Identification of endogenous carbonyl steroids in human serum by chemical derivatization, hydrogen/deuterium exchange mass spectrometry and the quantitative structure-retention relationship.

Steroids are tetracyclic aliphatic compounds, and most of them contain carbonyl groups. The disordered homeostasis of steroids is closely related to the occurrence and progression of various diseases. Due to high structural similarity, low concentrations in vivo, poor ionization efficiency, and interference from endogenous substances, it is very challenging to comprehensively and unambiguously identify endogenous steroids in biological matrix.

Qualitative Distribution of Endogenous Cholesteryl Esters in Plasma of Humans and Three Rodent Species Using Stepwise UPLC-Q-Exactive-MS.

Objective: Cholesteryl esters (CEs) are composed of various fatty acyl chains attached to the hydroxyl groups of cholesterol, and abnormalities in their metabolism are related to many diseases. This study aimed to develop an ultrahigh-performance liquid chromatography-quadrupole exactive mass spectrometry (UPLC-Q-Exactive MS) method to identify the CEs in plasma.

Methods: First, the MS fragmentation patterns were investigated using seven commercial CE standards.

Quantitative proteomics of plasma and liver reveals the mechanism of turmeric in preventing hyperlipidemia in mice.

Hyperlipidemia is manifested by abnormal levels of circulating lipids and may lead to various cardiovascular diseases. Studies have demonstrated that turmeric supplemented in food can effectively prevent hyperlipidemia. The aim of this study is to elucidate the underlying mechanism.

Experimental and theoretical study on the propagation characteristics of stress wave in filled jointed rock mass.

This study is to theoretically and experimentally investigate the propagation of stress waves in the filled joint set. The time-domain recursive method is used to derive the propagation equations in the filled joint set, and the filled joints are further simplified into structural planes without joint thickness. The split-Hopkinson rock bar is modified to simulate P wave propagation normally across the parallel filled joints.

Qualitative distribution of endogenous sphingolipids in plasma of human and rodent species by UPLC-Q-Exactive-MS.

Sphingolipids (SLs) are endogenously bioactive molecules with diverse structures, and its metabolic disorders are involved in the progression of many diseases. In this study, an ultra-performance liquid chromatography quadrupole exactive mass spectrometry (UPLC-Q-Exactive-MS) method was established to comprehensively profile SLs in plasma. First, the fragment patterns of SL standards of each subclass were investigated.

The Protein-Binding Behavior of Platinum Anticancer Drugs in Blood Revealed by Mass Spectrometry.

Cisplatin and its analogues are widely used as chemotherapeutic agents in clinical practice. After being intravenously administrated, a substantial amount of platinum will bind with proteins in the blood. This binding is vital for the transport, distribution, and metabolism of drugs; however, toxicity can also occur from the irreversible binding between biologically active proteins and platinum drugs.

Discrimination of turmeric from different origins in China by MRM-based curcuminoid profiling and multivariate analysis.

In this research, a three-step strategy was utilized for discriminating turmeric samples from different provinces and regions in China. Firstly, MRM-based UPLC-MS/MS method for chemical profiling of curcuminoids in turmeric samples was established. Then, response surface methodology was applied for optimizing the extraction process of targeted curcuminoids.

Qualitative distribution of endogenous phosphatidylcholine and sphingomyelin in serum using LC-MS/MS based profiling.

PCs and SMs are the major types of glycerophospholipids and sphingophospholipids, the two main categories of phospholipids (PLs). To study the qualitative distribution of serum phosphatidylcholine (PC) and sphingomyelin (SM) in human and three rodent species, liquid chromatography-Orbitrap mass spectrometry (LC-Orbitrap-MS/MS) was used to identify them comprehensively through the accurate mass measurement of both precursor ions and their corresponding product ions. Based on the fragmentation rules of standards, the product ions at m/z 184.

Spectrum-effect relationship for anti-tumor activity of shikonins and shikonofurans in medicinal Zicao by UHPLC-MS/MS and chemometric approaches.

