首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 130 毫秒
1.
用反相高效液相色谱法/质谱法对天然药物齐墩果酸及其以霉菌的P450酶系作为生物催化剂的齐墩果酸羟化体系中齐墩果酸和羟化齐墩果酸进行分离分析.方法选用Lichrospher C18柱,以乙腈-水为流动相,进行梯度洗脱,用二极管阵列检测器(DAD)和电喷雾质谱(ESI-MS)为检测手段,通过色谱图和对应质谱图,确定了齐墩果酸及其羟化产物的色谱行为,建立了HPLC/DAD/ESI-MS联用法分离鉴定齐墩果酸及羟化产物的快速有效的方法.  相似文献   

2.
用薄层色谱法和反相高效液相色谱法对青海两地区野生椭圆叶花锚中齐墩果酸和熊果酸进行定性定量分析。采用超声法提取椭圆叶花锚中的齐墩果酸和熊果酸,并采用反相高效液相色谱法测定其含量。测得青沙山地区花锚中齐墩果酸和熊果酸含量均高于大通宝库乡产地,两产地花锚中熊果酸含量均高于齐墩果酸含量。  相似文献   

3.
建立了一种同时检测中药材中齐墩果酸(OA)和熊果酸(UA)含量的超高效液相色谱串联质谱方法。采用超高效液相色谱-三级四极杆质谱(UPLC-TQMS)法对样品进行测定,Waters Acquity UPLC BEH C_(18)色谱柱(50 mm×2.1 mm,1.7μm)进行分离,以乙腈-5 mmol/L乙酸铵水溶液(氨水调至pH 9.24)为流动相,梯度洗脱;负离子模式下检测。结果表明,齐墩果酸和熊果酸在0.5~50.0 ng/mL浓度范围内线性关系良好,相关系数(r~2)分别为0.999 8和0.999 7;检出限(S/N=3)分别为0.006 6,0.012 8 ng/mL,定量下限(S/N=10)分别为0.002 0,0.003 8 ng/mL;对OA和UA进行加标回收实验,平均回收率分别为101.1%和100.8%,相对标准偏差(RSD,n=9)分别为1.8%和0.04%。对10种不同中药材中齐墩果酸和熊果酸含量进行检测,结果表明该方法快速简便、准确度高、重现性好,可用于含有齐墩果酸和熊果酸的中药材含量测定。  相似文献   

4.
川西獐牙菜及制剂中齐墩果酸的高效液相色谱测定   总被引:3,自引:0,他引:3  
中药及制剂中齐墩果酸分离测定的色谱方法的色谱条件是:ODS柱,甲醇一水(90:10V/V)为流动相,紫外检测器检测波长207nm。本研究为中药资源开发制剂的质量控制提供了简便、灵敏、准确、快速的分离测定方法。  相似文献   

5.
GC-MS同时测定番石榴叶中的齐墩果酸和熊果酸   总被引:4,自引:0,他引:4  
建立了测定番石榴叶中齐墩果酸和熊果酸的气相色谱-质谱(GC-MS)方法.以双(三甲硅烷)三氟乙酰胺(BSTFA)为衍生化试剂,将齐墩果酸和熊果酸制成三甲基硅烷衍生物后,在DB-5 MS毛细管柱上进行分离.柱升温程序为:柱初温100 ℃,恒温保持2 min, 以10 ℃/min的速度升温至300 ℃,保持14 min.通过与标准样品对照比较保留时间和质谱确认样品中齐墩果酸和熊果酸的色谱峰.以峰面积进行定量测定,齐墩果酸和熊果酸的线性范围分别为4.1~102 μg/mL和4.7~114 μg/mL,回收率分别为77.1%和89.4%,6次平行测定的相对标准偏差分别为3.7%和3.5%.  相似文献   

6.
用反相高效液相色谱法测定了吴茱萸及制剂中吴茱萸碱和吴茱萸次碱,建立了中药及制剂中吴茱萸碱、吴茱萸次碱分离、测定的色谱方法。色谱条件:ODS柱,乙腈+水+四氢呋喃+乙酸(52+48+1+0.1)为流动相,紫外检测波长280nm。方法简便、灵敏、准确、快速。  相似文献   

