固相萃取-高效液相色谱法测定马尾松组织中内源激素

建立了固相萃取-高效液相色谱法(SPE-HPLC)测定马尾松组织中内源激素赤霉素(GA3)、吲哚乙酸(IAA)、玉米素核苷(ZR)和脱落酸(ABA)的分析方法。采用WatersC18反相柱(250×4.6mmi.d.,5μm),以体积比为45∶54∶1的甲醇-水-乙酸溶液为流动相,流速1.0mL/min;进样量20μL;检测波长254nm;外标法定量测定。选用Sep-PakC18固相萃取小柱富集内源激素,再经流动相洗脱预处理。4种内源激素在1.0～3.0μg/g添加范围内的回收率为88.4%～108.3%,GA3、IAA、ZR和ABA检出限依次为0.05μg/g、0.02μg/g、0.03μg/g和0.01μg/g。     

高效液相色谱法测定菌肥中赤霉素和吲哚乙酸含量方法研究

建立了一种高效液相色谱法分离测定赤霉素(GA3)和吲哚乙酸(IAA)的方法.采用Agilent ZORBA×300SB-C18(4.6 mm×250 mm)色谱柱,以甲醇∶水=35∶65,(V/V,含2%冰醋酸)为流动相,柱温为25℃,流速为0.5 mL/min.系统讨论了流动相组成及pH对分离的影响.本法测定GA3和IAA的线性范围分别为25.0~1 000μg/mL、2.5~50.0μg/mL.方法回收率分别为85.63%、90.21%.并将该方法成功应用于菌肥中GA3和IAA的含量测定,为该类产品的质量控制提供了快速有效的方法.     

植物内源激素的反相高效液相色谱法测定

报道了以6－N－苄基腺嘌呤（BA）为内标的反相高效液相色谱法测定玉米素（ZT）、赤霉素（GA3）、激动素（KT）、3－吲哚乙酸（IAA）和脱落酸（ABA）等5种植物内源激素的条件;采用μBondapakC18柱、乙腈－甲醇－0．6％（φ）乙酸流动相、检测波长254nm,建立了一种从植物中提取5种激素的样品处理方法,并测定了马铃薯块茎中的5种植物内源激素的含量。     

超高效液相色谱-串联质谱法同时检测植物叶片中吲哚-3-乙酸及其3种氧化产物

以玉米叶片为供试材料,建立了同时测定植物体内吲哚-3-乙酸(IAA)及其3种氧化产物吲哚-3-甲醇(ICI)、吲哚-3-甲醛(ICA)、吲哚-3-羧酸(IFA)含量的超高效液相色谱-串联质谱(UPLC-MS/MS)方法。结果表明,该方法对IAA及其3种氧化产物检测的线性、精密度和重复性较好,灵敏度较高,4种化合物的检出限为0.002~1.63μg/kg,定量下限为0.007~5.43μg/kg;方法的加标回收率为89.5%~95.3%,相对标准偏差为2.3%~5.1%。玉米叶片的实际测定结果表明,IAA,ICI,ICA和IFA的含量分别为(196.25±7.10),(26.21±2.13),(18.65±2.02),(13.62±2.06)μg/kg。该方法已成功应用于小麦、豌豆、硬毛刺苞菊叶片的测定,通用性较好。     

高效液相色谱法同时测定鸭梨种子中3种内源激素

建立了高效液相色谱同时测定鸭梨种子中3种内源激素赤霉素(GA3)、生长素(IAA)和脱落酸(ABA)含量的方法.采用C18反相色谱柱,柱温35 ℃,以甲醇-水(含1%乙酸)(4∶ 6, V/V)为流动相,流速为1 mL/min, 检测器波长开始用254 nm, 2.5 min时将波长切换至210 nm,至3.8 min,GA3出峰结束后,再次将波长切换回254 nm测定IAA和ABA.GA3、IAA和ABA的平均回收率分别为92.8%、91.6%和94.7%.为快速、准确分离和测定鸭梨种子内源激素提供了一种可靠方法.     

