Design, synthesis and biological evaluation of alkynyl-containing maleimide derivatives for the treatment of drug-resistant tuberculosis.

A series of alkynyl-containing maleimides with potent anti-tuberculosis (TB) activity was developed through a rigid group substitution strategy based on our previous study. Systematic optimization of the two side chains flanking the maleimide core led to new compounds with potent activity against Mycobacterium tuberculosis (MIC < 1 µg/mL) and low cytotoxicity (IC50 > 64 µg/mL). Among them, compound 29 not only possessed good activity against extensively drug-resistant TB and favorable hepatocyte stability, but also displayed good intracellular antimycobacterial activity in macrophages. This study lays a good foundation for identifying new alkynyl-containing maleimides as promising leads for treating drug-resistant TB.

Pathogen detection in suspected spinal infection: metagenomic next-generation sequencing versus culture.

PURPOSE: The aim is to compare the pathogen detection performance of metagenomic next-generation sequencing (mNGS) and the culturing of percutaneous needle biopsy samples obtained from an individual with a suspected spinal infection. METHODS: A retrospective study of 141 individuals with a suspected spinal infection was conducted, and mNGS was performed. The microbial spectra and detection performance between mNGS and the culturing-based method were compared, and the effects of antibiotic intervention and biopsy on the detection performance were assessed. RESULTS: The microorganisms isolated most commonly via the culturing-based method were Mycobacterium tuberculosis (n = 21), followed by Staphylococcus epidermidis (n = 13). The most common microorganisms detected via mNGS were Mycobacterium tuberculosis complex (MTBC) (n = 39), followed by Staphylococcus aureus (n = 15). The difference in the type of detected microorganisms between culturing and mNGS was observed only in Mycobacterium (P = 0.001). mNGS helped identify potential pathogens in 80.9% of cases, which was significantly higher than the positivity rate of 59.6% observed for the culturing-based method (P < 0.001). Moreover, mNGS had a sensitivity of 85.7% (95% CI, 78.4% to 91.3%), a specificity of 86.7% (95% CI, 59.5% to 98.3%), and sensitivity gains of 35% (85.7% vs. 50.8%; P < 0.001) during culturing, while no differences were observed in the specificity (86.7% vs. 93.3%; P = 0.543). In addition, antibiotic interventions significantly lowered the positivity rate of the culturing-based method (66.0% vs. 45.5%, P = 0.021) but had no effects on the results of mNGS (82.5% vs. 77.3%, P = 0.467). CONCLUSION: The use of mNGS could result in a higher detection rate compared to that observed with the culturing-based method in an individual with spinal infection and is particularly valuable for evaluating the effects of a mycobacterial infection or previous antibiotic intervention.

A novel nano material for anti-cerebral ischaemia: preparation and application of borneol angelica polysaccharide liposomes.

OBJECTIVE: To investigate the preparation of novel nanoliposomes (Borneol Angelica Polysaccharide Liposomes, BAPL) for anti-cerebral ischaemia and verify its curative effects and mechanism. METHODS: By applying a uniform experiment design to investigate the fitting combination of BAPL. Encapsulation Efficiency Evaluation of BAPL Preparation; Particle Size and Surface Potential Evaluation of BAPL Biological activity; Cerebral ischaemia models of rats Evaluation of BAPL curative effects and mechanism. RESULTS: (1) The fitting combination of lecithin, Cholesterol, AP mass and the borneol mass was 60 mg, 60 mg, 45 mg and 5 mg. the highest encapsulation efficiency was 80.4%, the particle size was 179.1 nm, and the surface zeta potential was -17.2 mV. It conforms to the nano-material standards. (2) The results of animal experiments show that: In the BAPL group, the infarct volume of TTC staining was significantly decreased, and the expression levels of NF-κBp65, TLR-4, IL-8, IL-6, IL-1ß in brain tissue were significantly decreased, while the expression levels of ZO-1, ZO-2, IL-10 were significantly increased after cerebral ischaemia-reperfusion. CONCLUSION: BAPL is a novel nano and effective material for anti-cerebral ischaemia.

An Active-Oxygen-Scavenging Oriented Cathode-Electrolyte-Interphase for Long-Life Lithium-Rich Cathode Materials.

