scholarly journals Synthesis, Characterization, and Bioactivity of Schiff Bases and TheirCd2+,Zn2+,Cu2+, andNi2+Complexes Derived from Chloroacetophenone Isomers with S-Benzyldithiocarbazate and the X-Ray Crystal Structure of S-Benzyl-β-N-(4-chlorophenyl)methylenedithiocarbazate

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Mohammed Khaled bin Break ◽  
M. Ibrahim M. Tahir ◽  
Karen A. Crouse ◽  
Teng-Jin Khoo
Keyword(s):  
Crystal Structure ◽  
Phenyl Ring ◽  
Crystallographic Analysis ◽  
Gram Negative Bacteria ◽  
Schiff Base Ligands ◽  
Gram Negative ◽  
X Ray ◽  
X Ray Crystallography ◽  
Gram Positive Bacteria ◽  
Antimicrobial Assay

Two bidentate Schiff base ligands having nitrogen sulphur donor sequence were derived from the condensation of S-benzyldithiocarbazate (SBDTC) with 2-chloroacetophenone and 4-chloroacetophenone to give S-benzyl-β-N-(2-chlorophenyl)methylenedithiocarbazate (NS2) and S-benzyl-β-N-(4-chlorophenyl)methylenedithiocarbazate (NS4) isomers. Each of the ligands was then chelated with Cd2+, Zn2+, Cu2+, and Ni2+. The compounds were characterized via IR spectroscopy and melting point while the structure of NS4 was revealed via X-ray crystallography. Finally, the compounds were screened for antimicrobial activity to investigate the effect that is brought by the introduction of the chlorine atom to the benzene ring. X-ray crystallographic analysis showed that the structure of NS4 is planar with a phenyl ring that is nearly perpendicular to the rest of the molecules. The qualitative antimicrobial assay results showed that NS4 and its complexes lacked antifungal activity while Gram-positive bacteria were generally inhibited more strongly than Gram-negative bacteria. Furthermore, NS4 metal complexes were inhibited more strongly than the ligand while the opposite was seen with NS2 ligand and its complexes due to the partial solubility in dimethyl sulfoxide (DMSO). It was concluded that generally NS2 derivatives have higher bioactivity than that of NS4 derivatives and that the Cd complexes of both ligands have pronounced activity specifically onK. rhizophila.

ANTIMICROBIAL ACTIVITY OF COPPER KAOLINITE AND SURFACTANT MODIFIED COPPER KAOLINITE AGAINST GRAM POSITIVE AND GRAM NEGATIVE BACTERIA

2016 ◽  
Vol 78 (3-2) ◽  
Author(s):  
Nor Syafawani Sarah Md Saad ◽  
Nik Ahmad Nizam Nik Malek ◽  
Chun Shiong Chong
Keyword(s):  
Antimicrobial Activity ◽  
Synergistic Effects ◽  
Wide Spectrum ◽  
Copper Nitrate ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
X Ray ◽  
Gram Positive Bacteria ◽  
Diffusion Technique

The aim of this research was to determine the antimicrobial activity of kaolinite modified with antimicrobial compounds against Gram positive and Gram negative bacteria. Copper kaolinite (Cu-kaolinite) was prepared by loading raw kaolinite with copper nitrate trihydrate (CuNO3) while surfactant modified Cu-kaolinite (SM-Cu-kaolinite) was prepared by adding cationic surfactants hexadecyltrimethyl ammonium (HDTMA) on Cu-Kaolinite. Samples was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analyzer. The antimicrobial activity of the samples was tested against Gram negative bacteria (Escherichia coli ATCC 11229 and Pseudomonas aeruginosa ATCC 15442), and Gram positive bacteria (Staphylococcus aureus ATCC 6538 and Enterococcus faecalis ATCC 29212) through disc diffusion technique (DDT) and minimum inhibition concentration (MIC). The results showed that the antimicrobial activity of Cu-kaolinite increased after modified with HDTMA due to the synergistic effects of Cu ions and HDTMA molecules on the kaolinite. The antimicrobial activity for surfactant modified Cu-kaolinite was greater for Gram positive bacteria compared to Gram negative bacteria. In conclusion, the attachment of HDTMA on Cu-kaolinite contributed to the enhanced antimicrobial activity against wide spectrum of bacteria (Gram positive and Gram negative bacteria).

