Characterization of a Novel Co2TiO4 Nanopowder for the Rapid Identification of Latent and Blood Fingerprints

Co₂TiO₄ nanopowders for detecting latent and blood fingerprints were prepared by a traditional coprecipitation method and characterized by X-ray diffraction, transmission electron microscopy, energy-dispersive spectroscopy, and Fourier transform infrared spectroscopy. The results from morphological and componential characterization showed that green Co₂TiO₄ nanopowders with inverse spinel structure were almost spherical and uniform in size without any impurities. To demonstrate the effectiveness of Co₂TiO₄ nanopowders, powder dusting and small particle reagent methods were successfully used to develop latent and blood fingerprints on various substrates including nonporous surfaces, semiporous surfaces, and porous surfaces. The principles of the small particle reagent method for developing latent blood fingerprints were also investigated. Our experiments on lit aged fingerprints exhibited high sensitivity, high contrast, and high selectivity, suggesting that Co₂TiO₄ nanopowders may be a novel probe to develop both latent and blood fingerprints at crime scenes due to their fine ridge details, ease of use, and rapidness.     

Investigating the in vitro stereoselective metabolism of m‐nisoldipine enantiomers: characterization of metabolites and cytochrome P450 isoforms involved

m‐Nisoldipine, as a novel 1,4‐dihydropyridine calcium ion antagonist, was presented as a couple of enantiomers [(?), (+)‐m‐nisoldipine]. In this report, the in vitro metabolism of m‐nisoldipine enantiomers was investigated in rat liver microsomes (RLM) by the combination of two liquid chromatography mass spectrometric techniques for the first time. The metabolites were separated and assayed by ultra‐high performance liquid chromatography coupled to quadrupole time‐of‐flight mass spectrometry and further identified by comparison of their mass and chromatographic behaviors with reference substances. A total of 18 metabolites of (?)‐m‐nisoldipine and 16 metabolites of (+)‐m‐nisoldipine were detected, respectively, which demonstrated that (+)‐m‐nisoldipine is more metabolically stable than (?)‐m‐nisoldipine. In addition, the identified metabolic pathways of m‐nisoldipine enantiomers were involved in dehydrogenation, oxidation and ester hydrolysis. Afterwards, based on high‐performance liquid chromatography coupled to triple quadrupole linear ion trap mass spectrometry, various selective cytochrome P450 (CYP) enzyme inhibitors were employed to evaluate CYP isoforms. The results indicated that the inhibitors of CYP1A1/2, CYP2B1/2, 2D and 2C11 had no obvious inhibitory effects, yet the inhibitor of CYP 3A had a significant inhibitory effect on metabolism of m‐nisoldipine enantiomers. This showed that CYP 3A might primarily metabolize m‐nisoldipine in RLM. Copyright © 2015 John Wiley & Sons, Ltd.     

高光谱成像与图像结合进行油菜角果蚜虫侵染的定位识别

油菜蚜虫可造成油菜籽的严重减产,及早进行油菜蚜虫判别以及其侵染定位识别有助于精准喷药。采用可见-近红外高光谱成像技术结合图像分析对185个蚜虫侵染以及138个健康油菜角果进行判别,并进行蚜虫的定位分析。首先采用主成分分析法(PCA)对两类样本的平均光谱进行聚类分析,并基于X-loading得出737nm波段可作为判断蚜虫的重要波段,采用Boxplot进行两类样本间单波段处的统计分析,同时得出基于737nm波段判断蚜虫侵染油菜角果的线性公式为y=2.917 6-3.345 7x(x为样本在737nm处的光谱值,y为样本的分类预测值)。采用此公式对实验样本进行判别分析,可以发现角果蚜虫识别率为99.0%。同时基于737nm处的油菜角果单波段灰度图进行蚜虫的定位识别,可以得到蚜虫的识别率为81.1%。结果表明,采用737nm处的单波段光谱信息以及图像信息可进行油菜角果蚜虫侵染的定位识别,为进一步开发便携仪检测仪以及精准喷药提供理论和方法依据。     

