SYNTHESIS AND ANTIMICROBIAL EVALUATION OF SOME NEW OXAZINE DERIVATIVES DERIVED FROM COUMARINYL CHALCONES

A series of novel substituted 3-(2-amino-6-phenyl-6H-1,3-oxazin-4-yl)-2H-chromen-2-ones(AO1-AO10) was synthesized upon refluxing ethanolic solution of substituted 3-cinnamoyl-2H chromen-2-one with urea in presence of 20 % NaOH. The intermediate chalcones, substituted 3-cinnamoyl-2H-chromen2-ones, were synthesized by condensing 3-acetyl coumarin with various substituted benzaldehydes in presence of 20 % NaOH. The structures of the final synthesized compounds were characterized by UV, IR, 1 H NMR and mass spectra. The antibacterial activity of the synthesized compounds was estimated by tube dilution method. The turbidity was observed for the synthesized compounds. Few compounds showed promising minimum inhibitory concentration by tube dilution method.

OMPARATIVE ANTIFUNGAL ACTIVITY OF WILD AND CULTIVATED LEAVES OF FICUS CARICA LINN

Objective: To compare the antifungal activity of wild and cultivated Ficus carica Linn (common fig) leaves extract Materials and Methods: An experimental study was conducted in the department of Botany Islamia College Peshawar from June 2016 to December 2016 which was shaped in 2021 into a research study in the Department of Community Medicine, Khyber Medical College Peshawar. The agar tube dilution method was used for antifungal activity of the extracts. Results: Comparison of Zone of Inhibition (%) in both Aspergillus niger and Aspergillus fumigatus colonies revealed that cultivated species of Ficus carica Linn (common fig locally known as Anjeer ) had more antifungal property against both the fungal species (63% and higher compared that to wild species having maximum zone of inhibition of 54.54%) with the exception of wild plant extract in polar solvent such as chloroform which had high level of antifungal activity (61.53%) only against Aspegillus fumigatus. The experiment also revealed that extracts from both wild and cultivated Ficus carica Linn leaves in polar solvents such as methanol( also written and referred to methanolic in the article) and chloroform showed higher level of antifungal activity against both the fungal species compared to extract taken in non-polar solvents. Conclusion: Extract from cultivated species of Ficus carica Linn had higher level of activity against both the fungal species i.e. Aspergillus niger and Aspergillus fumigatus, especially extract taken in polar solvents. Key words: Ficus carica Linn, antifungal, tube dilution, zone of inhibition

Synthesis, Insilico and Antibacterial Activity Studies of Substituted Dihydro-1, 2-Oxazole Benzopyran-2-One Hybrids

A series of substituted dihydro-1, 2-oxazole benzopyran-2-one (SR1-SR6) were synthesized through the intermediate substituted benzopyran-2-one chalcones and were characterized using spectral analysis. Compounds were docked with receptor DNA Gyrase B (PDB code: 5L3J) to know its interaction and binding energy; ranges -3.38 to -2.15 kcal/mol. Further these compounds were tested for antibacterial activity using tube dilution method and MIC values were observed; ranges 3.12 to 25 µg/ml. Compound 3-(5-(m-tolyl)-4,5-dihydroisoxazol-3-yl)-2H-chromen-2-one (SR3) showed the best interaction with binding energy -3.38 kcal/mol and antimicrobial activity having MIC 3.12 µg/ml. GRAPHICAL ABSTRACT

Synthesis and Antimicrobial Activity of Some New Coumarin Incorporated Pyridine-3-carbonitrile Derivatives

Drug resistance causes serious difficulties in the routine therapy for curing common microbial infections. Thus it is very essential to develop new antimicrobial agents which can offer alternative treatments. The development of potent and effective antimicrobial agents is of utmost importance to overcome the emerging multidrug resistance strains of bacteria and fungi. The technique involves Knoevenagel reaction between substituted salicylaldehyde and ethyl acetoacetate in presence of piperidine as catalyst to give 3-acetyl coumarin. The intermediate coumarinyl chalcones was synthesized by condensing with various substituted benzaldehyde in presence of ethanolic KOH. The final synthesized pyridine-3-carbonitrile derivative was prepared upon refluxing with coumarinyl chalcones with malononitrile in presence of ammonium acetate. All the newly synthesized compounds were assigned on the basis of IR, 1H NMR and mass spectral data. The finalsynthesized compounds were screened for their antibacterial activity tube dilution method. Most of the compounds showed promising MIC by tube dilution method as compared to standard Cephalosporin.

