HPLC与MALDI-TOF MS联用技术分析蛋黄中的磷脂

蛋黄中含有大量磷脂,其中磷脂酰胆碱(PC)和磷脂酰乙醇胺(PE)最为丰富.本研究采用高效液相色谱法(HPLC)与基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)联用技术分析了蛋黄中磷脂粗提物.将从蛋黄中提取的多种磷脂通过HPLC预先分离,收集各组分后分别进行MAIDI-TOF MS分析得到比较清晰的质谱图.通过质谱图解析确定了蛋黄中磷脂酰胆碱、神经鞘磷脂(SM)的脂肪酸组成.     

基于超高效液相色谱-高分辨质谱法的油料作物脂质组学分析

针对油料脂质分子众多、结构难识别的难题,采用超高效液相色谱-高分辨质谱对油菜籽、大豆、花生、向日葵籽、玉米5种油料作物中脂质进行分析。使用反相色谱柱ACQUITY UPLC BEH C_(18)(2.1 mm×100 mm,1.7μm)分离脂质,超高效液相色谱-高分辨质谱仪(UPLC-Orbitrap Fusion Mass)正、负离子模式下采集Data Dependent MS~2数据,利用二级质谱碎片特征、精确分子质量、保留时间以及数据库匹配对脂质分子进行定性分析,获得脂质分子的唯一结构式。共鉴定出油料作物中132种脂质分子,包括8种甘油二酯(DG)、5种溶血磷脂酰胆碱(LPC)、2种溶血磷脂酰乙醇胺(LPE)、24种磷脂酰胆碱(PC)、18种磷脂酰乙醇胺(PE)、8种磷脂酰肌醇(PI)、1种磷脂酰甘油(PG)、1种磷脂酰丝氨酸(PS)以及65种甘油三酯(TG),并使用峰面积比进行相对含量的比较。该方法可以很好地实现脂质成分的分离,将油料作物中脂质成分的分析从脂肪酸分析水平提升到脂质分子层面,为更好地实现油料作物中脂质成分的应用提供了研究基础,并促进了脂质组学的发展。     

UPLC－ESI－Q－TOF MS结合裂解规律分析姜科植物中二苯基庚烷类成分

根据标准品的质谱数据,探讨二苯基庚烷类成分的裂解规律,并利用裂解规律分析姜科植物中的该类成分。采用针泵注射进样,利用高分辨率和高准确性的电喷雾－四极杆－飞行时间质谱（ESI－Q－TOF MS）得到正离子模式下（ESI+）11个标准品的质谱数据。在此基础上,分析标准品的裂解行为,归纳4类二苯基庚烷类化合物的裂解途径,总结出二苯基庚烷类化合物的裂解规律。据此建立快速识别二苯基庚烷类成分的方法,结合超高效液相色谱－电喷雾－四极杆－飞行时间串联质谱（UPLC－ESI－Q－TOF MS）,对姜科植物来源中药姜皮、草果、益智仁中的二苯基庚烷类成分进行识别,从中分别鉴定出14、11、10个此类成分。结果表明,该方法准确、可靠、高效,可快速鉴定和分析姜科植物中的二苯基庚烷类化合物。     

直接进样电喷雾串联质谱法测定草鱼肌肉组织中磷脂

建立了直接进样电喷雾串联质谱测定草鱼肌肉组织中磷脂的方法.以Bligh Dyer法提取总脂质,采用流动注射泵直接进样的方式将样品导人电喷雾离子源,利用串联三重四级杆质谱的母离子扫描和中性丢失扫描功能,通过扫描磷脂的特征性子离子或中性质量丢失实现对磷脂酰胆碱、磷脂酰乙醇胺、磷脂酰肌醇、磷脂酰丝氨酸、磷脂酰甘油和磷脂酸六类磷脂的源内分离和鉴定.结果显示,在-定的浓度范围内,磷脂的浓度与磷脂直接进样电喷雾电离后形成准分子离子的响应值呈现良好的线性关系,回收率(67.1％～96.6％)和精密度可以满足生物样品分析的要求.采用本方法测定了草鱼肌肉组织中磷脂酰胆碱、磷脂酰乙醇胺、磷脂酰肌醇和磷脂酰丝氨酸4类磷脂的分子种及含量.本方法前处理简单,定性和定量分析快速准确,可以应用于其它生物样本脂质组学中磷脂的分析.     

