scholarly journals DFT Calculations and In Silico Studies on the Schiff base derivatives with Antibacterial Activities

Author(s):  
Arthi P

Abstract             The heterocyclic Schiff bases (N1Z,N4Z)-N1,N4-bis(3,4-methoxyphenyl)methylidene) benzene-1,4-diamine (1), (N1Z,N4Z)-N1,N4-bis(4-bromobenzylidene)benzene-1,4-diamine (2) and (N1Z,N4Z)-N1,N4-bis(furan-2-ylmethyliden)benzene-1,4-diamine (1) were synthesized by the reported procedure. The molecular structure of the compounds (1‒3) was characterized by FT‒IR and 1H NMR. The bond length, bond angle and HOMO‒LUMO energy gap were calculated out by DFT calculations. The synthesized heterocyclic compounds (1‒3) were screened for their antibacterial activity against Staphylococcus aureus and Escherichia coli. The compound 3 displays superior antibacterial activity compared to standard drug Streptomycin. All the compounds significantly interact with antibacterial protein beta-ketoacyl-acp synthase III and anticancer protein c-Kit tyrosine kinase via p–p, σ–p, hydrogen bonding, electrostatic and van der Waals interactions.

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Ramakrishna Chintakunta ◽  
Geethavani Meka

Abstract Background The o-phenylenediamine is a versatile starting material for several compounds. Synthesized o-phenylenediamine and amino acids (glycine, alanine, aspartic acid, and l-proline) undergo condensation via Phillips reaction. The synthesized compound showed the promising antibacterial activity of Bacillus subtilis and Pseudomonas aeruginosa at the concentration of 100, 50, 25, 12.5, 6.25, 3.12, 1.6, 0.8, 0.4, and 0.2 μg/ml. Ciprofloxacin was used as standard drug. Synthesis of benzimidazole derivatives was carried out and purified by recrystallization process using ethanol. Substituted derivatives were characterized by melting point, TLC and spectroscopic methods include FT-IR and 1H-NMR. Results In silico studies were adopted for synthetic derivatives by Molinspiration, ChemDraw, and online software tool. Minimum inhibitory concentration (MIC) values of B. subtilis and P. aeruginosa were reported, and benzimidazole ligands and Molinspiration scores were generated and listed. Conclusion The more negative values indicate a higher binding affinity. The generated ligand observations can be visualized. Physical constants of synthesized derivates such as solubility and melting point were determined. Bioactivity scores were noted for different derivatives and predicted percentage absorption in the gut. The antibacterial activity was performed using the MIC method (aerobic).


2020 ◽  
Vol 15 (4) ◽  
pp. 145
Author(s):  
IRMA KRESNAWATY ◽  
ACHMAD ZAINUDDIN

<p>ABSTRAK</p><p>Banyak tanaman yang dilaporkan memiliki kandungan senyawabahan aktif antioksidan dan antibakteri. Salah satu tanaman Indonesia yangmemiliki aktivitas ini adalah gambir (Uncaria gambir). Pada penelitian ini,ekstrak etanol daun gambir diubah menjadi derivat metilnya untukmembuatnya lebih larut dalam lemak dan diamati pengaruh derivatisasitersebut terhadap aktivitas antioksidan di laboratorium kimia organik danpengujian aktivitas antibakteri di laboratorium mikrobiologi UniversitasPadjadjaran. Penelitian ini dilaksanakan di laboratorium Kimia OrganikJurusan Kimia dan laboratorium Mikrobiologi Jurusan Biologi UniversitasPadjadjaran dari bulan Desember 2004 - Juli 2005. Ekstrak gambirdimetilasi  menggunakan  dimetil  sulfat  (DMS)  dan  dimurnikanmenggunakan kromatografi kolom dengan pelarut bergradien (kloroform :metanol = 99:1 ; 98:2 ; 95:5 ; 80:20 ; 70:30; dan 50:50 v/v) dan kemudianmenggunakan kloroform : metanol = 99 : 1 v/v. Aktivitas antioksidanmenunjukkan penurunan yang tampak dari peningkatan, yaitu : IC 50  13,41ppm untuk ekstrak etanol menjadi 121,81 ppm untuk hasil metilasi.Aktivitas antibakteri juga menunjukkan penurunan setelah dimetilasikarena adanya penurunan diameter hambat pertumbuhan bakteri. Duaisolat (isolat 1 dan 2) yang diperoleh dari hasil pemurnian dikarakterisasimenggunakan spektrofotometer UV-Visible dan FT-IR. Hasil yangdiperoleh mengindikasikan adanya senyawa fenolik yang ditunjukkan olehregang –OH pada 3445 dan 3448 cm -1 dan regang CH aromatik pada 3010dan 3030 cm -1 . Isolat 1 memiliki aktivitas antioksidan dan antibakteri yanglebih tinggi dibandingkan isolat 2.</p><p>Kata kunci : Uncaria gambir, derivat metil, antibakteri dan aktivitasantioksidan</p><p>ABSTRACT</p><p>The antioxidant and antibacterial activities of ethanolextract of gambir leaves (Uncaria gambir)</p><p>There are many plants in Indonesia reported to contain antioxidantand antibacterial substances. One of them having these activities is gambir(Uncaria gambir). In this research, ethanol extract of gambir leaves waschanged into its methyl derivate in order to make it more soluble in fats.The effect of the derivatization on antioxidant activity was observed atorganic chemistry laboratory and antibacterial activity was observed atmicrobiology laboratory of the Padjadjaran University. This research wascarried out in December 2004 to July 2005. Gambir extract wasmethylized using dimethylsulphate (DMS) and then purified usingcoloumn chromatography with gradient solvents (chloroform : methanol =99:1; 98:2; 50:50; 80:20; 70:30; and 50:50 v/v), and then with chloroform :methanol = 99:1 v/v. The antioxidant activity showed a decrease indicatedby an increase of IC 50 from 13.41 ppm for ethanolic extract to become121.81 ppm for the methylated compounds. The antibacterial activity alsoshowed a decrease after methylization due to the decrease of inhibitiondiameter of bacteria growth. Two isolates (isolate 1 and 2) obtained fromthe  purification  steps  were  characterized  using  UV-Visiblespectrophotometer and FT-IR. The results indicated the existence ofphenolic compunds showed by -OH stretching in 3,445 and 3,448 cm -1 ;and CH aromatic stretching in 3,010 and 3,030 cm -1 . Isolate 1 was higherin antioxidant and antibacterial activities than isolate 2.</p><p>Key words : Uncaria gambir, methyl derivative, antibacterial, antioxidantactivities</p>