Chemical composition differentiation of Shen‐Shuai‐Ning granule between combined decoction and separated decoction using HPLC‐DAD‐ESI‐QTOF‐MS

Shen‐Shuai‐Ning (SSN) granule, a traditional Chinese medicine formula, is widely used in clinical practice for treating chronic renal failure. However, its detailed chemical profile is unknown. Here, HPLC‐ESI‐QTOF‐MS was employed for the systematic chemical analysis of SSN. A total of 52 compounds were identified and the characteristic ions of the compounds were described. Furthermore, chemical consistency between the combined decoction and the separated decoction of SSN was evaluated using HPLC‐DAD. A chemical comparison between two preparations of SSN granule (combined decoction and separated decoction of Coptides Rhizoma) indicated a significant difference in the content of many compounds, including salvianolic acid A, salvianolic acid B, berberine, palmatine and epiberberine. As a result, separated decoction of Coptides Rhizoma would lead to a significantly decrease in depsides in Salviae Miltiorrhizae Radix et Rhizoma and an increase in alkaloids in Coptidis Rhizoma.     

Rapid Characterization of the major chemical constituents from Polygoni Multiflori Caulis by liquid chromatography tandem mass spectrometry and comparative analysis with Polygoni Multiflori Radix

Polygoni Multiflori Caulis is a traditional Chinese medicine that has been used for a long time to treat sleep disorders. However, the multiple chemical composition analysis has not been reported. In this study, a simple, rapid and effective ultra‐high performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry method was established to characterize the components of Polygoni Multiflori Caulis. In addition, a chemical comparative analysis was performed with Polygoni Multiflori Radix, another traditional Chinese medicine from the same plant, through multivariate statistical analysis and semi‐quantitative analysis to screen the difference in chemical ingredients between these two herbal medicines from same medicinal plant. A total of 33 peaks were detected within 25 min, and 28 of them were identified or tentatively characterized by comparing the retention time and mass spectrometry data. Based on the results, 12 characteristic components were screened out by multivariate statistical analysis, and their content change trends were compared by semi‐quantitative analysis.     

Characterization of the metabolites of H3B-6545 in vitro and in vivo by using ultra-high performance liquid chromatography combined with electrospray ionization linear ion trap-orbitrap tandem mass spectrometry

H3B-6545 is a selective ERα covalent antagonist, which has been demonstrated to be effective in anti-tumor. To fully understand its mechanism of action, it is necessary to investigate the in vitro and in vivo metabolic profiles. For in vitro metabolism, H3B-6545 (50 μM) was incubated with the hepatocytes of rat and human for 2 h. For in vivo metabolism H3B-6545 was orally administered to rats at a single dose of 10 mg/kg, and plasma, urine and fecal samples were then collected. All samples were analyzed by using ultra-high performance liquid chromatography combined with linear ion trap-orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap-MS) operated in positive ion mode. The structures of the metabolites were elucidated by comparing their MS and MS² spectra with those of parent drug. A total of 11 metabolites, including a GSH adduct, were detected and structurally identified. M2, M7 and M8 were further unambiguously identified by using reference standards. Among these metabolites, M1, M5, M7 and M10 were newly found and reported for the first time. The metabolic pathways of H3B-6545 included deamination (M8 and M9), dealkylation (M2, M3 and M10), N-hydroxylation (M6), hydroxylation (M1 and M4), formation of amide derivatives (M5 and M7) and GSH conjugation (G1).     

De novo prediction of the elemental composition of peptides and proteins based on a single mass

Identification of peptides and proteins is a common task in mass spectrometry–based proteomics but often fails to deliver a comprehensive list of identifications. Downstream analysis, quantitative or qualitative, depends on the outcome of this process. Despite continuous improvement of computational methods, a large fraction of the screened peptides and/or proteins remains unidentified. We introduce here pacMASS, a method that de novo predicts the elemental composition of peptides and small proteins based on a single accurate mass, ie, the observed monoisotopic or average mass. This novel approach returns in a fast and memory efficient manner a limited number of elemental compositions per queried peptide or protein.     

