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1.
J Antibiot (Tokyo) ; 74(6): 381-396, 2021 06.
Article in English | MEDLINE | ID: mdl-33504919

ABSTRACT

Spectinomycin, an aminocyclitol antibiotic, is subject to inactivation by aminoglycoside modifying enzymes (AMEs) through adenylylation or phosphorylation of the 6-hydroxy group position. In this study, the effects of deoxygenation of the 2- and 6-hydroxy group positions on the spectinomycin actinamine ring are probed to evaluate their relationship to ribosomal binding and the antimicrobial activities of spectinomycin, semisynthetic aminomethyl spectinomycins (amSPCs), and spectinamides. To generate these analogs, an improved synthesis of 6-deoxyspectinomycin was developed using the Barton deoxygenation reaction. 6-Dehydrospectinamide was also synthesized from spectinamide 4 to evaluate the H-bond acceptor character on the C-6 position. All the synthesized analogs were tested for antibacterial activity against a panel of Gram (+) and Gram (-) pathogens, plus Mycobacterium tuberculosis. The molecular contribution of the 2- and 6-hydroxy group and the aryl functionalities of all analogs were examined by measuring inhibition of ribosomal translation and molecular dynamics experiments with MM/GBSA analysis. The results of this work indicate that the 6-hydroxy group, which is the primary target of AMEs, is a required motif for antimicrobial activity in current analogs. Removal of the 6-hydroxy group could be partially rescued by offsetting ribosomal binding contributions made by the aryl side chains found in the spectinamide and amSPCs. This study builds on the knowledge of the structure-activity relationships of spectinomycin analogs and is being used to aid the design of next-generation spectinomycins.


Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Ribosomes/drug effects , Spectinomycin/chemistry , Anti-Bacterial Agents/chemical synthesis , Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Microbial Sensitivity Tests , Molecular Dynamics Simulation , Mycobacterium tuberculosis/chemistry , Mycobacterium tuberculosis/drug effects , Spectinomycin/analogs & derivatives , Structure-Activity Relationship
2.
Chemosphere ; 261: 127821, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32750621

ABSTRACT

Alkaline-thermal (AT) pretreatment is an economical and efficient pretreatment method to improve anaerobic biodegradability of biowaste. This study investigated the effect of AT pretreatment of spectinomycin mycelial residues (SMRs) for promoting anaerobic biodegradability along with the reduction of antibiotic resistance genes (ARGs), and thus obtained the optimal conditions of AT pretreatment. Biomethane potential (BMP) test was conducted to evaluate the anaerobic biodegradability of untreated and pretreated SMRs, and the fate of ARGs was tracked by quantitative polymerase chain reaction. Results showed that the modified Gompertz model fitted the results of BMP tests satisfactorily. Furthermore, AT pretreatment promoted BMP (B0) and reduced lag phase (λ) effectively. These were attributed to the solubilization of SMRs. The analyses of the changes in dissolved organic matter indicated that AT pretreatment could facilitate the solubilization of both biodegradable (e.g. protein) and recalcitrant matter (e.g. humic-like, analyzing by EEMs-PARAFAC), which had a significant corresponding positive (Person correlation, p < 0.01) and negative (Partial correlation, p < 0.01) influences on anaerobic biodegradability. However, the positive effects surpassed the negative effects, promoting the overall anaerobic biodegradability of SMRs. In addition, a considerable reduction of ARGs (by 0.62-1.36 log units) was observed at pH ≥ 12, attributed to the hydrolysis of phosphodiester bond of DNA in strong alkaline solution. Considering both anaerobic biodegradability and ARGs, the optimal AT condition was concluded as pH 12, temperature 90 °C and time 120 min.


