This study presents the enzymatic synthesis of resveratrol-3,4'-O-α-diglucoside (RDG) using a hyperactive O-α-glycoligase (MalA-D416R/Q450S) and α-glucopyranosyl fluoride as the donor substrate. The transglycosylation rate for resveratrol by MalA-D416R/Q450S was maximized in 100 mM Tris-HCl (pH 9.5) containing 20 % DMSO at 45°C.
View Article and Find Full Text PDFMultiple sclerosis (MS) is an immune-mediated neurodegenerative disease of the central nervous system (CNS), which leads to demyelination, axonal loss, and neurodegeneration. Increased oxidative stress and neurodegeneration have been implicated in all stages of MS, making neuroprotective therapeutics a promising strategy for its treatment. We previously have reported vinyl sulfones with antioxidative and anti-inflammatory properties that activate nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor that induces the expression of cytoprotective genes against oxidative stress.
View Article and Find Full Text PDFThis study represents a visual detection for total biogenic monoamines with naked eye as a simple and rapid semi-quantitative method for biogenic amine monitoring. The equivalent reaction of HO with ascorbic acid resulted in color development by an amine oxidase-peroxidase coupling reaction in the samples containing the biogenic monoamines higher than the subjected ascorbic acid by 10 μM. Upon employing the commercial doenjang extracts as a model food, an additional heating step was requested, and the expected ranges for the biogenic monoamines from 360 to 480 μM covered the real contents of the samples (360.
View Article and Find Full Text PDFGenistein is one of isoflavones, showing various biological functions for human health. MalA-D416A, termed O-α-glycoligase, is an acid/base catalytic residue-deficient mutant of a α-glucosidase from Sulfolobus solfataricus, synthesizing genistein 7-O-α-glucoside using α-glucosyl fluoride as the donor substrate. Through mutagenesis toward MalA-D416A, an O-α-glycoligase variant with two mutations (D416R and Q450S) was identified as a biocatalyst with a 58.
View Article and Find Full Text PDFBecause of the wide use of Fingolimod for the treatment of multiple sclerosis (MS) and its cardiovascular side effects such as bradycardia, second-generation sphingosine 1-phosphate receptor 1 (S1P1) agonist drugs for MS have been developed and approved by FDA. The issue of bradycardia is still present with the new drugs, however, which necessitates further exploration of S1P1 agonists with improved safety profiles for next-generation MS drugs. Herein, we report a tetrahydroisoquinoline or a benzo[]azepine core-based S1P1 agonists such as and after systematic examination of hydrophilic groups and cores.
View Article and Find Full Text PDFA family of bacterial copper storage proteins (the Csps) possess thiolate-lined four-helix bundles whose cores can be filled with Cu(I) ions. The majority of Csps are cytosolic (Csp3s), and in vitro studies carried out to date indicate that the Csp3s from OB3b (Csp3), (Csp3), and (Csp3) are alike. Bioinformatics have highlighted homologues with potentially different Cu(I)-binding properties from these characterized "classical" Csp3s.
View Article and Find Full Text PDFPtaquiloside, a naturally occurring cancer-causing substance in bracken fern, has been detected in the meat and milk of cows fed a diet containing bracken fern. A rapid and sensitive method for the quantitative analysis of ptaquiloside in bracken fern, meat, and dairy products was developed using the QuEChERS method and liquid chromatography-tandem mass spectrometry. The method was validated according to the Association of Official Analytical Chemists guidelines and met the criteria.
View Article and Find Full Text PDFPhenols are significant environmental endocrine disruptors that can have adverse health effects on exposed individuals. Correlating phenol exposure to potential health implications requires the development of a comprehensive and sensitive analytical method capable of analyzing multiple phenols in a single sample preparation and analytical run. Currently, no such method is available for multiple classes of phenols due to electrospray ionization (ESI) limitations in concurrent ionization and lack of sensitivity to certain phenols, particularly alkylphenols.
View Article and Find Full Text PDFA family of cytosolic copper (Cu) storage proteins (the Csps) bind large quantities of Cu(I) via their Cys-lined four-helix bundles, and the majority are cytosolic (Csp3s). The presence of Csp3s in many bacteria appears inconsistent with the current dogma that bacteria, unlike eukaryotes, have evolved not to maintain intracellular pools of Cu due to its potential toxicity. Sporulation in has been used to investigate if a Csp3 binds Cu(I) in the cytosol for a target enzyme.
View Article and Find Full Text PDFEnvironmental pollutants (EPOLs), such as phthalates, volatile organic compounds, phenols, parabens, polycyclic aromatic hydrocarbons, pyrethroids, and environmental tobacco smoke, are highly heterogeneous compounds. Recently, attention has been drawn to the assessment of the combinatory effects of multiple EPs. To correlate multiple exposures with potential health implications, advanced comprehensive analytical methods covering multiclass EPOLs are essential.
View Article and Find Full Text PDFThe sphingosine-1-phosphate-1 (S1P) receptor agonists have great potential for the treatment of multiple sclerosis (MS) because they can inhibit lymphocyte egress through receptor internalization. We designed and synthesized triazole and isoxazoline derivatives to discover a novel S1P agonist for MS treatment. Of the two scaffolds, the isoxazoline derivative was determined to have excellent efficacy and drug-like properties.
