Characterization, multivariate analysis and bioactivity evaluation of coumarins in the bark of Fraxinus mandshurica.

The bark of Fraxinus mandshurica is a traditional folk herb used to clear heat and dry dampness. To investigate the differences in coumarins content in the bark of F. mandshurica, 24 batches of samples from four origins were collected and analyzed. Eight coumarins were obtained by traditional natural product extraction, isolation and identification techniques and quantified by high performance liquid chromatography-photodiode array (HPLC-DAD). The quantitative results showed that the overall content of compound 30 (Fraxinol) was higher at 100.23 mg/g, while the overall content of compound 23 (Cichoriin) was lower, which may be related to environmental factors in different regions. The method validation showed that the linear range of the eight standards was between 10 and 2500 µg/mL with correlation coefficient (R2) values >0.9991; the relative standard deviation (RSD, %) values of intra-day precision were between 0.35 and 1.38, while the RSD values of inter-day precision were between 0. 29-1.78; the RSD (%) values for the reproducibility experiments ranged from 0.29 to 1.87, while the RSD (%) values for the stability experiments ranged from 0.22 to 2.33; the spiked recovery of the samples ranged from 98.65 to 101.34%, and the RSD (%) values ranged from 0.22 to 1.96. The method validation results showed that the instrument used for the analysis had good precision, the reproducibility and stability of the samples were good, and the accuracy of the experimental method was high. In addition, a total of 54 chemical components were identified from F. mandshurica bark by ultra performance liquid chromatography-electrospray quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS). Based on this, fingerprinting, heatmap and multivariate analysis, including principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA), were established for 24 batches of samples, and four marker compounds that could be used to distinguish different origins of F. mandshurica were screened. To further investigate the bioactivities of the eight coumarins, in vitro enzyme activity inhibition studies were performed, and the results showed that they all exhibited different degrees of inhibition of acetylcholinesterase, tyrosinase and α-glucosidase, thus having potential applications in the treatment of Alzheimer's disease, blemish whitening and anti-diabetes, and becoming a new source of natural enzyme activity inhibitors. This study established an identification and evaluation method applicable to plants of different origins, which provides a strong reference for quality control, origin evaluation and clinical application of traditional medicinal plants.

Electrical-mechanical dynamical coupling between electrocardiographic and photoplethysmographic signals during cardiopulmonary resuscitation.

BACKGROUND AND OBJECTIVE: Cardiac arrest (CA) remains a significant cause of death and disability. High-quality cardiopulmonary resuscitation (CPR) can improve the survival rate of CA. A challenging issue is to find physiological indicators for screening and evaluating the cardiovascular function associated with CPR. This study aimed to investigate the electrical-mechanical dynamic coupling between electrocardiographic (ECG) and photoplethysmographic (PPG) signals for indicating cardiovascular function in the progress of CPR. METHOD: The ECG and PPG signals were simultaneously collected from a porcine CA model (n = 10) induced by ventricular fibrillation, and were further divided into four periods: Baseline, CA, CPR, and recovery of spontaneous circulation (ROSC). Recurrence quantitative analysis (RQA) was applied to examine the nonlinear dynamics of the ECG and PPG signals individually, and cross recurrence quantitative analysis (CRQA) was used to examine the ECG-PPG dynamical coupling. RESULTS: The CA influenced the dynamic patterns of electrical and mechanical activities and the electrical-mechanical coupling, which can be observed from the reduced entropy (ENTR) (p < 0.01), reduced determinism (DET) (p < 0.01) and reduced trapping time (TT) (p < 0.01) at CA compared to Baseline. The recurrence rate (RR), ENTR, DET, and TT at CPR were significantly lower than the parameters at ROSC but higher than those at CA. CONCLUSIONS: The electrical-mechanical dynamical coupling was sensitive to CPR and able to reflect the changes in cardiac function in the process of CPR.

A comprehensive analysis of the chemical composition of Fraxinus mandshurica roots based on HPLC-DAD-MS, GC-MS and UPLC-ESI-Q-TOF-MS.