Subject(s)
Biodegradation, Environmental , Drug Resistance, Microbial/genetics , Spectinomycin/chemistry , Anaerobiosis , Anti-Bacterial Agents , Hydrolysis , Methane , Sewage , Temperature
3.
J Antibiot (Tokyo) ; 72(9): 693-701, 2019 09.
Article in English | MEDLINE | ID: mdl-31164713

ABSTRACT

New antibiotics that are active against multi-drug-resistant strains and difficult-to-treat bacterial infections are needed. Synthetic modification of spectinomycin, a bacterial protein synthesis inhibitor, has been shown to increase antibacterial activity compared with spectinomycin. Aminomethyl spectinomycins are active against Gram-negative and Gram-positive bacterial pathogens. In this study, the ability of aminomethyl spectinomycins to treat biothreat pathogens is examined by MIC profiling, synergy testing, and in vivo efficacy experiments. Compound 1950 exhibited potent antibacterial activity against Gram-negative pathogens Brucella spp., Burkholderia mallei, and Francisella tularensis, but showed little to no growth inhibition against Burkholderia pseudomallei, Bacillus anthracis, and Yersinia pestis. Combination testing in checkerboard assays revealed that aminomethyl spectinomycin-antibiotic combinations had mainly an additive effect against the susceptible biodefense pathogens. The in vivo efficacy of compound 1950 was also demonstrated in mice infected with B. mallei (FMH) or F. tularensis (SchuS4). These results suggest that aminomethyl spectinomycins are promising new candidates for development of therapeutics against biodefense bacterial agents.


Subject(s)
Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/pharmacology , Spectinomycin/analogs & derivatives , Spectinomycin/pharmacology , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/therapeutic use , Bacterial Infections/drug therapy , Disease Models, Animal , Drug Interactions , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Mice , Microbial Sensitivity Tests , Molecular Structure , Spectinomycin/chemistry , Spectinomycin/therapeutic use , Treatment Outcome
4.
Article in English | MEDLINE | ID: mdl-30858215

ABSTRACT

The most frequent ailment for which antibiotics are prescribed is otitis media (ear infections), which is most commonly caused by Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae Treatment of otitis media is complicated by the fact that the bacteria in the middle ear typically form biofilms, which can be recalcitrant to antibiotic treatment. Furthermore, bacterial respiratory infections can be greatly exacerbated by viral coinfection, which is particularly evidenced by the synergy between influenza and S. pneumoniae In this study, we sought to ascertain the in vivo efficacy of aminomethyl spectinomycin lead 1950, an effective antibacterial agent both in vitro and in vivo against Streptococcus pneumoniae in the context of complex respiratory infections and acute otitis media. A single dose of 1950 significantly reduced bacterial burden in the respiratory tract for all three pathogens, even when species were present in a coinfection model. Additionally, a single dose of 1950 effectively reduced pneumococcal acute otitis media from the middle ear. The agent 1950 also proved efficacious in the context of influenza-pneumococcal super infection. These data further support the development of this family of compounds as potential therapeutic agents against the common causes of complex upper respiratory tract infections and acute otitis media.


Subject(s)
Respiratory Tract Infections/drug therapy , Spectinomycin/therapeutic use , Animals , Female , Haemophilus influenzae/drug effects , Haemophilus influenzae/pathogenicity , Mice , Mice, Inbred BALB C , Moraxella catarrhalis/drug effects , Moraxella catarrhalis/pathogenicity , Otitis Media/drug therapy , Otitis Media/microbiology , Pneumonia/drug therapy , Pneumonia/microbiology , Spectinomycin/administration & dosage , Spectinomycin/chemistry , Streptococcus pneumoniae/drug effects , Streptococcus pneumoniae/pathogenicity
5.
Chemistry ; 25(35): 8387-8392, 2019 Jun 21.
Article in English | MEDLINE | ID: mdl-30887578

ABSTRACT

A synthetic methodology to access all possible stereoisomers of spectomycin A1 (SMA1) and A2 (SMA2) has been established through late-stage diversification. The key reaction for the construction of all four diastereomers is an intramolecular cyclization based on the umpolung of π-allyl palladium species with bis(pinacolato)diborane (B2 (pin)2 ). Silyl group assisted direct benzylic oxidation of each isomer enabled construction of the fragile ß-hydroxytetralone skeleton to provide the SMAs. The relative and absolute stereochemistry of SMA2 was also determined, and the absolute stereochemistry of SMA1 was extrapolated based on the optical rotation of SMA2. The axial chirality of SMAs is discussed based on circular dichroism spectra and DFT calculations, and it is concluded that the M isomer is predominant in solution. Biochemical assessment of all isomers in vitro revealed that the C9 hydroxyl group and dimeric structure were both important for protein SUMOylation-inhibitory activity.