Nitric Oxide Inhibitory Activity of Xanthones from the Green Fruits of Cratoxylum formosum ssp. pruniflorum

2010 ◽  
Vol 63 (11) ◽  
pp. 1550 ◽  
Author(s):  
Nawong Boonnak ◽  
Achjana Khamthip ◽  
Chatchanok Karalai ◽  
Suchada Chantrapromma ◽  
Chanita Ponglimanont ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Antibacterial Activity ◽  
Inhibitory Activity ◽  
Spectroscopic Methods ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
X Ray ◽  
X Ray Crystallography ◽  
Ic50 Values ◽  
Mic Value

Three new xanthones, pruniflorone M-O (1–3), and a new xanthonolignoid, 3-methoxy-5′-demethoxycadensin G (4), were isolated from the green fruits of Cratoxylum formosum ssp. pruniflorum along with three known xanthones (5–7) and a known flavonoid (8). Their structures were elucidated by spectroscopic methods and the structure of 1 was also determined by X-ray crystallography. Compounds 2 and 7 showed potent nitric oxide inhibitory activity with IC50 values of 4.4 and 4.3 μM, respectively. Moreover, 7 also showed strong antibacterial activity against both Gram-positive and Gram-negative bacteria with an MIC value of 4.67 μg mL–1.

scholarly journals Synthesis, Characterization, and Antibacterial Activity of Diethyl 1-((4-Methyl-2-phenyl-4,5-dihydrooxazol-4-yl)methyl)-1H-1,2,3-triazole-4,5-dicarboxylate

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
S. Boukhssas ◽  
Y. Aouine ◽  
H. Faraj ◽  
A. Alami ◽  
A. El Hallaoui ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Cycloaddition Reaction ◽  
Bactericidal Effect ◽  
High Yield ◽  
Dipolar Cycloaddition ◽  
Gram Negative Bacteria ◽  
X Ray ◽  
X Ray Crystallography ◽  
Gram Positive Bacteria

The compound, diethyl 1-((4-methyl-2-phenyl-4,5-dihydrooxazol-4-yl)methyl)-1H-1,2,3-triazole-4,5-dicarboxylate 2, was synthesized in high yield, through 1,3-dipolar cycloaddition reaction of 4-(azidomethyl)-4-methyl-2-phenyl-4,5-dihydrooxazole and diethyl but-2-ynedioate in the absence of a solvent. The structure of the synthesized compound was established on the basis of NMR spectroscopy (1H, 13C), X-ray crystallography, and MS data. The prepared compound was also tested in vitro for its antibacterial activity against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli). The calculation of MBC/MIC ratio showed that this triazole derivative 2 had a bactericidal effect on the two strains tested.

Structural studies of some 1-polymethyleneimino-2,4-dinitrobenzenesand related compounds; crystal structure of 1-(cis-2′,6′-dimethylpiperidin-1′-yl)-2,4-dinitrobenzene

2000 ◽  
Vol 53 (8) ◽  
pp. 715 ◽  
Author(s):  
Maureen F. Mackay ◽  
Douglas J. Gale ◽  
John F. K. Wilshire
Keyword(s):  
Crystal Structure ◽  
Phenyl Ring ◽  
Ring Opening ◽  
Boat Conformation ◽  
Structural Studies ◽  
X Ray ◽  
X Ray Crystallography ◽  
The Mean ◽  
Related Compounds ◽  
Solid State Conformation

The ultraviolet and 1H n.m.r. spectra of some 1-polymethyleneimino-2,4-dinitrobenzenes and related compounds are discussed. The effect of trifluoroacetic acid on these spectra was also investigated; with 1-azetidinyl-2,4-dinitrobenzene, acid-catalysed ring opening was observed. The solid-state conformation of 1-(cis-2′,6′-dimethylpiperidin-1′-yl)-2,4-dinitrobenzene has been defined by single-crystal X-ray crystallography. Triclinic crystals belong to the space group P–1 with a 8.165(1), b 7.865(1), c 11.148(1) Å, α 95.23(1), β 106.00(1), γ 92.63(1)˚ and Z 2. The structure was refined to a final R of 0.048 for the 2222 observed data. In the crystal, the phenyl ring adopts a slight boat conformation, while the amino and o-nitro groups are significantly twisted from the mean plane of the ring.

scholarly journals Structure and Stoichiometry of the Ton Molecular Motor

2020 ◽  
Vol 21 (2) ◽  
pp. 375 ◽  
Author(s):  
Herve Celia ◽  
Nicholas Noinaj ◽  
Susan K Buchanan
Keyword(s):  
Outer Membrane ◽  
Mode Of Action ◽  
Molecular Motor ◽  
Proton Gradient ◽  
Gram Negative Bacteria ◽  
Periplasmic Space ◽  
Inner Membrane ◽  
Gram Negative ◽  
X Ray ◽  
X Ray Crystallography

