scholarly journals Synthesis and biological activities of some indoline derivatives

2009 ◽  
Vol 74 (12) ◽  
pp. 1377-1387 ◽  
Author(s):  
Milind Rode ◽  
Sahebrao Rindhe ◽  
Bhausaheb Karale

The reaction of indoline with a substituted benzoyl chloride in the presence of K2CO3 in THF gave compound 4. Compound 4 was subjected to chlorosulphonation to obtain compound 5. Condensation of aromatic amines with compound 5 led to the synthesis of indoline derivatives 6(a-f). Similarly, 5-nitroindoline was treated with a substituted benzoyl chloride to obtain the nitro compound 9, which was reduced using stannous chloride and reacted further with aromatic sulphonyl chloride to obtain the indoline derivatives 11(a-e). These compounds were tested for antibacterial, anti-tuberculosis and antifungal activity. Some of them showed very good activity against some gram-positive and gram negative bacteria, fungal strains and also Mycobacterium tuberculosis. All of the synthesized compounds were subjected to antioxidant activity testing using the in vitro DPPH assay and most of them showed very good activity.


2017 ◽  
Vol 82 (5) ◽  
pp. 495-508 ◽  
Author(s):  
Aleksandra Bozic ◽  
Nenad Filipovic ◽  
Irena Novakovic ◽  
Snezana Bjelogrlic ◽  
Jasmina Nikolic ◽  
...  

Fourteen mono- and bis-carbohydrazone ligands have been synthesized and characterized. Antioxidant activity of the substances was investigated together with possible (E)/(Z) isomerization, and explained on the most active antioxidant compound 4 in various dimethyl sulphoxide?water mixtures. The addition of water to the system was involved in the formation of hydrated molecules which was confirmed in NMR after the addition of D2O. The ligands were tested in vitro against Gram-positive and Gram-negative bacteria and fungi, and their activity was discussed in relation to the structure of investigated carbohydrazone.



2009 ◽  
Vol 59 (2) ◽  
pp. 145-158 ◽  
Author(s):  
Mosaad Mohamed ◽  
Ramdan El-Domany ◽  
Rania Abd El-Hameed

Synthesis of certain pyrrole derivatives as antimicro-bial agentsIn an effort to establish new pyrroles and pyrrolo[2,3-d] pyrimidines with improved antimicrobial activity we report here the synthesis andin vitromicrobiological evaluation of a series of pyrrole derivatives. A series of new 2-aminopyrrole-3-carbonitriles (1a-d) were synthesized from the reaction of benzoin, primary aromatic amines and malononitrile, from which a number of pyrrole derivatives (2a-dto5a-d) and pyrrolo[2,3-d]pyrimidines (6a-dto10a, d) were synthesized. Thein vitroantimicrobial testing of the synthesized compounds was carried out against Gram-positive, Gram-negative bacteria and fungi. Some of the prepared compounds, [2-amino-1-(2-methylphenyl)-4,5-diphenyl-1H-pyrrole-3-carbonitriles (1b), 2-amino-3-carbamoyl-1-(3-methylphenyl)-4,5-diphenyl-1H-pyrroles (2b),N-(3-cyano-1-(2-methylphenyl)-4,5-diphenyl-1H-pyrrol-2-yl)-acetamides (3b),N-(3-cyano-1-(3-methylphenyl)-4,5-diphenyl-1H-pyrrol-2-yl)-acetamides (3c), 2-amino-1-(4-methoxyphenyl)-4,5-diphenyl-3-tetrazolo-1H-pyrroles (5d),7-(4-methoxyphenyl)-5,6-diphenyl-7H-pyrrolo [2,3-d]pyrimidin-4(3H)-ones (7d), 7-(3-methylphenyl)-5,6-diphenyl-7H-pyrrolo[2,3-d]pyrimidin-4(3H)-thione (9b) andN-(7-(2-methylphenyl)-5,6-diphenyl-7H-pyrrolo[2,3-d] pyrimidine)-N-aryl amines (10a)] showed potent antimicrobial activity.



2019 ◽  
Vol 35 (2) ◽  
pp. 648-657 ◽  
Author(s):  
Wasim Ahmad ◽  
Ennus T. Tamboli ◽  
Abuzer Ali ◽  
Mohd Amir ◽  
S. M. A. Zaidi ◽  
...  