Subject(s)
Proteins/chemistry , Spectinomycin/chemistry , Streptomyces/chemistry , Catalysis , Coordination Complexes/chemistry , Cyclization , Density Functional Theory , Oxidation-Reduction , Palladium/chemistry , Protein Conformation , Spectinomycin/chemical synthesis , Stereoisomerism , Sumoylation , Thermodynamics
6.
J Chromatogr A ; 1569: 110-117, 2018 Sep 28.
Article in English | MEDLINE | ID: mdl-30033166

ABSTRACT

A method for the simultaneous analysis of veterinary drug residues (spectinomycin, halquinol, and zilpaterol) and contaminants (melamine) in feedingstuffs by liquid chromatography-tandem mass spectrometry was developed. Method performance for all analytes was evaluated by reversed-phase liquid chromatography, reversed-phase with altered chemical equilibrium, and hydrophilic interaction (HILIC) as chromatographic modes. Validation was in accordance to Commission Decision 657/2002/CE, by considering the best chromatographic approach. Ion-pair liquid chromatography with C18 as stationary phase led to the lowest random uncertainties, effective analyte separation and shorter time of analysis. Low precision deviations and good recovery rates were obtained and thus method reliability and sensitivity could be consolidated. Method applicability was evaluated by the analysis of samples of feedingstuffs, such as cattle, pig, and poultry feeds, feed ingredients of both animal and vegetable origins, and mineral feeds. Some samples showed quantifiable concentrations of halquinol and zilpaterol, reinforcing the importance of this new analytical control method.


Subject(s)
Animal Feed/analysis , Chloroquinolinols/analysis , Chromatography, Liquid/methods , Spectinomycin/analysis , Tandem Mass Spectrometry/methods , Triazines/analysis , Trimethylsilyl Compounds/analysis , Animals , Chloroquinolinols/chemistry , Chromatography, Reverse-Phase , Drug Residues/analysis , Hydrophobic and Hydrophilic Interactions , Ions , Reproducibility of Results , Spectinomycin/chemistry , Trimethylsilyl Compounds/chemistry , Uncertainty
7.
Chem Commun (Camb) ; 54(46): 5883-5886, 2018 Jun 05.
Article in English | MEDLINE | ID: mdl-29785422

ABSTRACT

Probing biomolecular motion beyond a single nucleotide is technically challenging but fundamentally significant. We have developed super-resolution force spectroscopy (SURFS) with 0.5 pN force resolution and revealed that the ribosome moves by half a nucleotide upon the formation of the pre-translocation complex, which is beyond the resolution of other techniques.


Subject(s)
Motion , RNA, Messenger/chemistry , Ribosomes/chemistry , DNA Probes/chemistry , Nucleotides/genetics , Oligodeoxyribonucleotides/chemistry , Oligodeoxyribonucleotides/genetics , Protein Conformation , Puromycin/chemistry , RNA, Messenger/genetics , Ribosomes/genetics , Spectinomycin/chemistry , Spectrum Analysis/instrumentation , Spectrum Analysis/methods , Ultrasonic Waves
8.
ACS Infect Dis ; 3(1): 72-88, 2017 01 13.
Article in English | MEDLINE | ID: mdl-28081607

