scholarly journals Synthesis, physicochemical characterization and antibacterial activity of novel (benzoylamino)methyl derivatives of quinolones

2016 ◽  
Vol 35 (2) ◽  
pp. 179 ◽  
Author(s):  
Pranvera Breznica-Selmani ◽  
Kristina Mladenovska ◽  
Gerald Dräger ◽  
Bozhana Mikhova ◽  
Nikola Panovski ◽  
...  

Herein we report the synthesis of different derivatives of (fluoro)quinolones norfloxacin, ciprofloxacin and pipemidic acid, by incorporating (benzoylamino)methyl on the free nitrogen of the pyperazinyl moiety. The compounds were structurally characterized by 1D and 2D NMR, FTIR and high-resolution mass spectroscopy. In addition, their physicochemical properties were a matter of interest to be correlated with their structure and antimicrobial activity<em> in vitro</em>. Their antimicrobial activities were screened against Gram-positive, Gram-negative bacteria and <em>C. albicans</em>. Higher distribution coefficients and consequently lower water solubility were determined for all synthesized compounds than the ones of the corresponding leading compounds. Inconsequential correlations between the lipophilicity of the compounds and MIC were observed, suggesting that passive diffusion is not the only mechanism for their penetration into bacterial cells. Further studies are needed to determine how substitutions in the (fluoro)quinolone moiety affect the primary target(s), substrate behavior in respect to bacterial transporters and overall bioavailability.

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 152
Author(s):  
Iulia Pinzaru ◽  
Cristian Sarau ◽  
Dorina Coricovac ◽  
Iasmina Marcovici ◽  
Crinela Utescu ◽  
...  

Betulinic acid (BA), a natural compound with various health benefits including selective antitumor activity, has a limited applicability in vivo due to its poor water solubility and bioavailability. Thus, this study focused on obtaining a BA nano-sized formulation with improved solubility and enhanced antitumor activity using silver nanocolloids (SilCo and PEG_SilCo) as drug carriers. The synthesis was performed using a chemical method and the physicochemical characterization was achieved applying UV-Vis absorption, transmission electron microscopy (TEM), Raman and photon correlation spectroscopy (PCS). The biological evaluation was conducted on two in vitro experimental models—hepatocellular carcinoma (HepG2) and lung cancer (A549) cell lines. The physicochemical characterization showed the following results: an average hydrodynamic diameter of 32 nm for SilCo_BA and 71 nm for PEG_SilCo_BA, a spherical shape, and a loading capacity of 54.1% for SilCo_BA and 61.9% for PEG_SilCo_BA, respectively. The in vitro assessment revealed a cell type- and time-dependent cytotoxic effect characterized by a decrease in cell viability as follows: (i) SilCo_BA (66.44%) < PEG_SilCo_BA (72.05%) < BA_DMSO (75.30%) in HepG2 cells, and (ii) SilCo_BA (75.28%) < PEG_SilCo_BA (86.80%) < BA_DMSO (87.99%) in A549 cells. The novel silver nanocolloids loaded with BA induced an augmented anticancer effect as compared to BA alone.


2013 ◽  
Vol 8 (1) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Ismail Kiran ◽  
Özge Özşen ◽  
Turgay Çelik ◽  
Semra İlhan ◽  
Bükay Yenice Gürsu ◽  
...  

Isophorone (3,5,5-trimethyl-2-cyclohexen-1-one), a monoterpene, and the structurally related 1,8-cineole and camphor, have demonstrated a protective effect against cancer, biological activity against a variety of microorganisms, and anti-oxidant properties. The derivatization of isophorone is, therefore, an important field of xenobiochemistry, pharmacology and toxicology. The aim of this study was to obtain derivatives of isophorone through microbial biotransformation and evaluate the biotransformation metabolites as potential antimicrobial agents. Incubation of isophorone with the fungi Alternaria alternata and Neurospora crassa afforded 4α-hydroxy- and 7-hydroxy-isophorone as transformation metabolites. The antimicrobial activities of isophorone and the metabolites were evaluated in vitro both by using agar dilution and microdilution methods. However, no significant antibacterial activity was observed when compared with those of standard substances.


Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2196 ◽  
Author(s):  
Silvana Alfei ◽  
Anna Maria Schito ◽  
Guendalina Zuccari

Ursolic acid (UA) is a pentacyclic triterpenoid found in many medicinal plants and aromas endowed with numerous in vitro pharmacological activities, including antibacterial effects. Unfortunately, UA is poorly administered in vivo, due to its water insolubility, low bioavailability, and residual systemic toxicity, thus making urgent the development of water-soluble UA formulations. Dendrimers are nonpareil macromolecules possessing highly controlled size, shape, and architecture. In dendrimers with cationic surface, the contemporary presence of inner cavities and of hydrophilic peripheral functions, allows to encapsulate hydrophobic non-water-soluble drugs as UA, to enhance their water-solubility and stability, and to promote their protracted release, thus decreasing their systemic toxicity. In this paper, aiming at developing a new UA-based antibacterial agent administrable in vivo, we reported the physical entrapment of UA in a biodegradable not cytotoxic cationic dendrimer (G4K). UA-loaded dendrimer nanoparticles (UA-G4K) were obtained, which showed a drug loading (DL%) much higher than those previously reported, a protracted release profile governed by diffusion mechanisms, and no cytotoxicity. Also, UA-G4K was characterized by principal components analysis (PCA)-processed FTIR spectroscopy, by NMR and elemental analyses, and by dynamic light scattering experiments (DLS). The water solubility of UA-G4K was found to be 1868-fold times higher than that of pristine UA, thus making its clinical application feasible.


2010 ◽  
Vol 7 (2) ◽  
pp. 496-500 ◽  
Author(s):  
Ravindra Kumar ◽  
Y. K. Srivastava

3, 5-Diaryl-2-pyrazoline-1-carbaldehyde(1)was condensed with hydrazine hydrate ando-phenylene diamine to afford corresponding hydrazones(2)and 3-benzimidazolyl-3, 5-diaryl-2-pyrazoline respectively under MWI condition. The newly synthesized compounds have been screened for their antibacterial activityin vitro.


2014 ◽  
Vol 37 (2) ◽  
pp. 145-158 ◽  
Author(s):  
Sarkar MA Kawsar ◽  
Abul K MS Kabir ◽  
Mohammad M R Bhuiyan ◽  
Jannatul Ferdous ◽  
Mohammad S Rahman

Regioselective pentanoylation of methyl 4,6-O-(4-methoxybenzylidene)-?-D-glucopyranoside by the direct acylation method provided the methyl 4,6-O-(4-methoxybenzylidene)-2-O-pentanoyl- ?-D-glucopyranoside in good yield. A number of 3-O-acyl derivatives of this 2-O-pentanoylation product were also prepared in order to obtain new compounds and also gather additional information for structure elucidation. The chemical structure of the newly synthesized compounds was characterized by analytical and spectral methods. Synthesized acylated derivatives of Dglucopyranoside were screened for in vitro antimicrobial activities against ten human pathogenic bacteria and four plant pathogenic fungi. The study revealed that the acylated products exhibited moderate to good antimicrobial activities. It was interesting to observe that the selected compounds were more sensitive against fungal phytopathogens than those of the bacterial strains. DOI: http://dx.doi.org/10.3329/jbas.v37i2.17554 Journal of Bangladesh Academy of Sciences, Vol. 37, No. 2, 145-158, 2013


2016 ◽  
Vol 71 (11-12) ◽  
pp. 381-386 ◽  
Author(s):  
Pierre Mkounga ◽  
Hermine L.D. Maza ◽  
Blandine M.W. Ouahouo ◽  
Lydie N. Tyon ◽  
Hayato Ishikawa ◽  
...  

Abstract Three new lupan-type triterpernoid derivatives, namely globimetulin A (1), B (2) and C (3), were isolated from the shoot of Globimetula dinklagei (Loranthaceae), a hemiparasitic plant growing on Manihot esculenta, along with five known compounds: friedelin (4), friedelan-3-ol (5), 28-hydroxyfriedelin (6), 4-hydroxy-3,5-dimethoxybenzoic acid (7) and (1R,5S,7S)-7-[2-(4-hydroxyphenyl)ethyl]-2,6-dioxabicyclo[3.3.1]nonan-3-one (8). The structures of the new compounds were elucidated by detailed analyses of their MS, IR, 1D and 2D NMR spectral data and chemical evidence. Some of these compounds were evaluated in vitro for their antimicrobial activities against a wide range of microorganisms, but none of them exhibited noticeable activity.