Shikonin, shikonofuran and their derivatives are the main bioactive components of Zicao, a traditional Chinese medicine prepared with the dried roots of Lithospermum erythrorhizon, Arnebia euchroma or Arnebia guttata. To establish an efficient and sensitive method for studying material basis of Zicao, different scan modes of ultra-high performance liquid chromatography quadrupole time of flight tandem mass spectrometry (UHPLC-QTOF-MS/MS) and UHPLC triple quadrupole linear ion trap mass spectrometry (QTRAP-MS/MS) were incorporated to make full use of the sensitivity of multiple reaction monitoring (MRM) and overcome its disadvantages. A total of 73 shikonins and shikonofurans compounds were detected in Zicao utilizing various scanning modes.

Identification of the lipid-lowering component of triterpenes from Alismatis rhizoma based on the MRM-based characteristic chemical profiles and support vector machine model.

It has been demonstrated that triterpenes in Alismatis rhizoma (Zexie in Chinese, ZX) contributed to the lipid-lowering effect on high-fat diet-induced hyperlipidemia. Alisol B 23-acetate, one of the abundant triterpenes in ZX, was used as the marker of quality control for ZX in Chinese Pharmacopoeia, while it could not reflect the lipid-lowering effect because other triterpenes in ZX also had prominent medicinal efficacy. To identify the significantly bioactive triterpenes in ZX, a multiple reaction monitoring (MRM)-based characteristic chemical profile (CCP)-support vector machine (SVM) model was used to explore the relationship between triterpenes and lipid-lowering effect of ZX.

Elucidation of the Mechanism of Action for Metal Based Anticancer Drugs by Mass Spectrometry-Based Quantitative Proteomics.

The discovery of the anticancer activity of cisplatin and its clinical application has opened a new field for studying metal-coordinated anticancer drugs. Metal-based anticancer drugs, such as cisplatin, can be transported to cells after entering into the human body and form metal⁻DNA or metal⁻protein adducts. Then, responding proteins will recognize adducts and form stable complexes.

The strategy for establishment of the multiple reaction monitoring based characteristic chemical profile of triterpenes in Alismatis rhizoma using two combined tandem mass spectrometers.

It was reported that triterpenes compounds in Alismatis rhizoma (AR) contributed to the lipid lowering effect on high fat diet (HFD)-induced hyperlipidemia. To date only 24 triterpenes (including the isomers) were characterized by LC-QTOF-MS/MS due to the lack of strategies for systematic discovery, classification and identification of triterpenes in AR. In this study, an integrated strategy combining various QTOF-MS/MS and QTRAP-MS/MS scan functions was developed for systematic identification and specific characterization of triterpenes in AR and processed AR.

Identification and characterization of curcuminoids in turmeric using ultra-high performance liquid chromatography-quadrupole time of flight tandem mass spectrometry.

A three-step strategy was developed for systematic characterization of curcuminoids in turmeric. Based on UHPLC-QTOF-MS/MS analysis, 89 curcuminoids including 16 novel ones were identified in the turmeric samples using this approach. During the identification process, false positive results were excluded by combining the positive and negative ESI-MS/MS analyses.

An integrated strategy for establishment of curcuminoid profile in turmeric using two LC-MS/MS platforms.

Turmeric and curcuminoids are used as natural food coloring and functional food additives in various parts of the world. In this study, ninety-six curcuminoids were fully characterized using a targeted curcuminoid profile, which established by integrated use of two complementary LC-MS/MS platforms (liquid chromatography-quadrupole time of flight mass spectrometry (LC-QTOF-MS/MS) and liquid chromatography-quadrupole linear ion trap mass spectrometry (LC-QTRAP-MS/MS)). The curcuminoid profile was represented in the form of a multiple reaction monitoring (MRM) mode based on LC-QTRAP-MS/MS analysis.

The Hypolipidemic Effect of Total Saponins from Kuding Tea in High-Fat Diet-Induced Hyperlipidemic Mice and Its Composition Characterized by UPLC-QTOF-MS/MS.

Kuding tea are used as a traditional tea material and widely consumed in China. In this study, total saponins (TS) from water extract of Kuding tea was prepared by D101 macroporous resins and analyzed by UPLC-QTOF-MS/MS. Then the hypolipidemic effect of TS extract was investigated in high-fat diet-induced hyperlipidemic mice.