View Article and Find Full Text PDFUnlabelled: Biogenic amines (BAs) produced by the action of bacterial amino acid decarboxylases in fermented foods cause various health problems in human. Despite the importance, detailed characterizations of the BA-producing decarboxylases are relatively less progressed than the studies on BA-producing bacteria, due to the time-consuming chromatography-based assay method. In this study, a simple and general colorimetric assay for aromatic amino acid decarboxylases coupled with an amine oxidase from (AMAO) and horseradish peroxidase was developed using a tyrosine decarboxylase from DSM20477 (EfmTDC) as a model enzyme.
View Article and Find Full Text PDFUnlabelled: S0904 was selected as a hyperproducer of a glutamine-hydrolyzing enzyme which was identified as a γ-glutamyltranspeptidase catalyzing both hydrolysis and transpeptidation of glutamyl substrates. The signal peptide-truncated recombinant enzyme (rBAGGT) showed two-fold enhanced specific activity for hydrolysis and optimum pH shift to pH 7 from pH 6 compared with the wild type. The hydrolysis activity of rBAGGT was tolerant against NaCl up to 2.
View Article and Find Full Text PDFThe misuse of propofol for recreational purposes has become a serious social issue. Accordingly, practical and sensitive analytical methods to investigate the chronic abuse and toxicity of propofol are required. However, current propofol determination methods using liquid chromatography-mass spectrometry (LC-MS/MS) suffer from problems associated with loss in sample preparation due to its volatility and its poor ionization efficiency and collision-induced dissociation in mass spectrometry.
View Article and Find Full Text PDFRetaining glycosidase mutants lacking its general acid/base catalytic residue are originally termed thioglycoligases which synthesize thio-linked disaccharides using sugar acceptor bearing a nucleophilic thiol group. A few thioglycoligases derived from retaining α-glycosidases have been classified into a new class of catalysts, O-glycoligases which transfer sugar moiety to a hydroxy group of sugar acceptors, resulting in the formation of O-linked glycosides or oligosaccharides. In this study, an efficient O-α-glucosylation of flavonoids was developed using an O-α-glycoligase derived from a thermostable α-glucosidase from Sulfolobus solfataricus (MalA-D416A).
View Article and Find Full Text PDFSensory discrimination is essential for survival. However, how sensory information is finely controlled in the brain is not well defined. Here, we show that astrocytes control tactile acuity via tonic inhibition in the thalamus.
View Article and Find Full Text PDFHydrocoptisonine is a new compound that has been isolated from the rhizomes of , which belongs to the Ranunculaceae family of Chinese medicines. Although studies on have been reported, the metabolic pathway of hydrocoptisonine in human liver microsomes (HLMs) remains unelucidated. We identified 13 metabolites in HLMs, including six Phase I metabolites and seven glucuronide conjugates, using a high-resolution quadrupole-orbitrap mass spectrometer.
View Article and Find Full Text PDFAmiodarone is known to induce hepatic injury in some recipients. We applied an untargeted metabolomics approach to identify endogenous metabolites with potential as biomarkers for amiodarone-induced liver injury. Oral amiodarone administration for 1 week in rats resulted in significant elevation of acylcarnitines and phospholipids in the liver.
View Article and Find Full Text PDFParkinson's disease (PD) is a neurodegenerative disorder characterized by abnormal movement, including slowed movements, shuffling gait, lack of balance, and tremor. Oxidative stress has been shown to play a decisive role in dopaminergic neuronal cell death in PD. The nuclear factor E2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) signaling pathway provides the main defense system against oxidative stress by inducing the expression of antioxidant enzyme genes.
View Article and Find Full Text PDFThe application of dried blood spots in clinical research is becoming increasingly popular owing to its convenient collection, storage, and transportation compared to that of conventional biological samples. The potential of trimethylamine N-oxide and its related compounds as biomarkers for various cardiovascular diseases, such as atherosclerosis, stroke, thrombosis, and heart failure, was recently highlighted, which was the driving force behind the development of an analytical method to identify trimethylamine N-oxide and eight related compounds in dried blood spots. In the proposed method, a novel "on-spot reaction" approach was introduced to overcome the low loading efficiency of trimethylamine in dried blood spots.
View Article and Find Full Text PDFPhthalates are commonly used as plasticizers and are known as risk factors toward several conditions such as cancer, birth defects, and endocrine disruption. Biomonitoring of phthalates is necessary to assess the potentially harmful effects of long-term exposure. In this work, we have developed a novel QuEChERS method to determine eight phthalate metabolites-mono-(3-carboxypropyl) phthalate, mono-(2-ethyl-5-carboxypentyl) phthalate, mono-(2-ethyl-5-hydroxyhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, mono-n-butyl phthalate, mono-benzyl phthalate, mono-(carboxyloctyl) phthalate, and mono-(carboxynonyl) phthalate-in human milk.
View Article and Find Full Text PDFhas a well-characterized copper (Cu) transporting ATPase (CopA) that removes this potentially toxic metal ion from the cytosol. Growth of the strain lacking CopA (Δ) is inhibited above 0.5 mM Cu, whilst a similar effect does not occur in wild type (WT) until over 2.
View Article and Find Full Text PDF1. Glycyrol is a coumestan derivative that is isolated from roots of . Glycyrol exhibits several biological effects, including anti-oxidative and anti-inflammatory effects.
View Article and Find Full Text PDFWe previously developed a novel series of vinyl sulfones as nuclear factor erythroid 2-related factor 2 (Nrf2) activators with therapeutic potential for Parkinson's disease (PD). However, the previously developed lead compound (1) exhibited undesirable druglike properties. Here, we optimized vinyl sulfones by introducing nitrogen heterocycles to improve druglike properties.
View Article and Find Full Text PDF