7.
青藏高原龙胆科植物药用有效成分的高效液相色谱分析   总被引:17,自引:0,他引:17  
胡凤祖  宋娅莉  刘梅  师治贤 《色谱》2003,21(1):63-65
采用高效液相色谱法,对青藏高原上9种龙胆科植物中的3种有效成分齐墩果酸、芒果甙和当药黄素进行了分离和分析。所用色谱柱为Supelco INC C18柱(150 mmX1.5 mm i.d., 5 μm);在选定的色谱条件下每种成分在各自的浓度范围内均具有较好的线性相关性。样品的加标回收率为102.4%106.7%,相对标准偏差为0.55%3.01%。  相似文献   

8.
以天然产物齐墩果酸为先导化合物,经过氧化、酯化(酰化)、水解等反应合成了8个齐墩果酸衍生物,以MCF-7和A549细胞为靶细胞,紫杉醇和吉非替尼为阳性对照物,采用磺酰若丹明B(SRB)法进行初步的体外抗肿瘤活性筛选。结果表明,化合物5a对A549细胞的抑制作用与母体齐墩果酸相当,化合物5d对A549细胞的抑制活性明显高于母体齐墩果酸。因此,化合物5a和5d值得进一步研究。  相似文献   

9.
采用动态微波提取技术和反相高效液相色谱方法来测定藏茵陈中齐墩果酸的含量。色谱条件:色谱柱Phenomenex Fusion-Rp column(250mm×4.6mmi.d.,4μm);流动相:甲醇-0.2%H3PO4水溶液(85∶15,v/v);流速:1.0mL/min;检测波长:210 nm;柱温:30℃。标准曲线方程为y=480.62 x+9.53(r=1),齐墩果酸对照品进样量在0.84~5.04μg范围内线性关系良好。结果表明,齐墩果酸在藏茵陈中的含量为0.67%,在藏茵陈提取物中的含量为2.64%。  相似文献   

10.
反相高效液相色谱法同时测定柿叶中齐墩果酸和熊果酸   总被引:1,自引:0,他引:1  
建立反相高效液相色谱法同时测定柿(Diospyros koki Linn.f.)叶中齐墩果酸和熊果酸的含量.采用Kromasil C18色谱柱(4.6 mm×250 mm,5 μm);流动相:V(甲醇):V(0.2%磷酸水溶液)=87:13;流速:0.8 mL/min;检测波长:210nm;柱温:30℃.齐墩果酸进样量在0.0848~1.696 μg范围内线性关系良好,r=0.9996,平均加样回收率为101.3%;熊果酸进样量在0.1408~2.816 μg范围内线性关系良好,r=0.9995,平均加样回收率为99.0%.3批样品测定结果表明,本法可作为柿叶中齐墩果酸和熊果酸含量测定的方法.  相似文献   

11.
Metathesis reactions of the alkali metal formamidinates M(RNC(H)NR), M = Li or K; R = C(6)H(3)-2,6-Pr(i)(2) (L(1)), C(6)H(3)-2,6-Et(2) (L(2)); C(6)H(2)-2,4,6-Me(3) (L(3)), C(6)H(3)-2,6-Me(2) (L(4)) or C(6)H(4)-2-Ph (L(5)), with BiX(3) (X = Cl or Br) gave a range of bismuth(iii) formamidinate complexes [Bi(L)Br(micro-Br)(thf)](2) (L = L(1), L(4)), [{Bi(L(1))Cl(2)(thf)}(2)Bi(L(1))Cl(2)], [Bi(L)(2)X] (L = L(2), L(5), X = Br; L = L(1), X = Cl), and [Bi(L)(3)] (L = L(2), L(3)). An analogous organometallic complex Bi(L(1))(2)Bu(n) was also isolated as a side product in one instance. Structural characterisation of the di-halide complexes show symmetrical dimers for X = Br, with two bromide bridges, and a coordinated thf molecule on each Bi atom, whereas for X = Cl a thf deficient species was crystallised, and has a weakly associated trinuclear array with two coordinated thf molecules per three Bi atoms. Complexes of the form Bi(L)(2)X (X = Br, Cl, Bu(n)) and Bi(L)(3) all have monomeric structures but the Bi(L)(3) species show marked asymmetry of the formamidinate binding, suggesting that they have reached coordination saturation.  相似文献   

