A fast atom bombardment mass spectrometric method to predict and detect the antioxidant ability of phenolic compounds was developed to accelerate the pace of finding the antioxidant with higher effect and low toxicity. The effect of experimental conditions on the relative peak intensity ratio of M+· ion to [ M+H]+ion in the FAB mass spectra of the compound was investigated, including matrix, scan time and concentration. The correlation of antioxidant activity with the I ( M+· )/I ( [ M+H ]+) value of flavonoids obtained in FAB mass spectra was studied. Then the antioxidant activity of 12 phenolic compounds was predicted using the above method and the results were compared with those obtained from thiobarbituric acid ( TBA) method. The results show that the I( M+· )/I( [ M+H]+) value of the phenolic compound obtained from FAB mass spectra could reflect their antioxidant activity, which could help to accelerate the development of the antioxidant drug.

The factor analysis method applied in imaging mass spectrometry data analysis was studied. The imaging mass spectrometric data were obtained by air flow-assisted ionization imaging mass spectrometry method. The sample contained some symbols which were drawn on slides using three different inks ( red, blue, black) . The imaging data analyzed by factor analysis method were divided into the background, black, blue and red factor. The results showed that the scores of m/z=443. 2, 478. 4, 322. 2(344. 2) in red, blue, black factor respectively were much larger than others. Therefore, they were markers of three inks. The results accorded with actual condition well and proved that the application of factor analysis in imaging mass spectrometric data analysis was feasible. The data analysis results of factor analysis and principal component analysis were compared. The results showed that the target sample markers could be extracted by factor analysis simply and quantitatively. It was of great potential in biomarker extraction, diseases diagnose and pharmacological analysis.

Chromatography, High Pressure Liquid ; Chromatography, Liquid ; Combinatorial Chemistry Techniques ; Electrophoresis, Capillary ; Mass Spectrometry ; methods ; Spectrometry, Mass, Electrospray Ionization

To screen the harmful substance 5-hydroxymethyl furfural content in commercially available traditional Chinese medicine injection which are commonly used, and to preliminarily evaluate the quality of these injections, 5-hydroxymethyl furfural was taken as an index. The contents of 5-hydroxymethyl furfural in 56 samples which consist of 23 kinds of traditional Chinese medicine injections and glucose injection were determined using LC-MS/MS, and 5-hydroxymethyl furfural was detected in 52 of these samples. The minimal content was 0.0038 microg x L(-1) and the maximum content was 1420 microg x mL(-1). The contents of 5-hydroxymethyl furfural were significantly different in traditional Chinese medicine injection which came from different kinds, manufacturers or batches. The results showed the quality difference of commercially available traditional Chinese medicine injection is significant taking 5-hydroxymethyl furfural content as assessment index. More attention should be paid to the safety of 5-hydroxymethyl furfural in traditional Chinese medicine injection, and unified limitation standard should be set to improve medication safety of traditional Chinese medicine injection.

Alkaloids ; analysis ; chemistry ; isolation & purification ; Chromatography, Liquid ; Flavonoids ; analysis ; chemistry ; isolation & purification ; Gas Chromatography-Mass Spectrometry ; Plant Extracts ; analysis ; Plants, Medicinal ; chemistry ; Saponins ; analysis ; chemistry ; isolation & purification ; Spectrometry, Mass, Electrospray Ionization

In this review, we provide information on hydroxyl radical generation, trapping and detection methods, including electron spin resonance (ESR), electrochemistry detection (ECD), fluorescence detection, UV detection, chemoluminescence and mass spectrometry (MS). In addition, the advantages and disadvantages of the above methods were discussed.
Chromatography, Liquid ; methods ; Electron Spin Resonance Spectroscopy ; methods ; Electrophoresis, Capillary ; methods ; Hydroxyl Radical ; analysis ; chemistry ; Luminescent Measurements ; methods ; Mass Spectrometry ; methods ; Spectrophotometry, Ultraviolet ; methods ; Spin Trapping ; methods

To elucidate further sequence selectivity and nature of the binding of anticancer drugs to DNA, the interaction between anticancer drugs, which are minor groove ligands (distamycin A, DM and netropsin, NP) and intercalator (mitoxantrone, MT), and DNA were studied by electrospray ionization mass spectrometry. The 2 : 1 specific complex of DM and AT-rich DNA were observed principally, while only 1 : 1 specific complex of NP and AT-rich DNA were observed. MT specifically binds to GC-rich DNA. In addition, DM binds to DNA containing 5 A/T bases minor groove almost in a 2 : 1 mode and does not bind to DNA containing 3 A/T bases minor groove. NP binds most strongly to DNA containing 4 A/T bases minor groove. The 1 : 1 specific complex of MT and 6-mer DNA was also observed. The result of competitive binding experiment shows that DM binds more strongly to AT-rich DNA than NP does. These results provide bases for investigating the mechanism of interaction between the drugs and DNA and for improving the structure of target drug.
Antineoplastic Agents ; chemistry ; DNA ; chemistry ; Spectrometry, Mass, Electrospray Ionization ; methods

AIMTo develop a sensitive and rapid HPLC method for the determination of tanshinone IIA (TS) in rat plasma and to study its pharmacokinetics in rats.