非小细胞肺癌患者尿中Exosomes蛋白质组的差异表达分析

除血浆之外,尿液是另一种寻找潜在生物标志物的重要生物材料。本研究以200000×g超速离心法分离正常人和非小细胞肺癌(NSCLC)患者尿液中的Exosomes,运用1DSDS-PAGE对Exosomes蛋白质组进行分组,从电泳胶上切取正常组和疾病组的20～31kDa条带,胰蛋白酶酶解后,进行HPLC-CHIP-MS/MS分析,并通过UniProtKB/SWISS-PORT数据库搜索鉴定了24种蛋白质,其中在NSCLC患者尿液Exosomes蛋白质组中发现了8种差异表达蛋白,包括免疫球蛋白κ的3个片段、2种Ras相关蛋白、谷胱甘肽S转移酶A2、血清淀粉样P成分前体和磷脂酰乙醇胺结合蛋白1。     

脂质体药用辅料mPEG2000-DSPE的合成

以氧氯化磷、乙醇胺及1,2-二硬脂酸甘油酯为原料,经环合、磷酰化及水解反应制得1,2-二硬脂酰甘油磷酰乙醇胺（DSPE）;在N,N′-羰基二咪唑作用下,DSPE与甲氧基聚乙二醇（mPEG2000）反应合成了1,2-二硬脂酰甘油磷脂酰乙醇胺N-甲氧基聚乙二醇2000（mPEG2000-DSPE）,其结构经¹H NMR, IR和MS（ESI）确证。     

基于UPLC-Q/TOF MS技术探讨竹节参总皂苷对HepG2细胞脂质代谢的改善作用

基于细胞代谢组学技术研究竹节参总皂苷改善HepG2细胞脂质代谢的机制。应用棕榈酸和油酸诱导HepG2细胞脂质沉积模型，竹节参总皂苷干预24 h后进行油红O染色和甘油三酯分析。采用改良的Bligh-Dyer法将细胞内源性代谢物分为极性和非极性部位，运用超高效液相色谱-四极杆飞行时间质谱（UPLC-Q/TOF MS）技术检测代谢物，结合多元统计分析和火山图筛选差异代谢物，并富集代谢通路。结果显示，竹节参总皂苷可显著改善HepG2细胞脂质沉积模型的脂质代谢。从极性部位鉴定了34个差异代谢物，主要为脂肪酸和氨基酸类成分；从非极性部位鉴定了28个差异代谢物，主要为磷脂酰胆碱、磷脂酰乙醇胺、神经酰胺类成分。差异代谢物在竹节参总皂苷干预后均有恢复至正常水平的趋势。该研究提示竹节参总皂苷改善HepG2细胞脂质沉积模型的脂质代谢与调控鞘脂代谢、甘油磷脂代谢、脂肪酸代谢、炎症反应密切相关。     

甲氧基聚乙二醇-1,2-二硬脂酰甘油磷酰乙醇胺的合成

以1,2-二硬脂酸甘油酯为原料,依次与三氯氧磷和乙醇胺反应,得到1,2-二硬脂酰甘油磷酰乙醇胺(DSPE),其在N,N’-羰基二咪唑作用下与甲氧基聚乙二醇(mPEG2000)反应,生成甲氧基聚乙二醇2000-1,2-二硬脂酰甘油磷酰乙醇胺(mPEG2000-DSPE)。产物结构经过红外光谱、质谱及核磁氢谱等表征确证。     

基于液相色谱与质谱联用技术的良性前列腺肥大小鼠血清代谢组学分析

良性前列腺肥大已成为影响老龄男性生活质量的一个常见因素,其发病机制迄今尚未完全阐明。本研究采用超高压液相色谱-四极杆飞行时间串联质谱(UPLC-QTOF-MS)技术检测正常小鼠、良性前列腺肥大和非那雄胺干预的模型小鼠血清中代谢物的变化,对3组小鼠的血清代谢谱进行了分析。采用偏最小二乘-判别分析(PLS-DA)对3组小鼠代谢物分类并寻找潜在生物标志物。数据显示,3组小鼠的血清代谢物谱得到了很好的区分,发现并鉴定了3个潜在生物标志物,分别为1-棕榈酰溶血磷脂酰胆碱、1-O-十六烷基-2-O-乙酰基-SN-甘油基-3-磷酸胆碱和(Z)-13-二十二烯酰胺。结果表明良性前列腺肥大的发生与脂质代谢紊乱密切相关。     

高效液相色谱-蒸发光散射检测法分析何首乌中磷脂类化合物

建立了高效液相色谱测定何首乌中磷脂类化合物的新方法.采用Nuclesil100-5色谱柱(250×4.6 mm i.d.5 μm),以甲醇为流动相,流速0.8 mL/min,等度洗脱.蒸发光散射检测器的气体流速1.8 L/min,漂移管温度66℃,进样量15μL.四种磷脂类化合物的线性范围分别为:磷脂酰甘油(PG):0.0388～0.388 mg/mL(r2=0.9991),磷脂酰乙醇胺(PE):0.0500～0.250 mg/mL(r2=0.9996),磷脂酰胆碱(PC):0.0103～0.165 mg/mL(r2=0.9995),溶血磷脂酰胆碱(LPC):0.0103～0.343 mg/mL(r20.9995).该方法应用于首鸟中磷脂类化合物的分析,取得了较好的结果.     

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.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

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.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

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.     

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.