UPLC-Q-TOF-MS

UPLC - Q - ToF - MS
  • 文章类型: Journal Article
    沉香是由受伤的植物生产的含树脂的木材。它广泛用于草药,香,装饰物品,等等。在这项研究中,我们进行了树脂面积统计分析,测定淀粉颗粒和还原糖含量,并通过GC-MS和UPLC-Q-TOF-MS对化学成分进行多元统计分析,以探索沉香柱切片中的不同成分,指定为A1-A4。结果表明,经琼脂-Bit诱导剂刺激后,柱子的内部韧皮部薄壁组织细胞开始形成沉香,然后将淀粉颗粒转化为可溶性还原糖和沉香树脂。A1部分显示淀粉颗粒的快速损失,导致还原糖和树脂的含量较高。各个部分的沉香树脂面积不同,从A1到A4逐渐减少。通过GC-MS和UPLC-Q-TOF-MS鉴定了87和63的代谢物总数,分别。其中,通过多变量统计分析选择具有显著差异(变量重要性投影>1)的10种和16种代谢物。这些代谢物包括色酮,倍半萜,烷烃,和脂肪酸。其中,6-甲氧基-2-(2-苯基乙基)色酮和6,7-二甲氧基-2-(2-苯基乙基)色酮是GC-MS和UPLC-Q-TOF-MS检测到的重要标记,这可能是导致切割部分沉香形成能力差异的必需物质。总之,关于沉香柱不同沉香形成能力的研究有限。这里,我们通过化学分析探索了沉香各部分的差异,以提供对其构成的更全面和深入的了解。
    Agarwood is resin-containing wood produced by plants that have been injured. It is widely used in herbal medicine, incense, decorative items, and so on. In this study, we conducted resin area statistical analysis, determined starch particle and reducing sugar contents, and performed multivariate statistical analysis of chemical composition by GC-MS and UPLC-Q-TOF-MS to explore the different components in sections cut from an agarwood column, designated as A1-A4. The results showed that after stimulation by Agar-Bit inducer, the internal phloem parenchyma cells of the column started to form agarwood, and then starch granules were converted into soluble reducing sugars and agarwood resin. Section A1 showed rapid loss of starch granules, resulting in higher contents of reducing sugars and resin. The resin areas of agarwood in the respective sections were different, gradually decreasing on going from A1 to A4. Total numbers of metabolites of 87 and 63 were identified by GC-MS and UPLC-Q-TOF-MS, respectively. Of these, 10 and 16 metabolites with significant differences (variable importance projection >1) were selected through multivariate statistical analysis. These metabolites included chromones, sesquiterpenes, alkanes, and fatty acids. Among them, 6-methoxy-2-(2-phenylethyl)chromone and 6,7-dimethoxy-2-(2-phenylethyl)chromone were significant markers detected by both GC-MS and UPLC-Q-TOF-MS, which may be essential substances responsible for differences in the agarwood-forming capacities of the cut sections. In conclusion, there has been limited research on the different agarwood-forming capacities of agarwood columns. Here, we explored the differences in various sections of agarwood through chemical analysis to provide a more comprehensive and in-depth understanding of its constitution.
