高效液相色谱/大气压化学电离质谱分析银杏叶中聚戊烯醇化合物

采用高效液相色谱，大气压化学电离质谱法(HPLC/APCIMS)分析银杏叶中聚戊烯醇化合物。在ODS-3柱上，以异丙醇-甲醇-正己烷-水(50：25：15：2，V/V)为流动相分离银杏叶中不同碳链长度的聚戊烯醇，通过质谱分析对每种聚戊烯醇化合物进行定性鉴定，外标法定量分析各聚戊烯醇含量。经HPLC/APCIMS分析，银杏叶中含有C75-C105聚戊烯醇，其中主要为C85、C90和C95聚戊烯醇。该方法简便，快速。     

制备反相高效液相色谱法用于从杉材中分离制备倍半萜类化合物

利用制备高效液相色谱法从日本产杉材(Cryptomeria japonica D.Don)中分离制备倍半萜类化合物。在YWC-Pack C18柱上,以异丙醇-甲醇-正己烷-水(体积比为50∶35∶10∶5)为流动相,流速为5 mL/min,制备了2种倍半萜类化合物,经紫外光谱、红外光谱及核磁、质谱分析,确认它们分别为(-)-cubebol和(+)-2,7(14),10-bisa-bolatrien-1-ol-4-one。所制备的两个化合物的纯度分别为98.7%和99.1%。     

乌骨藤中五环三萜类化合物的分离鉴定

利用硅胶柱色谱法、Sephadex LH-20凝胶柱色谱法及半制备高效液相色谱法,从乌骨藤的正丁醇萃取物中分离得到4种五环三萜类化合物。利用核磁共振谱、质谱、红外光谱等分析方法对化合物结构进行了分析和表征,确定了4种化合物分别为β-香树脂醇(β-amyrin)、白桦酯醇(betulin)、白桦酯酸(betulinic acid)和羽扇豆醇(lupeol),它们为首次在牛奶菜属植物中发现,其中后3种化合物具有抗肿瘤活性。     

高速逆流色谱法分离制备乌药叶中的黄酮类成分

应用高速逆流色谱法分离制备了乌药叶中的黄酮类成分。以正己烷-乙酸乙酯-正丁醇-冰醋酸-水(体积比为2∶4∶2∶1.5∶6)为两相溶剂系统,在主机转速800 r/min、流速2.0 mL/min、检测波长280 nm条件下进行分离制备。所得流分经高效液相色谱法检测,并经电喷雾电离质谱、核磁共振氢谱、碳谱鉴定化合物的结构。结果表明,从乌药叶总黄酮粗提物中分离得到了5个化合物,分别为槲皮素-3-O-β-D-葡萄糖苷(1)、槲皮素-5-O-β-D-葡萄糖苷(2)、槲皮素-3-O-β-D-呋喃阿拉伯糖苷(3)、槲皮素-3-O-吡喃鼠李糖苷(4)、山奈酚-7-O-α-L-吡喃鼠李糖苷(5),其中化合物1,2,3和5 为首次从该植物中分离得到。该法具有简便、快速的优点。     

高效制备液相色谱法从荷叶中分离制备黄酮类化合物

采用高效制备液相色谱法从荷叶(Nelumbo nucifera Gaertn)中分离制备荷叶黄酮类化合物。用60%乙醇回流提取荷叶，粗提液浓缩后经D-101柱及聚酰胺柱色谱分离，再在Symmetry PrepTM C18柱上分离,以水-乙腈为流动相进行梯度洗脱（流速为5.0 mL/min）,得到了3种黄酮类化合物。经紫外光谱、红外光谱、核磁共振及质谱分析,确定该3种物质分别为金丝桃苷、异槲皮苷和紫云英苷。所制备的3种化合物的纯度都在97%以上,其中紫云英苷为首次从荷叶中分离得到。     

反相高效液相色谱法制备喜树细胞内生物碱单体

利用制备高效液相色谱法从喜树细胞中分离制备了在原植株内不存在的两种全新的生物碱单体．喜树异碱A和喜树异碱B。在C18柱上，以乙腈-水(体积比为35：65)为流动相，流速为5mL／min，采用等度洗脱方式，制备了这两种化合物。经紫外光谱、红外光谱及质谱分析，对这两种化合物进行了确认。高效液相色谱分析表明，制备的喜树异碱A和喜树异碱B的纯度均在97％(质量分数)以上。在该色谱条件下，各色谱峰达到了基线分离，且分离时间短，溶剂用量少。     