2020 ◽  
Vol 17 (7) ◽  
pp. 631-638
Author(s):  
Dele ABDISSA ◽  
Gezahegn FAYE ◽  
Melkamu FAYERA ◽  
Shiferaw DEMISSIE

Kniphofia pumila has been traditionally used for the treatment of different diseases in Oromiya regional state, western part of Ethiopia. Thus, the main objective of this study was to extract bioactive natural products from the roots of K. pumila and perform in vitro antibacterial activity tests against selected pathogens. Extraction of compound from the roots of K. pumila was carried out by maceration method at room temperature and its antibacterial activity was done using agar disc diffusion method. The crude extracts alone and along with ZnCl2 were tested against pathogenic bacteria Escherichia coli (ATCC 25722), Klebsiella pneumoniae subsp. pneumoniae (DSM 19613), Staphylococcus aureus (ATCC 25925) and Salmonella Typhimurium (ATCC 13311). Following its promising activity, the acetone crude extract that have shown better antibacterial activity was subjected to column chromatography for isolation of pure compound. Hence, one pure compound (GZ-1) was obtained from acetone crude extract. Meanwhile, the antibacterial activities of the isolated compound alone and in combination with ZnCl2 were also performed against all aforementioned bacterial strains. Then, isolated compound was characterized by using NMR spectroscopic techniques such as 1H-NMR, 13C-NMR and, 2D NMR, so as to establish its structure as 3’-acetyl-2’,6’-dihydroxy-4-methoxyphenyl-1,8-dihydroxy-3-methylanthraquinone, trivial name knipholone. Finally, GZ-1 was isolated from the roots of K. pumila and it was noted that the antibacterial activities of ZnCl2 in combination with crude extract as well as with isolated compound against E. coli (ATCC 25722), S. aureus (ATCC 25925) and S. Typhimurium (ATCC 13311) bacterial strains showed remarkable results which were greater than the antibacterial activity of the positive standard drug (gentamycin). To sum up, from the chromatographic isolation of roots acetone extract of K. pumila one pure compound (knipholone) was obtained. Its antibacterial activity was also evaluated in combination with ZnCl2 salt and alone.


Author(s):  
Sarath Sasikumar ◽  
Haripriya M. ◽  
Anjali T.

Objective: A series of 1, 2-Benzisoxazole derivatives were synthesized and characterized by various analytical techniques like Melting point, Rf, FTIR, and NMR spectra.Methods: Structures of the compounds were elucidated and evaluated for anti-inflammatory activity by HRBC membrane stabilization method, antibacterial activity against Escherichia coli and Staphylococcus aureus by cup plate method.Results: The compounds 4a and 4e showed good anti-inflammatory activity compared with standard drug Diclofenac sodium and compounds 4b and 4d showed good antibacterial activity on compared with standard drug Gentamycin.Conclusion: These compounds may serve as future leads for anti-inflammatory and antibacterial drug discovery.


2018 ◽  
Vol 68 (12) ◽  
pp. 2845-2849
Author(s):  
Muhammad Liaqat ◽  
Tariq Mahmud ◽  
Muhammad Ashraf ◽  
Muhammad Muddassar ◽  
Muhammad Imran ◽  
...  