Lithium-rich layered oxides with high energy density are promising cathode materials, thus having attracted a large number of researchers. However, the materials cannot be commercialized for application so far. The crucial problem is the releasing of lattice oxygen at high voltage and resulting consequence, such as decomposition of electrolyte, irreversible phase transition of crystal structure, capacity degradation, and voltage decay. Therefore, capturing active-oxygen and further constructing a cathode-electrolyte-interface (CEI) protective layer via the scavenging effects should be a fundamental step to solve these issues. Herein, ß-carotene with antioxidant properties is used as a scavenging molecule to achieve this goal. The control of active oxygen species effectively alleviates the decomposition of carbonate electrolyte under high voltage. The introduction of ß-carotene additives can also be adjusted in situ to generate a customized CEI film, which is a double-layer structure with external organic components and internal inorganic components. Moreover, the ß-carotene-containing electrolyte system exhibits better thermal stability. Benefited from these, Lithium-rich cathode of ß-carotene-containing electrolyte shows outstanding long-life cycle stability, with 93.4% capacity retention rate after 200 cycles at 1 C; this electrochemical stability is superior to other electrolyte additive systems reported at present.

Discovery of biphenyls bearing thiobarbiturate fragment by structure-based strategy as Mycobacterium tuberculosis protein tyrosine phosphatase B inhibitors.

Mycobacterium tuberculosis protein tyrosine phosphatase B (MptpB) is an important virulence factor that blocks the host immune response and facilitates M. tuberculosis growth in host cells. MptpB inhibitors are potential components of tuberculosis combination treatment. Herein, we present the development of new biphenyls MptpB inhibitors with greatly improved MptpB inhibition based on our reported thiobarbiturate lead 6 by rational design with the structure-based strategy. The eight biphenyls bearing thiobarbiturate fragment target compounds showed more potent MptpB inhibition (IC50: 1.18-14.13 µM) than the lead compound 6. Further molecular docking studies showed that compounds 13, 26, 27 and 28 had multiple interactions with active sites. Among them, compound 13 exhibited dose-dependent increased antituberculosis activity in mouse macrophages. The results displayed that the strategy of modification utilizing biphenyl scaffold was efficient. Our study identifies biphenyls bearing thiobarbiturate fragment as new MptpB inhibitors and verifies the therapeutic potential of antimycobacterial agent targeting MptpB.

[Design and Verification of Human Metabolic Measurement System Based on STM32].

A high-precision human metabolic measurement system is designed. The system uses STM32F103 as the main control chip to acquire oxygen, carbon dioxide and flow signals to calculate four quantitative indicators: oxygen consumption(VO2), carbon dioxide production(VCO2), respiratory entropy(RQ) and resting energy metabolism(REE), and finally uses an upper computer to display the calculation results.In this paper, the signal acquisition circuit design was carried out for the oxygen sensor, carbon dioxide sensor and flow sensor, and the validity of the device was verified with the American machine MGCDiagnositcs using Bland-Altman analysis method, and the results showed that the four parameters of VO2,VCO2, RQ and REE of both devices fell in the agreement interval of more than 95%. The device thus provides accurate metabolic measurements and offers an effective tool for the field of general health and clinical nutrition support in China.

Activity of Clofazimine and TBI-166 against Mycobacterium tuberculosis in Different Administration Intervals in Mouse Tuberculosis Models.

Clofazimine (CLO) and TBI-166 belong to the riminophenazine class of antimicrobial agent. TBI-166 exhibited promising antituberculosis activity in vitro and in animal models and is currently under phase I clinical development for the treatment of tuberculosis in China. To identify an optimal dosing regimen to support further clinical development of TBI-166, the efficacies of CLO and TBI-166 were evaluated in two aerosol infection models utilizing BALB/c and C3HeB/FeJNju mice. TBI-166 and CLO were dosed at 20 mg/kg daily for 2 weeks, followed by QD (once daily), TIW (thrice weekly), and BIW (twice weekly) for an additional 10 weeks at the same dose level. The bactericidal activities of TBI-166 and clofazimine via QD, TIW, and BIW dosing regimens were determined after treatment. Once-daily administration of CLO and TBI-166 appeared to be more efficacious than the two intermittent dosing regimens. Once-daily administration of TBI-166 increased the bactericidal activity by approximately 1 log10 CFU in the lung and spleen compared with TIW or BIW dosing after 12 weeks of treatment, while once-daily administration of CLO increased the bactericidal activity by 1.27 to 1.90 log10 CFU/lung and by 1.61 to 2.22 log10 CFU/spleen in the BALB/c mouse model compared to the intermittent therapies. The differences between QD and TIW and between QD and BIW were significant (P < 0.05). The data suggest that accumulated total doses correlate with the log10 CFU reductions. Therefore, intermittent administration of TBI-166 and CLO should be further evaluated at the same accumulated total doses in preclinical and clinical studies.