制备型高效液相色谱法制备纯化3种辣椒素单体

利用制备型反相高效液相色谱法从辣椒素类物质中制备了3种辣椒素单体。在PRC-ODS色谱柱(250 mm×21.5 mm,13 μm)上,以甲 醇-水(体积比为70∶30)为流动相,流速为15 mL/min,采用等度洗脱方式,从80%的辣椒素类物质中制备了3种辣椒素单体。经核磁共振 氢谱(1H NMR)及电子轰击离子源质谱(EI-MS)分析,确认它们分别为降二氢辣椒素、辣椒素和二氢辣椒素,收率分别为60.1%,58.9%和 72.3%。高效液相色谱分析表明所制备的3种化合物的纯度分别达到了98.12%,99.93%及100.7%。     

鲜人参中2种丙二酰基人参皂苷的分离鉴定

采用硅胶柱层析方法,流动相分别为氯仿-甲醇-水(65∶35∶10,V/V)、氯仿-甲醇-水(6∶4∶1)和正丁醇-乙酸乙脂-甲醇-水(4∶2∶1∶1)和高效液相(Nuc leosil C18(250 mm×10 mm,5μm)色谱柱;流动相为己腈-水(75∶25);流速为3.0 mL/m in;柱温30℃;检测波长203 nm。从中国鲜人参中分离得到丙二酰基人参皂苷R c和丙二酰基人参皂苷Rb2,并通过其理化性质、红外光谱、质谱和核磁共振谱对化合物的结构进行了鉴定,证明其结构分别为3-O-[6-O-丙二单酰-β-D-葡萄吡喃糖(1→2)-β-D-葡萄吡喃糖]-20-O-[α-L-阿拉伯呋喃糖(1→6)-β-D-葡萄吡喃糖]-20(S)-原人参二醇和3-O-[6-O-丙二单酰-β-D-葡萄吡喃糖(1→2)-β-D-葡萄吡喃糖]-20-O-[α-L-阿拉伯吡喃糖(1→6)-β-D-葡萄吡喃糖]-20(S)-原人参二醇;丙二酰基人参皂苷R c为首次从中国鲜人参中分得。     

超高效液相色谱法快速分离卷烟主流烟气中8种羰基化合物

建立了超高效液相色谱法(UPLC),分离卷烟主流烟气中8种羰基化合物。采用Acquity UPLC BEH 2-EP色谱柱(100×3mm,1.7μm)分离,以纯水-乙腈/异丙醇/四氢呋喃(89.9∶10∶0.1,V/V/V)为流动相,等度洗脱8种羰基化合物在12min内可实现有效分离。采用建立的UPLC法和高效液相色谱法对卷烟主流烟气中8种羰基化合物进行分离,结果表明,相比于传统的高效液相色谱法,UPLC法更为快速、高效。     

高速逆流色谱分离制备椭圆叶花锚中的2种口山酮苷元

椭圆叶花锚的主要活性成分为口山酮类化合物,这类化合物具有利胆、抗炎、抗菌及抗病毒活性。应用高速逆流色谱法建立了2种高纯度口山酮苷元的分离制备方法。对椭圆叶花锚氯仿萃取部位运用高速逆流色谱分离纯化,以正己烷-乙酸乙酯-甲醇-水(5:5:7:5, v/v/v/v)为两相溶剂系统,上相为固定相,下相为流动相。在主机转速800 r/min,流动相流速1.5 mL/min,检测波长254 nm条件下进行分离制备。所得产物经高效液相色谱分析检测,其化学结构由核磁共振氢谱(1H NMR)和核磁共振碳谱(13C NMR)鉴定。在此条件下,从100 mg粗样品中一步分离得到18 mg 1-羟基-2,3,5-三甲氧基口山酮,14 mg 1-羟基-2,3,4,5-四甲氧基口山酮。经高效液相色谱分析,其纯度均达98%以上。该方法简便、快速,所得产物纯度高,适合于椭圆叶花锚口山酮苷元的制备分离。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.