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  • 文章类型: Journal Article
    JusticiavahliiRoth.是传统上用于治疗炎症和各种常见疾病的重要野生药用食品植物。这项研究调查了化学成分,抗氧化剂,J.vahlii的正己烷(nHEJv)和氯仿(CEJv)提取物的酶抑制和毒性谱。此外,评价提取物对CCl4诱导的肝损伤的作用。两种提取物中都存在大量的总酚和类黄酮含量。CEJv的UPLC-Q-TOF-MS和GC-MS图谱初步鉴定了几种重要的植物化合物。CEJv提取物对抗氧化活性和α-淀粉酶抑制活性相对较高,而nHEJv提取物对脲酶表现出更高的抑制潜力,酪氨酸酶,和α-葡萄糖苷酶。同样,四种主要化合物的计算机内研究,即,1-乙酰氧基戊醇,3-羟基癸二酸,nortrachogenin,和粘蛋白-III对临床上有意义的酶显示出良好的对接评分。急性口服毒性和盐水虾致死率试验显示提取物无毒。CCl4处理的动物显示出各种抗氧化酶的定向消耗,这些酶在提取物的处理下明显逆转。总的来说,该研究的发现揭示了J.vahlii具有抗氧化剂介导的肝保护和酶抑制潜力,并需要进一步研究生物活性化合物的分离。
    Justicia vahliiRoth. is an important wild medicinal food plant traditionally used for treating inflammation and various common ailments. This study investigated the chemical composition,antioxidant, enzyme inhibition and toxicity profiles of n-hexane (nHEJv) and chloroform (CEJv) extracts of J. vahlii. Moreover, the effect of the extracts was evaluated on CCl4 induced liver injury. The total phenolic and flavonoid contents were present in both extracts in significant amount. The UPLC-Q-TOF-MS and GC-MS profiling of CEJv tentatively identified several important phytocompounds. The CEJv extract was comparatively more active for antioxidant activity and α-amylase inhibition, whereas the nHEJv extract presented higher inhibition potential against urease, tyrosinase, and α-glucosidase enzymes. Similarly, the in-silico study of four major compounds, i.e., 1-acetoxypinoresinol, 3-hydroxysebacic acid, nortrachelogenin, and viscidulin-III have shown a good docking score against the clinically significant enzymes. The acute oral toxicity and brine shrimp lethality assaysrevealed the extracts as non-toxic. The CCl4 treated animals showed a geared depletion of various antioxidant enzymes which were significantly reversed with the treatment of the extracts. Overall, the study\'s findings revealed J. vahliiwith antioxidant mediated hepatoprotective and enzyme inhibition potential and warrant further research on isolation of the bioactive compounds.
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  • 文章类型: Journal Article
    麦卢卡蜂蜜(MH)因其卓越的抗菌作用而备受关注,抗癌,免疫调节和伤口愈合特性。这项研究比较了原始和粉状MH(pMH)对各种人和鼠癌细胞系的抗增殖作用。还使用非靶向超高效液相色谱-四极杆-飞行时间质谱(UPLC-Q-TOF-MS)进行了详细的代谢组学分析,以比较原始MH和pMH中的成分。活力研究的结果显示,在>1%w/v(相当于~10mg/ml)的浓度下,原始MH和pMH均引起肿瘤细胞生长的剂量依赖性抑制。在人MDA-MB-231和A549细胞以及鼠B16的细胞系中观察到对MH的差异易感性。F10细胞对MH具有相对抗性,而鼠MC38结直肠腺癌细胞表现出最大的敏感性。使用2个独立测定来验证原始MH和pMH对细胞活力的影响。代谢组学分析检测到2440种化合物,其中833人被成功识别。其中,90种植物化学化合物,主要包括萜类化合物,黄酮类化合物,香豆素及其衍生物,和苯基丙酸,和79脂质是可识别的。5个代谢物类别的显着差异,包括类黄酮,酚类物质,萜类化合物,碳水化合物,在原料和pMH之间观察到有机酸。此外,与原始MH相比,在pMH中鉴定出几种改变的代谢途径,比如能量代谢,氨基酸代谢,和其他各种共同影响与细胞生长相关的生物学功能的途径,信令,和应激反应。
    Manuka honey (MH) has garnered much attention due to its remarkable antimicrobial, anticancer, immunomodulatory and wound-healing properties. This study compared the antiproliferative effects of raw and powdered MH (pMH) on various human and murine cancer cell lines. A detailed metabolomics analysis was also carried out using untargeted ultrahigh-performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry (UPLC-Q-TOF-MS) to compare the constituents in raw MH and pMH. The results of the viability studies showed that both raw MH and pMH caused a dose-dependent inhibition of tumor cell growth at concentrations of > 1% w/v (equivalent to ~ 10 mg/ml). A differential susceptibility to MH was observed among the cell lines with the human MDA-MB-231 and A549 cells and murine B16.F10 cells being relatively resistant to MH while the murine MC38 colorectal adeno-carcinoma cells showing the most sensitivity. The effect of raw MH and pMH on cell viability was validated using 2 indepndent assays. Metabolomics analysis detected 2440 compounds, out of which 833 were successfully identified. Among these, 90 phytochemical compounds, predominantly comprising terpenoids, flavonoids, coumarins and derivatives, and phenylpropanoic acids, and 79 lipids were identifiable. Significant differences in 5 metabolite classes, including flavonoids, phenols, terpenoids, carbohydrates, and organic acids were observed between the raw and pMH. Moreover, several altered metabolic pathways were identified in pMH compared to raw MH, such as energy metabolism, amino acid metabolism, and various other pathways that collectively influence biological functions associated with cellular growth, signaling, and stress response.