Fraxinus mandshurica is widely distributed around the world, which has significant economic value and pharmacological effects. However, its roots are often overlooked during processing and use. In this study, the preliminary identification of chemical components in F. mandshurica roots was carried out using ultra-performance liquid chromatography coupled with electrospray quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS), and a total of 37 characteristic components were identified, including 13 secoiridoids, 7 lignans, 6 coumarins, 4 flavonoids, 4 phenylethanols, 1 terpenoid and 2 other compounds. Meanwhile, to evaluate the 6 lignans content of F. mandshurica roots, the identification, quantitation analysis and methodological validation were performed by high-performance liquid chromatography with diode array detection mass spectrometry (HPLC-DAD-MS), which showed that the concentration range of standard compounds was 0.5-1000 µg/mL. The standard curve correlation coefficients (R2) were all greater than 0.9991, indicating that the linearity of the fitted curves was good. The highest lignan content in F. mandshurica roots was olivil (461.11 µg/g) and the lowest in buddlenol E (11.14 µg/g), and the total lignan content was 764.63 µg/g. The relative standard deviations (RSD, %) of both intra-day and inter-day precision were less than 1.95%. The RSD (%) of the reproducibility and stability experiments was less than 2.91%. The spiked recoveries of the samples were in the range of 98.29-102.62%, and the RSD (%) was in the range of 0.43-1.73, indicating that the method has high accuracy. In addition, a total of 20 volatile components in F. mandshurica roots were identified and quantified by gas chromatography-mass spectrometer (GC-MS) in this study, which laid a solid foundation for the comprehensive development and utilization of F. mandshurica resources.

Monitoring diacylglycerols in biofluids by non-isotopically paired charge derivatization combined with LC-MS/MS.

Diacylglycerols (DAGs) are important lipid mediators in cellular signaling transduction and metabolism. Imbalanced production or consumption of DAGs has a negative impact on the physiological functions of the body. However, comprehensive monitoring of structurally diverse DAGs remains a daunting task due to the rapid metabolism and ion suppression characteristics in biofluids. These bottlenecks call for developing a method that enables sensitive quantification of DAGs in biological sample. In this work, a straightforward charge derivatization strategy was developed to insert a series of structure analogs charge label, i.e., N, N-dimethylglycine (DMG) and N, N-dimethylalanine (DMA), on the free hydroxyl group of the DAGs. Owing to the existence of tertiary amino groups in charge label, the mass spectrometry ionization response of the derivatized DAGs was significantly increased in comparison with traditional metal ion adducts. After charge derivatization, the specific neutral loss diagnostic ions (DMG, 103 Da and DMA, 117 Da) were captured by mass spectrometry. Then, the DMG/DMA-oriented paired multiple reaction monitoring methods based on the characteristic diagnostic ions of the derivatized DAGs have been developed as sensitive methods for the detection (detection limit = 16 aM) and quantification (quantification limit = 62.5 aM) of DAGs in serum. Moreover, the tagged 1,2-DAGs and 1,3-DAGs sn-isomers have been well separated on the reversed-phase column in combination with ultra-performance liquid chromatography. Finally, metabolic characterizations of the tagged DAGs were further explored in L-Arginine-induced acute pancreatitis mice and resveratrol treated model mice. The results indicated that 1,2-DAGs were increased in the serum of model mice relative to normal controls and resveratrol significantly altered this metabolic abnormality. The currently established DMG/DMA-oriented paired charge derivatization strategy is promising for depicting DAGs changes more accurately in metabolic studies of lipid-related diseases and accurately evaluating drug treatment strategies.

