A New UPLC-MS/MS Method for the Characterization and Discrimination of Polysaccharides from Genus Ephedra Based on Enzymatic Digestions.
Molecules. 2017 Nov 17;22(11):
Authors: Xia YG, Wang TL, Sun LM, Liang J, Yang BY, Kuang HX
Ephedra sinica polysaccharides have been reported to possess important activities, so quality evaluation of polysaccharides from the genus Ephedra is urgent. In this study, enzymatic digestions were performed to establish multiple saccharide fingerprints by ultra-performance liquid chromatography with electrospray ionization triple quadrupole linear ion trap mass spectrometry (UPLC-ESI-TQ-MS/MS) based on a multiple-reaction monitoring in negative mode. Under optimum UPLC-ESI⁻-TQ-MS/MS conditions, excellent separation and quantification of 21 constituents were achieved within 20 min on a solid core column with a 1.6 μm particle using pre-column derivatization with a PMP reagent. This method, coupled with enzymatic digestions and principal component analysis, has been successfully applied to characterize and discriminate Ephedra polysaccharides attributed to different species and plant parts. The results suggest that the proposed analytical strategy could achieve a quality evaluation of plant polysaccharides from traditional Chinese medicines.
PMID: 29149068 [PubMed - in process]
Simultaneous determination of tilianin and its metabolites in mice using ultra-high-performance liquid chromatography with tandem mass spectrometry and its application to a pharmacokinetic study.
Biomed Chromatogr. 2017 Nov 16;:
Authors: Wang L, Chen Q, Zhu L, Zeng X, Li Q, Hu M, Wang X, Liu Z
Tilianin is an active flavonoid glycoside found in many medical plants. Data are lacking regarding its pharmacokinetics and disposition in vivo. The objective of this study was to develop a sensitive, reliable, and validated ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) method to simultaneously quantify tilianin and its main metabolites and to determine its pharmacokinetics in wild-type and breast cancer resistance protein knockout (Bcrp1-/-) FVB mice. Chromatographic separation was accomplished on a C18 column by utilizing acetonitrile and 0.5 mM ammonium acetate as the mobile phase. Mass spectrometric detection was performed using electrospray ionization in both positive and negative modes. The results showed that the precision, accuracy, and recovery, as well as the stability of tilianin and its metabolites in mouse plasma were all within acceptable limits. Acacetin-7-glucuronide (Aca-7-G) and acacetin-7-sulfate (Aca-7-S) were the major metabolites of tilianin in mouse plasma. Moreover, systemic exposure of Aca-7-S was significantly higher in Bcrp1 (-/-) FVB mice compared with wild-type FVB mice. In conclusion, the fully validated UHPLC-MS/MS method was sensitive, reliable, and successfully applied to assess the pharmacokinetics of tilianin in wild-type and Bcrp1 (-/-) FVB mice. BCRP had a significant impact on the elimination of the sulfated metabolite of tilianin in vivo.
PMID: 29144552 [PubMed - as supplied by publisher]
Determination of tubuloside B by LC-MS/MS and its application to a pharmacokinetic study in rats.
Biomed Chromatogr. 2017 Nov 16;:
Authors: Yang S, Qu R, Sun P, Xiong S, Yan S, Deng Z
Tubuloside B, a novel neuroprotective phenylethanoid, is a major active constituent of Cistanche tubulosa and Cistanche deserticola. A specific and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the quantification of tubuloside B in rat plasma. Sample preparation was conducted through a protein-precipitation extraction with methanol using tubuloside A as internal standard (IS). Chromatographic separation was achieved by using a Capcell Pak C18 column (2.0 mm × 50 mm, 5 μm) with a mobile phase of methanol-10 mM ammonium acetate buffer (70:30, v/v) in an isocratic elution way. Mass spectrometry (MS) analysis was performed in negative ionization mode with selection reaction monitoring (SRM) transitions at m/z 665.1 → 160.9 for tubuloside B, and m/z 827.1 → 160.9 for IS. Calibration curves were linear over the ranges of 1.64-1640 ng/mL for plasma samples samples (R(2) > 0.990). The lower limit of quantification (LLOQ) was 1.64 ng/mL. The intra-day and inter-day accuracy was between 92.3% and 113.0% with the RSD less than 9.23% at all LLOQ and QC levels. Finally, this method was successfully applied in the pharmacokinetics study of tubuloside B after intravenous administration.
PMID: 29143972 [PubMed - as supplied by publisher]
Flavonoidal Constituents, Antioxidant, Antimicrobial, and Cytotoxic Activities of Dipterygium glaucum Grown in Kingdom of Saudi Arabia.
Pharmacogn Mag. 2017 Oct;13(Suppl 3):S484-S488
Authors: Shaheen U, Shoeib NA, Temraz A, Abdelhady MIS
Background: Dipterygium glaucum Decne. herb is one of the common traditional plants with multiple medicinal uses.
Objective: To isolate the major constituents and to investigate the antioxidant, antimicrobial, and cytotoxic activities of this herb.
Materials and Methods: Methanolic extract of D. glaucum herb was fractionated using n-hexane, dichloromethane, and n-butanol. Butanol fraction was chromatographed using column chromatography and preparative thin layer chromatography to isolate the major constituents. Isolated compounds were elucidated by means of spectroscopic methods, including 1D, 2D NMR ((1)H, (13)C, DEPT, COSY, HSQC, HMBC, NEOSY) and MS analysis. Total phenolic content using Folin-Ciocalteu reagent and antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay of the total methanolic extract were evaluated. Cytotoxic potential of both methanolic extract and butanol fraction was tested using a crystal violet viability assay. Antimicrobial activities of both extracts were investigated using diffusion agar technique.
