Discovery of novel multi-substituted benzo-indole pyrazole schiff base derivatives with antibacterial activity targeting DNA gyrase

2020 ◽  
Vol 99 ◽  
pp. 103807 ◽  
Author(s):  
Hao Liu ◽  
Zhi-Wen Chu ◽  
Dong-Guo Xia ◽  
Hai-Qun Cao ◽  
Xian-Hai Lv
Keyword(s):  
Antibacterial Activity ◽  
Schiff Base ◽  
Dna Gyrase ◽  
Schiff Base Derivatives

scholarly journals Synthesis and Characterization of O-(carboxyl) Chitosan Schiff Base Derivatives and Study Antibacterial Activity

2020 ◽  
Vol 10 (03) ◽  
pp. 402-407
Author(s):  
Ruwaidah S. Saeed
Keyword(s):  
Antibacterial Activity ◽  
Schiff Base ◽  
Analytical Data ◽  
Aromatic Aldehydes ◽  
Distilled Water ◽  
Chitosan Derivative ◽  
Scanning Calorimetry ◽  
Schiff Base Derivatives ◽  
Vis Spectroscopy ◽  
Chitosan Schiff Base

2-mercaptobenzothiazol [1] was reacted with anhydrous carbonate sodium and ClCH2COOH in distilled water to produce a compound [2]. Compound [3] was synthesized by reaction compound [2] with SOCl2 in benzene. O,N-chitosan derivative [4] had synthesized by reacted chitosan with compound [3] in trichloromethane and pyridine. O-chitosan derivative synthesized according to the method of Fischer and Speier from the reaction of chitosan with compound [2] in distilled water in acidic media to produce compound [5]. O-(carboxyl) chitosan Schiff base derivatives [6-9] had synthesized by reaction O-(carboxyl) chitosan [5] with aromatic aldehydes (syringaldehyde, 3-methoxy,4-hydroxybenzeldehyde, 4-nitrobenzeldehyde, 4-bromobenzeldehyde). The structure of produced compounds has been characterized through their spectral and analytical data, as in fourier transform infrared (FTIR) spectra,1H-NMR, UV-vis spectroscopy, elemental analysis (CHNS), scanning electron microscope (SEM), differential scanning calorimetry (DSC), and thermo gravimetry analysis (TGA). Finally, study the antibacterial activity of some prepared polymers.

scholarly journals Synthesis of chiral 3,5-bis(l-phenylalaninyl-l-leucinyl)pyridine Schiff base and their macrocyclic carboxaimide derivatives using 3,5-bis(l-phenylalaninyl)-pyridine methyl ester

2020 ◽  
Vol 75 (3) ◽  
pp. 251-258 ◽  
Author(s):  
Ahmed M. Naglah ◽  
Abd El-Galil E. Amr ◽  
Randa E. Abdel-Mageid ◽  
Elsayed A. Elsayed ◽  
Osama I. Abd El-Salam
Keyword(s):  
Antibacterial Activity ◽  
Schiff Base ◽  
Methyl Ester ◽  
Dicarboxylic Acid ◽  
Acid Hydrazide ◽  
Schiff Base Derivatives ◽  
Antibiotic Drug ◽  
Dicarboxylic Acid Anhydrides ◽  
Acid Anhydrides ◽  
Heterocyclic Aldehydes

AbstractA series of linear tetrapeptides 2–7 and cyclooctapeptedopyridine derivatives 8 and 9, were synthesized using Nα-dinicotinoyl-bis[(l-phenylalaninyl-l-leucyl)hydrazide] 2 as starting material. Acid hydrazide 2 was reacted with aromatic or heterocyclic aldehydes to give Schiff base derivatives 3 and 4, respectively. Additionally, compound 2 was reacted with dicarboxylic acid anhydrides ortetracarboxylic diacid anhydrides to give the corresponding linear diimide carboxamides 5–7, and octapeptide tetraimides 8 and 9, respectively. The synthesized products were elucidated by using spectroscopic evidences and they were evaluated for their antibacterial activity by using streptomycin as reference antibiotic drug.

scholarly journals Synthesis and characterization of some new Schiff base derivatives of gabapentin, and assessment of their antibacterial, antioxidant and anticonvulsant activities

2021 ◽  
Vol 20 (1) ◽  
pp. 145-153
Author(s):  
Muhammad Farrukh Saleem ◽  
Mohsin Abbas Khan ◽  
Irshad Ahmad ◽  
Naveed Aslam ◽  
Umair Khurshid
Keyword(s):  
Antibacterial Activity ◽  
Schiff Base ◽  
Anticonvulsant Activity ◽  
Bacterial Infections ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Parent Drug ◽  
Schiff Base Derivatives ◽  
Zones Of Inhibition ◽  
Derivatives Of

