Jae Sung Pyo

Design, synthesis, and biological evaluation of novel 1-oxo-1,2,3,4-tetrahydropyrazino[1,2-a]indole-3-carboxamide analogs in MCF-7 and MDA-MB-468 breast cancer cell lines

A series of novel 1-oxo-1,2,3,4-tetrahydropyrazino[1,2-a]indole-3-carboxamide analogs were designed and synthesized for developing pyrazinoindolone scaffolds as anti-breast cancer agents. Compounds 1h and 1i, having a furan-2-yl-methylamide and benzylamide group, respectively, exhibited more potent cytotoxicity in MDA-MB-468 triple-negative breast cancer (TNBC) cells than compounds possessing aliphatic groups. Compounds 2a and 2b, as (R)-enantiomers of 1h and 1i, also had inhibitory activity against MDA-MB-468 cells. Moreover, analogs (3a-b and 3d-e) bearing a benzyl group at the N-2 position showed more potent activity than gefitinib, as a potent EFGR-TK inhibitor. Especially, compound 3a exhibited selective cytotoxic activity against MDA-MB-468 cells; it also had a synergistic effect in combination with gefitinib against MDA-MB-468 cells. In addition, we confirmed that compounds 3a and 3d inhibit phosphorylation of Akt in MDA-MB-468 cells using western blot analysis. Therefore, these 1-oxo-1,2,3,4-tetrahydropyrazino[1,2-a]indole-3-carboxamide analogs may be helpful for investigating new anti-TNBC agents.

Determination of propofol glucuronide from hair sample by using mixed mode anion exchange cartridge and liquid chromatography tandem mass spectrometry

The main objective of this study was to develop and validate a simpler and less time consuming analytical method for determination of propofol glucuronide from hair sample, by using mixed mode anion exchange cartridge and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The study uses propofol glucuronide, a major metabolite of propofol, as a marker for propofol abuse. The hair sample was digested in sodium hydroxide solution and loaded in mixed-mode anion cartridge for solid phase extraction. Water and ethyl acetate were used as washing solvents to remove interfering substances from the hair sample. Consequently, 2% formic acid in ethyl acetate was employed to elute propofol glucuronide from the sorbent of mixed-mode anion cartridge, and analyzed by LC-MS/MS. The method validation parameters such as selectivity, specificity, LOD, LLOQ, accuracy, precision, recovery, and matrix effect were also tested. The linearity of calibration curves showed good correlation, with correlation coefficient 0.998. The LOD and LLOQ of the propofol glucuronide were 0.2 pg/mg and 0.5 pg/mg, respectively. The intra and inter-day precision and accuracy were acceptable within 15%. The mean values of recovery and matrix effect were in the range of 91.7-98.7% and 87.5-90.3%, respectively, signifying that the sample preparation, washing and extraction procedure were efficient, and there was low significant hair matrix effect for the extraction of propofol glucuronide from hair sample on the mixed mode anion cartridge. To evaluate the suitability of method, the hair of propofol administered rat was successfully analyzed with this method.

Characterization of Apoptosis Induced by Ginsenosides in Human Lung Cancer Cells

ABSTRACT Proteomics is a powerful tool to study molecular pathways and identify protein changes in cells. Anticancer drugs have been used in proteomics to evaluate molecular pathways. Ginsenosides Rg5 and Rk1 are key components of heat-processed ginseng, acknowledged for its anticancer properties causing apoptosis in some cancer cells. In this work, ginsenosides Rg5 and Rk1 were applied to lung cancer cells for the first time, and the proteins differentially affected by these ginsenosides treatment were analyzed. Twenty-five specific proteins from ginsenosides Rg5 and Rk1 treated A549 cells were compared and analyzed. After treatment by ginsenosides Rg5 and Rk1, a calmodulin-like protein, purine nucleoside phosphorylase, and transaldolase increased in concentration. These compounds induce apoptosis by controlling interleukin 2 and glutathione. In addition, after application of ginsenosides Rg5 and Rk1, biliverdin reductase, aldehyde dehydrogenase, dihydropteridine reductase, and transactive response DNA binding protein-43 decreased in concentration. These species have been reported to trigger apoptosis by controlling reactive oxygen species, nitric oxide, and Cl- channel control. The adapter molecule crk protein, which causes apoptosis through a Ras-dependent pathway, and dihydropteridine reductase was decreased to a higher extent in ginsenoside Rg5-treated cells than in ginsenoside Rk1-treated cells. The anticancer activities of ginsenoside Rg5 and Rk1 were evaluated using human lung cancer cells. The results demonstrated that proteomics techniques were effective in distinguishing activities between the ginsenosides.