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  • 文章类型: Journal Article
    麻黄桂枝汤(MGD),中药中必不可少的草药对,能够释放寒冷,发烧和哮喘,主要含有生物碱,黄酮类化合物,苯丙素类和氨基酸。然而,这四类化合物在体内的吸收和分布仍不清楚。
    在我们的研究中,我们利用UPLC-Q-TOF-MS技术来鉴定MGD中的成分,以及MGD的原型及其在血浆和大脑中吸收的代谢物。我们进一步描绘了MGD的原型和代谢物在血浆和脑中的药物-时间曲线。
    我们的结果表明,MGD中表征了105种成分。其中30种可以被血液吸收,其中十个可以分布到大脑中。我们还在血液中发现了八种新的生物转化代谢物,其中一半可以通过血脑屏障。此外,体内检测到的所有成分都可以立即吸收和分布。
    这些发现为分析MGD中潜在的生物活性化合物及其体内行为提供了一种可行的方法,可促进MGD的有效物质基础研究和临床应用的安全性。
    UNASSIGNED: Mahuang Guizhi Decoction (MGD), an essential herbal pair in traditional Chinese medicine, is able to release cold, fever and asthma, mainly containing alkaloids, flavonoids, phenylpropanoids and amino acids. However, the absorption and distribution of these four category compounds in vivo still remained unclearly.
    UNASSIGNED: In our research, we utilized UPLC-Q-TOF-MS technique to identify the constituents within MGD, as well as the prototypes of MGD and their metabolites absorbed in plasma and brain. We further profiled the drug-time curve of prototypes and metabolites of MGD both in plasma and brain.
    UNASSIGNED: Our results showed that 105 constituents were characterized in MGD. Thirty of them could be absorbed into blood, and ten of them could be distributed into brain. We also discovered eight new bio-transformed metabolites in blood, and a half of which could pass through the blood-brain barrier. In addition, all components detected in vivo could be absorbed and distributed immediately.
    UNASSIGNED: These findings provide an approachable method to analyze the potential bio-active compounds in MGD and their in vivo behaviors, which could promote the efficacious material basis study of MGD and the security of clinical utilization.