ABSTRACT

Spectinamides are a novel class of antitubercular agents with the potential to treat drug-resistant tuberculosis infections. Their antitubercular activity is derived from both ribosomal affinity and their ability to overcome intrinsic efflux mediated by the Mycobacterium tuberculosis Rv1258c efflux pump. This study explores the structure-activity relationships through analysis of 50 targeted spectinamides. Compounds are evaluated for ribosomal translational inhibition, MIC activity in Rv1258c efflux pump deficient and wild type tuberculosis strains, and efficacy in an acute model of tuberculosis infection. The results of this study show a narrow structure-activity relationship, consistent with a tight ribosome-binding pocket and strict structural requirements to overcome native efflux. Rationalization of ribosomal inhibition data using molecular dynamics simulations showed stable complex formation for halogenated spectinamides consistent with the long post antibiotic effects observed. The lead spectinamides identified in this study demonstrated potent MIC activity against MDR and XDR tuberculosis and had desirable antitubercular class specific features including low protein binding, low microsomal metabolism, no cytotoxicity, and significant reductions in bacterial burdens in the lungs of mice infected with M. tuberculosis. The structure-activity relationships detailed here emphasize the need to examine efflux-mediated resistance in the design of antituberculosis drugs and demonstrate that it is possible to overcome intrinsic efflux with synthetic modification. The ability to understand the structure requirements for this class has produced a variety of new substituted spectinamides, which may provide useful alternative candidates and promote the further development of this class.


Subject(s)
Antitubercular Agents/pharmacology , Ribosomes/drug effects , Spectinomycin/analogs & derivatives , Spectinomycin/pharmacology , Antitubercular Agents/chemistry , Drug Discovery , Models, Molecular , Molecular Structure , Spectinomycin/chemistry , Structure-Activity Relationship
9.
J Antimicrob Chemother ; 72(3): 770-777, 2017 03 01.
Article in English | MEDLINE | ID: mdl-27999020

ABSTRACT

Objectives: New drug regimens employing combinations of existing and experimental antimicrobial agents are needed to shorten treatment of tuberculosis (TB) in humans. The spectinamides are narrow-spectrum semisynthetic analogues of spectinomycin, modified to avoid intrinsic efflux by Mycobacterium tuberculosis . Spectinamides, including lead 1599, have been previously shown to exhibit a promising therapeutic profile in mice as single agents. Here we explore the in vivo activity of lead spectinamides when combined with other agents. Methods: The efficacy of 1599 or 1810 was tested in combination in three increasingly advanced TB mouse models. Mice were infected by aerosol and allowed to establish acute or chronic infection, followed by treatment (≤4 weeks) with the spectinamides alone or in two- and three-drug combination regimens with existing and novel therapeutic agents. Bacteria were enumerated from lungs by plating for cfu. Results: Herein we show the following: (i) 1599 exhibits additive or synergistic activity with most of the first-line agents; (ii) 1599 in combination with rifampicin and pyrazinamide or with bedaquiline and pyrazinamide promotes significantly improved efficacy in the high-dose aerosol model; (iii) 1599 enhances efficacy of rifampicin or pyrazinamide in chronically infected BALB/c mice; and (iv) 1599 is synergistic when administered in combination with rifampicin and pyrazinamide in the C3HeB/FeJ mouse model showing caseous necrotic pulmonary lesions. Conclusions: Spectinamides were effective partner agents for multiple anti-TB agents including bedaquiline, rifampicin and pyrazinamide. None of these in vivo synergistic interactions was predicted from in vitro MIC chequerboard assays. These data support further development of the spectinamides as combination partners with existing and experimental anti-TB agents.


Subject(s)
Antitubercular Agents/therapeutic use , Spectinomycin/chemistry , Spectinomycin/therapeutic use , Tuberculosis/drug therapy , Animals , Disease Models, Animal , Drug Synergism , Drug Therapy, Combination , Lung/drug effects , Lung/microbiology , Mice , Mice, Inbred BALB C , Mycobacterium tuberculosis/drug effects , Pyrazinamide/therapeutic use , Quinolines/therapeutic use , Rifampin/therapeutic use , Tuberculosis/microbiology
10.
J Pharm Biomed Anal ; 112: 8-14, 2015 Aug 10.
Article in English | MEDLINE | ID: mdl-25938473

ABSTRACT

Novel and simple liquid chromatography methods with charged aerosol detection (LC-CAD) for simultaneous quantitation of lincomycin and spectinomycin and its related substances have been developed and tested. This type of analysis is complicated due to the different chromatographic behavior of these two agents and the lack of chromophores in spectinomycin complex. CAD seems to be a promising alternative to overcome these difficulties. It shows a consistent inter-analyte response, independent of chemical structure of an analyte. It also enables the direct quantification of related substances for which no reference standards were available, with good accuracy and precision. Chromatographic separations were achieved using a C18 Hypersil(®) Gold column, with mobile phases consisting of water, acetonitrile and trifluoroacetic acid. All impurities were identified using time-of-flight mass spectrometry with electrospray ionization. The developed methods have been successfully used in the routine quality control analysis of pharmaceutical preparations.