A Gas Chromatography and Maas Spectroscopy method was developed and validated for determination and identification of α-humulene in a traditional medicinal herb Didymocarpous pedicellatus R. Br. (DP) (Gesneriaceae) and its poly herbal formulation, Safoof-e-pathar phori (SPP) including their essential oil. Hydrodistillation method were used for the isolation of essential oils from the leaves of DP and SPP herbal formulation. The proposed analysis method was found to be linear r2 = 0.999 in a wide concentration range (0.1-1000 µgmL-1), with good precision (RSD < 2.0%). Antimicrobial activity of α-humulene, DP and SPP oil was assessed by using agar well diffusion method against clinically important Gram-positive, Gram-negative bacteria and fungi. α-Humulene was found to be more active in contrast to Gram-negative bacteria while DP oil and SPP oil were exhibited maximum inhibition against fungal strains. Antioxidant activity of α-humulene, DP oil and SPP oil were determined using 2, 2-diphenyl-1-picryl hydrazyl radical (DPPH) 96 well plate method, which showed antioxidant activity in the following order: standard ascorbic acid (DPPH FRS50 = 2.40 µg) > DP oil (DPPH FRS50 = 3.68 µg) > SPP oil (DPPH FRS50 = 12.54 µg) > and α-humulene (DPPH FRS50 = 36.19 µg).



2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Nada K. Alharbi ◽  
Souheila Naghmouchi ◽  
Mayasar Al-Zaban

In the present study, the relationship between the phenolic counts, chemical composition, and biological activities of two Mentha species (Mentha rotundifolia (MR) and Mentha pulegium (MP)) was analyzed. The characterization of the action mode against pathogenic bacteria and the inhibition of spore germination of two fungal species using prepared methanolic extracts were studied here for the first time. The obtained data highlighted the presence of positive correlation between the secondary metabolites contents and the biological activities of the investigated extracts. In fact, HPLC analysis showed that the major components in both the extracts were eriocitrin and rosmarinic acid (25 and 20 mg/ml and 12 and 8 mg/ml in methanolic extracts of MR and MP, respectively). Moreover, the MR extract was rich in polyphenols and presents the highest antioxidant activity than MP ones. In addition, both extracts possess an antimicrobial activity against four Gram-positive and five Gram-negative bacteria and one yeast species (Candida albicans) and were able to inhibit the spore germination of two fungi species (Aspergillus niger and Aspergillus flavus). But, the significant activity was observed in the presence of MR methanolic extract. The effect of time on cell integrity of E. coli and L. monocytogenes determined by time-kill and bacteriolysis assays showed that the MR extract had a rapid bacteriolytic effect compared to the MP extract, and their capacities were significant against Gram-negative bacteria than positive ones. Based on the obtained data, it can be concluded that Saudi Mentha species have high pharmacological and industrial importance and they can be used in preparation of food or drugs.



2018 ◽  
Vol 83 (3) ◽  
pp. 271-284 ◽  
Author(s):  
Mădălina Mihalache ◽  
Ticuţa Negreanu-Pîrjol ◽  
Florea Dumitraşcu ◽  
Constantin Drăghici ◽  
Mirela Călinescu

Six new coordination compounds of Ni(II), Pd(II) and Cr(III) with chlorhexidine, 1,1?-hexamethylenebis[5-(4-chlorophenyl)biguanide], were prepared, characterized and examined for their potential as antimicrobial agents, as well as for their antioxidant activity. The metal complexes correspond to the formulas: [Ni(CHX)]Cl2?2H2O, [Ni(CHX)]Br2?2H2O, [Ni(CHX)](CH3COO)2?C2H5OH, [Pd(CHX)][PdCl4]?2H2O, [Pd(CHX)](CH3COO)2 and [Cr(CHX)Cl2](CH3COO), where CHX = chlorhexidine. Investigations on the in vitro antimicrobial activity of the complexes indicated that all have high activity against the tested bacteria, but are less active against fungi. Among the six complexes, those of Pd(II) showed the highest antibacterial activity, [Pd(CHX)][PdCl4]?2H2O being more active against Gram-positive and Gram-negative bacteria than chlorhexidine diacetate. The antioxidant activity of the metal complexes was investigated by photochemiluminescence and the results showed that the palladium( II) complexes have high antioxidant activities.



Antibiotics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 968
Author(s):  
Hani A. Alhadrami ◽  
Raha Orfali ◽  
Ahmed A. Hamed ◽  
Mohammed M Ghoneim ◽  
Hossam M. Hassan ◽  
...  

