高效液相色谱-串联质谱法同时测定精油类化妆品中31种生物碱

建立了一种同时测定精油类化妆品中31种生物碱的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法。样品以含有2%甲酸的甲醇-水(3∶1,体积比)为提取溶剂,正己烷除脂;采用HPH-C_(18)色谱柱(2.7μm,100 mm×2.1 mm)分离,以0.2%甲酸水溶液-乙腈为流动相梯度洗脱,流速为0.35 mL/min,在电喷雾正离子模式下以多反应监测(MRM)方式测定。结果表明:31种生物碱在相应的质量浓度范围内线性关系良好,相关系数(r)为0.992 8～1.000 0。方法检出限为0.09～3.03μg/kg,定量下限为0.31～10.12μg/kg,3个加标水平下的回收率为63.3%～126%,相对标准偏差为0.73%～17%。该方法前处理简便高效,测定结果准确,灵敏度高,适用于精油类化妆品中生物碱的检测及化妆品的安全性评价。     

基于UHPLC-Q-TOF MS结合分子网络技术快速分析荷叶中生物碱类成分

该研究采用超高效液相色谱-四极杆-飞行时间串联质谱（UHPLC-Q-TOF MS）和分子网络整合技术,快速分析和鉴定了荷叶中的生物碱类化学成分。采用Acquity UPLC HSS T3色谱柱（100 mm×2.1 mm,1.8μm）,以0.1%甲酸水和0.1%甲酸乙腈溶液为流动相进行梯度洗脱,流速为0.3 mL/min,在正离子模式下采集质谱数据信息。将经格式转换后的荷叶提取物二级质谱数据上传至全球天然产物社会分子网络（GNPS）平台计算分析,借助Cytoscape 3.6. 1软件构建可视化分子网络,获得了单苄基异喹啉类、双苄基异喹啉类和阿朴啡类生物碱类型的粒子簇。根据对照品、色谱保留时间、特征碎片离子、MS/MS裂解规律和文献报道等信息,从荷叶中共鉴定和推测57种生物碱类成分,包括27个单苄基异喹啉类、2个双苄基异喹啉类、25个阿朴啡类和3个其他类生物碱,其中19个成分为潜在新化合物,30个成分在荷叶中首次报道。该方法快速、准确,可为荷叶的药效物质基础研究提供参考,为中药化学成分的快速定性分析提供借鉴。     

UPLC-Q-TOF-MS/MS法分析栾樨叶的化学成分北大核心CSCD

采用超高效液相色谱-四极杆-飞行时间高分辨质谱(UPLC-Q-TOF-MS/MS)对栾樨叶的化学成分进行定性分析。栾樨叶提取液经Waters UPLC BEH C_(18)柱(2.1 mm×100 mm,1.7μm)分离,以乙腈-0.1%甲酸水溶液为流动相进行梯度洗脱,正、负离子模式下采集得到基峰色谱图。通过质谱数据库、化合物质谱裂解规律,并结合相关文献及对照品的保留时间与质谱信息,从栾樨叶中共鉴别出52个化学成分,包括2个香豆素类,15个黄酮类,16个苯丙素类,5个生物碱类,5个脂肪酸类,3个有机酸类,3个氨基酸类,1个酚酸类和2个其他类化合物,其中23个成分为栾樨叶中首次报道,11个化合物经对照品验证。该方法准确、可靠、高效,适用于栾樨叶化学成分的快速鉴定,可为栾樨叶的药效机制研究及临床应用提供依据。     

基于UPLC-LTQ-Orbitrap-MS技术快速解析杜仲颗粒化学成分

建立了定性分析杜仲颗粒化学成分的超高效液相色谱-线性离子阱-静电场轨道阱组合式高分辨质谱(UPLC-LTQ-Orbitrap-MS)方法。杜仲颗粒采用甲醇超声提取,Thermo Scientific Syncronis C_(18)色谱柱(100 mm×2.1 mm,1.9μm)分离,以乙腈-0.1%甲酸溶液为流动相进行梯度洗脱。利用LTQ-Orbitrap-MS负离子模式采集,通过对照品比对及高分辨质谱数据解析,鉴定了25种化学成分,包括8种环烯醚萜类、8种黄酮类、5种苯丙素类、3种木脂素类化合物及1种非还原性双糖。该方法简便、快速、准确,可为进一步分析杜仲颗粒的药效物质基础提供依据。     

基于超高效液相色谱-四极杆-飞行时间串联质谱联用技术的黄英咳喘糖浆化学成分分析

采用超高效液相色谱-四极杆-飞行时间串联质谱联用技术(UPLC-Q-TOF-MS~E),结合UNIFI科学信息系统分析鉴定黄英咳喘糖浆中化学成分。使用Waters CORTECS Shield RP18 C18色谱柱(4.6 mm×100 mm, 2.7μm)和乙腈(A)-0.1%甲酸水溶液(B)流动相系统进行梯度洗脱;质谱采用电喷雾(ESI)离子源,通过UPLC-Q-TOF-MS~E技术在正、负离子模式下采集质谱数据,将化合物精确相对分子质量和串联质谱信息通过UNIFI软件进行辅助解析,结合对照品质谱信息以及相关参考文献,共推断和鉴定出化合物93个,其中包含生物碱类9个、黄酮类43个、三萜及三萜皂苷类21个、氰苷类2个、有机酸类13个、其它类6个。UPLC-Q-TOF-MS~E法可快速、高效地对黄英咳喘糖浆进行全成分分析,为进一步筛选该药的药效成分、提高产品质量控制标准提供了科学依据。     

生附片化学成分的HPLC/ESI-MSn研究

采用高效液相色谱与电喷雾质谱联用技术, 对生附片的化学成分进行了系统的研究. 并辅以提取离子色谱方法, 发现微量的化学成分. 通过保留时间, 质荷比及多级串联质谱数据, 共鉴定了48个成分, 其中双酯型生物碱8个, 单酯型生物碱7个, 脂型生物碱29个. 其中双酯型生物碱是生附片中的主要成分, 而单酯型和脂型生物碱的含量和种类较少.     