The titled Mannich base 2-[(3,4-dimethoxyphenyl)(pyrrolidin-1-yl)methyl]cyclohexanone (DPC) was synthesized by condensing 3,4-dimethoxybenzaldehyde, pyrrolidine and cyclohexanone. The synthesis was carried out by using ethanol as solvent. The development of the reaction was monitored on TLC. The complexation of synthesized Mannich base was carried out with Cu(II) chloride, Co(II) chloride, Ni(II) chloride and Fe(II) chloride. The structures of the synthesized Mannich base and its complexes were confirmed by FT-IR, UV-Vis, 1H-NMR, 13C-NMR, MS and TGA techniques. The proposed geometries of the metal complexes were established on the basis of metal/ligand ratio through AAS/ICP and electronic spectra. The synthesized compounds were evaluated for their antiurease and antibacterial activities. The complex with Co(II) show potent antiurease and antibacterial activity. The nature of SAR of Co(II) has been demonstrated using docking studies.


2019 ◽  
Vol 17 (1) ◽  
pp. 936-942
Author(s):  
Sadia Rehman ◽  
Muhammad Ikram ◽  
Fazle Subhan ◽  
Mutasem Sinnokrot ◽  
Waliullah Khan

AbstractThe titled compound 1,4-diazacycloheptane have vibrational freedom which allows it to coordinate to metal through 1st and 4th positions. Copper (II) and Nickel (II) complexes of DACH were prepared and characterized through UV-Visible, FT-IR, elemental analyses, conductance, and magnetic susceptibilities and compared to the results published in Inorg. Chem., 8(3), 528 (1969). The prepared complexes bearing different coordinating or non-coordinating anions were screened against four different pathogenic bacterial strains to study anionic effect on antibacterial activity. The MIC values of all the compounds suggest that [Cu(DACH)2Br2] is almost inactive against the tested microbes except Staph aureus. Rest of the metal complexes are active at their respective MIC values.


Author(s):  
Md. Ali Asraf ◽  
Md. Mahbubur Rahman ◽  
D. C. Kabiraz ◽  
Rezaul H. Ansary ◽  
Md. Faruk Hossen ◽  
...  

The salophen ligand and its complexes of Ni(II), Co(II), Cu(II), and Mn(II) are explored in terms of synthesis, conductivity; magnetic measurements, elemental analysis, FT-IR; electronic spectra, and antibacterial activities. The 3D molecular modeling structures of the ligand and its metal complexes are obtained by using Argus lab software. The experimental data shows that the ligand is tetradentate and bonded to the metal ion via N2O2 donor atoms. Antibacterial activity of the synthesized compounds are checked against the microbes Bacillus cereus and Escherichia coli. The metal complexes exhibit antibacterial activity higher than that of the free ligand. This works contributes to the science of Schiff base compounds, in addition to stimulating the synthesis of new ligands and its complexes for the future advancement of coordination chemistry.


2020 ◽  
Vol 32 (3) ◽  
pp. 619-626
Author(s):  
D. Sam Daniel Prabu ◽  
Sivalingam Lakshmanan ◽  
K. Thirumurugan ◽  
N. Ramalakshmi ◽  
S. Arul Antony

A series of febuxostat based new chemical entities was synthesized using microwave method and characterized by NMR, mass and FT-IR spectral studies. Molecular docking of febuxostat amide nucleus substitution compounds 8c (-7.91kcal/mol), 8g (-7.94 kcal/mol) exhibiting high binding energy against ALK receptors. Theoretical investigation of MEPs, HOMO, LUMO and energy gap of HOMO-LUMO were calculated by B3LYP/6-31G method. Among the tested compounds, methoxy substituted compound 8g showed highest antibacterial activity against S. aereus and B. subtilis.


2018 ◽  
Vol 16 (S1) ◽  
pp. S48-S54
Author(s):  
Y. Ez zoubi ◽  
S. Lairini ◽  
A. Farah ◽  
K. Taghzouti ◽  
A. El Ouali Lalami

The purpose of this study was to determine the chemical composition and to evaluate the antioxidant and antibacterial effects of the Moroccan Artemisia herba-alba Asso essential oil against foodborne pathogens. The essential oil of Artemisia herba-alba was analyzed by gas chromatography coupled with mass spectroscopy. The antibacterial activity was assessed against three bacterial strains isolated from foodstuff and three bacterial strains referenced by the ATCC (American Type Culture Collection) using the disk diffusion assay and the macrodilution method. The antioxidant activity was evaluated using the DPPH (2, 2-diphenyl-1- picrylhydrazyl) method. The fourteen compounds of the Artemisia herba-alba essential oil were identified; the main components were identified as β-thujone, chrysanthenone, α-terpineol, α-thujone, α-pinene, and bornyl acetate. The results of the antibacterial activity obtained showed a sensitivity of the different strains to Artemisia herba-alba essential oil with an inhibition diameter of 8.50 to 17.00 mm. Concerning the MICs (minimum inhibitory concentrations), the essential oil exhibited much higher antibacterial activity with MIC values of 2.5 μl/ml against Bacillus subtilis ATCC and Lactobacillus sp. The essential oil was found to be active by inhibiting free radicals with an IC50 (concentration of an inhibitor where the response is reduced by half) value of 2.9 μg/ml. These results indicate the possible use of the essential oil on food systems as an effective inhibitor of foodborne pathogens, as a natural antioxidant, and for potential pharmaceutical applications. However, further research is needed in order to determine the toxicity, antibacterial, and antioxidant effects in edible products.


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