基于超高效液相色谱-串联高分辨质谱的血清代谢组学用于探索区分结直肠腺瘤和结直肠癌的生物标志物

结直肠腺瘤（Colorectal adenoma,CA）发展成为结直肠癌（Colorectal cancer,CRC）是一个相对漫长而隐匿的过程,然而,目前仍缺乏微创且可靠的生物标志物来区分CA和CRC患者。该文采用超高效液相色谱-串联高分辨质谱（UHPLC-HRMS）技术结合多元统计分析方法对64例CA患者和84例CRC患者的血清样本进行代谢组学比较分析,结合P <0.05和倍数变化> 1.50或<0.67筛选两者的血清差异代谢物,并通过受试者工作特征曲线（ROC）分析考察其对CA和CRC的鉴别能力。同时利用差异代谢物的通路及富集分析初步探索CA癌变的代谢机制。结果表明,两组的血清代谢谱存在差异,据此筛选并鉴定获得66种组间差异代谢物,主要涉及不饱和脂肪酸的生物合成、嘌呤代谢、亚油酸代谢,提示其可能与CA癌变有关。此外,PC 36∶3、腺嘌呤、鞘氨醇、PC 18∶0、PC 20∶4标志物组合的ROC曲线下面积为0.941,对CA和CRC表现出良好的判别效能,可为CRC的临床早期预防提供有价值的参考。     

基于超高效液相色谱-四极杆-静电场轨道阱质谱的结直肠腺瘤患者血清代谢组学研究

采用超高效液相色谱－四极杆－静电场轨道阱质谱结合主成分分析、正交偏最小二乘判别分析对46例结直肠腺瘤患者（年龄57.8 ± 10.7岁）和45例健康人（年龄54.4 ± 8.2岁）的血清样本进行分析,通过变量权重投影分析和火山图筛选结直肠腺瘤患者血清中的代谢标志物,利用受试者工作特征曲线（ROC）验证代谢标志物的诊断能力。结果表明,两组血清的代谢轮廓有显著差异,筛选并鉴定了20个生物标志物,涉及缬氨酸、亮氨酸和异亮氨酸合成,花生四烯酸代谢、α-亚麻酸代谢、亚油酸代谢、氨酰-tRNA合成、鞘脂代谢、甘油磷脂代谢、色氨酸代谢,其生物标志物16-羟基棕榈酸、花生四烯酸、肌酸、缬氨酸、亮氨酸、色氨酸、α-亚麻酸、牛磺鹅脱氧胆酸、LysoPC（20∶3）的ROC曲线面积（AUC）均大于0.90,特异性与灵敏度较高,对于结直肠腺瘤筛查具有较高的诊断价值和临床应用潜力。研究结果可为基于代谢组学的结直肠腺瘤筛查提供参考资料。     

基于UPLC-Q/TOF MS技术的痛风患者血清代谢组学研究

采用超高效液相色谱-飞行时间质谱联用技术（UPLC-Q/TOF MS）对恩施土家族苗族自治州60例健康志愿者（对照组）和65例痛风患者（痛风组）的血清样本建立代谢图谱,基于主成分分析及正交偏最小二乘判别分析对所得数据进行模式识别,并结合变量权重投影分析及火山图筛选出痛风患者的血清代谢标志物。通过数据分析和数据库检索,共筛选出63种差异代谢物,其中27种代谢物显著上调（P <0.05）,36种代谢物显著下调（P <0.05）,主要包括甘油磷脂类、氨基酸类及胆碱等成分。首先,对以上差异代谢物进行受试者工作特征曲线（ROC）分析,其中曲线下面积（AUC）大于0.8的14种代谢物是诊断效能较好的代谢物;然后对筛选的63种差异代谢物进行代谢通路富集分析,以Impact> 0.1且P <0.05为标准,得到影响最大的代谢通路主要有甘油磷脂代谢、醚性脂质代谢、亚油酸代谢、半胱氨酸和蛋氨酸代谢、花生四烯酸代谢及戊糖和葡萄醛酸的互相转化等。综上,痛风患者和健康对照人群的血清代谢水平有明显差异,差异代谢物的鉴定为痛风的发病机制和早期筛查提供了实验依据。     

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。     

液相色谱-质谱用于卵巢肿瘤中磷脂轮廓的分析

卵巢肿瘤日益影响女性的健康和生活质量,其中的卵巢癌是女性三大恶性肿瘤之一,死亡率高居三者之首。因此卵巢肿瘤尤其卵巢癌是目前的一个研究热点。本研究利用液相色谱-质谱(LC-MS)联用技术对卵巢肿瘤进行磷脂轮廓分析,研究良性卵巢肿瘤(B)和卵巢癌(M)的患者血清中磷脂代谢的差异情况。首先用LC-MS采集血清中磷脂的指纹图谱,通过峰识别、峰匹配等得到峰表,然后利用正交校正的偏最小二乘法(OSC-PLS)进行多种分型,根据模型的变量重要因子(VIP)、VIP值的置信区间、S图和显著性差异检验结果等筛选有差异的磷脂。结果显示: M组和B组与正常对照(N)组比较都存在明显的磷脂代谢差异,发生改变的磷脂主要为缩醛磷脂酰乙醇胺、磷脂酰胆碱、缩醛磷脂酰胆碱、鞘磷脂和溶血磷脂酰胆碱。     

一种基于液相色谱-质谱技术进行血清代谢组学研究的方法：从代谢指纹到潜在标志物

本文描述了一种基于液相色谱-质谱技术（LC-MS）的代谢组学发现疾病潜在标志物的方法.该方法利用LC-MS获得代谢指纹图谱,并通过多种统计分析方法对产生的海量数据进行分析,最终筛选出潜在标志物.数据分析过程包括：通过归一化、修正80%规则、数据集分割和数据缩放等方法对数据集进行预处理 通过正交校正的偏最小二乘（OPLS）模式识别方法对样品进行分型 根据模型的变量重要性因子（VIP值）、非参数检验结果和z值筛选潜在标志物.以宫颈癌血清样本为例,应用上述方法,15个变量被确认为潜在标志物,操作者接受曲线（ROC）下的面积为0.667～0.956.经过相关性分析和结构鉴定,发现这15个变量来自9个化合物.其中7个化合物被鉴定为色氨酸、硬脂酸、花生四烯酸、溶血磷脂酰胆碱（0：0/16：0,16：0/0：0,18：1/0：0和18：0/0：0）,说明在宫颈癌中花生四烯酸和溶血磷脂酰胆碱的代谢发生异常.     