Correlation between right atrial volume and function and liver function grading in patients with hepatitis B cirrhosis by four-dimensional ultrasound automatic quantitation analysis / 中华超声影像学杂志

Objective:To evaluate right atrial (RA) volume and function in patients with hepatitis B cirrhosis by four-dimensional automatic quantitation analysis technique, and to explore its correlation with liver function grading.Methods:Ninety patients with hepatitis B cirrhosis who were clinically confirmed in Henan Provincial People′s Hospital from December 2020 to July 2021 were randomly enrolled as the research subjects. According to Child-Pugh liver function score criteria, the patients were divided into three groups: Child-Pugh A group ( n=31), Child-Pugh B group ( n=31), Child-Pugh C group ( n=28). Another 30 healthy volunteers with gender and age matched at the same period were selected as the control group. The RA maximum volume (RAVmax), RA minimum volume (RAVmin), RA presystolic volume (RAVpreA), RA maximum volume index (RAVImax), RA emptying volume (RAEV), RA ejection fraction (RAEF), RA reservoir longitudinal and circumferential strains (RASr, RASr-c), RA conduit longitudinal and circumferential strains (RAScd, RAScd-c), RA contraction longitudinal and circumferential strains (RASct, RASct-c) were obtained by four-dimensional automatic quantitation analysis technique. Spearman correlation analysis was used to explore the correlation between the volume and strain parameters of right atrium and liver function grading, and the independent correlation factors of RASr-c were analyzed by univariate and multivariate linear regression analyses. Results:Compared with the control group, Child-Pugh A and Child-Pugh B groups, RAVmax, RAVmin, RAVpreA, RAVImax, and RAEV were all increased in Child-Pugh C group (all P<0.05). Compared with control group, the absolute values of RASr, RASct, RASr-c and RASct-c were increased, and the absolute values of RAScd and RAScd-c were decreased in Child-Pugh A group (all P<0.05). Compared with control group, Child-Pugh A and Child-Pugh B groups, the absolute values of RASr, RAScd, RASct, RASr-c, RAScd-c and RASct-c were decreased in the Child-Pugh C group (all P<0.05). Correlation analysis showed that the volume and strain parameters of the right atrium were correlated with liver function grading. RASr-c was independently correlated with E/e, ALB and BNP(β=-0.543, 0.521, and -0.562 respectively, all P<0.05). Conclusions:During the compensatory stage in patients with hepatitis B cirrhosis, the RA functions of reservoir and contractile were increased, but the function of conduit was decreased. With the aggravation of liver cirrhosis, the RA functions of reservoir, conduit and contractile were all decreased. The four-dimensional volume and strain parameters of the right atrium were correlated with Child-Pugh liver function grading, and RASr-c was independently correlated with E/e, ALB and BNP.

iTRAQ-based quantitative proteomic analysis and bioinformatics study of proteins in retinoblastoma.

The aim of the present study was to analyze proteins in the aqueous humor (AH) of patients' retinoblastoma (RB), and investigate their potential role in RB using the comparative proteomic technique of isobaric tags for relative and absolute quantitation (iTRAQ) coupled with offline two-dimensional liquid chromatography-tandem mass spectrometry. A total of 0.1 ml AH was collected from 10 children with RB (mean age, 3.8 years; range, 2-5 years) and patients with senile cataracts (mean age, 70.4 years; range, 65-79 years), which was used as the control. iTRAQ was used to analyze proteins in the AH of patients and controls. Proteins with a fold change of >1.20 or <0.83 were considered to be significantly differentially expressed (with corrected P<0.05). The identified proteins were subjected to subsequent gene ontology (GO) analysis using the DAVID database. A total of 83 proteins that were expressed differently between the controls and patients' AH samples were identified using iTRAQ analysis. Of these proteins, 44 were upregulated and 39 were downregulated. On the basis of biological processes in GO, the identified proteins were primarily involved in glycoprotein, amyloid acute-inflammatory and defensive responses. Among these proteins, pigment epithelium-derived factor serves a potential role in the treatment of RB, and stimulated by retinoic acid 6 may serve as a potential protein involved in RB development. To the best of our knowledge, the present study is the first to identify 83 proteins associated with RB using iTRAQ technology. The results of the present study will aid in furthering the understanding of RB and developing novel therapy targets in the future.