超临界二氧化碳萃取秋水仙碱（英文）

 利用超临界二氧化碳对秋水仙块根（经粉碎）中的秋水仙碱进行了萃取,采用高效液相色谱法对萃取出的秋水仙碱的质量分数进行了测定。实验选择40℃20～40MPa作为超临界苹取的操作条件,采用体积分数为95％的乙醇在索氏提取器中对样品进行了对比苹取实验。结果表明:不加浸泡剂进行浸泡处理的样品中的秋水仙碱很难被超临界二氧化碳萃取,在40℃,35MPa条件下,消耗1．28mol的二氧化碳只得到3％的萃取率。加入极少量的有机溶剂浸泡处理样品15min后再进行超临界萃取,可以极大程度地提高秋水仙碱的萃取率。     

超临界CO2萃取异甘草素的提取工艺

采用正交试验与单因素试验相结合方法对异甘草素的超临界CO2提取工艺进行了研究,并与常规索氏提取法的实验结果进行了对比。得到的最佳工艺参数为:萃取压力30 MPa、萃取温度45℃、夹带剂85％乙醇、液固比为5:1、CO2流量10 kg／h、分离压力5．5 MPa、分离温度35℃。实验结果表明,在优化的条件下,超临界CO2萃取异甘草素的提取率为0．035％,异甘草素在提取物中的质量分数为0．84％,分别是索氏提取法提取率的3．5倍,质量分数的3．0倍。超临界CO2萃取异甘草素所用时间短、溶剂用量少、提取效率高、环境友好,是一种高效、快速提取异甘草素的方法。     

超临界流体萃取气相色谱法测定鱼肉中的毒死蜱残留

建立了利用离线超临界CO2萃取气相色谱(SFE-GC)测定鱼肌肉中毒死蜱残留量的分析方法。超临界CO2萃取鱼肌肉中毒死蜱的适宜条件为：温度100℃,压力41．370MPa,CO2流量为1mL／min,动态萃取30min,静态萃取时间15min,调节剂甲醇(添加量0．5mL),收集液丙酮。最小检出量为0．01ng;添加回收率为77.3％～105．1％;相对标准偏差(RSD)为2．4％～15．4％,符合残留分析要求。全程分析时间小于2h。     

藜蒿中黄酮类化合物的微波辅助萃取研究

应用密闭微波萃取装置,分别对藜蒿茎和藜蒿叶中黄酮类化合物进行微波萃取研究。采用正交试验方法得到微波提取藜蒿中黄酮类化合物的最佳条件。微波提取藜蒿茎的最佳条件为乙醇体积分数70％,微波功率800W,提取温度80℃和料液比1：20;微波提取藜蒿叶的最佳条件为乙醇体积分数70％,微波功率600W,照射时间12min,提取温度70℃和料液比1：20;在最佳条件下,藜蒿茎和叶中总黄酮提取率分别为6．43％和7．01％。并将微波萃取与乙醇回流提取进行了比较。     

超临界CO2萃取薰衣草的挥发性组分

1.1样品来源及制备薰衣草：购于新疆远馨香料开发公司。超临界CO2萃取：薰衣草经农用粉碎机粉碎后,用自制的0．5L超临界装置进行萃取(萃取压力：10MPa,萃取温度：321K,萃取时间：120min),得到橙色透明油状物,得率约为2．0％～2．5％,水汽蒸馏：薰衣草粉碎后,经共水蒸馏同时用油水分离器分离精油,3h后收集精油并用无水硫酸钠干燥,得淡黄色油状物,得率约为0．8％～1．0％。     

超临界CO_2萃取桑叶总黄酮工艺的研究

采用超临界CO2萃取桑叶总黄酮,以得率为指标,对萃取压力、萃取温度、夹带剂乙醇的浓度和流量等影响因素进行正交试验。结果表明最佳工艺条件为:萃取压力35 MPa,温度55℃,乙醇质量分数90%,乙醇流量0.01 mL/min。此条件下桑叶总黄酮得率2.28%。该方法简便、可靠、选择性高,适于工业化生产。     

白术挥发性成分的超临界流体萃取及其分析

采用超临界流体萃取白术挥发油成分,对萃取条件进行优化,并用气相色谱、气相色谱－质谱分析鉴定出超临界流体萃了的挥发油中22个化合物。最佳的超临界流体萃取条件为压力22.0MPa,温度60℃,0.5mL乙醇作改性,先静态萃取10min(CO2用量2.0mL),再动态萃取40min(CO2流速为0.3mL/min)。将超临界流体萃取与水蒸气蒸馏进行对比,水蒸气蒸馏5h的油收率仅为超临界流体萃取1h油收率的10.32%,证明超临界流体萃取替代传统萃取的必要性。     

丹参中3种丹参酮的超临界二氧化碳萃取及液相分析

 用超临界CO2 流体及共溶剂乙醇萃取丹参中的 3种丹参酮 ,分别采用正交设计法和系统法考察了萃取中的主要影响因素 ;采用高效液相法 (HPLC) ,在甲醇 水 (体积比为 80∶2 0 )溶液为流动相和检测波长为 2 80nm的条件下 ,以外标法检测了萃取产物中 3种丹参酮的含量。实验得到的最佳条件为 :萃取压力 2 0MPa ;萃取温度 4 5℃ ;分离温度 35℃ ;共溶剂 95 % (体积分数 )乙醇 ;流量 1 0mL/min。建立的HPLC测定方法简便快捷 ,准确度高 ,重现性良好 ,相关系数r为 0 9994～ 0 9998,相对标准偏差RSD为 2 37%～ 3 4 7%。     