In Vitro and In Vivo Activity of Oxazolidinone Candidate OTB-658 against Mycobacterium tuberculosis.

In this work, we assess antituberculosis activity of OTB-658 in vitro and in vivo. In vitro, OTB-658 showed bacteriostatic effectiveness with a lower MIC than linezolid against Mycobacterium tuberculosis. The minimal bactericidal concentrations and time-kill curves for OTB-658 indicated inhibition activity similar to that of linezolid. OTB-658 entered macrophages to inhibit M. tuberculosis growth. OTB-658 had a low mutation frequency (10-8), which would prevent drug-resistant mutations from emerging in combination regimens. In vivo, OTB-658 reduced CFU counts in the lungs and slightly inhibited bacterial growth in the spleen in the early stage and steady state in acute and chronic murine TB models. These results support the preclinical evaluation of OTB-658 and further clinical trials in China.

The optimization and characterization of functionalized sulfonamides derived from sulfaphenazole against Mycobacterium tuberculosis with reduced CYP 2C9 inhibition.

In this study, a series of sulfonamide compounds was designed and synthesized through the systematic optimization of the antibacterial agent sulfaphenazole for the treatment of Mycobacterium tuberculosis (M. tuberculosis). Preliminary results indicate that the 4-aminobenzenesulfonamide moiety plays a key role in maintaining antimycobacterial activity. Compounds 10c, 10d, 10f and 10i through the optimization on phenyl ring at the R2 site on the pyrazole displayed promising antimycobacterial activity paired with low cytotoxicity. In particular, compound 10d displayed good activity (MIC = 5.69 µg/mL) with low inhibition of CYP 2C9 (IC50 > 10 µM), consequently low potential risk of drug-drug interaction. These promising results provide new insight into the combination regimen using sulfonamide as one component for the treatment of M. tuberculosis.

Identifying Regimens Containing TBI-166, a New Drug Candidate against Mycobacterium tuberculosis In Vitro and In Vivo.

TBI-166, derived from riminophenazine analogues, is under development in a phase I clinical trial in China. TBI-166 showed more potent anti-tuberculosis (anti-TB) activity than did clofazimine in in vitro and animal experiments. To identify potent regimens containing TBI-166 in TB chemotherapy, TBI-166 was assessed for pharmacological interactions in vitro and in vivo with several anti-TB drugs, including isoniazid (INH), rifampin (RFP), bedaquiline (BDQ), pretomanid (PMD), linezolid (LZD), and pyrazinamide (PZA). Using an in vitro checkerboard method, we found that TBI-166 did not show antagonism or synergy with the tested drugs. The interaction relationship between TBI-166 and each drug was indifferent. In in vivo experiments, aerosol infection models with BALB/c and C3HeB/FeJNju mice were established, testing drugs were administered either individually or combined in treatments containing TBI-166 and one, two, or three other drugs, and the bactericidal activities were determined after 4- and 8-week therapeutic treatments. In BALB/c mice, five TBI-166-containing regimens-TBI-166+BDQ, TBI-166+PZA, TBI-166+BDQ+LZD, TBI-166+BDQ+PMD, and TBI-166+BDQ+PMD+LZD-showed significantly more potent efficacy after 4 weeks of treatment compared to the control regimen, INH+RFP+PZA. At the end of an 8-week treatment, lung log CFU counts decreased to undetectable levels in mice treated with each of the five regimens. The rank order of the potency of the five regimens was as follows: TBI-166+BDQ+LZD > TBI-166+BDQ > TBI-166+PZA > TBI-166+BDQ+PMD+LZD > TBI-166+BDQ+PMD. In C3HeB/FeJNju mice, TBI-166+BDQ+LZD was also the most effective of the TBI-166-containing regimens. In conclusion, five potent chemotherapy regimens that included TBI-166 were identified. The TBI-166+BDQ+LZD regimen is recommended for further testing in a TBI-166 phase IIb clinical trial.

In Vitro and In Vivo Activities of the Riminophenazine TBI-166 against Mycobacterium tuberculosis.