The Ton complex is a molecular motor that uses the proton gradient at the inner membrane of Gram-negative bacteria to generate force and movement, which are transmitted to transporters at the outer membrane, allowing the entry of nutrients into the periplasmic space. Despite decades of investigation and the recent flurry of structures being reported by X-ray crystallography and cryoEM, the mode of action of the Ton molecular motor has remained elusive, and the precise stoichiometry of its subunits is still a matter of debate. This review summarizes the latest findings on the Ton system by presenting the recently reported structures and related reports on the stoichiometry of the fully assembled complex.

scholarly journals Purification, crystallization and preliminary X-ray crystallographic analysis of TssL fromVibrio cholerae

2014 ◽  
Vol 70 (9) ◽  
pp. 1260-1263
Author(s):  
Jae-Hee Jeong ◽  
Jeong Ho Chang ◽  
Yeon-Gil Kim
Keyword(s):  
Structural Information ◽  
Crystallographic Analysis ◽  
Effector Proteins ◽  
Macromolecular Complex ◽  
Gram Negative Bacteria ◽  
Dependent Manner ◽  
Type Vi Secretion System ◽  
Gram Negative ◽  
X Ray ◽  
Cell Parameters

The type VI secretion system (T6SS) is a macromolecular complex that is conserved in Gram-negative bacteria. The T6SS secretes effector proteins into recipient cells in a contact-dependent manner in order to accomplish cooperative and competitive interactions with the cells. Although the composition and mechanism of the T6SS have been intensively investigated across many Gram-negative bacteria, to date structural information on T6SS components from the important pathogenVibrio choleraehas been rare. Here, the cloning, purification, crystallization and preliminary X-ray crystallographic analysis of the cytoplasmic domain of TssL, an inner membrane protein of the T6SS, fromV. choleraeare reported. Diffraction data were collected to 1.5 Å resolution using synchrotron radiation. The crystal belonged to the hexagonal space groupP61, with unit-cell parametersa= 78.4,b= 78.4, c= 49.5 Å. The successful structural characterization of TssL fromV. choleraewill contribute to understanding the role of the membrane-associated subunits of the T6SS in more detail.

Antimicrobial Evaluation and Efficient Green Synthesis of 8-Substituted-2,5-dihydro-1,5-benzothiazepine Derivatives

2019 ◽  
Vol 4 (1) ◽  
pp. 32-35
Author(s):  
Priyanka Sharma
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Gram Negative Bacteria ◽  
Aluminium Nitrate ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Hcl Gas ◽  
Antimicrobial Evaluation ◽  
Antimicrobial Assay

8-Substituted-2,5-dihydro-1,5-benzothiazepine derivatives have been synthesized by the reaction of 1-(2-furyl)-3-(3,4-dimethoxyphenyl)-2-propenone with six 5-substiuted-2-minobenzenethiols in dry ethanol saturated with dry HCl gas and also in the presence of aluminium nitrate as catalyst in dry ethanol. All the newly synthesized compounds were characterized by analytical and spectral data comprising IR, 1H NMR, 13C NMR, 19F NMR and mass studies. All these compounds have also been evaluated for their antimicrobial assay against the Gram-positive bacteria, Staphylococcus aureus and the Gram-negative bacteria, Pseudomonas aeruginosa and the fungus, Candida albicans. The antifungal activity was found to be more significant than antibacterial activity.

scholarly journals Synthesis and Conformational Analysis of Sterically Congested (4R)-(−)-1-(2,4,6-Trimethylbenzenesulfonyl)-3-n-butyryl-4-tert-butyl-2-imidazolidinone: X-Ray Crystallography and Semiempirical Calculations

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Ibrahim A. Al-Swaidan ◽  
Adel S. El-Azab ◽  
Amer M. Alanazi ◽  
Alaa A.-M. Abdel-Aziz
Keyword(s):  
Crystal Structure ◽  
Conformational Analysis ◽  
Phenyl Ring ◽  
Crystal Packing ◽  
Molecular Mechanic ◽  
Structural Data ◽  
Am1 Method ◽  
Geometrical Parameters ◽  
X Ray ◽  
X Ray Crystallography

