Comparative Analysis of Polycyclic Aromatic Hydrocarbons and Halogenated Polycyclic Aromatic Hydrocarbons in Different Parts of Perilla frutescens (L.) Britt.

Perilla frutescens (L.) Britt., a medicinal herb and edible plant, is very popular among East Asian countries. The perilla leaves, stems and seeds can be used as traditional medicines and foods. Polycyclic aromatic hydrocarbons (PAHs) and halogenated PAHs (HPAHs) are organic pollutants that are widely present in the environment, such as in water, air and soil, and are harmful to humans. In this study, the contents of 16 PAHs and 4 HPAHs in perilla leaves, stems and seeds were determined by gas chromatography tandem mass spectrometry (GC-MS). A total of 12 PAHs were detected in all samples, and no HPAHs were detected. The total contents of PAHs in perilla leaves, stems and seeds varied from 41.93 to 415.60 ng/g, 7.02 to 51.52 ng/g and 15.24 to 180.00 ng/g, respectively. The statistical analyses showed that there were significant differences in the distribution of PAHs in perilla leaves, stems and seeds. On the basis of the toxic equivalent quantity (TEQ) and incremental lifetime cancer risk (ILCR) model, the cancer risks of the intake of perilla leaves, stems and seeds were assessed to be from 3.30 × 10-8 to 2.11 × 10-5, 5.52 × 10-9 to 5.50 × 10-8 and 1.20 × 10-8 to 1.41 × 10-7, respectively. These were lower than 10-4 (the priority risk level of the EPA) and suggested that there may be almost no cancer risk from the intake of these traditional Chinese medicines (TCMs).

Identification of the New In Vivo Metabolites of Ilaprazole in Rat Plasma after Oral Administration by LC-MS: In Silico Prediction of the H+/K+-ATPase Inhibitor.

Ilaprazole is a proton pump inhibitor used to treat digestive diseases. In this study, blood samples were collected after oral administration of ilaprazole and prepared by liquid-liquid extraction. The metabolites of ilaprazole were detected by liquid chromatography-high-resolution mass spectrometry (LC-HRMS) and LC-MSn. A total of twelve in vivo metabolites were detected in rat plasma and six new metabolites of ilaprazole, including one reductive metabolite with sulfide (M3), two hydroxylated metabolites with sulfoxide (M7 and M8), and three oxidative metabolites with sulfone (M9, M11, and M12), were identified. The possible metabolic pathways of ilaprazole and the fragmentation behaviors of its metabolites were elucidated. The result of the in silico prediction indicates that all the new metabolites showed the potential ability to inhibit H+/K+-ATPase activity.

Thoracic Pedicle Screw Placement Guide Plate Produced by Three-Dimensional (3-D) Laser Printing.

BACKGROUND The aim of this study was to evaluate the accuracy and feasibility of an individualized thoracic pedicle screw placement guide plate produced by 3-D laser printing. MATERIAL AND METHODS Thoracic pedicle samples of 3 adult cadavers were randomly assigned for 3-D CT scans. The 3-D thoracic models were established by using medical Mimics software, and a screw path was designed with scanned data. Then the individualized thoracic pedicle screw placement guide plate models, matched to the backside of thoracic vertebral plates, were produced with a 3-D laser printer. Screws were placed with assistance of a guide plate. Then, the placement was assessed. RESULTS With the data provided by CT scans, 27 individualized guide plates were produced by 3-D printing. There was no significant difference in sex and relevant parameters of left and right sides among individuals (P>0.05). Screws were placed with assistance of guide plates, and all screws were in the correct positions without penetration of pedicles, under direct observation and anatomic evaluation post-operatively. CONCLUSIONS A thoracic pedicle screw placement guide plate can be produced by 3-D printing. With a high accuracy in placement and convenient operation, it provides a new method for accurate placement of thoracic pedicle screws.

Identification of a novel xanthine oxidoreductase inhibitor for hyperuricemia treatment with high efficacy and safety profile.

