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 Fusarins G–L with Inhibition of NO in RAW264.7 from Marine-Derived Fungus Fusarium solani 7227

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 305
Author(s):  
Guangyuan Luo ◽  
Li Zheng ◽  
Qilin Wu ◽  
Senhua Chen ◽  
Jing Li ◽  
...  
Keyword(s):  
Fusarium Solani ◽  
2D Nmr ◽  
Inflammatory Activity ◽  
Raw264.7 Cells ◽  
Spectroscopic Methods ◽  
X Ray ◽  
X Ray Crystallography ◽  
Structure Activity ◽  
Ic50 Values ◽  
New Compounds

Six new fusarin derivatives, fusarins G–L (1–6), together with five known compounds (5–11) were isolated from the marine-derived fungus Fusarium solani 7227. The structures of the new compounds were elucidated by means of comprehensive spectroscopic methods (1D and 2D NMR, HRESIMS, ECD, and ORC) and X-ray crystallography. Compounds 5–11 exhibited potent anti-inflammatory activity by inhibiting the production of NO in RAW264.7 cells activated by lipopolysaccharide, with IC50 values ranging from 3.6 to 32.2 μM. The structure–activity relationships of the fusarins are discussed herein.

Mannich Reaction Product of Quinolin-8-ol (Oxine) and its Antibacterial Activity

1997 ◽  
Vol 50 (8) ◽  
pp. 861 ◽  
Author(s):  
Shaheen Faizi ◽  
Bina Shaheen Siddiqui ◽  
Rubeena Saleem ◽  
Farzana Akhtar ◽  
Khursheed Ali Khan ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Single Crystal ◽  
Mannich Reaction ◽  
Gram Negative Bacteria ◽  
X Ray Diffraction ◽  
Gram Positive ◽  
Gram Negative ◽  
Antimicrobial Screening ◽  
X Ray

Quinolin-8-ol (1) on reaction with 2,6-dichloroaniline and m-nitrobenzaldehyde afforded 7-(α-hydroxy- m-nitrobenzyl)quinolin-8-ol (2), which is an unusual Mannich reaction product. The structure of (2) was determined by spectroscopic and single-crystal X-ray diffraction studies. Preliminary antimicrobial screening showed that (1) and (2) have activity against a large number of Gram-positive and Gram-negative bacteria.

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.

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.

Bismuth(III) Thiophosphinates: Understanding How a Small Atomic Change Influences Antibacterial Activity and Mammalian Cell Viability

2020 ◽  
Vol 73 (12) ◽  
pp. 1226
Author(s):  
Dimuthu C. Senevirathna ◽  
Rebekah N. Duffin ◽  
Liam J. Stephens ◽  
Megan E. Herdman ◽  
Melissa V. Werrett ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Cell Viability ◽  
Mammalian Cell ◽  
Mammalian Cells ◽  
Bacterial Strains ◽  
X Ray Diffraction ◽  
Gram Negative ◽  
X Ray ◽  
X Ray Crystallography ◽  
Biological Studies

Diphenylphosphinothioic acid (HSP(=O)Ph2) and diphenylphosphinodithioic acid (HSP(=S)Ph2) have been used to synthesise four BiIII complexes: 1 [Bi(SP(=O)Ph2)3], 2 [BiPh(SP(=O)Ph2)2], 3 [BiPh2(SP(=O)Ph2)], and 4 [Bi(SP(=S)Ph2)3], using BiPh3 and [Bi(OtBu)3] as bismuth sources. The complexes have been characterised by NMR spectroscopy, mass spectrometry, infrared spectroscopy, powder X-ray diffraction, and singe crystal X-ray crystallography (2–4). Biological studies indicated that despite complexes 2 and 3 reducing mammalian cell viability, their antibacterial activity provides a good degree of selectivity towards both Gram positive and Gram negative bacterial strains. The minimum inhibitory concentrations for complexes 2 and 3 are in the range of 0.52–5.5µM towards the bacteria tested. Homoleptic complexes 1 and 4 were generally less active towards both bacterial and mammalian cells.

scholarly journals Green Synthesis of Gold and Silver Nanoparticles by Using Amorphophallus paeoniifolius Tuber Extract and Evaluation of Their Antibacterial Activity

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4773
Author(s):  
S. M. Abu Nayem ◽  
Nasrin Sultana ◽  
Md. Aminul Haque ◽  
Billal Miah ◽  
Md. Mahmodul Hasan ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Green Synthesis ◽  
Inhibitory Effect ◽  
Reducing Agent ◽  
Gram Negative Bacteria ◽  
Gold And Silver Nanoparticles ◽  
Gram Negative ◽  
X Ray ◽  
Tuber Extract