Biomolecules ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 118 ◽  
Author(s):  
Mercedeh Tajbakhsh ◽  
Maziar Akhavan ◽  
Fatemeh Fallah ◽  
Abdollah Karimi

The emergence of antimicrobial resistance among pathogenic microorganisms has been led to an urgent need for antibiotic alternatives. Antimicrobial peptides (AMPs) have been introduced as promising therapeutic agents because of their remarkable potentials. A new modified cathelicidin-BF peptide (Cath-A) with 34 amino acid sequences, represents the potential antimicrobial effects against methicillin-resistant Staphylococcus aureus (MRSA) with slight hemolytic and cytotoxic activities on eukaryotic cells. In this study, the effects of Cath-A on Acinetobacter baumannii, and Pseudomonas aeruginosa isolated from medical instruments were studied. Cath-A inhibited the growth of bacterial cells in the range of 8–16 μg/mL and 16-≥256 μg/mL for A. baumannii and P. aeruginosa, respectively. The peptide significantly removed the established biofilms. To display a representative approach for the cost-effective constructions of peptides, the recombinant Cath-A was cloned in the expression vector pET-32a(+) and transformed to Escherichia coli BL21. The peptide was expressed with a thioredoxin (Trx) sequence in optimum conditions. The recombinant peptide was purified with a Ni2+ affinity chromatography and the mature peptide was released after removing the Trx fusion protein with enterokinase. The final concentration of the partially purified peptide was 17.6 mg/L of a bacterial culture which exhibited antimicrobial activities. The current expression and purification method displayed a fast and effective system to finally produce active Cath-A for further in-vitro study usage.


2017 ◽  
Vol 72 (1) ◽  
pp. 49-52 ◽  
Author(s):  
Yu Lu ◽  
Ming Zhao

AbstractTwo new highly acetylated steroids, named dysiroid A (1) and dysiroid B (2), together with a known compound (3) were isolated from the marine sponges Dysidea sp. The chemical structures of 1 and 2 were elucidated by spectroscopic analyses including 1D and 2D NMR experiments and high-resolution electrospray impact mass spectroscopy. Their in vitro antimicrobial activities against a panel of bacterial strains were evaluated. Compounds 1 and 2 showed potent activity against some of the strains with minimum inhibitory concentrations ranging from 4 to 8 μg mL−1.


2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Isaac Asusheyi Bello ◽  
George Iloegbulam Ndukwe ◽  
Joseph Olorunju Amupitan ◽  
Rachael Gbekele Ayo ◽  
Francis Oluwole Shode

In our continued attempts at designing new antibiotics based on the structure of the C-9154 antibiotic, to simultaneously improve activity and lower toxicity, an analogue to the C-9154 antibiotic and six derivatives of this analogue were synthesized. The approach was to significantly reduce the polarity of the synthesized analogue in the derivatives to achieve increased permeability across cell membranes by conversion of the highly polar carboxylic group to an ester functional group. The compounds were synthesized using a two-step reaction which involved an additional reaction between benzyl amine and maleic anhydride and then conversion of the terminal carboxylic acid functional group to an ester functional group using a thionyl chloride mediated esterification reaction. The compounds were fully characterized using Infrared, GC-MS, and 1D and 2D NMR experiments. The in vitro biological activity of the compounds showed that the derivatives were more active than the analogues as was anticipated with minimum inhibitory concentration in the range 0.625–5 μg/mL. The analogue had minimum inhibitory concentration in the range 2.5–10 μg/mL. These values are significantly better than that obtained for the original C-9154 antibiotic which had activity in the range 10–>100 μg/mL.


2012 ◽  
Vol 2012 ◽  
pp. 1-7
Author(s):  
Isaac Asusheyi Bello ◽  
George Iloegbulam Ndukwe ◽  
Joseph Olorunju Amupitan ◽  
Rachael Gbekele Ayo ◽  
Francis Oluwole Shode

This research was undertaken to design several new antibiotics, by structurally modifying the C-9154 antibiotic, simultaneously improving its activity and lowering toxicity. This was achieved by synthesizing an analogue to the C-9154 antibiotic and seven derivatives of this analogue. The approach was to significantly reduce the polarity of the synthesized analogue in the derivatives to achieve increased permeability across cell membranes by conversion of the highly polar carboxylic group to an ester functional group. The compounds were fully characterized using infrared, GC-MS, and 1D and 2D NMR experiments. The in vitro biological activity of the compounds showed that the derivatives were more active than the analogue as was anticipated and both were more active than the standard drugs used for comparison. Work is ongoing to establish applications for the compounds as antiplasmodials, antivirals, anticancers/tumours, antitrypanosomiasis, anthelminthic, and as general antibiotics for human, veterinary, and even agricultural use as they had marked effect on both Gram-positive and Gram-negative bacteria and some fungi.


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