Subject(s)
Aerosols/chemistry , Chromatography, High Pressure Liquid/methods , Lincomycin/analysis , Lincomycin/chemistry , Spectinomycin/analysis , Spectinomycin/chemistry , Acetonitriles/chemistry , Anti-Bacterial Agents/analysis , Anti-Bacterial Agents/chemistry , Drug Contamination , Quality Control , Spectrometry, Mass, Electrospray Ionization/methods , Trifluoroacetic Acid/chemistry , Water/chemistry
11.
Proc Natl Acad Sci U S A ; 111(37): 13325-30, 2014 Sep 16.
Article in English | MEDLINE | ID: mdl-25187561

ABSTRACT

During ribosomal translocation, a process central to the elongation phase of protein synthesis, movement of mRNA and tRNAs requires large-scale rotation of the head domain of the small (30S) subunit of the ribosome. It has generally been accepted that the head rotates by pivoting around the neck helix (h28) of 16S rRNA, its sole covalent connection to the body domain. Surprisingly, we observe that the calculated axis of rotation does not coincide with the neck. Instead, comparative structure analysis across 55 ribosome structures shows that 30S head movement results from flexing at two hinge points lying within conserved elements of 16S rRNA. Hinge 1, although located within the neck, moves by straightening of the kinked helix h28 at the point of contact with the mRNA. Hinge 2 lies within a three-way helix junction that extends to the body through a second, noncovalent connection; its movement results from flexing between helices h34 and h35 in a plane orthogonal to the movement of hinge 1. Concerted movement at these two hinges accounts for the observed magnitudes of head rotation. Our findings also explain the mode of action of spectinomycin, an antibiotic that blocks translocation by binding to hinge 2.


Subject(s)
Models, Molecular , Ribosome Subunits/chemistry , Rotation , Base Sequence , Escherichia coli/metabolism , Molecular Sequence Data , Nucleic Acid Conformation , RNA, Ribosomal, 16S/chemistry , Spectinomycin/chemistry , Spectinomycin/metabolism , Thermus thermophilus/metabolism
12.
Talanta ; 126: 27-37, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24881531

ABSTRACT

The integration of nanotechnology with mass spectrometry for sensitive and selective detection of molecules is a hot/important field of research. Synthesis of graphene (G) coated with mesoporous silica (SiO2, G@SiO2) for mass spectrometric application has been demonstrated. For the first time, we proposed the significant role of surfactant that used during the synthesis of mesorporous silicate (SiO2) in mass spectrometry. It was noticed that G could initiate SiO2 via surfactants which work as initiators for further ionization. The porosity of SiO2 trapped the analytes that was released and ionized with the surfactant fragments. Undoubtedly, strong background interferences were present in the case of organic matrix, which greatly obscured the detection of low molecular weight compounds. G@SiO2 nanocomposite affords several advantages, such as the ability to detect small molecules (<500Da), high sample localization through silica mesoporosity, and high ionization efficiency over than G or conventional matrices. The high performance of G@SiO2 is not only due to the large surface area but also due to high desorption/ionization efficiency of inevitably surfactant (cetyltrimethylammonium chloride, CATB). Unlike the conventional MALDI-MS, the G@SiO2-MS is capable of generating multiply charged polysaccharides. The present method was validated to detect surfactants with low limits of detection.


