Chemical profiling and characterization of phenolic acids,flavonoids, terpene glycosides from Vangueria agrestis using ultra-high-performance liquid chromatography/ion mobility quadrupole time-of-flight mass spectrometry and metabolomics approach

Vangueria agrestis is a shrub indigenous to tropical Africa, belonging to family Rubiaceae and is traditionally used as a decoction for treatment of fever, pain, and malaria. This study was undertaken to investigate the chemical constituents based on precursor exact mass and fragment ion information. The chemical profiling and structural characteristics of chemical constituents from methanolic extracts of dried aerial parts and roots of V. agrestis and dietary supplements were analyzed using ultra-high-performance liquid chromatography/ion mobility quadrupole time-of-flight mass spectrometry coupled with UNIFI platform and multivariate analysis in both negative and positive ion modes. A non-targeted ultra-high-performance liquid chromatography-mass spectrometry analysis was carried out to profile the chemical constituents of crude extracts of V. agrestis, and 73 compounds, including reference compounds, were identified. The fragments of flavonoids, monoterpene, and triterpene glycosides revealed the characteristic cleavage of glycosidic linkages, and the fragmentation pattern provided the identity of the sugars. This analytical method provides a quick method for quality assessment of dietary supplements. Finally, a chemometrics approach with multivariate statistical tools was used to visualize the differences between root and aerial parts of plant samples and to find the potential chemical markers that differentiate among these parts of V. agrestis samples and dietary supplements.     

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,1.7μm)为色谱柱...     

Determination of ivacaftor by liquid chromatography techniques in pharmaceutical formulation with interlaboratory comparison and characterization of five novel degradation products by high-performance liquid chromatography ion trap time-of-flight mass spectrometry

Cystic fibrosis is a life-threatening genetic disease that causes damage to the lungs. Ivacaftor, the first drug to target the underlying defect of the disease caused by specific mutations, improves outcomes and reduces hospitalizations. In this study, quantitative determination of ivacaftor was performed by liquid chromatography, while high-resolution mass spectrometric analyses were performed for qualitative determination. The validation studies of the developed methods were performed according to International Conference on Harmonisation Q2(R1) guideline. Ivacaftor was separated from its degradation product by using Phenomenex Kinetex C₁₈ (150 × 3 mm, 2.6 µm) column. The isocratic mobile phase for binary pump configuration was 0.1% (v/v) formic acid in water and 0.1% (v/v) formic acid in acetonitrile (27:63) (v/v), pH = 2.5; the flow rate of 0.25 mL/min was used in all methods. In the degradation studies, five degradation products were identified using high-performance liquid chromatography ion trap time-of-flight mass spectrometric analyses: three of them have never been reported up to date; whereas the other two were existing in the literature and they were having Chemical Abstracts Services registry numbers since they were synthesized before for various other purposes. Also, analysis of an in-lab prepared chemical equivalent of Kalydeco^® and interlaboratory comparison were performed.     

液相色谱/线性离子阱-静电场轨道阱高分辨质谱法快速筛查葡萄酒中的合成色素

基于液相色谱/线性离子阱-静电场轨道阱高分辨质谱(LC/LTQ-orbitrap MS)技术构建了合成色素的质谱数据库,利用精确质量数和该数据库中二级质谱图的匹配度分析筛查,建立了葡萄酒中15种水溶性合成色素的快速筛查方法。葡萄酒样品通过弱阴离子交换柱进行净化后经苯基色谱柱分离,然后用LTQ-orbitrap MS对样品中的色素进行筛查和定量检测。结果显示,葡萄酒中15种色素的检出限在0.00040~0.18 mg/L之间,3个加标水平的回收率在43.1%~127%之间,平均相对标准偏差均小于10%。加标样品的二级质谱图与数据库中标准样品二级质谱图的匹配度均达到98%以上。该方法可在无标准物质的情况下对葡萄酒中的15种合成色素进行筛查检测。     

Untargeted metabolomics analysis to unveil the chemical markers for the differentiation among three Gleditsia sinensis-derived herbal medicines by ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry

Precise identification and differentiation among those congeneric Traditional Chinese Medicines (TCMs) or derived from the same plant trend to be more challenging, particularly in the absence of appearance characteristics. Three TCMs, involving Gleditsiae Sinensis Fructus (GSF), Gleditsiae Fructus Abnormalis (GFA), and Gleditsiae Spina (GS), recorded in Chinese Pharmacopoeia (2020 edition) are derived from Gleditsia sinensis, but prescribed for different clinical uses. The documents aimed to compare their chemical differences are rare, to date. An untargeted metabolomics approach, based on ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC/QTOF-MS), was elaborated to unveil the potential chemical markers to differentiate among GSF, GFA, and GS. Good chromatographic separation of all the GSF/GFA/GS components was achieved within 33 min by utilizing a BEH C18 column, while data-independent MS^E in the positive mode was selected for profiling the metabolic features. Notably, the high-mass saponins (1300–2500 Da) gave unique protonated precursors ([M + H]⁺) in the positive ESI mode, compared with those complicated ion species occurring in the negative mode. Pattern recognition chemometrics analysis of 45 batches of G. sinensis samples could unveil 70 significantly altered ions assigned as 46 potentially differential components. The positive/negative high-accuracy MS² data analysis, phytochemical isolation/NMR analysis, and searching of an in-house library of G. sinensis, were utilized for structural elucidation. Three compounds (saikachinoside A, locustoside A, and locustoside B) rich in GSF could be the markers to differentiate from GFA/GS, while four components were characteristic for GS. These results obtained can greatly benefit the quality control of TCMs derived from G. sinensis.     