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  • 文章类型: Journal Article
    经典的黄芪-决明子小枝药物对具有悠久的疗效。然而,目前对黄芪桂枝汤(ACD)物质基础的研究较少。建立了UPLC-Q-TOF-MS对ACD主要化学成分进行分类鉴定的方法,并利用HPLC-UV比较了单汤和共汤的成分差异。研究了ACD对2型糖尿病(T2D)大鼠的治疗作用。从ACD中拆分出35种化合物。从黄芪汤剂中推导出15个化合物,而从决明子枝中鉴定出9种化合物。中药配对对中药汤剂的化学成分有显着影响。ACD对T2D大鼠的症状有较明显的缓解作用。与单一草药的应用相比。
    The classic Astragalus-Cassia twig drug pair has a long history of proven efficacy. However, a fewer studies on material basis of the Astragalus and Cassia twig decoction (ACD) was researched at present. The method of UPLC-Q-TOF-MS for classifying and identifying the main chemical components of ACD was established and the differences in composition between single decoction and co-decoction were compared by using HPLC-UV. The therapeutic role of ACD on type 2 diabetes (T2D) rats was investigated. Thirty-five compounds were resolved from the ACD. Fifteen compounds were deduced from the decoction of Astragalus, whereas nine compounds were identified from Cassia twig. Pairing of herbs make a significant effect on the chemical composition of herbal decoction. ACD can play a more obvious role in alleviating the symptoms of T2D rats, compared to the application of single herb.
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  • 文章类型: Journal Article
    背景:肾小球油菜(Blum)Regel(B.肾小球)被认为是一种传统中药(TCM),主要用于活血化瘀。它经常用于治疗跌倒和颠簸造成的伤害。
    目的:尽管其在缺血性卒中(IS)的临床治疗中有效使用,目前没有关于其组成和作用机制的报告,这影响了它的推广。本研究探讨了肾小球芽孢杆菌的化学成分和分子机制。具有以下组件:UPLC-Q-TOF-MS,体内外网络药理学分析和实验验证。
    方法:在MCAO/R大鼠和ORD细胞模型上评估肾小球芽孢杆菌对缺血性脑卒中的干预作用。然后使用UPLC-Q-TOF-MS进行组成分析。此外,探索了网络药理学和分子对接技术以确定潜在的靶标和途径。预测的作用机制最终通过免疫组织化学和蛋白质印迹得到证实。
    结果:B.通过减少海马和皮质神经元损伤,肾小球在MCAO/R大鼠中表现出神经保护作用,脑梗塞,和脑水肿。体内和体外实验表明,它降低了ROS和MDA水平,增加SOD和GSH水平,从而抑制氧化应激。此外,神经元形态的改善和Nissl体的调节提示了其神经保护作用的潜在机制。此外,肾小球芽孢杆菌表现出Bax和Caspase-3表达的浓度依赖性降低,随着GFAP的增加,Bcl2/Bax比值,p-PI3K,p-AKT,和p-mTOR水平。
    结论:B.肾小球在体内和体外均对脑缺血再灌注损伤具有神经保护作用。它通过PI3K/AKT/mTOR通路预防氧化应激损伤并抑制细胞凋亡。
    BACKGROUND: Brassaiopsis glomerulata (Blum) Regel (B.glomerulata) is recognized as a traditional Chinese medicine (TCM) primarily used for promoting blood circulation and removing stasis. It is frequently utilized in the treatment of injuries resulting from falls and bumps.
    OBJECTIVE: Despite its effective use in clinical treatment for ischemic stroke (IS), there are currently no reports on its composition and mechanism of action, which affects its promotion. The study investigated the chemical components and molecular mechanisms of B.glomerulata, with the following components: UPLC-Q-TOF-MS, network pharmacology Analysis and experimental verification in vivo and vitro.
    METHODS: The effect of B.glomerulata on interfering with ischemic stroke was assessed on MCAO/R rats and ORD cell model. Then the compositional analysis was conducted using UPLC-Q-TOF-MS. Furthermore, network pharmacology and molecular docking techniques were explored to identify potential targets and pathways. The predicted mechanisms of action were ultimately confirmed by immunohistochemistry and protein blotting.
    RESULTS: B. glomerulata exhibited neuroprotective effects in MCAO/R rats by reductions in hippocampal and cortical neuronal damage, brain infarction, and cerebral edema. Both in vivo and in vitro experiments demonstrated that it decreased ROS and MDA levels, increased SOD and GSH levels, thereby inhibiting oxidative stress. Moreover, the improvements in neuronal morphology and the modulation of Nissl bodies suggested a potential mechanism underlying its neuroprotective action. Additionally, B.glomerulata exhibited concentration-dependent reductions in Bax and Caspase-3 expressions, along with increases in GFAP, Bcl2/Bax ratio, p-PI3K, p-AKT, and p-mTOR levels.