In this report, we discussed rapid, facile one-pot green synthesis of gold and silver nanoparticles (AuNPs and AgNPs) by using tuber extract of Amorphophallus paeoniifolius, and evaluated their antibacterial activity. AuNPs and AgNPs were synthesized by mixing their respective precursors (AgNO3 and HAuCl4) with tuber extract of Amorphophallus paeoniifolius as the bio-reducing agent. Characterization of AuNPs and AgNPs were confirmed by applying UV-vis spectroscopy, field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR), and energy dispersive X-ray spectroscopy (EDS). From UV-vis characterization, surface plasmon resonance spectra were found at 530 nm for AuNPs and 446 nm for AgNPs. XRD data confirmed that both synthesized nanoparticles were face-centered cubic in crystalline nature, and the average crystallite sizes for the assign peaks were 13.3 nm for AuNPs and 22.48 nm for AgNPs. FTIR data evaluated the characteristic peaks of different phytochemical components of tuber extract, which acted as the reducing agent, and possibly as stabilizing agents. The antibacterial activity of synthesized AuNPs and AgNPs were examined in Muller Hinton agar, against two Gram-positive and four Gram-negative bacteria through the disc diffusion method. AuNPs did not show any inhibitory effect, while AgNPs showed good inhibitory effect against both Gram-positive and Gram-negative bacteria.

scholarly journals Antibacterial Activities of Actinomycete Isolates Collected from Soils of Rajshahi, Bangladesh

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Md. Ajijur Rahman ◽  
Mohammad Zahidul Islam ◽  
Md. Anwar Ul Islam
Keyword(s):  
Antibacterial Activity ◽  
Secondary Metabolites ◽  
Inhibitory Activity ◽  
Pure Culture ◽  
Agar Medium ◽  
Antibacterial Activities ◽  
Soil Samples ◽  
Indicator Bacteria ◽  
Gram Negative Bacteria ◽  
Gram Negative

This study was performed to isolate actinomycete colonies having antibacterial activity from soil samples collected from different places around Rajshahi, Bangladesh. Thirty actinomycete colonies were isolated in pure culture from five soil samples using Starch-casein-nitrate-agar medium. The isolates were grouped in five color series based on their aerial mycelia color and screened for their antibacterial activity against a range of test bacteria. Sixteen isolates (53.3%) were found to have moderate to high activity against four gram-positive and four gram-negative bacteria. Since many isolates showed inhibitory activity against indicator bacteria, it is suggestive that Bangladeshi soil could be an interesting source to explore for antibacterial secondary metabolites.

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.

Al2O3 Nanopowders, a Suitable Compound for Active Control of Biofouling

2015 ◽  
Vol 32 ◽  
pp. 71-80
Author(s):  
Mohsen Mehregan ◽  
Hossein Soltaninejad ◽  
Behnaz Toluei Nia ◽  
Hadi Zare-Zardini ◽  
Masoud Zare-Shehneh ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Antibacterial Activity ◽  
Blood Cells ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
X Ray Diffraction ◽  
Gram Positive ◽  
Gram Negative ◽  
X Ray

The formation of biofilm (Biofouling) in different surface is the great concern in types of fields, especially in medical and health system as well as in membrane technology. The present study deals with the synthesis and characterization of Al2O3 nanopowders with antibacterial activity which can be a potentially utilized material for biocompatible implants. Nanostructure was synthesized based on sol-gel method and then, crystallite size, and microstructural and morphological characterization of nanostructure were determined by X-ray diffraction, electron-microscopic techniques - scanning electron microscopy (SEM) and transmission electron microscopy (TEM). According to X-ray diffraction, the value of particle size for Al2O3 nanopowders is 20.85 nm. In the following, the antibacterial activity of Al2O3 nanoparticles was assessed on three gram positive and three gram negative bacteria by radial diffusion assay and measurement of minimum inhibitory concentration (MIC). The toxicity of Al2O3 nanopowders on blood cells was also assessed. The results showed that this nanostructure has potent antibacterial activity against gram positive and gram negative bacteria. The synthesized Al2O3 nanopowders showed the antimicrobial activity against antibiotic resistant bacterium, Staphylococcus aureus. Significant antibacterial activity of this nanostructure was seen to have a greatest effect on Bacillus cereus with the MIC value of 9.2 μg/ml; while, among bacterial strains, Salmonellatyphimurium was investigated to be the most resistant one with the MIC of 35.6 μg/ml. Al2O3 nanopowders showed no toxicity on blood cells. according to acquired data in this study, Al2O3 nanopowders may be a good material for inhibition of biofilm formation.

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.

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