况又不明,因此采用液相色谱方法对体内检材乌头碱成分仅靠保留时间确定依据不足,定量工作更是无法开展。但在现实生活中炮制后的乌头植物可入药,且炮制过的乌头植物也可检出少量原碱。遇到体内检材中检验出乌头生物碱成分时,办案单位往往希望有一个量的甄别。经查阅资料,未见体内检材(如血、肝、尿等)中乌头碱含量的报道。我们应用LC-MS,采用646.4单离子扫描方式对实际案例血中乌头碱含量进行了测定,为今后的进一步研究和同行提供数据积累。     

三尖杉属植物中生物碱的研究--Ⅱ.三尖杉(Cephalotaxus fortunei Hook.f.)中的四种微量生物碱的分离和鉴定及福建三尖杉碱的化学结构

本文报导了三尖杉中分离得到的四种微量生物碱的理化性质.三尖杉碱-9(Ⅰ)、三尖杉碱-3(Ⅱ)分别鉴定为已知生物碱,11-羟基三尖杉碱和表-台湾三尖杉碱.三尖杉碱-15为一种新生物碱,命名为福建三尖杉碱(cephalofortuneine),经光谱分析(红外、紫外、核磁共振和质谱)推测其化学结构为Ⅳ.三尖杉碱-2的结构未定.     

E.p.r. spectra of mixed valence copper(II)-copper(I) systems

Summary Mixed valence (thiosemicarbazone)₂Cu^II-Cu^I complexes were prepared and their e.p.r. spectra in the polycrystalline state studied. Complexes derived from acetophenone- and propiophenonethiosemicarbazones exhibit strong copper(II)-copper(II) and copper(II)-copper(I) interactions, whereas those derived from benzyl methyl ketone and cyclohexanone show strong copper(II)-copper(I) interaction but almost no copper(II)-copper(II) interaction.     

Coordination compounds of transition metal hydrazine derivatives. Part 25. Monohydrazine-S-methylcarbodithioate schiff bases derived from α-dicarbonyl compounds

Summary The monohydrazones derived from the condensation of diacetyl and benzil with hydrazine-S-methylcarbodithioate (Dahydth) and (Benhydth) were prepared and their ligation properties with nickel(II), copper(II), palladium(II), zinc(II) and cadmium(II) were studied. A series of bisligand chelates were isolated and characterized. In the zinc(II), cadmium(II) copper(II) and palladium(II) bisligand chelates, both Dahydth and Benhydth act as mononegative bidentate molecules. The Ni(Dahydth-H)₂ chelate possesses an octahedral structure where Dahydth acts as a mononegative tridentate ligand. The¹H n.m.r. spectra of the two ligands as well as of the diamagnetic metal(II) chelates are discussed. The fragmentation in a mass spectrometer of all these chelates was also studied.     

Naphthyl- vs. anthrylpyridine-2,6-dicarboxamides in cation binding studies. Synthesis and spectroscopic properties

Pyridine-2,6-carboxamides bearing α- or β-naphthyl- and α- or β-anthryl residues were prepared using simple method from pyridine-2,6-carboxylic acid dichloride and the respective aromatic amines. For the obtained receptors, selective binding of lead(II) and copper(II) was found. Ion–receptor interactions were studied using UV–vis spectroscopy, spectrofluorimetry, ¹H NMR and FTIR spectroscopy. The reversible lead(II) and copper(II) binding was discussed in regard of type of aromatic residue and amide bond localisation in aromatic ring, and binding model was proposed.     

Functional metallomacrocycles and their polymers. XXII. Thermally stable metallophthalocyanine formaldehyde condensation resins

A novel class of urea-formaldehyde condensation resins containing covalently bound metallophthalocyanine [M = A1(III), Co(II), Ni(II), or Cu(II)] was synthesized from [tetrakis(methyl-olamide)phthalocyaninato] metal complexes and dimethylolurea in aqueous solution by heating at 120°C for 10 h, followed by heating at 150°C for about 1 day. The structures of the polymers obtained were characterized by infrared and reflection electronic spectra. The thermal stabilities of the resins were evaluated by dynamic thermogravimetric analyses. The resin containing 21.3 wt % Ni(II)-metallophthalocyanine had the greatest thermal stability, with 82 wt-% char yield at 600°C in air atmosphere.     

Influence and role of metal ions in enzymatic catalysis with e.c. 1.2.3.2. xanthine oxidase Application to trace analysis

The effect of metal ions on the reductive half-reaction of xanthine oxidase (XOD) in the catalytic conversion of xanthine into uric acid has been studied spectrophotometrically in Tris-HCl buffer at pH 7.4, 37 +/- 0.1 degrees and ionic strength 0.04M. Some metal ions display inhibitor properties, the sequence of inhibiting efficiency being Ag(I) > Hg(II) > Cu(II) > Cr(VI) > V(V) > Au(III) > Tl(I) and for these the I(50) values were determined. Only Tl(I), V(V) and Cu(II) showed reversible inhibition and therefore for these the mechanisms were assessed [competitive for V(V) and Tl(I); uncompetitive for Cu(II)]. The conditional inhibition constants (K(i)) were also determined. The effect of EDTA for protection of the enzyme against metal inhibition, and for its reactivation after inhibition, was also investigated. Utilization of the linear relationship between relative enzyme activity and inhibitor concentration allowed sensitive and selective (though not specific) determination of Ag(I) and Hg(II) (10(-9)-10(-8)M), and of Cu(II) and Cr(VI) (10(-7)-10(-6)M), the maximum relative error being +/- 4%. For a few metal ions, e.g., Ag(I) and Cr(VI), in the presence of EDTA, a certain specificity is observed.     