    CONCLUSIONS: B.glomerulata exhibited neuroprotective effects against cerebral ischemia-reperfusion injury both in vivo and in vitro. It prevented oxidative stress damage and inhibited apoptosis of ischemic stroke through the PI3K/AKT/mTOR pathway.
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  • 文章类型: Journal Article
    黄芩(SR),来源于黄芩的根,是一种清热凉血的传统中药。它已被用作传统草药,并在当今的亚洲国家中作为功能性食品而流行。
    在这项研究中,UPLC-Q-TOF-MS首次用于鉴定SR乙醇提取物中的化学成分。然后,采用星点设计-响应面法对提取工艺进行了优化。建立了不同批次和加工产品的指纹图谱,和化学标记物通过各种人工神经网络模型的组合进行筛选。最后,网络药理学和分子模拟技术用于验证以确定质量标记。
    共鉴定出SR中的35种化学成分,并确定最佳提取工艺为:用80%甲醇以120:1的比例超声提取70分钟,浸泡时间为30分钟。通过使用各种人工神经网络模型的判别分析,SR的样品可以根据其生长年限分为两类:库琴(较老植物的干燥根)和紫琴(较年轻植物的根)。此外,每个类别中的样本可以根据其来源进一步聚类。SR的四种不同的加工产品也可以分别区分。最后,通过网络药理学和分子模拟技术的整合,确定黄芩苷,黄芩素,Wogonin,诺沃金宁,去甲Wogonin-8-O-葡糖苷酸,黄芩黄酮II,hispidulin,8,8“-bibaicalein,和OxylinA-7-O-β-D-葡糖苷酸可以作为SR的质量标记。
    影响SR质量的主要因素是其生长年限。SR的地理起源被确定为影响其质量的次要因素。加工对其质量也有很大影响。选定的质量标记为SR的质量控制奠定了基础,这一研究策略也为提高中药质量提供了研究范式。
    UNASSIGNED: Scutellariae Radix (SR), derived from the root of Scutellaria baicalensis Georgi, is a traditional Chinese medicine (TCM) for clearing heat and cooling blood. It has been used as a traditional herbal medicine and is popular as a functional food in Asian countries today.
    UNASSIGNED: In this study, UPLC-Q-TOF-MS was first employed to identify the chemical components in the ethanol extract of SR. Then, the extraction process was optimized using star point design-response surface methodology. Fingerprints of different batches and processed products were established, and chemical markers were screened through a combination of various artificial neural network models. Finally, network pharmacology and molecular simulation techniques were utilized for verification to determine the quality markers.
    UNASSIGNED: A total of 35 chemical components in SR were identified, and the optimal extraction process was determined as follows: ultrasonic extraction with 80% methanol at a ratio of 120:1 for 70 minutes, with a soaking time of 30 minutes. Through discriminant analysis using various artificial neural network models, the samples of SR could be classified into two categories based on their growth years: Kuqin (dried roots of older plants) and Ziqin (roots of younger plants). Moreover, the samples within each category could be further clustered according to their origins. The four different processed products of SR could also be distinguished separately. Finally, through the integration of network pharmacology and molecular simulation techniques, it was determined that baicalin, baicalein, wogonin, norwogonin, norwogonin-8-O-glucuronide, skullcapflavone II, hispidulin, 8, 8\"-bibaicalein, and oroxylin A-7-O-beta-D-glucuronide could serve as quality markers for SR.
    UNASSIGNED: The primary factors affecting the quality of SR were its growth years. The geographic origin of SR was identified as a secondary factor affecting its quality. Processing also had a significant impact on its quality. The selected quality markers have laid the foundation for the quality control of SR, and this research strategy also provides a research paradigm for improving the quality of TCM.