杨梅素的提取工艺研究

对杨梅树叶中杨梅素的提取有影响的有机溶剂浓度、提取温度、料液比、提取时间进行正交优化。结果表明,最佳提取工艺条件是乙醇体积分数95％,提取温度95℃,提取时间1．5h,料液比1：15,在此工艺条件下杨梅素提取率达到0．088％。     

超临界流体萃取和高效液相色谱法测定银杏酸

介绍了一种用改性的超临界二氧化碳萃取和离线的反相高效液相色谱分析银杏叶提取物中银杏酸含量的方法。对萃取条件进行了优化,结果表明以硅胶为载体,在３０ＭＰａ、５５℃条件下,８％甲醇作改性剂时的超临界二氧化碳对银杏酸有最理想的回收率和选择性。最小检测限为０．４２ｍｇ／Ｌ。     

高效液相色谱-质谱联用法同时测定体液中麻黄碱和秋水仙碱

建立了血液与尿液中麻黄碱和秋水仙碱的高效液相色谱-质谱联用(HPLC-MS)的同时测定方法。血液与尿液样品经三氟乙酸-乙腈(1∶99)溶液提取后,用Waters Oasis(MCX固相萃取小柱进行净化,在XDB-C8柱上以甲醇-0.04%(体积分数)三氟乙酸(33+67)为流动相,采用电喷雾电离(ESI)在选择离子监测(SIM)模式下测定。定量分析离子:麻黄碱(m/z)166[M+H]+;秋水仙碱(m/z)400[M+H]+。麻黄碱和秋水仙碱在4.0~1 000.0和6.0~1 000.0μg.L-1范围内均呈线性关系,检出限分别为4.0和6.0μg.L-1,回收率在81.0%~109.0%范围内,其日内精密度<6.4%,日间精密度<9.9%。     

秋水仙碱的氨(胺)解反应及其衍生物体外抗癌活性研究

秋水仙碱(Colchicine,1)用于治疗痛风乳腺癌、皮肤癌、白血病、何杰金氏病等[1,2],但其毒性过大限制了它的应用[3].因此,对1结构修饰寻求高效低毒的衍生物引起了人们的兴趣.构效研究表明:秋水仙碱的C-10位的取代基对其活性、毒性影响较大,C-10位被氨解或甲胺解后,活性提高,而毒性降低 [4～6].     

PHOTOPHYSICAL PROCESSES IN TROPOLONE, α-METHOXY-TROPONE AND COLCHICINE

Abstract— The spectral characteristics of the emission observed from tropolone, α-methoxy-tropone and colchicine in EPA at 77 K are reported. Luminescence polarization, lifetime, quantum yield and energy transfer experiments provide evidence that the luminescence observed is S₁→ S₀ fluorescence and that the lowest excited singlet state is π, π* The two compounds α-methoxy-tropone and colchicine have been found to exhibit dual luminescence. No phosphorescence could be detected in these three molecules. The photophysical processes for each molecule are discussed and their respective energy level diagrams are also suggested.     

POSSIBLE IN VIVO FORMATION OF LUMICHOLCHICINES FROM COLCHICINE BY ENDOGENOUSLY GENERATED TRIPLET SPECIES

Abstract In Colchicum autumnale L., colchicine is accompanied by its photoproducts, mainly β-lumicholchicine, even in parts not exposed to light such as the corm of plants grown in the dark. The transformation of colchicine into lumicolchicines can be efficiently accomplished in vitro by energy transfer from enzyme-generated triplet species to colchicine, thus providing additional evidence for'photobiochemistry without light'.     

SYNTHESIS AND EVALUATION OF 2-DIAZO-3,3,3-TRIFLUOROPROPANOYL DERIVATIVES OF COLCHICINE AND PODOPHYLLOTOXIN AS PHOTOAFFINITY LABELS: REACTIVITY, PHOTOCHEMISTRY, AND TUBULIN BINDING

Derivatives of the tubulin polymerization inhibitors colchicine and podophyllotoxin bearing the photoreactive 2-diazo-3,3,3-trifluoropropanoyl (DTFP) group were synthesized for evaluation as potential photoaffinity labels of the tubulin binding site. All labels were assayed for their ability to inhibit tubulin polymerization, and N-DTFP-deacetylthiocolchicine was shown to competitively inhibit tubulin-colchicine binding with a Ki of 4-5 microM. The tubulin off-rate of this analog was similar to that of podophyllotoxin, rather than to the relatively irreversibly bound colchicine. Photochemical solvent insertion reactions of the labels were investigated. Radioactive samples of the two most active labels were prepared and used in initial protein-labeling experiments, during which the fractional occupancy of tubulin and extent of covalent incorporation were determined. A rearrangement of DTFP amides was encountered which is relevant to the utility of this moiety for use in synthesis of photoaffinity labels.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.