The crystal structure of (4R)-(−)-1-(2,4,6-trimethylbenzenesulfonyl)-3-n-butyryl-4-tert-butyl-2-imidazolidinone(3)was determined by single-crystal X-ray diffraction. Compound3crystallizes in triclinic system in space groupP1 (≠1). The crystal data area=10.62165 Å,b=16.5321 Å,c=8.95729 Å,∝=91.1936∘,β=93.8496∘,γ=88.0974∘,V=1568.22 Å3,Z=3,Dcalc=1.253 g/cm3,μCuKα=15.98 cm−1,F000=636.00,T=20.0°C, andR=0.037. The crystal structure confirmed the occurrence of three molecules of3A,3B, and3Cin which then-butyryl moiety adopted thes-transoidconformation. Crystal structure also revealed that the conformation of 2,4,6-trimethylbenzenesulfonyl groups was inanti-position relative totert-butyl group. The crystal packing showed that three molecules of compound3are stacked as a result of intermolecularπ-πinteractions between the phenyl ring of one molecule and the phenyl ring of the other molecule by approaching each other to an interplanar separation of 5.034 Å. Interestingly, these stacked molecules are also connected by intermolecularCH-πinteraction. The conformational analysis of thes-transoid  3A,3B, and3Cwas separately performed by molecular mechanic MM+ force field. Additionally, computational investigation using semiempirical AM1 and PM3 methods was performed to find a correlation between experimental and calculated geometrical parameters. The data obtained suggest that the structural data furnished by the AM1 method is in better agreement with those experimentally determined for the above compound. It has been found that the lowest energetic conformer computed gives approximate correspondence with experimental solid state data.

scholarly journals Hexameric and pentameric complexes of the ExbBD energizer in the Ton system

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Saori Maki-Yonekura ◽  
Rei Matsuoka ◽  
Yoshiki Yamashita ◽  
Hirofumi Shimizu ◽  
Maiko Tanaka ◽  
...  
Keyword(s):  
Proton Motive Force ◽  
Motive Force ◽  
Membrane Receptors ◽  
Proton Channel ◽  
Gram Negative Bacteria ◽  
Transmembrane Helices ◽  
Gram Negative ◽  
X Ray ◽  
X Ray Crystallography ◽  
Channel Current

Gram-negative bacteria import essential nutrients such as iron and vitamin B12 through outer membrane receptors. This process utilizes proton motive force harvested by the Ton system made up of three inner membrane proteins, ExbB, ExbD and TonB. ExbB and ExbD form the proton channel that energizes uptake through TonB. Recently, crystal structures suggest that the ExbB pentamer is the scaffold. Here, we present structures of hexameric complexes of ExbB and ExbD revealed by X-ray crystallography and single particle cryo-EM. Image analysis shows that hexameric and pentameric complexes coexist, with the proportion of hexamer increasing with pH. Channel current measurement and 2D crystallography support the existence and transition of the two oligomeric states in membranes. The hexameric complex consists of six ExbB subunits and three ExbD transmembrane helices enclosed within the central channel. We propose models for activation/inactivation associated with hexamer and pentamer formation and utilization of proton motive force.

Synthesis, crystal structure and antimicrobial activities of a dinuclear silver(I) complex of bis(diphenylphosphano)methane and thiourea

2019 ◽  
Vol 74 (10) ◽  
pp. 745-750 ◽  
Author(s):  
◽  
Muhammad Aziz Choudhary ◽  
Saeed Ahmad ◽  
Muhammad Aslam ◽  
Muhammad Saleem ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Three Dimensional ◽  
Antimicrobial Activities ◽  
Gram Negative Bacteria ◽  
Significant Activity ◽  
X Ray ◽  
X Ray Crystallography ◽  
Hydrogen Bonding Interactions ◽  
Dimensional Network ◽  
Tetrahedral Environment

AbstractA heteroleptic silver(I) complex of bis(diphenylphosphano)methane (DPPM) and thiourea (tu) with the formula [Ag2(DPPM)2(tu)3](NO3)2 · 2H2O (1) was prepared and characterized by infrared (IR) and nuclear magnetic resonance (1H, 13C, and 31P) spectroscopic methods, and X-ray crystallography. The crystal structure determination has shown that the complex (1) is dinuclear having each silver(I) ion coordinated by two phosphorus atoms of DPPM molecules and two sulfur atoms of tu ligands adopting a distorted tetrahedral environment. The two silver atoms are bridged by one of the three tu molecules. The other two tu ligands are coordinated in a terminal mode; one with each silver(I) ion. The dinuclear units are associated to each other through hydrogen bonding interactions to form a three-dimensional network in the solid state. Complex 1 showed significant activity against two Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa), and molds (Aspergillus niger, Penicillium citrinum), while the activities were poor towards yeasts (Candida albicans, Saccharomyces cerevisiae).

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