Subject(s)
Graphite/chemistry , Nanocomposites/chemistry , Silicon Dioxide/chemistry , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Environmental Pollutants/analysis , Environmental Pollutants/chemistry , Gramicidin/analysis , Gramicidin/chemistry , Microscopy, Electron, Transmission , Molecular Structure , Nanocomposites/ultrastructure , Particle Size , Porosity , Reproducibility of Results , Spectinomycin/analysis , Spectinomycin/chemistry , Spectrophotometry, Ultraviolet , Surface-Active Agents/analysis , Surface-Active Agents/chemistry , Tobramycin/analysis , Tobramycin/chemistry , beta-Cyclodextrins/analysis , beta-Cyclodextrins/chemistry
14.
J Antibiot (Tokyo) ; 67(7): 511-8, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24736854

ABSTRACT

Analysis of commercial spectinomycin samples with ion-pairing reversed-phase LC coupled with electrospray ionization tandem MS (LC/ESI-MS/MS) indicates that eight additional compounds are present, including actinamine, (4R)-dihydrospectinomycin, (4S)-dihydrospectinomycin and dihydroxyspectinomycin, as well as four new impurities reported, to our knowledge, for the first time. The structures of these compounds were elucidated by comparing their fragmentation patterns with known structures, and NMR was employed to characterize and distinguish (4R)-dihydrospectinomycin and (4S)-dihydrospectinomycin. Identification of dihydrospectinomycin isomers is necessary because (4R)-dihydrospectinomycin is a minor active pharmaceutical ingredient of spectinomycin, whereas (4S)-dihydrospectinomycin is considered to be an impurity (impurity C) by the European Pharmacopoeia (Ph. Eur.).


Subject(s)
Anti-Bacterial Agents/chemistry , Spectinomycin/chemistry , Chromatography, Liquid/methods , Drug Contamination , Spectrometry, Mass, Electrospray Ionization/methods , Tandem Mass Spectrometry/methods
15.
J Biotechnol ; 174: 57-63, 2014 Mar 20.
Article in English | MEDLINE | ID: mdl-24503209

ABSTRACT

Spectinomycin is an aminoglycoside antibiotic composed of actinamine and actinospectose, which are fused together by a putative glycosyltransferase, SpcG, during spectinomycin biosynthesis. Although previous studies have revealed the involvement of SpcA (myo-inositol monophosphatase), SpcB (dehydrogenase), SpcS2 (aminotransferase), and SpcM (methyltransferase) in the biosynthesis of actinamine, heterologous biosynthesis of spectinomycin via actinospectose has not been clearly elucidated. In this study, Streptomyces venezuelae was utilized as a source of dTDP-actinospectose from the pikromycin biosynthetic desosamine sugar pathway, and a recombinant vector, pSM5, carrying spcA, spcB, spcS2, spcM, and spcG was inserted into S. venezuelae. The formation of dTDP-spectinose was suspected through the use of dehydrogenase in the S. venezuelae chromosome. Herewith, the genetically engineered strain, S. venezuelae SM5, effectively produced up to 89.2mg/L in optimized medium. However, pSM5 in S. venezuelae YJ003, a dTDP-actinospectose-deficient strain, did not produce spectinomycin. This result demonstrates the use of a dTDP-actinospectose precursor produced in the desosamine pathway for heterologous production of spectinomycin in S. venezuelae.


Subject(s)
Anti-Bacterial Agents/biosynthesis , Bioreactors/microbiology , Spectinomycin/biosynthesis , Streptomyces/metabolism , Amino Sugars/metabolism , Anti-Bacterial Agents/chemistry , Genes, Bacterial , Genetic Engineering , Models, Chemical , Multigene Family , Spectinomycin/chemistry , Streptomyces/classification , Streptomyces/genetics
16.
Nat Med ; 20(2): 152-158, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24464186

ABSTRACT

Although the classical antibiotic spectinomycin is a potent bacterial protein synthesis inhibitor, poor antimycobacterial activity limits its clinical application for treating tuberculosis. Using structure-based design, we generated a new semisynthetic series of spectinomycin analogs with selective ribosomal inhibition and excellent narrow-spectrum antitubercular activity. In multiple murine infection models, these spectinamides were well tolerated, significantly reduced lung mycobacterial burden and increased survival. In vitro studies demonstrated a lack of cross resistance with existing tuberculosis therapeutics, activity against multidrug-resistant (MDR) and extensively drug-resistant tuberculosis and an excellent pharmacological profile. Key to their potent antitubercular properties was their structural modification to evade the Rv1258c efflux pump, which is upregulated in MDR strains and is implicated in macrophage-induced drug tolerance. The antitubercular efficacy of spectinamides demonstrates that synthetic modifications to classical antibiotics can overcome the challenge of intrinsic efflux pump-mediated resistance and expands opportunities for target-based tuberculosis drug discovery.