Flavonoids are a class of bioactive plant-derived natural products that exhibit a broad range of biological activities, including antibacterial ones. Their inhibitory activity toward Gram-positive bacterial was found to be superior to that against Gram-negative ones. In the present study, a number of flavonoid-coated gold nanoparticles (GNPs) were designed to enhance the antibacterial effects of chrysin, kaempferol, and quercetin against a number of Gram-negative bacteria. The prepared GNPs were able to conjugate to these three flavonoids with conjugation efficiency ranging from 41% to 80%. Additionally, they were able to exert an enhanced antibacterial activity in comparison with the free flavonoids and the unconjugated GNPs. Quercetin-coated GNPs were the most active nano-conjugates and were able to penetrate the cell wall of E. coli. A number of in silico experiments were carried out to explain the conjugation efficiency and the antibacterial mechanisms of these flavonoids as follows: (i) these flavonoids can efficiently bind to the glutathione linker on the surface of GNPs via H-bonding; (ii) these flavonoids, particularly quercetin, were able to increase the bacterial membrane rigidity, and hence decrease its functionality; (iii) these flavonoids can inhibit E. coli’s DNA gyrase (Gyr-B) with IC50 values ranging from 0.9 to 3.9 µM. In conclusion, these bioactive flavonoid-based GNPs are considered to be very promising antibiotic candidates for further development and evaluation.



2020 ◽  
Vol 21 (10) ◽  
pp. 927-938 ◽  
Author(s):  
Roktim Gogoi ◽  
Rikraj Loying ◽  
Neelav Sarma ◽  
Twahira Begum ◽  
Sudin K. Pandey ◽  
...  

Background: The essential oil of methyl eugenol rich Cymbopogon khasianus Hack. was evaluated and its bioactivities were compared with pure methyl eugenol. So far, methyl eugenol rich essential oil of lemongrass was not studied for any biological activities; hence, the present study was conducted. Objective: This study examined the chemical composition of essential oil of methyl eugenol rich Cymbopogon khasianus Hack., and evaluated its antioxidant, anti-inflammatory, antimicrobial, and herbicidal properties and genotoxicity, which were compared with pure compound, methyl eugenol. Material and Methods: Methyl eugenol rich variety of Cymbopogon khasianus Hack., with registration no. INGR18037 (c.v. Jor Lab L-9) was collected from experimental farm CSIR-NEIST, Jorhat, Assam (26.7378°N, 94.1570°E). The essential oil wasobtained by hydro-distillation using a Clevenger apparatus. The chemical composition of the essential oil was evaluated using GC/MS analysis and its antioxidant (DPPH assay, reducing power assay), anti-inflammatory (Egg albumin denaturation assay), and antimicrobial (Disc diffusion assay, MIC) properties, seed germination effect and genotoxicity (Allium cepa assay) were studied and compared with pure Methyl Eugenol compound (ME). Results: Major components detected in the Essential Oil (EO) through Gas chromatography/mass spectroscopy analysis were methyl eugenol (73.17%) and β-myrcene (8.58%). A total of 35components were detected with a total identified area percentage of 98.34%. DPPH assay revealed considerable antioxidant activity of methyl eugenol rich lemongrass essential oil (IC50= 2.263 μg/mL), which is lower than standard ascorbic acid (IC50 2.58 μg/mL), and higher than standard Methyl Eugenol (ME) (IC50 2.253 μg/mL). Methyl eugenol rich lemongrass EO showed IC50 38.00 μg/mL, ME 36.44 μg/mL, and sodium diclofenac 22.76 μg/mL, in in-vitro anti-inflammatory test. Moderate antimicrobial activity towards the 8 tested microbes was shown by methyl eugenol rich lemongrass essential oil whose effectiveness against the microbes was less as compared to pure ME standard. Seed germination assay further revealed the herbicidal properties of methyl eugenol rich essential oil. Moreover, Allium cepa assay revealed moderate genotoxicity of the essential oil. Conclusion: This paper compared the antioxidant, anti-inflammatory, antimicrobial, genotoxicity and herbicidal activities of methyl eugenol rich lemongrass with pure methyl eugenol. This methyl eugenol rich lemongrass variety can be used as an alternative of methyl eugenol pure compound. Hence, the essential oil of this variety has the potential of developing cost-effective, easily available antioxidative/ antimicrobial drugs but its use should be under the safety range of methyl eugenol and needs further clinical trials.



2020 ◽  
Vol 20 (3) ◽  
pp. 192-208 ◽  
Author(s):  
Talita Odriane Custodio Leite ◽  
Juliana Silva Novais ◽  
Beatriz Lima Cosenza de Carvalho ◽  
Vitor Francisco Ferreira ◽  
Leonardo Alves Miceli ◽  
...  