The riminophenazine agent clofazimine (CFZ) is repurposed as an important component of the new short-course multidrug-resistant tuberculosis regimen and significantly shortens first-line regimen for drug-susceptible tuberculosis in mice. However, CFZ use is hampered by its unwelcome skin discoloration in patients. A new riminophenazine analog, TBI-166, was selected as a potential next-generation antituberculosis riminophenazine following an extensive medicinal chemistry effort. Here, we evaluated the activity of TBI-166 against Mycobacterium tuberculosis and its potential to accumulate and discolor skin. The in vitro activity of TBI-166 against both drug-sensitive and drug-resistant M.tuberculosis is more potent than that of CFZ. Spontaneous mutants resistant to TBI-166 were found at a frequency of 2.3 × 10-7 in wild strains of M. tuberculosis TBI-166 demonstrates activity at least equivalent to that of CFZ against intracellular M. tuberculosis and in low-dose aerosol infection models of acute and chronic murine tuberculosis. Most importantly, TBI-166 causes less skin discoloration than does CFZ despite its higher tissue accumulation. The efficacy of TBI-166, along with its decreased skin pigmentation, warrants further study and potential clinical use.

Docking- and pharmacophore-based virtual screening for the identification of novel Mycobacterium tuberculosis protein tyrosine phosphatase B (MptpB) inhibitor with a thiobarbiturate scaffold.

Mycobacterium tuberculosis (Mtb) protein tyrosine phosphatase B (MptpB) is an important virulence factor for Mtb that contributes to survival of the bacteria in macrophages. The absence of a human ortholog makes MptpB an attractive target for new therapeutics to treat tuberculosis. MptpB inhibitors could be an effective treatment to overcome emerging TB drug resistance. Adopting a structure-based virtual screening strategy, we successfully identified thiobarbiturate-based drug-like MptpB inhibitor 15 with an IC50 of 22.4 µM, and as a non-competitive inhibitor with a Ki of 24.7 µM. Importantly, not only did it exhibit moderate cell membrane permeability, compound 15 also displayed potent inhibition of intracellular TB growth in the macrophage, making it an excellent lead compound for anti-TB drug discovery. To the best of our knowledge, this novel thiobarbiturate is the first class of MptpB inhibitor reported so far that leveraged docking- and pharmacophore-based virtual screening approaches. The results of preliminary structure-activity relationship demonstrated that compound 15 identified herein was not a singleton and may inspire the design of novel selective and drug-like MptpB inhibitors.

An Efficient Synthesis of Aryl-Substituted Pyrroles by the Suzuki⁻Miyaura Coupling Reaction of SEM-Protected Pyrroles.

An efficient arylation of SEM-protected pyrroles by the Suzuki-Miyaura coupling reaction has been developed. The reaction can be carried out under mild conditions to provide aryl-substituted pyrroles in moderate to excellent yields. The scope and limitations of the methodology were evaluated, and the reaction was tolerant of a wide range of functionalities. Compared to the reported methods, the protocol has some advantages, such as commercially available materials, no debrominated by-products being formed, and the amine-protecting group being stable under the reaction conditions. The synthetic utility of the product has also been demonstrated, with several common transformations of the aryl-substituted pyrrole product being conducted. This protocol will offer the opportunity to explore other metal-catalyzed cross-coupling reactions employing SEM-protected pyrroles.

An efficient and concise access to 2-amino-4H-benzothiopyran-4-one derivatives.

A highly efficient and convenient protocol was developed to access 2-amino-4H-benzothiopyran-4-ones through a process of conjugated addition-elimination. The sulfinyl group was proved to be the optimum leaving group by thorough investigations on the elimination of sulfide, sulfinyl, and sulfonyl groups at the 2-position of benzothiopyranone. Most 2-aminobenzothiopyranones were obtained in good to excellent yields under refluxing in isopropanol within 36 h. This method is base-free and the substrate scope in terms of electronic properties of the substituents of the benzothiopyranone is broad. The ten grams scale-up synthesis of the representative compounds 4a and 4d was implemented to show the practical application of this reaction, which afforded the corresponding compounds in good yields and excellent chemical purity without requiring column chromatographical purification.

An efficient and facile access to highly functionalized pyrrole derivatives.

A straightforward and one-pot synthesis of pyrrolo[3,4-c]pyrrole-1,3-diones via Ag(I)-catalyzed 1,3-dipolar cycloaddition of azomethine ylides with N-alkyl maleimide, followed by readily complete oxidation with DDQ, has been successfully developed. Further transformation with alkylamine/sodium alkoxide alcohol solution conveniently afforded novel polysubstituted pyrroles in good to excellent yields. This methodology for highly functionalized pyrroles performed well over a broad scope of substrates. It is conceivable that this efficient construction method for privileged pyrrole scaffolds could deliver more active compounds for medicinal chemistry research.

A study of waste liquid crystal display generation in mainland China.