Hyperuricemia is with growing incidence and of high risk to develop into gout and other metabolic diseases. The key enzyme catalyzing uric acid synthesis, xanthine oxidoreductase (XOR) is a vital target for anti-hyperuricemic drugs, while XOR inhibitors characterized as both potent and safe are currently in urgent need. In this study, a novel small molecule compound, CC15009, was identified as a specific XOR inhibitor. CC15009 exerted strongest in vitro XOR inhibitory activity among current XOR inhibitors. It also showed favorable dose-dependent uric acid-lowering effects in two different XOR substrate-induced hyperuricemic mouse models, which was significantly superior than the current first-line drug, allopurinol. Mechanically, the direct binding of CC15009 against XOR was confirmed by molecular docking and SPR analysis. The inhibition mode was competitive and reversible. Besides, the potential antioxidant activity of CC15009 was indicated by its strong inhibitory activity against the oxidized isoform of XOR, which reduced ROS generation as the byproduct. Regarding the safety concerns of current XOR inhibitors, especially in cardiovascular risks, the safety of CC15009 was comprehensively evaluated. No significant abnormality was observed in the acute, subacute toxicity tests and mini-AMES test. Notably, there was no obvious inhibition of CC15009 against cardiac ion channels, including hERG, Nav1.5, Cav1.2 at the concentration of 30 µM, indicating its lower cardiovascular risk. Taken together, our results supported CC15009 as a candidate of high efficacy and safety profile to treat hyperuricemia through direct XOR inhibition.

Characterization of stress degradation products of bedaquiline fumarate and bedaquiline by LC-PDA and LC-MS.

Bedaquiline fumarate was a first-in-class diarylquinoline drug used for the treatment of M. tuberculosis and its main biologically active form was bedaquiline. This paper studied and compared the degradation products of bedaquiline fumarate and bedaquiline using LC-PDA, LC-MS, and NMR techniques under thermal, alkaline, acidic, oxidative, and photolytic conditions respectively. A LC method was established and optimized to separate all analytes of bedaquiline fumarate and bedaquiline. All degradation products were identified by LC-HRMS/MS and LC-MSn. Bedaquiline fumarate formed three degradation products (DP1, DP2, and DP3) related to fumarate under photolytic condition and formed demethylation product DP4 under acid condition. Bedaquiline formed four degradation products (IM1, IM2, IM3, and IM4) related to the side chains of tertiary alcohol and tertiary amine groups under photolytic condition and formed DP4 under acid condition. The two compounds were stable under thermal, alkaline, and oxidative conditions. DP1 and DP2 indicate that the fumarate could take cis-trans isomerization under light condition. DP3, IM3 and IM4 were first reported degradation products of bedaquiline fumarate and bedaquiline. Compared the degradation behavior of bedaquiline fumarate with bedaquiline, the fumarate form can make the side chain of bedaquiline more stable. It is better to avoid acid and light contact during their storage and manufacturing process.

Characterisation of degradation products of tegoprazan by LC-MS and GC-MS.

Tegoprazan is a novel orally active potassium-competitive acid blocker (P-CAB), capable of binding to the K+ binding site of H+/K+-ATPase in a reversible way to inhibit gastric acid secretion. Tegoprazan has been approved for treating acid-related diseases. In this study, stress testings of tegoprazan were performed under various conditions, including hydrolysis (acidic, alkaline, and neutral), oxidation, photolysis, and thermal stress. Tegoprazan showed instability in acidic, alkaline, and oxidative conditions. Eight degradation products (DPs) were identified. The DPs were characterized by LC-HRMS, LC-MSn, or GC-Q-TOF-MS. Meanwhile, DP-1, DP-2 and DP-3 were successfully synthesized and confirmed by NMR. The degradation pathway of tegoprazan was summarized. To the best of our knowledge, this is the first study on the forced degradation of tegoprazan.

Mechanism of XiJiaQi in the treatment of chronic heart failure: Integrated analysis by pharmacoinformatics, molecular dynamics simulation, and SPR validation.