Purpose: To synthesize and characterize some new gabapentin Schiff base derivatives, and to assess their antibacterial, antioxidant and antiepileptic activities.Methods: Four Schiff base derivatives of gabapentin, termed G1, G2, G3 and G4, were synthesized by condensation with benzoin, vanillin, acetophenone, and benzophenone, respectively. Their chemical identities were established by FTIR, 1 H NMR and 13C NMR techniques. The new compounds were screened for antibacterial activity using agar well method, antioxidant activity by DPPH assay, and anticonvulsant activity against pentylenetetrazole (PTZ) induced seizures in mice.Results: All the compounds showed antibacterial activity against the test strains to variable degrees, while the parent drug did not exhibit antibacterial activity. The zones of inhibition of compound G2 against Micrococcus luteus (36.2 ± 1.0 mm) and Serratia marcescens (28.2 ± 1.0 mm), and of compound G4 against Stenotrophomonas maltophilia (36.8 ± 1.0 mm) were larger compared to thestandard drug, doxycycline, exhibiting zones of inhibition 28.2 ± 1.3, 28.2 ± 0.9 and 20.0 ± 0.9 mm, respectively. In addition, compounds G1 and G2 possessed significantly greater (p < 0.05) radical scavenging activity (82.3 ± 1.8 and 92.3 ± 2.2 %, respectively) than the precursor drug, gabapentin (63.2± 2.6 %). The seizure scores for compounds G1 (0.7 ± 0.06) and G2 (0.9 ± 0.07) were comparable(p ˃ 0.05) with gabapentin (0.8 ± 0.06), while compounds G3 and G4 were less active (p < 0.05) than gabapentin.Conclusion: Compounds G1 and G2 exhibit good antibacterial and antioxidant activities while retaining the anticonvulsant activity of the parent drug, gabapentin, thus making them suitable candidates for further development for the treatment of neurodegenerative pathologies associated with bacterial infections. Keywords: Gabapentin, Antibacterial, Seizures, Antioxidant, Anticonvulsant

Green Synthesis of Some Novel Imidazole Schiff base Derivatives Under Microwave Irradiation / Reflux Conditions and Evaluations of the Antibacterial Activity

2020 ◽  
Vol 7 (3) ◽  
pp. 207-215
Author(s):  
Samaneh Eftekhari ◽  
Naser Foroughifar ◽  
Sara Hallajian ◽  
Alireza Khajeh-Amiri
Keyword(s):  
Antibacterial Activity ◽  
Schiff Base ◽  
Microwave Irradiation ◽  
Schiff Bases ◽  
Synthetic Method ◽  
Antibacterial Effects ◽  
Gram Positive ◽  
Imidazole Derivatives ◽  
Schiff Base Derivatives ◽  
Wide Range

Background: Schiff bases are excellent compounds. They were synthesized by condensation of active carbonyl and amines. They were widely used as a substrate in the preparation of industrial compounds as well as pharmaceutical purposes. They exhibit a wide range of biological activities. In this study, based on the importance of Schiff bases, a sustainable synthetic method was developed employing reflux and microwave irradiation. Objective: Develop a new synthetic method for imidazole Schiff base derivatives synthesis employing reflux, microwave irradiation, and ethanol as a green solvent. Methods: Synthesis of imidazole Schiff base derivatives was carried out under reflux and microwave irradiation conditions. Antibacterial activity of imidazole derivatives and standard drugs was examined against two Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and two Gramnegative bacteria (Proteus mirabilis, Escherichia coli). Results: Schiff bases were synthesized in the presence of microwave irradiation and ethanol in high yields 90-98% for 2-4 min. The antibacterial effects of Schiff bases were evaluated against both strains of Gram-positive and Gram-negative. Conclusion: In this paper, a novel series of imidazole Schiff base derivatives were synthesized using reflux, microwave irradiation, and ethanol. Antibacterial effects were investigated. The excellent advantages of microwave irradiation in the synthesis of imidazole derivatives include reduction of reaction time from an hour to a minute, high product yield. In this study, the measurement of antibacterial activity was also important. Imidazole derivatives with Cl, OH, and CH3 groups showed antibacterial effects.

Antibacterial Activity of Dodecylamine Dialdehyde Starch Schiff Base Derivatives

2021 ◽  
pp. 2100178
Author(s):  
Zhenbiao Li ◽  
Xiaojuan Wang ◽  
Jincheng Miao ◽  
Lei Xing ◽  
Shufen Zhang
Keyword(s):  
Antibacterial Activity ◽  
Schiff Base ◽  
Dialdehyde Starch ◽  
Schiff Base Derivatives
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