The generation of liquid crystal display waste is becoming a serious social problem. Predicting liquid crystal display waste status is the foundation for establishing a recycling network; however, the difficulty in predicting liquid crystal display waste quantity lies in data mining. In order to determine the quantity and the distribution of liquid crystal display waste in China, the four top-selling liquid crystal display products (liquid crystal display TVs, desktop PCs, notebook PCs, and mobile phones) were selected as study objects. Then, the extended logistic model and market supply A method was used to predict the quantity of liquid crystal display waste products. Moreover, the distribution of liquid crystal display waste products in different regions was evaluated by examining the consumption levels of household equipment. The results revealed that the quantity of waste liquid crystal displays would increase rapidly in the next decade. In particular, the predicted quantity of waste liquid crystal displays would rise to approximately 4.262 × 10(9) pieces in 2020, and the total display area (i.e. the surface area of liquid crystal display panels) of waste liquid crystal displays would reach 5.539 × 10(7) m(2). The prediction on the display area of waste liquid crystal display TVs showed that it would account for 71.5% of the total display area by 2020. Meanwhile, the quantity of waste mobile phones would significantly grow, increasing 5.8 times from 2012 to 2020. In terms of distribution, Guangdong is the top waste liquid crystal display-generating province in China, followed by Jiangsu, Shandong, Henan, Zhejiang, and Sichuan. Considering its regional characteristics, Guangdong has been proposed to be the most important location of the recycling network.

Ti(IV)-catalyzed cascade synthesis of tetrahydrofuro[3,2-d]oxazole from arene-1,4-diones.

A tetrahydrofuro[3,2-d]oxazole scaffold was synthesized efficiently and stereoselectively. The tandem ionic hydrogenation, ketalization, and intramolecular cyclization of arene-1,4-diones with a combination of TiCl4/Et3SiH give facile access to tetrahydrofuro[3,2-d]oxazole derivatives in good yields at room temperature.

An improved efficient synthesis of the antibacterial agent torezolid.

An improved and efficient method for the preparation of torezolid based on Suzuki cross-coupling reaction as the key step was developed on a gram scale in five steps. The total yield was 44% and the optical purity of torezolid by the improved method was above 99%.

Synthesis and biological evaluation of novel 2-methoxypyridylamino-substituted riminophenazine derivatives as antituberculosis agents.

Clofazimine, a member of the riminophenazine class, is one of the few antibiotics that are still active against multidrug-resistant Mycobacterium tuberculosis (M. tuberculosis). However, the clinical utility of this agent is limited by its undesirable physicochemical properties and skin pigmentation potential. With the goal of maintaining potent antituberculosis activity while improving physicochemical properties and lowering skin pigmentation potential, a series of novel riminophenazine derivatives containing a 2-methoxypyridylamino substituent at the C-2 position of the phenazine nucleus were designed and synthesized. These compounds were evaluated for antituberculosis activity against M. tuberculosis H37Rv and screened for cytotoxicity. Riminophenazines bearing a 3-halogen- or 3,4-dihalogen-substituted phenyl group at the N-5 position exhibited potent antituberculosis activity, with MICs ranging from 0.25~0.01 µg/mL. The 3,4-dihalogen- substituted compounds displayed low cytotoxicity, with IC50 values greater than 64 µg/mL. Among these riminophenazines, compound 15 exhibited equivalent in vivo efficacy against M. tuberculosis infection and reduced skin discoloration potential in an experimental mouse infection model as compared to clofazimine. Compound 15, as compared to clofazimine, also demonstrated improved physicochemical properties and pharmacokinetic profiles with a short half-life and less drug tissue accumulation. This compound is being evaluated as a potential drug candidate for the treatment of multidrug resistant tuberculosis.

Design and synthesis of novel benzimidazole derivatives as anti-tuberculosis agents.

In recent studies some urea derivatives have been identified as potent anti-tuberculosis agents by targeting mycobacterial membrane protein large 3 (MmpL3). However, this compound series as exemplified by AU1235 exhibited poor in vitro pharmacokinetic profile. With AU1235 as the lead, we have identified a novel benzimidazole series as potential anti-tuberculosis agents by using scaffold hopping approach. Among these synthesized compounds, 2-aminobenzimidazole derivative 8b showed the potent anti-tuberculosis activity with the MIC value of 0.03 microg x mL(-1). This compound also showed improved metabolic stability compared to AU1235. Our investigation indicated that benzimidazole derivatives are the promising lead for further optimization as anti-tuberculosis agents.