Selective and Accurate Determination Method of Propofol in Human Plasma by Mixed-Mode Cation Exchange Cartridge and GC-MS

A gas chromatography-mass spectrometry (GC-MS) method for the determination of propofol in human plasma has been developed and validated. Propofol was extracted from human plasma by using mixed-mode cation exchange/reversed-phase (MCX) cartridges. As propofol easily volatilizes during concentration, 100% methanol was injected directly into GC-MS to elute propofol. Despite avoiding concentration process of the eluted solution, lower limit of quantization (LLOQ) of propofol was 25 ng/mL. The validated method exhibited good linearity (R 2 = 0.9989) with accuracy and precision −5.8%~11.7% and 3.7%~11.6%, respectively. The other validation parameters, recovery and matrix effect, ranged from 96.6% to 99.4% and 95.3% to 101.4%, respectively. Propofol standard was quantified to evaluate possible loss due to the concentration processes, nitrogen gas and centrifugal vacuum. These two concentration processes resulted in notable decrease in the quantity of propofol, signifying avoiding any concentration processes during propofol quantification. Also, to confirm suitability of the developed method, authentic human plasma samples were analyzed. The selective assay method using MCX cartridge and GC-MS facilitated quantification of propofol in plasma sample accurately by preventing any losses due to the concentration processes.

Biological Control of Plant Growth Using the Plant Growth-Promoting Rhizobacterium Bacillus mojavensis KJS-3

Biological control using the plant growth-promoting Rhizobacterium (PGPR) has received significant attention in recent years. PGPR has been linked with promoting growth in economically important crops, such as potatoes, tomatoes, and rice. Bacillus mojavensis KJS-3 (Moja-3), isolated from food waste, possesses antifungal properties against Aspergillus terreus, A. fumagatus, A. flavus, and Fusarium redolense, and it may have potential in the development of products for industrial applications. The main purpose of this study was to determine the effects of spraying the PGPR Bacillus mojavensis KJS-3 on the growth of altari radish (leaf number, leaf length, leaf weight, root length, and rhizome length, adjacent portion diameter, and weight) and lettuce (leaf number, length, width, and weight). Three different concentrations of the foliar spray treatment of B. mojavensis KJS-3 were applied to the altari radish and lettuce: the recommended standard concentration of 1×10 9 cfu/g, half the standard concentration of 0.5×10 9 cfu/g, and double the standard concentration of 2×10 9 cfu/g). The B. mojavensis strain foliar spray treatment increased the growth of the leaves and roots of the altari radish and increased the growth of the lettuce leaves. For both plants, the recommended concentration of B. mojavensis KJS-3 produced better growth than half the standard concentration, and the growth was similar with the double dose. This study demonstrates positive effects of Moja-3, suggesting it may be a potential new bio-fertilizer for improving the growth of altari radish and lettuce.

New metabolites of hongdenafil, homosildenafil and hydroxyhomosildenafil

HighlightsThe new metabolites of hongdenafil, homosildenafil, and hydroxyhomosildenafil were determined using LC‐Q TOF‐MS/MS.Biological samples of rats for in vivo study and human liver microsome for in vitro study were determined and compared.Major metabolites were identified at m/z 461.1966 or 439.2455 by piperazine N‐dehydroxyethylation or N‐deethylation.From five to seven metabolites were identified in hongdenafil, homosildenafil and hydroxy homosildenafil treated samples.These new metabolites could be fundamental data for the toxicity study of sildenafil analogues and forensic science fields. ABSTRACT Recently, illegal sildenafil analogues have emerged, causing serious social issues. In spite of the importance of sildenafil analogues, their metabolic profiles or clinical effects have not been reported yet. In this study, new metabolites of illegal sildenafil analogues such as hongdenafil, homosildenafil, and hydroxyhomosildenafil were determined using liquid chromatography quadrupole‐time of flight mass spectrometry (LC‐Q‐TOF‐MS) and tandem mass spectrometry (LC‐Q‐TOF‐MS/MS). To prepare metabolic samples, in vitro and in vivo studies were performed. For in vivo metabolites analysis, urine and feces samples of rats treated with sildenafil analogues were analyzed. For in vitro metabolites analysis, human liver microsomes incubated with sildenafil analogues were extracted and analyzed. All metabolites were characterized by LC‐Q‐TOF‐MS and LC‐Q‐TOF‐MS/MS. As a result, five, six, and seven metabolites were determined in hongdenafil, homosildenafil, and hydroxyhomosildenafil treated samples, respectively. These results could be applied to forensic science and other analytical fields. Moreover, these newly identified metabolites could be used as fundamental data to determine the side effect and toxicity of illegal sildenafil analogues.