OBJECTIVE: Chronic heart failure (CHF) is a complicated clinical syndrome with a high mortality rate. XiJiaQi (XJQ) is a traditional Chinese medicine used in the clinical treatment of CHF, but its bioactive components and their modes of action remain unknown. This study was designed to unravel the molecular mechanism of XJQ in the treatment of CHF using multiple computer-assisted and experimental methods. METHODS: Pharmacoinformatics-based methods were used to explore the active components and targets of XJQ in the treatment of CHF. ADMETlab was then utilized to evaluate the pharmacokinetic and toxicological properties of core components. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were to explore the underlying mechanism of XJQ treatment. Molecular docking, surface plasmon resonance (SPR), and molecular dynamics (MD) were employed to evaluate the binding of active components to putative targets. RESULTS: Astragaloside IV, formononetin, kirenol, darutoside, periplocin and periplocymarin were identified as core XJQ-related components, and IL6 and STAT3 were identified as core XJQ targets. ADME/T results indicated that periplocin and periplocymarin may have potential toxicity. GO and KEGG pathway analyses revealed that XJQ mainly intervenes in inflammation, apoptosis, diabetes, and atherosclerosis-related biological pathways. Molecular docking and SPR revealed that formononetin had a high affinity with IL6 and STAT3. Furthermore, MD simulation confirmed that formononetin could firmly bind to the site 2 region of IL6 and the DNA binding domain of STAT3. CONCLUSION: This study provides a mechanistic rationale for the clinical application of XJQ. Modulation of STAT3 and IL-6 by XJQ can impact CHF, further guiding research efforts into the molecular underpinnings of CHF.

Solubility-driven optimization of benzothiopyranone salts leading to a preclinical candidate with improved pharmacokinetic properties and activity against Mycobacterium tuberculosis.

Solubility-driven optimization of the salts of nitro benzothiopyranone 1, which targets DprE1, led to an antimycobacterial preclinical candidate 2. Five pharmaceutically acceptable salts, including the maleate (2), fumarate (3), citrate (4, 5), and l-malate (6) of compound 1, were prepared via the salt formation reaction and evaluated for their physicochemical and pharmacokinetic properties. Compared with 1, all the target salts exhibited greatly increased aqueous solubility and improved oral bioavailability in mice. Maleate salt 2, which displayed higher chemical stability and lower log P, showed substantially improved bioavailability in rats and a much better in vivo effect compared with free base 1 at the same dose. The X-ray crystal structure of 2 revealed that the exposed hydrophilic piperazine-maleate moiety in the crystal structure cell may be critical in increasing the solubility of 2. Thus, this maleate salt 2 overcame the poor druggability of benzothiopyranone derivatives and was identified as a promising preclinical candidate for treating tuberculosis.

Characterization of degradation products of Macozinone by LC-MS/MS and elucidation of their degradation pathway.

Macozinone has high activity against tuberculosis and is a promising candidate compound with a new target DprE1for the treatment of tuberculosis. This study described the degradation behavior of Macozinone. Macozinone was subjected to forced degradation in solid-state and solution-state under oxidative, thermal, hydrolytic (alkaline and acidic) and photolytic conditions. A total of nineteen DPs were detected. When Macozinone in solid-state and solution-state was treated with oxidative degradation condition, seven DPs were detected. Three DPs were found from Macozinone in the solution-state under thermal degradation condition, and five DPs were discovered in the solution-state under alkaline degradation condition. Both the solid-state and solution-state degradation of Macozinone detected two DPs under acidic degradation condition. Macozinone was highly unstable under photolytic degradation condition, as nine DPs in all were found when exposed to strong light in solid-state and solution-state. No obvious DPs were observed under alkaline and thermal degradation conditions from Macozinone in solid-state. All DPs were characterized based on LC-MSn and LC-HRMS/MS techniques. The degradation mechanism and pathway of Macozinone were discussed and summarized. To the best of our knowledge, the DPs of Macozinone were identified for the first time.

Identification of novel benzothiopyranones with ester and amide motifs derived from active metabolite as promising leads against Mycobacterium tuberculosis.

We reported three distinct series of novel benzothiopyranones, derived from an active metabolite (M-1) of anti-TB agent 6b. These small molecules were evaluated for their biological activities against a range of Mycobacterium tuberculosis (M. tuberculosis) strains. Preliminary druggability evaluation demonstrated that M-1 showed good aqueous solubility and hepatocyte stability. Benzothiopyranones with acyl, sulfonyl and phosphoryl groups exhibited potent in vitro inhibitory activity against M. tuberculosis H37Rv and low cytotoxicity. In particular, compound 3d, containing a benzoate fragment, displayed marked metabolic stability and potent in vitro activity against drug-resistant tuberculosis clinical strains. Further druggability evaluation based on the identified compounds 3d, 4e and 5b is ongoing for the discovery of promising anti-TB agents.