Inorganic coordination polymers. VIII. Cobalt(II) and zinc(II) phosphinate polymers and copolymers

The preparation, properties, x-ray powder patterns, and TGA curves are given for cobalt(II) dimethyl-, methylphenyl- and diphenylphosphinate. The polymeric character of cobalt(II) methylphenylphosphinate is demonstrated by its colligative properties and melt indexes. These cobalt(II) phosphinates along with hybrid copolymers of zinc(II) or cobalt(II) were prepared by the reaction of the metal acetate with the appropriate phosphinic acid or mixture of phosphinic acids. A consideration of the hybrid copolymers leads to the conclusion that both the zinc(II) and cobalt(II) dimethyl- and diphenylphosphinates are likewise polymeric. Thermal stability is discussed in terms of the structures suggested, and it is shown that crystallinity is related to polymer symmetry.     

Dünnschichtchromatographie anorganischer Ionen. V

Zusammenfassung Dünnschichtchromatographische Trennungen auf Schichten aus Kieselgel-HR, gemischt mit Ammoniumphosphordodekamolybdat bzw. Zinkcyanoferrat(II) und Kobaltcyanoferrat(II) wurden durchgeführt. Für Alkalimetallionen eignen sich Ammoniumphosphordodekamolybdat und Zinkcyanoferrat(II), für zwei- und dreiwertige Elemente Ammoniumphosphordodekamolybdat und Kobaltcyanoferrat(II). Eine Trennung des Mutter-Tochter-Systems Strontium-90/Yttrium-90 wurde durchgeführt und für die Systeme Barium-140/Lanthan-140, Barium-131/ Cäsium-131 und Cäsium-137/Barium-137 Trennungen mit Modellsubstanzen beschrieben.

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Thin-layer chromatography of inorganic ions. V

Summary Thin-layer chromatographic separations were carried out on layers consisting of silica gel-HR, mixed with ammonium phosphododecamolybdate or zinc cyanoferrate(II) and cobalt cyanoferrate(II). Ammonium phosphododecamolybdate and zinc cyanoferrate(II) are suitable for alkali metal ions, while ammonium phosphododecamolybdate and cobalt cyanoferrate(II) are suitable for di- and trivalent elements. A separation was conducted of the mother-daughter system strontium-90/yttrium-90 and separations with model substances were described for the systems barium- 140/lanthanum-140, barium-131/cesium-131 and cesium-137/barium-137.

     

Polymerization of propadiene. II. Catalyst systems based on 3d transition metals and various stabilizing ligands

A variety of catalyst systems based on 3d transition metals, i.e., V(III), Cr(III), Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and various stabilizing ligands, i.e., propadiene, methylacetylene, phenylacetylene, and 1,4-butadiene, were prepared. The activity of these catalytic systems towards the polymerization of a series of monomers (propadiene, methylacetylene, phenylacetylene, 1,4-butadiene, ethene, and propene) is investigated. Optimum conditions for the preparation of 1,2-polyallene, polymethylacetylene and polyphenylacetylene are given.     

Voltammetric determination of lead at chemically modified electrodes based on crown ethers.

The feasibility of fabricating lead-sensitive chemically modified electrodes (CMEs) for trace analysis in aqueous and 40% (v/v) ethanol-water media was investigated. Carbon paste electrodes modified with crown ethers were constructed by mixing the crown ethers into a graphite powder-paraffin oil matrix. The thus-formed electrodes were able to bind Pb(II) ions chemically, and gave better voltammetric responses than unmodified ones. The crown ethers studied and compared were 18-crown-6 and dibenzo-18-crown-6. With a 5% 18-crown-6 CME, Pb(II) could be quantified at sub-ppm levels by differential pulse voltammetry with a detection limit of 0.02 ppm. It was possible to selectively pick up Pb(II) from a solution of several other ions at an open circuit through complexation. A simultaneous analysis of Cu(II) and Pb(II) was also attempted. By differential pulse anodic stripping voltammetry Pb(II) could be quantified over the range of 1 to 100 ppb. Interference from metal ions like Ni(II), Co(II), Mn(II), Zn(II), Cd(II), Ag(I), Fe(III), Ca(II) and Mg(II) was also studied. The method was successfully applied to artificial as well as commercial samples of alcoholic beverages.     

Condensed heteroaromatic systems including a thiophene ring.

The thermal stabilities of 2-mercapto-3-formylbenzo[b]thiophene and its chelates with Cu(II) and Co(II), of 2-mercapto-3-iminomethylbenzo[b]thiophene and its chelates with Cu(II), Co(II), Ni(II), and Zn(II), and of N,N′-bis(2-mercaptobenzo [b]-3-thenylidene)ethylenediamine and its chelates with Cu(II), Co(II), and Ni(II) were investigated by differential-thermal and thermogravimetric analysis. The temperature of the onset of decomposition and the character of the decomposirion of the ligands and chelates were established. It was found that the investigated chelates can be arranged in the following order with respect to increasing thermal stability: Cu < Co < Zn < Ni. The most thermally stable ligand is N,N-bis (2-mercaptobenzo[b]-3-thenylidene)ethylenediamine. The effectiveness of the ligands and chelates as stabilizers for polycaproamide fibers were compared. It was found that of the investigated compounds, the copper chelates are effective stabilizers. In a study of the thermal behavior of the copper chelates in an inert gas atmosphere it was established that the character of the thermal decomposition of the most effective of them — {it(N,N′-bis)2-mercaptobenzo[b]-3-thenylidene)-ethylenediaminato} Cu(II) — is identical both in the presence of air oxygen and in a nitrogen atmosphere, i.e., the chelate does not undergo oxidation at temperatures up to 270?C.