PI3Kδ contributes to ER stress-associated asthma through ER-redox disturbances: the involvement of the RIDD–RIG-I–NF-κB axis

Hyperactivation of phosphoinositol 3-kinase (PI3K) has been suggested to be a potential mechanism for endoplasmic reticulum (ER) stress-enhanced airway hyperresponsiveness, and PI3K inhibitors have been examined as asthma therapeutics. However, the regulatory mechanism linking PI3K to ER stress and related pathological signals in asthma have not been defined. To elucidate these pathogenic pathways, we investigated the influence of a selective PI3Kδ inhibitor, IC87114, on airway inflammation in an ovalbumin/lipopolysaccharide (OVA/LPS)-induced asthma model. In OVA/LPS-induced asthmatic mice, the activity of PI3K, downstream phosphorylation of AKT and activation of nuclear factor-κB (NF-κB) were all significantly elevated; these effects were reversed by IC87114. IC87114 treatment also reduced the OVA/LPS-induced ER stress response by enhancing the intra-ER oxidative folding status through suppression of protein disulfide isomerase activity, ER-associated reactive oxygen species (ROS) accumulation and NOX4 activity. Furthermore, inositol-requiring enzyme-1α (IRE1α)-dependent degradation (RIDD) of IRE1α was reduced by IC87114, resulting in a decreased release of proinflammatory cytokines from bronchial epithelial cells. These results suggest that PI3Kδ may induce severe airway inflammation and hyperresponsiveness by activating NF-κB signaling through ER-associated ROS and RIDD–RIG-I activation. The PI3Kδ inhibitor IC87114 is a potential therapeutic agent against neutrophil-dominant asthma.

Proteomic Evaluation of Biomarkers to Determine the Postmortem Interval

ABSTRACT Proteomics separates and analyzes proteins for investigation at the cellular level in regard to disease processing by analyzing the proteins’ expression, function, structure, post-translational modification, and protein–protein interaction. In general forensic investigations, the postmortem interval was evaluated by measuring changes in body temperature after death, along with forensic entomological knowledge. These investigations may be restrictive and subjective because of external factors. The objectives of this study are to sort biomarker candidates and develop a direct postmortem-interval characterization method using proteomics through analyzing and tracking down proteins in the deceased that change in accordance with the postmortem interval. The liver and heart tissues of rats were collected for protein extraction in the 24-h interval following death, and two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis was conducted based on the isoelectric point and the molecular weight for separation. To validate protein spot changes on the gel, the stained electrophoresis gels were scanned and converted to digital images. Through image analysis, 14 liver proteins and 12 heart proteins were sorted and classified into four groups based on pattern changes. These proteins containing spots were extracted from the gel and analyzed by high-performance liquid chromatography with tandem mass spectrometry. Finally, 26 protein postmortem-interval relevant biomarker candidates were identified using software. Some of the proteins were muscle proteins while others were oxidation-related proteins. This study presents a new approach to the postmortem-interval research using proteomics and could be substituted for postmortem-interval evaluation.

Characterization of Carbon Monoxide Fatalities by Metabolomics

ABSTRACT Metabolite profiling of postmortem blood in carbon monoxide poisoning cases was performed with gas chromatography-mass spectrometry based on metabolomics. All data were processed with an automated mass spectral deconvolution and identification system and the metabolites were characterized using the National Institute of Standards and Technology library. Discriminant analysis was performed and the carbon monoxide-induced biomarkers were determined with a variable importance parameter in the projection plot obtained from partial least square discriminant analysis. This metabolomics approach, including global metabolites profiling, is useful in improving the interpretation of metabolism in carbon monoxide poisoning deaths.

Determination of Gamma-Hydroxybutyric Acid in Urine by Solid Phase Extraction and Gas Chromatography—Mass Spectrometry

ABSTRACT Gamma-hydroxybutyric acid has a short half-life in the human body and may be determined at less than 8 h in blood and 12 h in urine. Consequently, the sensitivity of the instrumentation and the extraction procedure for gamma-hydroxybutyric acid from biological samples are important factors in its determination. In this study, solid-phase extraction was compared to the commonly used liquid–liquid extraction with analysis by gas chromatography—mass spectrometry. Solid-phase extraction enhanced the recovery of 0.5, 1.0, 2.5, 5.0, and 10.0 mg/L gamma-hydroxybutyric acid. The recovery for gamma-hydroxybutyric acid by solid-phase extraction was 64.5–70.9% compared to 32.6–47.5% by liquid–liquid extraction. Solid-phase extraction also offered shorter analysis time, smaller sample quantities and solvent volumes, and better separation. Solid phase extraction for gamma-hydroxybutyric acid analysis in urine was fully validated and the results were satisfactory. Both extraction methods were used to analyze urine from an individual that was sexually assaulted. Significant differences were observed in the concentrations of the gamma-hydroxybutyric acid with values of 148.07 and 233.15 µg/mL by liquid–liquid extraction and solid-phase extraction, respectively.