Characterization of in vitro metabolites of trimethoprim and diaveridine in pig liver microsomes by liquid chromatography combined with hybrid ion trap/time-of-flight mass spectrometry

Trimethoprim (TMP) and diaveridine (DVD) are used in combination with sulfonamides and sulfaquinoxlaine as an effective antibacterial agent and antiprotozoal agent, respectively, in humans and animals. To gain a better understanding of the metabolism of TMP and DVD in the food-producing animals, the metabolites incubated with liver microsomes of pigs were analyzed for the first time with high-performance liquid chromatography combined with hybrid ion trap/time-of-flight mass spectrometry. Seven TMP-related and six DVD-related metabolites were characterized based on the accurate MS2 spectra and known structure of the parent drug, respectively. The metabolites of TMP were identified as two O-demethylation metabolites, a di-O-demethylation metabolite, two N-oxides metabolites, a hydroxylated metabolite on the methylene carbon and a hydroxylated metabolite on the methyl group. DVD was also biotransformed to two O-demethylation metabolites, a di-O-demethylation metabolite, an N-oxide metabolite, a hydroxylation metabolite on the methylene carbon and a hydroxylation metabolite followed by O-demethylation. The results indicate that the two compounds have similar biotransformation pathways in pigs. O-Demethylation was the major metabolic route of TMP and DVD in the pig liver microsomes. The proposed metabolic pathways of TMP and DVD in liver microsomes will provide a basis for further studies of the in vivo metabolism of the two drugs in food-producing animals.     

高效液相色谱-离子阱/飞行时间质谱鉴定违禁药品邻氯苯基环戊酮中杂质及其标准物质的制备

建立了高效液相色谱-离子阱/飞行时间质谱（HPLC-IT/TOF MS）分析违禁药品邻氯苯基环戊酮样品中杂质成分的方法。对邻氯苯基环戊酮标准品进行多级质谱分析,根据各碎片离子的精确质量数推测邻氯苯基环戊酮的裂解路径,并利用该方法检测出邻氯苯基环戊酮样品中的2种杂质成分：2-氯苯甲酸酸酐和1,2-二邻氯苯甲酰基环戊烯,推断出该违禁药品的合成方法,为追溯其来源提供了重要依据。同时建立了制备邻氯苯基环戊酮标准品的方法,制备高效液相色谱条件是流动相甲醇-水（85∶15,v/v）,流速8 mL/min,进样量1 mL。制备得到的邻氯苯基环戊酮标准物质纯度为99.53%。该方法简单、高效,可拓展应用于其他违禁药物标准物质的制备。     

Diagnostic filtering to screen polycyclic polyprenylated acylphloroglucinols from Garcinia oblongifolia by ultrahigh performance liquid chromatography coupled with ion mobility quadrupole time-of-flight mass spectrometry

A novel multistage MS approach, insource collision-induced dissociation (CID) combined with Time Aligned Parallel (TAP) fragmentation, was established to study the fragmentation behavior of polycyclic polyprenylated acylphloroglucinols (PPAPs), which could provide a more reliable fragmentation relationship between precursor and daughter ions. The diagnostic ions for different subtypes of PPAPs and their fragmentation behaviors have been summarized. Moreover, a new and reliable multidimensional analytical workflow that combines ultrahigh performance liquid chromatography (UHPLC), data-independent mass spectrometry (MS^E), and tandem MS with ion mobility (IM) has been optimized and established for the analysis of PPAPs in the plant Garcinia oblongifolia by diagnostic filtering. Diagnostic fragment ions were used to selectively screen PPAPs from extracts, whereas IM coupled to MS was used to maximize the peak capacity. Under the optimized UHPLC-IM-MS^E and UHPLC-IM-MS/MS method, 140 PPAPs were detected from the crude extract of G. oblongifolia, and 10 of them were unambiguously identified by comparing them to the reference compounds. Among those PPAPs, 7 pairs of coeluting isobaric PPAPs that were indistinguishable by conventional UHPLC-HRMS alone, were further resolved using UHPLC-IM-MS. It is anticipated that the proposed method will be extended to the rapid screening and characterization of the other targeted or untargeted compounds, especially these coeluting isomers in complex samples.     

Comparison of electrospray ionization and atmospheric pressure chemical ionization techniques in the analysis of the main constituents from Rhodiola rosea extracts by liquid chromatography/mass spectrometry

Rhodiola rosea L. (Golden Root) has been used for a long time as an adaptogen in Chinese traditional medicine and is reported to have many pharmacological properties. A liquid chromatographic (LC) method with mass spectrometric (MS) detection based on selected ion monitoring (SIM) was developed for determining salidroside, sachaliside 1, rosin, 4-methoxycinnamyl-O-beta-glucopyranoside, rosarin, rosavin, cinnamyl-(6'-O-beta-xylopyranosyl)-O-beta-glucopyranoside, 4-methoxy-cinnamyl-(6'-O-alpha-arabinopyranosyl)-O-beta-glucopyranoside, rosiridin and benzyl-O-beta-glucopyranoside from the callus and plant extracts in one chromatographic run. Good linearity over the range 0.5-500 ng ml(-1) for salidroside, 2-2000 ng ml(-1) for rosavin and 2-500 ng ml(-1) for benzyl-O-beta-glucopyranoside was observed. The intra-assay accuracy and precision within quantitation ranges varied between -10.0 and +13.2% and between 0.7 and 9.0%, respectively. Optimization of the ionization process was performed with electrospray and atmospheric pressure chemical ionization techniques using four different additive compositions for eluents in the LC/MS scan mode, using both positive and negative ion modes. The best ionization sensitivity for the compounds studied was obtained with electrospray ionization when using pure water without any additives as the aqueous phase.