Background: According to the World Health Organization, antimicrobial resistance is one of the most important public health threats of the 21st century. Therefore, there is an urgent need for the development of antimicrobial agents with new mechanism of action, especially those capable of evading known resistance mechanisms. Objective: We described the synthesis, in vitro antimicrobial evaluation, and in silico analysis of a series of 1H-indole-4,7-dione derivatives. Methods: The new series of 1H-indole-4,7-diones was prepared with good yield by using a copper(II)- mediated reaction between bromoquinone and β-enamino ketones bearing alkyl or phenyl groups attached to the nitrogen atom. The antimicrobial potential of indole derivatives was assessed. Molecular docking studies were also performed using AutoDock 4.2 for Windows. Characterization of all compounds was confirmed by one- and two-dimensional NMR techniques 1H and 13C NMR spectra [1H, 13C – APT, 1H x 1H – COSY, HSQC and HMBC], IR and mass spectrometry analysis. Results: Several indolequinone compounds showed effective antimicrobial profile against Grampositive (MIC = 16 µg.mL-1) and Gram-negative bacteria (MIC = 8 µg.mL-1) similar to antimicrobials current on the market. The 3-acetyl-1-(2,5-dimethylphenyl)-1H-indole-4,7-dione derivative exhibited an important effect against different biofilm stages formed by a serious hospital life-threatening resistant strain of Methicillin-Resistant Staphylococcus aureus (MRSA). A hemocompatibility profile analysis based on in vitro hemolysis assays revealed the low toxicity effects of this new series. Indeed, in silico studies showed a good pharmacokinetics and toxicological profiles for all indolequinone derivatives, reinforcing their feasibility to display a promising oral bioavailability. An elucidation of the promising indolequinone derivatives binding mode was achieved, showing interactions with important sites to biological activity of S. aureus DNA gyrase. These results highlighted 3-acetyl-1-(2-hydroxyethyl)-1Hindole- 4,7-dione derivative as broad-spectrum antimicrobial prototype to be further explored for treating bacterial infections. Conclusion: The highly substituted indolequinones were obtained in moderate to good yields. The pharmacological study indicated that these compounds should be exploited in the search for a leading substance in a project aimed at obtaining new antimicrobials effective against Gram-negative bacteria.



2019 ◽  
Vol 15 (4) ◽  
pp. 341-351 ◽  
Author(s):  
Ana P. Bettencourt ◽  
Marián Castro ◽  
João P. Silva ◽  
Francisco Fernandes ◽  
Olga P. Coutinho ◽  
...  

Background: Previous publications show that the addition of a phenolic antioxidant to an antifungal agent, considerably enhances the antifungal activity. Objective: Synthesis of novel compounds combining phenolic units with linear or cyclic nitrogencontaining organic molecules with antioxidant/antifungal activity using methodologies previously developed in the group. Methods: Several N- [1,2-dicyano-2- (arylidenamino) vinyl]-O-alkylformamidoximes 3 were synthesized and cyclized to 4,5-dicyano-N- (N´-alcoxyformimidoyl)-2-arylimidazoles 4 upon reflux in DMF, in the presence of manganese dioxide or to 6-cyano-8-arylpurines 5 when the reagent was refluxed in acetonitrile with an excess of triethylamine. These compounds were tested for their antioxidant activity by cyclic voltammetry, DPPH radical (DPPH•) assay and deoxyribose degradation assay. The minimum inhibitory concentration (MIC) of all compounds was evaluated against two yeast species, Saccharomyces cerevisiae and Candida albicans, and against bacteria Bacillus subtilis (Gram-positive) and Escherichia coli (Gram negative). Their cytotoxicity was evaluated in fibroblasts. Results: Among the synthetised compounds, five presented higher antioxidant activity than reference antioxidant Trolox and from these compounds, four presented antifungal activity without toxic effects in fibroblasts and bacteria. Conclusion: Four novel compounds presented dual antioxidant/antifungal activity at concentrations that are not toxic to bacteria and fibroblasts. The active molecules can be used as an inspiration for further studies in this area.



Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 952
Author(s):  
Małgorzata Chrząszcz ◽  
Barbara Krzemińska ◽  
Rafał Celiński ◽  
Katarzyna Szewczyk

The genus Cephalaria, belonging to the Caprifoliaceae family, is a rich source of interesting secondary metabolites, including mainly saponins which display a variety of biological activities, such as immunomodulatory, antimicrobial and hemolytic effects. Besides these compounds, flavonoids and phenolic acids were identified in Cephalaria species. Cephalaria is employed in traditional medicine e.g., to cure cardiac and lung diseases, rheumatism, and regulate menstruation. In this review we focus on the phenolic compound composition and antioxidative activity of Cephalaria species. The antioxidant effect can be explained by flavonoids present in all parts of these plants. However, future efforts should concentrate more on in vitro and in vivo studies and also on clinical trials in order to confirm the possibility of using these plants as natural antioxidants for the pharmacology, food or cosmetic industries.



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