12.
The condensation reaction between 2-pyridinecarboxaldehyde and diethylenetriamine, 3-[(2-aminoethyl)amino]propylamine, and 3,3'-iminobis(propylamine) in a 2:1 molar ratio yields ligands that may be isolated exclusively in the dissymmetric (cyclic) isomeric forms L(A), L(B)/L(B*), and L(C). The template effect of a metal center (Fe(II), Ni(II), and Zn(II)) results in the ring opening of L(C) including one hexahydropyrimidine ring and one (long) propylene bridge. The resulting symmetric bis-Schiff base isomeric form L(C') is stabilized through pentacoordination, yielding [Fe(II)L(C')(NCS)](NCS) (3), [Ni(II)L(C')(NCS)](NCS) (6), and [Zn(II)L(C')(NCS)](NCS) (9). The same metal centers are too bulky to exert a template effect on L(A) including one imidazolidine ring and one (short) ethylene bridge. L(A) acts as a tetradentate ligand yielding [Fe(II)L(A)(NCS)2] (1), [Ni(II)L(A)(NCS)2] (4), and [Zn(II)L(A)(NCS)2] (7). The template effect of the metal center is selective toward the ligand L(B)/L(B*) including a hexahydropyrimidine (imidazolidine) ring and the shorter ethylene (longer propylene) bridge. The Fe(II) cation is small enough to exert a template effect, resulting in the ring opening of L(B)/L(B*). The resulting bis-Schiff base L(B') is stabilized through pentacoordination, yielding [Fe(II)L(B')(NCS)](NCS) (2). Ni(II) is too bulky to promote the ring opening of L(B)/L(B*): L(B) acts as a tetradentate ligand, yielding [Ni(II)L(B)(NCS)2] (5) (the L(B*) isomer is totally converted to L(B)). The coordinative requirements and stereochemical preference of the bulkier Zn(II) cation allow neither the ring opening of L(B)/L(B*) nor the tetracoordination of L(B) or L(B*) but stabilize the novel tetradentate dissymmetric form L(B degrees) in [Zn(II)L(B degrees)(NCS)2].H2O (8) (L(B degrees) results from MeOH addition across the imine bond of L(B)). Density functional theory calculations performed for Ni(II) and Zn(II) complexes of the L(B)/L(B*)/L(B degrees) set of ligands allowed one to compare the relative stabilities of all possible isomers, showing that the most stable ones correspond to those experimentally obtained: isomerization, or methanol addition across the imine bond, of the tetradentate ligand depends on the relative stabilities of all possible isomeric complexes.  相似文献   

13.
Magnesium and zinc complexes of the monoanionic ligands N,N'-bis(2,6-di-isopropylphenyl)triazenide, L1, N,N'-bis(2,6-di-isopropylphenyl)acetamidinate, L2, and N,N'-bis(2,6-di-isopropylphenyl)tert-butylamidinate, L3, have been synthesized, but only L3 possesses sufficient steric bulk to prevent bis-chelation. Hence, the reaction of L1H with excess ZnEt2 leads to the isolation of (L1)2Zn, 1; L1H also reacts with Bu2Mg in Et2O to afford (L1)2Mg(Et2O), 2. Similar reactivity is observed for L2H, leading to the formation of (L2)2Zn, 3, and (L2)2Mg, 4. The reaction of L2H with ZnR2 may also afford the tetranuclear aggregates {(L2)Zn2R2}2O, 5 (R=Me) and 6 (R=Et). By contrast, the tert-butylamidinate ligand was found to exclusively promote mono-chelation, allowing (L3)ZnCl(THF), 7, [(L3)Zn(micro-Cl)]2, 8, (L3)ZnN(SiMe3)2, 9, (L3)MgiPr(Et2O), 10, and (L3)MgiPr(THF), 11, to be isolated. X-ray crystallographic analyses of 1, 2, 3, 4, 5, 6, 8, and 10 indicate that the capacity of L3 to resist bis-chelation is due to greater occupation of the metal coordination sphere by the N-aryl substituents.  相似文献   