METHODSTS and 4-chlorodiphenyl (internal standard) were extracted from plasma with ethyl acetate. After liquid-liquid extraction, the sample was analyzed by HPLC with YMC C18 column (5 microns, 150 mm x 3.0 mm ID). The mobile phase consisted of acetontrile-water-acetic acid (74:26:1) at the flow rate of 0.3 mL.min-1, the UV detection wave length was 270 nm.

RESULTSThe calibration curve was linear (r = 0.9981) in the range from 0.05 to 6.40 mg.L-1. The lowest detectable concentration was 0.05 mg.L-1. The recoveries at the concentration of 0.05, 1.60 and 6.40 mg.L-1 were 98.9%, 102.1% and 100.4%, respectively. The inter- and intra-day RSDs were all less than 5%.

CONCLUSIONThis method is proved to be rapid, precise and reliable enough to be applied to the pharmacokinetics studies of TS in rats after a single dose of 15 mg.kg-1 by oral administration.

Animals ; Anti-Infective Agents ; blood ; pharmacokinetics ; Area Under Curve ; Chromatography, High Pressure Liquid ; methods ; Diterpenes, Abietane ; Drug Stability ; Male ; Phenanthrenes ; blood ; pharmacokinetics ; Random Allocation ; Rats ; Rats, Sprague-Dawley

Evaluating toxicity and decoding the underlying mechanisms of active compounds are crucial for drug development.In this study,we present an innovative,integrated approach that combines air flow-assisted desorption electrospray ionization mass spectrometry imaging(AFADESI-MSI),time-of-flight secondary ion mass spectrometry(ToF-SIMS),and spatial metabolomics to comprehensively investi-gate the nephrotoxicity and underlying mechanisms of nitidine chloride(NC),a promising anti-tumor drug candidate.Our quantitive AFADESI-MSI analysis unveiled the region specific of accumulation of NC in the kidney,particularly within the inner cortex(IC)region,following single and repeated dose of NC.High spatial resolution ToF-SIMS analysis further allowed us to precisely map the localization of NC within the renal tubule.Employing spatial metabolomics based on AFADESI-MSI,we identified over 70 discriminating endogenous metabolites associated with chronic NC exposure.These findings suggest the renal tubule as the primary target of NC toxicity and implicate renal transporters(organic cation transporters,multidrug and toxin extrusion,and organic cation transporter 2(OCT2)),metabolic en-zymes(protein arginine N-methyltransferase(PRMT)and nitric oxide synthase),mitochondria,oxidative stress,and inflammation in NC-induced nephrotoxicity.This study offers novel insights into NC-induced renal damage,representing a crucial step towards devising strategies to mitigate renal damage caused by this compound.

As a promising new molecular imaging technique,mass spectrometry imaging(MSI) has attracted more and more attention in the field of biomedicine. A method of air flow assisted ionization-ultra high resolution mass spectrometry-based mass spectrometric imaging (AFAI-MSI) was developed to profile endogenous metabolites in rat kidney tissue in this study. Rat kidneys were collected and cut into frozen tissue sections,and then were analyzed on an AFAI-MSI system in positive ion mode using acetonitrile-isopmpyl alcohol-water (4:4:2,V/V,5 μL/min) as spray solvent,N2as spray gas(0.6 MPa) and air as assisting gas (45 L/min). The mass range and resolution were set to be 70-1000 Da and 70000, respectively. As a result,a total of 38 metabolites, including organic amines, sugars, vitamins, peptides, neurotransmitters, organic acids,phospholipids,sphingolipids,glyceride,and cholesterol esters, were identified and imaged to characterize their tissue-specific distribution in kidney tissues, and some metabolites, such as choline, acetylcoline,betaine,phoshocholine,and glycerophosphocholine were found to have distinct distribution along the cortex-medulla axis,which may be involved in the formation of osmotic pressure gradient in the kidney. The proposed ultra high resolution mass spectrometry based AFAI-MSI method could work without sample pretreatment, showed high sensitivity and wide metabolite coverage, and was expected to provide a new analytical approach for the research of in situ characterization and metabolic regulation mechanism of endogenous metabolites in kidney.