Rapid identification of glycerophospholipids from RAW264.7 cells by UPLC/ESI ‐QTOF‐MS

The study aims to develop a rapid, sensitive ultra‐performance liquid chromatography coupled with an electrospray ionization quadruple time‐of‐flight tandem mass spectrometry (UPLC/Q‐TOF‐MS) analytical method for identifying glycerophospholipids (GPLs) from RAW264.7 cells. A total of 78 GPLs including 22 phosphatidylethanolamines (PEs), 49 phosphatidylcholines (PCs), four phosphatidylglycerols, one phosphatidylinositol and two unknown GPLs were identified. PC (14:0/16:1), PC (14:0/16:0), PE (0:0/20:3), PE (22:5/0:0) and PE (22:3/0:0) were identified for the first time. The UPLC/Q‐TOF‐MS method is suitable for targeting analysis of GPLs from RAW264.7 cells, which allows us to find out new GPLs compositions related to inflammatory diseases and to explain their pharmacological roles in inflammatory process. Copyright © 2014 John Wiley & Sons, Ltd.     

Seeding-inspired chemotaxis genetic algorithm for the inference of biological systems

A large challenge in the post-genomic era is to obtain the quantitatively dynamic interactive information of the important constitutes of underlying systems. The S-system is a dynamic and structurally rich model that determines the net strength of interactions between genes and/or proteins. Good generation characteristics without the need for prior information have allowed S-systems to become one of the most promising canonical models. Various evolutionary computation technologies have recently been developed for the identification of system parameters and skeletal-network structures. However, the gaps between the truncated and preserved terms remain too small. Additionally, current research methods fail to identify the structures of high dimensional systems (e.g., 30 genes with 1800 connections). Optimization technologies should converge fast and have the ability to adaptively adjust the search. In this study, we propose a seeding-inspired chemotaxis genetic algorithm (SCGA) that can force evolution to adjust the population movement to identify a favorable location. The seeding-inspired training strategy is a method to achieve optimal results with limited resources. SCGA introduces seeding-inspired genetic operations to allow a population to possess competitive power (exploitation and exploration) and a winner-chemotaxis-induced population migration to force a population to repeatedly tumble away from an attractor and swim toward another attractor. SCGA was tested on several canonical biological systems. SCGA not only learned the correct structure within only one to three pruning steps but also ensures pruning safety. The values of the truncated terms were all smaller than 10⁻¹⁴, even for a thirty-gene system.     

Characterization of forsythoside A metabolites in rats by a combination of UHPLC‐LTQ‐Orbitrap mass spectrometer with multiple data processing techniques

Forsythoside A (FTA), the main active constituent isolated from Fructus Forsythiae, has various biological functions including anti‐oxidant, anti‐viral and anti‐microbial activities. However, while research on FTA has been mainly focused on the treatment of diseases on a material basis, FTA metabolites in vivo have not been comprehensively evaluated. Here, a rapid and sensitive method using a UHPLC‐LTQ‐Orbitrap mass spectrometer with multiple data processing techniques including high‐resolution extracted ion chromatograms, multiple mass defect filters and diagnostic product ions was developed for the screening and identification of FTA metabolites in rats. As the result, a total of 43 metabolites were identified in biological samples including 42 metabolites in urine, 22 metabolites in plasma and 15 metabolites in feces. These results demonstrated that FTA underwent a series of in vivo metabolic reactions including methylation, dimethylation, sulfation, glucuronidation, diglucuronidation, cysteine conjugation and their composite reactions. The research enhanced our understanding of FTA metabolism and built a foundation for further toxicity and safety studies.