分散固相萃取-高效液相色谱-串联质谱法测定蜂蜜中生物碱

建立了分散固相萃取-高效液相色谱-串联质谱法(QuEChERS-HPLC-MS/MS)同时测定蜂蜜中吡咯里西啶生物碱(倒千里光、千里光菲林、千里光宁、克氏千里光宁)和异喹啉类生物碱(小檗碱、荷叶碱)的方法。蜂蜜样品经乙腈提取,乙二胺-N-丙基硅烷(PSA)吸附剂净化,HPLC-MS/MS测定。采用Agilent Poroshell 120SB-C18色谱柱(100 mm×2.1 mm,2.7μm)分离。以0.1%甲酸溶液和乙腈为流动相进行梯度洗脱,电喷雾正离子(ESI+)模式电离,多反应监测模式(MRM)下进行测定,外标法定量。结果表明,在0.1~100μg/L范围内,6种生物碱的相关系数均大于0.99;在1~100μg/kg的添加水平下,所有生物碱回收率均在70%~110%之间;6种生物碱日内精密度小于15%,日间精密度小于20%;方法检出限和定量限分别为0.3和1.0μg/kg。本方法可用于蜂蜜中吡咯里西啶生物碱和异喹啉类生物碱的同时定性和定量分析。     

生附片化学成分的HPLC/ESI-MSn研究

采用高效液相色谱与电喷雾质谱联用技术, 对生附片的化学成分进行了系统的研究. 并辅以提取离子色谱方法, 发现微量的化学成分. 通过保留时间, 质荷比及多级串联质谱数据, 共鉴定了48个成分, 其中双酯型生物碱8个, 单酯型生物碱7个, 脂型生物碱29个. 其中双酯型生物碱是生附片中的主要成分, 而单酯型和脂型生物碱的含量和种类较少.     

高效液相色谱-串联质谱法同时测定夏天无中的4种生物碱

建立了高效液相色谱-电喷雾串联四极杆质谱同时测定夏天无中4种生物碱的分析方法。夏天无样品用甲醇超声提取,提取溶液过滤并用甲醇稀释后分析。色谱分离采用C18反相色谱柱(150 mm×2.1 mm, 3.5 μm),流动相为0.2%乙酸水溶液和乙腈,梯度洗脱。电喷雾串联质谱在多反应监测(MRM)模式下检测目标分析物,以保留时间和特征离子对(母离子和两个碎片离子)信息比较进行定性分析和定量分析。4种生物碱的检出限(LOD)为0.02～0.2 μg/L,定量限(LOQ)为0.07～0.66 μg/L,加标回收率为93.6%～103.5%,相对标准偏差小于3.8%。该方法简便、准确、灵敏,可用于夏天无中药材的质量控制。     

超高效液相色谱-四极杆-飞行时间质谱法快速辨识芪玉三龙汤化学成分

利用超高效液相色谱-四极杆-飞行时间质谱(UPLC-QTOF-MS)的数据非依赖性采集(DIA)技术,结合靶向筛查方法,快速辨识芪玉三龙汤(Qi-Yu-San-Long decoction, QYSLD)化学成分。以Waters ACQUITY UPLC BEH C₁₈柱(100 mm×2.1 mm, 1.7 μm)为色谱柱,流速为0.2 mL/min,柱温为35 ℃,进样量为2 μL,以0.1%(v/v)甲酸水溶液-乙腈为流动相进行梯度洗脱。采用电喷雾电离(ESI)源,以全信息串联质谱(MS^E)技术在正、负离子模式下分别采集QYSLD复杂组分的质谱数据。通过检索文献和在线数据库,建立QYSLD中各单味药材化学成分库。将采集到的样品原始质谱数据与QYSLD化学成分库导入天然产物后处理筛查(UNIFI)平台;在UNIFI平台中设置参数(保留时间偏差为±0.1 min,精确质量数偏差阈值为±5×10^-6,正离子模式下,选择[M+H]⁺和[M+Na]⁺为准分子离子或加合离子,负离子模式下,选择[M-H]^-和[M+HCOO]^-)。经UNIFI平台对MS^E模式下采集的质谱数据与自建数据库中成分作靶向筛查,结合化合物准分子离子、质谱裂解途径及部分对照品进行结构确认。从QYSLD中共识别出166种化学成分,其中皂苷类22种,生物碱类13种,黄酮类27种,萜类32种,氨基酸类20种,苯丙素类16种,有机酸类9种,甾醇类6种,蒽醌类6种,其他类15种。其中16种成分使用对照品作验证。研究建立的方法能够快速、可靠的表征QYSLD中的化学成分,为该复方的药效物质及质量控制研究奠定了基础。     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

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。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

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.