Subject(s)
Amides/pharmacology , Antitubercular Agents/pharmacology , Drug Design , Models, Molecular , Mycobacterium tuberculosis/drug effects , Spectinomycin/pharmacology , Tuberculosis, Multidrug-Resistant/drug therapy , ATP-Binding Cassette Transporters/metabolism , Amides/chemical synthesis , Amides/chemistry , Animals , Antitubercular Agents/chemical synthesis , Antitubercular Agents/chemistry , Bacterial Proteins/metabolism , Drug Resistance, Multiple, Bacterial/drug effects , Mice , Ribosomes/drug effects , Spectinomycin/chemistry , Structure-Activity Relationship
17.
ACS Chem Biol ; 8(12): 2635-42, 2013 Dec 20.
Article in English | MEDLINE | ID: mdl-24143955

ABSTRACT

Conjugation of small ubiquitin-like modifier (SUMO) to protein (SUMOylation) regulates multiple biological systems by changing the functions and fates of a large number of proteins. Consequently, abnormalities in SUMOylation have been linked to multiple diseases, including breast cancer. Using an in situ cell-based screening system, we have identified spectomycin B1 and related natural products as novel SUMOylation inhibitors. Unlike known SUMOylation inhibitors such as ginkgolic acid, spectomycin B1 directly binds to E2 (Ubc9) and selectively blocks the formation of the E2-SUMO intermediate; that is, Ubc9 is the direct target of spectomycin B1. Importantly, either spectomycin B1 treatment or Ubc9 knockdown inhibited estrogen-dependent proliferation of MCF7 human breast-cancer cells. Our findings suggest that Ubc9 inhibitors such as spectomycin B1 have potential as therapeutic agents against hormone-dependent breast cancers.


Subject(s)
Gene Expression Regulation, Neoplastic , Protein Processing, Post-Translational , Spectinomycin/pharmacology , Ubiquitin-Conjugating Enzymes/metabolism , Cell Line, Tumor , Female , High-Throughput Screening Assays , Humans , Kinetics , Protein Binding , Salicylates/chemistry , Salicylates/isolation & purification , Salicylates/pharmacology , Signal Transduction , Spectinomycin/chemistry , Sumoylation , Ubiquitin-Conjugating Enzymes/antagonists & inhibitors , Ubiquitin-Conjugating Enzymes/genetics
18.
Environ Sci Technol ; 46(24): 13539-44, 2012 Dec 18.
Article in English | MEDLINE | ID: mdl-23163404

ABSTRACT

With fast development of industry large quantities of hazardous waste are produced in China. Today, incineration plays an important role in the disposal of hazardous waste. Co-incineration of some types of hazardous wastes with municipal solid waste (MSW) has been suggested in the Proposed Standards for Pollutants for MSW combustors in China, published in 2010. According to this proposal, coincinerated hazardous waste should have similar combustion characteristics with MSW, such as bioferment residue (HW02-276-001-02 in China Hazardous Waste List). In this study, residue from the production of hydrochloride salt spectinomycin, a bioferment process, was studied by thermogravimetric analysis (TGA) coupled with Fourier transform infrared (TG-FTIR) analysis. In TGA, the sample attains its final weight before 800 °C. No gaseous pollutants evolve in large amount during FTIR analysis. During test runs at a MSW incineration plant in Jinhua, Zhejiang Province, bioferment residue was added to MSW at a rate of 24 ton/day and fed to the circulated fluidized bed (CFB) incineration system with capacity of 500 ton/day MSW. The operating parameters and emissions were monitored. The system performance was obviously not affected by addition of bioferment residue to MSW/coal and the pollutant emissions met the Chinese standard, with or without addition of bioferment into feedstock.