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  • 文章类型: Journal Article
    UPLC-Q-TOF-MS结合质量缺陷过滤策略用于穿孔虫的植物化学研究,导致分离出13种未描述的柠檬苦素类化合物,命名为haperforatononeA-M(1-13)和17种已知化合物(14-30)。特别是,haperforatonesD-E(4-5)有一个前所未有的A,B,C,D-seco-6,7-nor-C-24-limonoid骨架,结构上剥离五元内酯环B并在C-5和C-10位形成双键。使用光谱数据鉴定了它们的2D结构和相对构型。通过X射线衍射晶体学确定1、4和6的绝对构型。评价所有30种化合物在LPS诱导的Raw264.7细胞系中的抗炎潜力。在这些测试的化合物中,haperforatoneF(6)证明了对LPS诱导的NO产生的最有效活性,抑制NO产生的IC50值为7.2µM。此外,6可以显着抑制IL-1β和IL-6的释放,并显着下调10µMLPS刺激的RAW264.7细胞中iNOS的蛋白表达水平。还使用分子对接研究了NO抑制6的可能机制,这揭示了化合物6与iNOS蛋白的相互作用。
    UPLC-Q-TOF-MS combined with mass defect filtering strategies were applied for the phytochemical investigation of Harrisonia perforata, leading to the isolation of thirteen undescribed limonoids named haperforatones A-M (1-13) and seventeen known compounds (14-30). Particularly, haperforatones D-E (4-5) have an unprecedented A, B, C, D-seco-6, 7-nor-C-24-limonoid skeleton, structurally stripped of the five-membered lactone ring B and formed a double bond at the C-5 and C-10 positions. Their 2D structures and relative configurations were identified using spectroscopic data. The absolute configurations of 1, 4, and 6 were established via X-ray diffraction crystallography. All 30 compounds were evaluated for anti-inflammatory potential in LPS-induced Raw 264.7 cell lines. Among those tested compounds, the most potent activity against LPS-induced NO generation was demonstrated by haperforatone F (6), with the IC50 value of inhibition NO production of 7.2 µM. Additionally, 6 could significantly inhibit IL-1β and IL-6 release and markedly downregulate the protein expression level of iNOS in the LPS-stimulated RAW264.7 cells at 10 µM. The possible mechanism of NO inhibition of 6 was also investigated using molecular docking, which revealed the interaction of compound 6 with the iNOS protein.
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  • 文章类型: Journal Article
    白芍。(PLP)被以为活血化瘀。这项研究使用血液成分分析,网络药理学,和分子对接预测PLP治疗血瘀证(BSS)的作用机制。将PLP加工成白芍(PRA)和赤芍(PRR)。PRA和PRR在1/s剪切速率下能显著降低全血黏度(WBV),提高红细胞聚集指数(EAI),血浆粘度(PV),和急性血瘀大鼠的红细胞沉降率(ESR)。他们延长了凝血酶原时间(PT),PRR延长了活化的部分凝血活酶时间(APTT)。PRA和PRR增加了凝血酶时间(TT),降低了纤维蛋白原(FBG)含量。所有结果均具有显著性(p<0.05)。芍药苷的十种成分,Albiflorin,牡丹宁C,使用超高效液相色谱-四极杆飞行时间质谱(UPLC-Q-TOF-MS)在大鼠血浆中鉴定出其他人。蛋白质-蛋白质相互作用网络(PPI)分析表明,AKT1、EGFR、SRC,MAPK14、NOS3和KDR是PLP治疗BSS的关键靶点,分子对接结果进一步验证了这一点。这项研究表明,PLP可以通过多种途径改善BSS,其潜在的药理机制可能与血管生成有关。血管收缩和舒张,凝血,以及血管细胞的迁移和增殖。
    Paeonia lactiflora Pall. (PLP) is thought to promote blood circulation and remove blood stasis. This study used blood component analysis, network pharmacology, and molecular docking to predict the mechanism of PLP in the treatment of blood stasis syndrome (BSS). PLP was processed into Paeoniae Radix Alba (PRA) and Paeoniae Radix Rubra (PRR). PRA and PRR could significantly reduce whole blood viscosity (WBV) at 1/s shear rates and could increase the erythrocyte aggregation index (EAI), plasma viscosity (PV), and erythrocyte sedimentation rate (ESR) of rats with acute blood stasis. They prolonged the prothrombin time (PT), and PRR prolonged the activated partial thromboplastin time (APTT). PRA and PRR