改性苯乙烯-马来酸酐共聚物色谱固定相用于磷脂分离分析北大核心CSCD

磷脂是重要的信号分子,磷脂的代谢与多种疾病密切相关。因此,开展磷脂的分离分析研究至关重要。苯乙烯-马来酸酐共聚物(SMA)作为一种新型两亲性交替共聚物可以插入生物膜的磷脂双分子层中,形成以膜蛋白质为中心的脂质纳米盘,对膜蛋白质和磷脂具有良好的增溶作用。本文基于“点击”反应和自由基聚合反应,将对磷脂具有良好增溶性能的SMA接枝到硅胶表面,然后以蛋氨酸甲酯盐酸盐(MME·HCl)为开环试剂,通过亲核开环反应对SMA进行修饰,制备了新型的改性SMA修饰色谱固定相(Sil-SMA-MME)。结合高效液相色谱-紫外检测法,利用酰胺类和核苷/核酸碱基类以及苯酚类3类小分子物质对填充Sil-SMA-MME色谱柱的保留机制和分离性能进行了系统评价,Sil-SMA-MME色谱柱具有典型的亲水作用保留机制,其柱效最高可达90900 N/m,并显示了良好的分离选择性。进一步结合高效液相色谱-蒸发光散射检测法,考察了Sil-SMA-MME色谱柱对磷脂样品的分离性能。二棕榈酰磷脂酰丝氨酸钠(DPPS)、二油酰磷脂酰胆碱(DOPC)、二棕榈酰磷脂酰乙醇胺(DPPE)和4种磷脂酰胆碱(PC)类标准品溶血卵磷脂(LysoPC)、二肉豆蔻酰磷脂酰胆碱(DMPC)、二硬脂酰磷脂酰胆碱(DSPC)、二棕榈酰磷脂酰胆碱(DPPC)均可实现基线分离,并且成功地实现了南极磷虾油和人血清磷脂提取物的分离分析。以上结果表明,所制备的Sil-SMA-MME色谱柱在磷脂类物质分离分析中具有良好的应用潜力。     

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。     

基于超高效液相色谱-四极杆-静电场轨道离子阱串联质谱的冷链贮藏过程中滩羊肉的脂质组学研究

该文建立了超高效液相色谱-四极杆-静电场轨道离子阱串联质谱(UHPLC-Q-Orbitrap MS/MS)结合脂质组学分析滩羊肉在冷链贮藏过程中脂质变化规律和脂质分子碎裂机理的方法。样品经异丙醇提取后,采用质谱全扫描模式和二级扫描模式对目标物质进行定性。共鉴定出48个变化显著性脂质,包括8个脂肪酰基肉碱、23个磷脂酰胆碱(PC)、3个溶血性磷脂酰胆碱(LPC)、13个磷脂酰乙醇胺(PE)、1个溶血性磷脂酰乙醇胺(LPE)。含量差异表现为部分PC、PE和脂肪酰基肉碱在前12 d短暂性升高,12 d后开始降低,而LPE和LPC在整个冷链贮藏期间表现为上升趋势。PC、PE和脂肪酰基肉碱短暂性的积累易导致大量的脂质氧化反应,进一步阐明最佳冷链时间为12 d。该方法适用于复杂基质中脂质分子的分离与定量,为肉及肉类产品在冷链贮藏过程中的脂质变化规律研究及质量控制提供了依据。     

氟功能化胆碱磷酸脂质体用于胰岛素的口服给药

皮下注射胰岛素（INS）作为治疗糖尿病主要的治疗方式,存在使用抵触和低血糖等副作用,而开发口服给药途径更具有应用前景。脂质体作为最成熟的药物递送体系,在蛋白或多肽口服给药方面存在着稳定性差、载药率低和粘液渗透有限等问题。基于细胞膜骨架成分磷酸酰胆碱（PC）设计合成了三氟乙基修饰两性离子头部的二棕榈酰胆碱磷酸脂质分子（DPFCP）,并构建了负载胰岛素口服给药的脂质体递送体系（INS@DPFCP）。对比二棕榈酰磷脂酰胆碱（INS@DPPC）和未功能化二棕榈酰胆碱磷酸（INS@DPCP）脂质体,系统地研究了INS@DPFCP理化性质、释放药物稳定性、粘液渗透性、生物相容性和细胞内吞效率及转运能力等。结果表明,INS@DPFCP的粒径为185 nm,包封率为（47.1±3.9）%。相比于INS@DPPC(27.2%)和INS@DPCP(24.5%),INS@DPFCP粘液聚集量仅有17.15%。溶血和细胞毒性实验证明,INS@DPFCP具有良好的生物相容性,质量浓度高达1.2 mg/mL时,溶血率为6.88%,细胞存活率在90%以上。此外,细胞摄取及转运测试表明,Caco-2细胞对INS@DP...     

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.     

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.     

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.     

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%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

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.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.