Subject(s)
Cities , Fermentation , Incineration , Solid Waste/analysis , Air Pollutants/analysis , Benzofurans/analysis , Carbon/analysis , China , Dibenzofurans, Polychlorinated , Dioxins/analysis , Polychlorinated Dibenzodioxins/analogs & derivatives , Polychlorinated Dibenzodioxins/analysis , Spectinomycin/chemistry , Spectroscopy, Fourier Transform Infrared , Temperature , Thermogravimetry
19.
J Pharm Biomed Anal ; 56(4): 736-42, 2011 Dec 05.
Article in English | MEDLINE | ID: mdl-21839597

ABSTRACT

Liquid chromatography with tandem mass spectrometry (LC/MS/MS) methods for the determination of gentamicin, lincomycin and spectinomycin in the presence of their impurities were developed and tested. Chromatographic separations were achieved using gradient elution on a C18 column. All components were ionized by positive-ion electrospray and detected by multi reaction monitoring (MRM) with an LC-tandem mass spectrometer. Calibration curves were linear with correlation coefficients better than 0.99. The developed method for the determination of gentamicin provides complete base line separation of components C1, C1a, C2, C2a and C2b mentioned in the European and British Pharmacopoeias. The second developed method makes possible a simultaneous analysis of the active compounds of both lincomycin and spectinomycin. Additionally, all impurities defined in the pharmacopoeias for all three active components were determined and their identities confirmed. The methods were tested in routine quality control analysis.


Subject(s)
Drug Contamination , Gentamicins/analysis , Lincomycin/analysis , Spectinomycin/analysis , Tandem Mass Spectrometry/methods , Aminoglycosides/analysis , Aminoglycosides/chemistry , Calibration , Chromatography, Liquid/methods , Gentamicins/chemistry , Humans , Lincomycin/chemistry , Linear Models , Pharmaceutical Preparations/analysis , Pharmaceutical Preparations/chemistry , Reproducibility of Results , Sensitivity and Specificity , Spectinomycin/chemistry
20.
Article in English | MEDLINE | ID: mdl-21240824

ABSTRACT

A new multi-dimensional analytical method using gas chromatography-nitrogen phosphorus detection (GC-NPD) and gas chromatography-mass spectrometry (GC-MS) was developed for qualitative and quantitative measurement of lincomycin and spectinomycin residues in food animal tissues. This method is based on a new extraction procedure using accelerated solvent extraction (ASE). The analytes were extracted by phosphate buffer with trichloroacetic acid deproteinization and clean-up by C18 solid-phase extraction (SPE) adding dodecanesulfonic acid sodium salt as an ion-pair reagent. The eluted fraction was evaporated and derivatised with N,O-bis(trimethylsilyl) trifluoroacetamide (BSTFA) for GC-NPD analysis and GC-MS confirmation. Parameters for extraction pressure, temperature and cycle of ASE, clean-up, derivatisation and analysis procedure were optimised. The method was validated in muscle, kidney and liver of swine, bovine with a low concentration (limit of quantification) of 16.4 and 21.4 µg kg⁻¹ for these two analytes using GC-NPD. For GC-MS, the limits of quantification were 4.1 and 5.6 µg kg⁻¹, respectively. Spiked recoveries from levels of 20 to 200 µg kg⁻¹ were found to be between 73% and 99% with a relative standard deviation (RSD) of less than 17% in GC-NPD. For GC-MS, levels from 5 to 20 µg kg⁻¹ had between 70% and 93% with an RSD of less than 21%. This rapid and reliable method can be used for the characterisation and quantification of residues of lincomycin and spectinomycin in animal tissues.


Subject(s)
Anti-Bacterial Agents/analysis , Drug Residues/analysis , Food Contamination , Lincomycin/analysis , Meat/analysis , Spectinomycin/analysis , Analytic Sample Preparation Methods , Animals , Cattle , Chromatography, Gas , Drug Residues/chemistry , Drug Residues/standards , Gas Chromatography-Mass Spectrometry , Hot Temperature , Kidney/chemistry , Limit of Detection , Lincomycin/chemistry , Liver/chemistry , Muscle, Skeletal/chemistry , Pressure , Reproducibility of Results , Solid Phase Extraction , Spectinomycin/chemistry , Sus scrofa
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