14.
The copper(II) coordination chemistry of westiellamide (H(3)L(wa)), as well as of three synthetic analogues with an [18]azacrown-6 macrocyclic structure but with three imidazole (H(3)L(1)), oxazole (H(3)L(2)), and thiazole (H(3)L(3)) rings instead of oxazoline, is reported. As in the larger patellamide rings, the N(heterocycle)-N(peptide)-N(heterocycle) binding site is highly preorganized for copper(II) coordination. In contrast to earlier reports, the macrocyclic peptides have been found to form stable mono- and dinuclear copper(II) complexes. The coordination of copper(II) has been monitored by high-resolution electrospray mass spectrometry (ESI-MS), spectrophotometric and polarimetric titrations, and EPR and IR spectroscopies, and the structural assignments have been supported by time-dependent studies (UV/Vis/NIR, ESI-MS, and EPR) of the complexation reaction of copper(II) with H(3)L(1). Density functional theory (DFT) calculations have been used to model the structures of the copper(II) complexes on the basis of their spectroscopic data. The copper(II) ion has a distorted square-pyramidal geometry with one or two coordinated solvent molecules (CH(3)OH) in the mononuclear copper(II) cyclic peptide complexes, but the coordination sphere in [Cu(H(2)L(wa))(OHCH(3))](+) differs from those in the synthetic analogues, [Cu(H(2)L)(OHCH(3))(2)](+) (L = L(1), L(2), L(3)). Dinuclear copper(II) complexes ([Cu(II) (2)(HL)(mu-X)](+); X = OCH(3), OH; L = L(1), L(2), L(3), L(wa)) are observed in the mass spectra. While a dipole-dipole coupled EPR spectrum is observed for the dinuclear copper(II) complex of H(3)L(3), the corresponding complexes with H(3)L (L = L(1), L(2), L(wa)) are EPR-silent. This may be explained in terms of strong antiferromagnetic coupling (H(3)L(1)) and/or a low concentration of the dicopper(II) complexes (H(3)L(wa), H(3)L(2)), in agreement with the mass spectrometric observations.  相似文献   

15.
The N(2)-donor bidentate ligands di(1H-indazol-1-yl)methane (L(1)) and di(2H-indazol-2-yl)methane (L(2)) (L in general) have been synthesized, and their coordination behavior toward Zn(II), Cd(II), and Hg(II) salts has been studied. Reaction of L(1) and L(2) with ZnX(2) (X = Cl, Br, or I) yields [ZnX(2)L] species (1-6), that, in the solid state, show a tetrahedral structure with dihapto ligand coordination via the pyrazolyl arms. The reaction of L(1) and L(2) with Zn(NO(3))(2)·6H(2)O is strongly dependent on the reaction conditions and on the ligand employed. Reaction of L(1) with equimolar quantities of Zn(NO(3))(2)·6H(2)O yields the neutral six-coordinate species [Zn(NO(3))(2)(L(1))], 7. On the other hand the use of L(1) excess gives the 2:1 adduct [Zn(NO(3))(2)(L(1))(2)], 8 where both nitrates act as a unidentate coordinating ligand. Analogous stoichiometry is found in the compound obtained from the reaction of L(2) with Zn(NO(3))(2)·6H(2)O which gives the ionic [Zn(NO(3))(L(2))(2)](NO(3)), 10. Complete displacement of both nitrates from the zinc coordination sphere is observed when the reaction between L(1) excess and the zinc salt was carried out in hydrothermal conditions. The metal ion type is also determining structure and stoichiometry: the reaction of L(2) with CdCl(2) gave the 2:1 adduct [CdCl(2)(L(2))(2)] 11 where both chlorides complete the coordination sphere of the six-coordinate cadmium center; on the other hand from the reaction of L(1) with CdBr(2) the polynuclear [CdBr(2)(L(1))](n) 12 is obtained, the Br(-) anion acting as bridging ligands in a six-coordinate cadmium coordination environment. The reaction of L(1) and L(2) with HgX(2) (X = Cl, I, SCN) is also dependent on the reaction conditions and the nature of X, two different types of adducts being formed [HgX(L)] (14: L = L(1), 16, 17: L = L(1) or L(2), X = I, 19: L = L(2), X = SCN) and [HgX(L)(2)] (15: L = L(2), X = Cl, 18: L = L(1), X = SCN). The X-ray diffraction analyses of compounds 1, 2, 4, 5, 7, 8, 10-12, 14, 15, and 19 are also reported. The variations of the coordination geometry parameters in the complexes are compared and discussed.  相似文献   