increased the thrombin time (TT) and decreased the fibrinogen (FBG) content. All the results were significant (p < 0.05). Ten components of Paeoniflorin, Albiflorin, Paeonin C, and others were identified in the plasma of rats using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). A protein-protein interaction network (PPI) analysis showed that AKT1, EGFR, SRC, MAPK14, NOS3, and KDR were key targets of PLP in the treatment of BSS, and the molecular docking results further verified this. This study indicated that PLP improves BSS in multiple ways and that the potential pharmacological mechanisms may be related to angiogenesis, vasoconstriction and relaxation, coagulation, and the migration and proliferation of vascular cells.
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  • 文章类型: Journal Article
    在电喷雾电离质谱(ESI-MS)领域,区分异构体提出了一个重大的挑战,由于最小的光谱差异,往往产生于其细微的结构差异。这使得仅通过实验光谱来准确识别这些化合物是一项艰巨的任务。计算化学已成为弥合实验观察与理论理解之间差距的关键工具。本研究使用MS碎片模拟软件,QCxMS,模拟五组异构体的光谱,包括11种化合物,在传统中药中发现,栀石泻白桂枝汤。通过将计算方法预测的光谱与超高效液相色谱-四极杆-飞行时间质谱(UPLC-Q-TOF-MS)实验得出的光谱进行比较,据观察,在优化仿真参数之后,QCxMS能够为所有检查的化合物产生可靠的光谱。值得注意的是,在GFN1-xTB和GFN2-xTB水平下计算的数据没有显著差异.进一步的分析能够从理论数据中识别11种化合物的主要片段,促进其碎片化途径的演绎。随后应用密度泛函理论(DFT)方法来计算这些化合物的初级断裂能。研究结果表明,使用热力学和动力学方法计算的能量数据与观察到的异构体片段丰度之间存在一致性。这种比对提供了更精确的理论框架,用于理解异构体之间碎片离子差异产生的机制。
    In the realm of electrospray ionization mass spectrometry (ESI-MS), distinguishing among isomers poses a significant challenge due to the minimal spectral differences that often arise from their subtle structural differences. This makes the accurate identification of these compounds through solely experimental spectra a daunting task. Computational chemistry has emerged as a pivotal tool in bridging the gap between experimental observations and theoretical understanding. This study used the MS fragmentation simulation software, QCxMS, to model the spectra of five groups of isomers, encompassing 11 compounds, found in the traditional Chinese medicine, Zhishi Xiebai Guizhi Decoction. By comparing the spectra predicted through computational methods with those derived from Ultra-high performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF-MS) experiments, it was observed that, following the optimization of simulation parameters, QCxMS was capable of generating reliable spectra for all examined compounds. Notably, the data calculated under both GFN1-xTB and GFN2-xTB levels exhibited no significant discrepancies. Further analysis enabled the identification of the principal fragments of the 11 compounds from the theoretical data, facilitating the deduction of their fragmentation pathways. The Density Functional Theory (DFT) method was subsequently applied to compute the primary fragmentation energies of these compounds. The findings revealed a congruence between the energy data calculated using both thermodynamic and kinetic approaches and the observed fragment abundance of the isomers. This alignment providing a more precise theoretical framework for understanding the mechanisms underlying the generation of fragment ion differences among isomers.
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