Results: Apigenin 6, 8-di-C-glucopyranoside (vicenin-2), quercetin-3`-O-methyl-3-O-glucopyranoside, quercetin-3`-O-methyl-3-O-galactopyranoside, quercetin-3-O-β-D-glucopyranoside, and quercetin-3-O-β-D-galactopyranoside were isolated and elucidated. Total phenolic content was (83.89 mg gallic acid equivalent/g extract). The EC50 value of scavenging DPPH radical was 152.0 ± 2 mg/mL. Butanol fraction showed the highest cytotoxic activity against cervical and breast carcinoma cells (IC50 3.6 and 6.1 mg/mL, respectively). Both methanolic extract and butanol fraction showed wide spectrum antimicrobial activity against Gram-positive and Gram-negative bacteria and some fungi. The highest activity was from methanolic extract against Enterococcus faecalis (83.25%) and against Candida tropicalis (77.03%) as compared to reference antibiotics.
Conclusion: Data obtained from this study demonstrate that D. glaucum possesses significant antioxidant, cytotoxic, and antimicrobial activities which could be ascribed to its flavonoidal content.
SUMMARY: Dipterygium glaucum Decne. herb is one of the common traditional plants with multiple medicinal uses in KSAFive flvonidal glycosides were isolated and elucidatedThis study demonstrated that D. glaucum possesses significant antioxidant, cytotoxic, and antimicrobial activities. Abbreviations used: KSA: Kingdom of Saudi Arabia; TLC: Thin Layer Chromatography; DPPH: 2,2`-diphenyl-1-picrylhydrazyl; EC50: Half maximal effective concentration; IC50: Half maximal inhibitory concentration; DMSO: dimethyl sulfoxide; NMR: Nuclear Magnetic Resonance; ESIMS: Electrospray ionization mass spectrometry; MeOH: Methyl alcohol.
PMID: 29142403 [PubMed]
Biomarker analysis of hemoglobin adducts of acrylamide and glycidamide enantiomers for mid-term internal exposure assessment by isotope dilution ultra-high performance liquid chromatography tandem mass spectrometry.
Talanta. 2018 Feb 01;178:825-833
Authors: Zhang Y, Wang Q, Zhang G, Jia W, Ren Y, Wu Y
Hemoglobin (Hb) adducts of acrylamide (AA) and its oxidative metabolite glycidamide (GA) are important biomarkers for evaluating the mid-term exposure of acrylamide toxicity in vivo. Taking pentafluoro-2-methylphenyl isothiocyanates of N-(2-carbamoylethyl)valine (AAVal-PFPTH) and N-(2-carbamoyl-2-hydroxyethy)valine (GAVal-PFPTH) as target analytes, we developed an isotope dilution ultra-high performance liquid chromatograph tandem mass spectrometry (UHPLC-MS/MS) method for the simultaneous determination of AA and GA hemoglobin (Hb) adducts under the electroscopy ionization negative (ESI‾) mode in the present work. Among them, the enantiomer pair of GA-Hb adducts was firstly identified and successfully separated at baseline level. The method achieved high sensitivity with the LOD and LOQ ranging 1.43-5.05pmol/g Hb and 4.78-16.82pmol/g Hb, respectively. The recovery rates with low, intermediate and high spiking levels were calculated as 97.0-105.2%, 97.4-106.4% and 100.3-111.2%, respectively. Acceptable within-laboratory reproducibility (RSD < 13.7%) substantially supported the robustness of current UHPLC-MS/MS method, which was successfully applied to measure the hemoglobin adducts of acrylamide and glycidamide enantiomers in blood of both rats and humans. A linear exposure assessment model was developed for estimating the daily exposure to acrylamide in humans via considering acrylamide hemoglobin adducts as variables, indicating a novel connect between biomarker-based internal exposure and dietary-based external exposure. Overall, the present instrumental analysis and related internal exposure assessment model provide a substantially methodological support for profiling the internal biological exposure and estimating the external dietary exposure to acrylamide.
PMID: 29136901 [PubMed - in process]
Short-term incubation of positive blood cultures in brain-heart infusion broth accelerates identification of bacteria by matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry.
J Med Microbiol. 2017 Nov 14;:
Authors: Torres I, Gimenez E, Pascual T, Bueno F, Huntley D, Martínez M, Navarro D
PURPOSE: Fast identification of bacteria directly from positive blood cultures (BCs) by matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry (MALDI-TOF MS) can be achieved either using the MALDI Sepsityper kit (protein extraction method) or after a short-term pre-cultivation step on solid medium. We developed a new method that involves short-term enrichment of positive BCs in brain-heart infusion broth (BHI) prior to MALDI-TOF MS analysis.
METHODOLOGY: Eighty-four BCs flagged as positive were included in this study; these were processed in parallel either directly using the MALDI Sepsityper kit or following a short-term culture either in BHI or on Columbia blood agar with 5 % sheep blood (CBA).
RESULTS: Bacterial species were successfully identified in 91.6, 89.2 and 65.4 % of cases after pre-cultivation for 4 h in BHI, on CBA, or by using the MALDI Sepsityper kit, respectively. Overall, the mean incubation time to correct identification was shorter when pre-cultures were performed in BHI; the mean time for Gram-negative rods was 78.2 min in BHI and 108.2 min on CBA (P=0.045), and the mean time for Gram-positive cocci was 128.5 min in BHI and 169.6 min on CBA (P=0.013).
CONCLUSION: Short-term enrichment of BCs in BHI accelerates identification of a number of bacterial species by MALDI-TOF MS. Further prospective studies are needed to validate our method and gauge its potential clinical impact on the management of bloodstream bacterial infections.
PMID: 29134938 [PubMed - as supplied by publisher]