16.
The aquachromyl ion, Cr(IV)aqO2+, reacts with the hydrides L(H2O)RhH2+ (L = L1 = [14]aneN4 and L2 = meso-Me6-[14]aneN4) in aqueous solutions in the presence of molecular oxygen to yield Cr(aq)3+ and the superoxo complexes L(H2O)RhOO2+. At 25 degrees C, the rate constants are approximately 10(4) M(-1) s(-1) (L = L1) and 1.12 x 10(3) M(-1) s(-1) (L = L2). Both reactions exhibit a moderate deuterium isotope effect, kRhH/kRhD = approximately 3 (L1) and 3.3 (L2), but no solvent isotope effect, kH2O/kD2O = 1. The proposed mechanism involves hydrogen atom abstraction followed by the capture of LRh(H2O)2+ with molecular oxygen. There is no evidence for the formation of L(H2O)Rh2+ in the reaction between L(H2O)RhH2+ and (salen)CrVO+. The proposed hydride transfer is supported by the magnitude of the rate constants (L = L1, k = 8,800 M(-1) s(-1); (NH3)4, 2,500; L2, 1,000) and isotope effects (L = L1, kie = 5.4; L2, 6.2). The superoxo complex [L1(CH3CN)RhOO](CF3SO3)2.H2O crystallizes with discrete anions, cations, and solvate water molecules in the lattice. All moieties are linked by a network of hydrogen bonds of nine different types. The complex crystallized in the triclinic space group P1 with a = 9.4257(5) A, b = 13.4119(7) A, c = 13.6140(7) A, alpha = 72.842(1)degrees, beta = 82.082(1) degrees, gamma = 75.414(1) degrees, V = 1587.69(14) A3, and Z = 2.  相似文献   

17.
The new unsymmetrical, optically active ligands 1,2-C(2)H(4)(PPh(2))(2'R,5'R-2',5'-dimethylphospholanyl) (L(a)) and 1,3-C(3)H(6)(PPh(2))(2'R,5'R-2',5'-dimethylphospholanyl) (L(b)) form complexes of the type [Rh(L)(cyclooctadiene)][BF(4)] where L = L(a) (1a) or L(b) (1b), [PtCl(2)(L)] where L = L(a) (2a) or L(b) (2b) and [PdCl(2)(L)] where L = L(a) (3a) or Lb (3b). The crystal structures of 2a and 2b show the chelate ligand backbones adopt delta-twist and flattened chair conformations respectively. Asymmetric hydrogenation of enamides and dehydroaminoesters using 1a and 1b as catalysts show that the ethylene-backboned diphosphine L(a) gives a more efficient catalyst in terms of asymmetric induction than the propylene-backboned analogue L(b). The greatest enantioselectivities were obtained with 1a and enamide substrates with ees up to 91%. Substrate-induced conformational changes in the Rh-diphosphine chelates are proposed to explain some of the ees observed in the hydrogenation of enamides.  相似文献   

18.
Five new Zn(II)/Cd(II) coordination polymers constructed from di(1H-imidazol-1-yl)methane (L) mixed with different auxiliary carboxylic acid ligands formulated as [Zn(L)(H(2)L(1))(2)·(H(2)O)(0.2)](n) (1), {[Zn(L)(L(2))]·H(2)O}(n) (2), {[Cd(2)(L)(2)(L(2))(2)]·2H(2)O}(n) (3), {[Cd(L)(L(3))]·H(2)O}(n) (4) and [Cd(L)(L(4))](n) (5) (H(3)L(1) = 1,3,5-benzenetricarboxylic acid, H(2)L(2) = 4,4'-oxybis(benzoic acid), H(2)L(3) = m-phthalic acid and H(2)L(4) = p-phthalic acid) have been synthesized under hydrothermal conditions and structurally characterized. Four related auxiliary carboxylic acids were chosen to examine the influences on the construction of these coordination frameworks with distinct dimensionality and connectivity. The coordination arrays of 1-5 vary from 1D zigzag chain for 1, 2D (4,4) layer for 2-4, to 2-fold interpenetrated 3D coordination network with the α-Po topology for 5. The thermal and photoluminescence properties of complexes 1-5 in the solid state have also been investigated.  相似文献   