Characterization of degradation products and process-related impurity of sutezolid by liquid chromatography/electrospray ionization tandem mass spectrometry.

Sutezolid was a new oxazolidinone compound used for the treatment of M. tuberculosis. This study describes the separation, characterization and in silico toxicity prediction of three degradation products and one process-related impurity of sutezolid. Sutezolid was subjected to forced degradation including hydrolytic (acidic, alkaline and neutral), oxidative, photolytic and thermal conditions according to the ICH guidelines Q1A(R2) and Q3A(R2) and yielded three degradation products. Two degradation products were formed under oxidative condition and one degradation product was formed in hydrolytic condition. This drug substance was found to be stable in thermal and photolytic conditions. The three forced degradation products were identified and characterized based on QTRAP MSn, Q-TOF and NMR techniques. One process-related impurity was found in sutezolid substance and was identified and characterized by QTRAP MSn and Q-TOF. The in silico toxicity prediction of the four impurities were performed using CISOC-PSCT system and CISOC-PSMT system. To the best of our knowledge, the hydrolysis product and the process-related impurity were identified for the first time.

Simultaneous Determination of 15 Sulfonate Ester Impurities in Phentolamine Mesylate, Amlodipine Besylate, and Tosufloxacin Tosylate by LC-APCI-MS/MS.

Sulfonate esters have been recognized as potential genotoxic impurities (PGIs) in pharmaceuticals. An LC-MS/MS method was developed and validated for the simultaneous determination of 15 sulfonate esters, including methyl, ethyl, propyl, isopropyl, and n-butyl esters of methanesulfonate, benzenesulfonate, and p-toluenesulfonate in drug products. The method utilized atmospheric pressure chemical ionization (APCI) in multiple reaction monitoring (MRM) mode for the quantitation of impurities. The method employed an ODS column as the stationary phase and water-acetonitrile as the solvents for gradient elution without derivatization steps. The method was specific, linear, accurate, precise, and robust. Recoveries of the sulfonic esters from three drug matrices were observed in the range of 91.6∼109.0% with an RSD of not greater than 17.9% at the concentration of the LOQ and in the range of 90.4%∼105.2% with an RSD of not greater than 7.1% at the concentration of 50 ng/mL for the methanesulfonates and 10 ng/mL for the benzenesulfonates and p-toluenesulfonates. The LOD was not greater than 15 ng/mL, 2 ng/mL, and 1 ng/mL for the methanesulfonate, benzenesulfonate, and p-toluenesulfonate esters, respectively. This method was sufficiently sensitive to detect the 15 PGIs in the phentolamine mesylate tablet, amlodipine besylate tablet, and tosufloxacin tosylate tablet. This analytical method is a direct, specific, rapid, and accurate quality control tool for the determination of the 15 sulfonate esters that are most likely to exist in drug products.

A Cinchona Alkaloid Antibiotic That Appears To Target ATP Synthase in Streptococcus pneumoniae.

Optochin, a cinchona alkaloid derivative discovered over 100 years ago, possesses highly selective antibacterial activity toward Streptococcus pneumoniae. Pneumococcal disease remains the leading source of bacterial pneumonia and meningitis worldwide. The structure-activity relationships of optochin were examined through modification to both the quinoline and quinuclidine subunits, which led to the identification of analogue 48 with substantially improved activity. Resistance and molecular modeling studies indicate that 48 likely binds to the c-ring of ATP synthase near the conserved glutamate 52 ion-binding site, while mechanistic studies demonstrated that 48 causes cytoplasmic acidification. Initial pharmacokinetic and drug metabolism analyses of optochin and 48 revealed limitations of these quinine analogues, which were rapidly cleared, resulting in poor in vivo exposure through hydroxylation pendants to the quinuclidine and O-dealkylation of the quinoline. Collectively, the results provide a foundation to advance 48 and highlight ATP synthase as a promising target for antibiotic development.