液相色谱-串联质谱分析盐胁迫下植物激素的含量变化

建立了高效液相色谱．离子阱串联质谱高灵敏、快速测定多种内源植物激素的新方法。在最佳条件下,吲哚乙酸（IAA）、脱落酸（ABA）和赤霉酸（GA3）在5min内实现完全分离,最低检测限为8．0ng．mL-1．借助串联质谱技术,解释了三种激素的结构碎裂过程．探讨了盐胁迫下,上述内源激素含量的变化趋势．研究表明,随着NaCl浓度增大,IAA和GA3含量降低,ABA含量明显升高．初步揭示了内源激素和植物抗盐性之间的相互关系．     

液相色谱-串联质谱法同时测定油茶不同组织中5类内源激素

本文以油茶枝条、嫩叶、花芽和种仁为材料,建立高效液相色谱-串联质谱法同时对油茶不同组织中内源激素生长素(IAA)、赤霉素A4(GA4)、玉米素(tZ)、脱落酸(ABA)、茉莉酸(JA)5类内源激素的测定方法。油茶不同组织经液氮研磨后用提取液(含75%甲醇、5%甲酸水溶液)提取,通过固相萃取柱(MCX)纯化,用甲醇洗脱得到IAA、ABA、JA、GA4;氨化甲醇洗脱得到tZ;合并洗脱液后,利用液相色谱-串联质谱在多反应检测(MRM)模式下进行定量分析。IAA、ABA、JA、GA4的最佳洗脱体积为2mL,tZ的最佳洗脱体积为3mL。测定5种激素线性相关系数R20.995;方法检出限为0.4~1.2ng/g,加标回收率范围在88%~101%之间,相对标准偏差为7.3%。应用该方法对油茶不同组织内源激素含量的测定结果表明,油茶的花芽和嫩叶的生长素水平较枝条和果实高,种子中茉莉酸含量最高为978.3ng/g,GA4/ABA比例为嫩叶种仁花芽枝条,与油茶各部位生长速度一致。建立的方法适于对弱酸性和碱性激素进行快速纯化分析。     

多功能柱净化-高效液相色谱法同时检测小麦中雪腐镰刀菌烯醇和脱氧雪腐镰刀菌烯醇

建立了小麦中雪腐镰刀菌烯醇（NIV）和脱氧雪腐镰刀菌烯醇（DON）的高效液相色谱同时检测方法。样品采用乙腈-水（体积比85：15）混合溶剂进行提取．通过多功能净化柱（MFC）进行一次性净化，以C18柱为分离柱，水-乙腈-甲醇（体积比90：5：5）混合溶剂为流动相进行高效液相色谱分离和检测。在小麦样品中，本方法在0．2～5μg／g添加范围内的凹收率为87％～99％；相对标准偏差为1．5％～8．3％；DON和NIV的检出限分别为0．12和0、16μg／g（5／N=3）。     

UiO-67分散固相萃取/超高效液相色谱-串联质谱法测定猪肉中6种大环内酯类兽药残留

建立了以金属有机框架材料UiO-67作为吸附剂的分散固相萃取/超高效液相色谱-串联质谱测定猪肉中6种大环内酯类兽药残留的方法。样品经pH 6.0的磷酸盐缓冲溶液提取,加入自制金属有机框架材料UiO-67吸附目标物。经甲醇洗脱后,超高效液相色谱-串联质谱多反应监测模式（MRM）定量分析：6种大环内酯类药物在0.1～200μg/L浓度范围内线性关系良好,相关系数均大于0.99;在3个不同浓度添加水平下,回收率为74.8%～102.5%,相对标准偏差（RSD）为4.3%～9.3%,检出限为0.05～0.5μg/kg,定量限为0.2～1.5μg/kg。     

液相色谱-串联质谱法测定吉非替尼中4种基因毒性杂质

建立了一种同时测定吉非替尼中4种基因毒性杂质3-氯-4-氟苯胺、3,4-二氟苯胺、3-氟-4-氯苯胺和3,4-二氯苯胺的高效液相色谱-串联质谱（HPLC-MS/MS）方法。用Inertsil ODS-3柱（100 mm×3.0 mm,3μm）为色谱柱,以0.1%（体积分数,下同）甲酸水溶液-0.1%甲酸乙腈溶液为流动相,在电喷雾正离子模式下进行测定。该方法在特异性、线性、精密度、准确性、稳定性和耐用性方面得到了验证。4种基因毒性杂质在0.6~96.0μg/L范围内与峰面积呈良好线性关系。检测限和定量限分别为0.2~2.0μg/L和0.6~6.0μg/L。所有杂质的回收率为91.0%~98.5%。检测后,在批号16052301和R16052501-1样品中仅检测到3-氯-4-氟苯胺,但低于杂质限度（6 mg/L）。该方法简便可靠,可用于吉非替尼中4种基因毒性杂质的测定,并为质量控制提供参考。     

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%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

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.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).