19.
A series of mononuclear, octahedral first-row transition metal ion complexes mer-[M(II)L0(2)](PF6)2 containing the tridentate neutral ligand 2,6-bis[1-(4-methoxyphenylimino)ethyl]pyridine (L0) and a Mn(II), Fe(II), Co(II), Ni(II), Cu(II), or Zn(II) ion have been synthesized and characterized by X-ray crystallography. Cyclic voltammetry and controlled potential coulometry show that each dication (except those of Cu(II) and Zn(II)) can be reversibly one-electron-oxidized, yielding the respective trications [M(III)L0(2)]3+, and in addition, they can be reversibly reduced to the corresponding monocations [ML2]+ and the neutral species [ML2]0 by two successive one-electron processes. [MnL2]PF6 and [CoL2]PF6 have been isolated and characterized by X-ray crystallography; their electronic structures are described as [Mn(III)L1(2)]PF6 and [Co(I)L0(2)]PF6 where (L1)1- represents the one-electron-reduced radical form of L0. The electronic structures of the tri-, di-, and monocations and of the neutral species have been elucidated in detail by a combination of spectroscopies: UV-vis, NMR, X-band EPR, Mossbauer, temperature-dependent magnetochemistry. It is shown that pyridine-2,6-diimine ligands are noninnocent ligands that can be coordinated to transition metal ions as neutral L0 or, alternatively, as monoanionic radical (L1)1-. All trications are of the type [M(III)L0(2)]3+, and the dications are [M(II)L0(2)]2+. The monocations are described as [Mn(III)L1(2)]+ (S = 0), [Fe(II)L0L1]+ (S = 1/2), [Co(I)L0(2)]+ (S = 1), [Ni(I)L0(2)]+ (S = 1/2), [Cu(I)L0(2)]+ (S = 0), [Zn(II)L1L0]+ (S = 1/2) where the Mn(II) and Fe(II) ions are low-spin-configurated. The neutral species are described as [Mn(II)L1(2)]0, [Fe(II)L1(2)]0, [Co(I)L0L1]0, [Ni(I)L0L1]0, and [Zn(II)L1(2)]0; their electronic ground states have not been determined.  相似文献   

20.
The syntheses, characterisation and complexation reactions of a series of binucleating Schiff-base calixpyrrole macrocycles are described. The acid-templated [2+2] condensations between meso-disubstituted diformyldipyrromethanes and o-phenylenediamines generate the Schiff-base pyrrolic macrocycles H(4)L(1) to H(4)L(6) upon basic workup. The single-crystal X-ray structures of both H(4)L(3).2 EtOH and H(4)L(6).H2O confirm that [2+2] cyclisation has occurred, with either EtOH or H2O hydrogen-bonded within the macrocyclic cleft. A series of complexation reactions generate the dipalladium [Pd2(L)] (L=L(1) to L(5)), dinickel [Ni2(L(1))] and dicopper [Cu2(L)] (L=L(1) to L(3)) complexes. All of these complexes have been structurally characterised in the solid state and are found to adopt wedged structures that are enforced by the rigidity of the aryl backbone to give a cleft reminiscent of the structures of Pacman porphyrins. The binuclear nickel complexes [Ni2(mu-OMe)2Cl2(HOMe)2(H(4)L(1))] and [Ni2(mu-OH)2Cl2(HOMe)(H(4)L(5))] have also been prepared, although in these cases the solid-state structures show that the macrocyclic ligand remains protonated at the pyrrolic nitrogen atoms, and the Ni(II) cations are therefore co-ordinated by the imine nitrogen atoms only to give an open conformation for the complex. The dicopper complex [Cu2(L(3))] was crystallised in the presence of pyridine to form the adduct [Cu2(py)(L(3))], in which, in the solid state, the pyridine ligand is bound within the binuclear molecular cleft. Reaction between H(4)L(1) and [Mn(thf){N(SiMe(3))2}2] results in clean formation of the dimanganese complex [Mn2(L(1))], which, upon crystallisation, formed the mixed-valent complex [Mn2(mu-OH)(L(1))] in which the hydroxo ligand bridges the metal centres within the molecular cleft.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号