A Synthetic Approach, Characterization and Biological Evaluation of Novel 5-(Arylidene)-2-(5-methyl-1,3,4-thiadiazol-2-ylimino)thiazolidin-4-one Derivatives

The extensive biological potential of thiazolidin-4-one and 1,3,4-thiadiazole moieties, the novel string of 5-(arylidene)-2-(5-methyl-1,3,4-thiadiazol-2-ylimino)thiazolidin-4-one has been synthesized and characterized. The synthesized derivatives were screened for antimicrobial potential using serial tube dilution method. The results showed that all the synthesized compounds have significant biological activity against the microorganisms being tested. The antimicrobial activity of the compounds TA2, TA3, TA4, TA9, TA10 and TA20 against the tested microbial strains was promising. Compound TA4 (2-((5-methyl-1,3,4-thiadiazol-2-yl)imino)-5-(4-nitrobenzylidene)- thiazolidin-4-one) and TA2 (5-(4-chlorobenzylidene)-2-((5-methyl-1,3,4-thiadiazol-2-yl)imino)thiazolidin-4-one) showed promising antimicrobial activity against microbial strains. Compound TA9 (5-(4-(benzyloxy)benzylidene)-2-((5-methyl-1,3,4-thiadiazol-2-yl)imino)thiazolidin-4-one) was found to be the most effective towards B. subtilis. Compound TA10 (5-(3,4-dimethoxybenzylidene)-2-((5- methyl-1,3,4-thiadiazol-2-yl)imino)thiazolidin-4-one) was discovered to be the most potent against the Gram-negative bacteria. Compounds TA3 (5-(4-bromobenzylidene)-2-((5-methyl-1,3,4-thiadiazol- 2-yl)imino)thiazolidin-4-one) and TA20 (5-(2-bromobenzylidene)-2-((5-methyl-1,3,4-thiadiazol-2- yl)imino)thiazolidin-4-one) were the most effective compounds against the fungal strain.

Synthesis of some novel 1H-indole derivatives with antibacterial activity and antifungal activity

The present research works a series of new 1H-Indole derivatives were synthesized. The title compound was obtained by the reaction of indole with chloroacetylchloride in toluene afforded 2-chloro-1-(indoline-1-yl) ethanone which reacts with 1,4 diamine benzene in chloroform afforded 2-((4-aminophenyl)amino)-1-(1H-indol-1-yl)ethan-1-one, on further reaction with various acetophenone in presence of acetic acid in ethanol gave various final derivatives. After synthesis of compounds, the synthesized compounds were characterized by their IR, 1HNMR spectral data and elemental analysis. These derivatives were screened for their antimicrobial activity (Paper-disk-plate technique (disc diffusion method) and Tube-dilution technique (broth microdilution technique), antifungal activity of all synthesized compounds were evaluated against Aspergillus niger and Candida albicans (ATCC 10231) using Fluconazole as the standard drug using the paper plate method and antibacterial activity against both Gram-positive (Bacillus subtilis) and Gram-negative bacteria (Escherichia coli) using Ampicillin as standard medication at a concentration of 50g/ml, 100g/ml. The collected compounds were evaluated for antibacterial activity and antifungal activity. All compounds exhibit significant antimicrobial activity.

Synthesis and Antimicrobial Activities of Containing Sulfur Heterocyclic Curcumin Derivatives

Eight novel containing sulfur heterocyclic curcumins were synthesized and characterized by 1H-NMR, FTIR and MS spectroscopy. Their antimicrobial activities against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Aspergillus niger were also tested for MIC by using serial tube dilution method. The results showed that the antimicrobial activities of synthesized curcumin derivatives were better than curcumin. Especially, the compound 4-(1,3-dithiolan-2-ylidene)-1,7-di(thiophen-2-yl) hepta-1,6-diene-3,5- dione (2g) exhibited excellent the antimicrobial activities among these curcumin derivatives.

Synthesis, Characterization & Antimicrobial Evaluation of New bis(5-Biphenyl-3-alkoxyphenyl-4,5-dihydro-1H-pyrazole-N-carbothioamide) Derivatives

In this study, a series of new symmetrical N-carbothioamide substituted bispyrazolines (2a-f) had been systematically synthesized by using ring closure reactions of bischalcones (1a-f) with thiosemicarbazide under the alkaline-alcoholic conditions. The structures of bisheterocyclic products have been fully characterized on the basis of their IR, 1H & 13C NMR and ESI-MS spectral strategies. All the prepared compounds were also evaluated for their in vitro antimicrobial assay with the help of serial tube dilution procedure against the selected numbers of microbes (seven bacterial and five fungal strains). The most of the synthesized bisheterocycles exhibited noticeable antimicrobial potencies against the tested strains

Improved Methods of Extraction and In Vitro Evaluation of Antimicrobial Potential of Stem Bark of Terminalia arjuna

Background:he Terminalia arjuna has been reported for the antimicrobial activity using classical methods of extraction in the literature. As novel extraction methods have gained importance to carry out the extraction of different plant materials, hence it was planned to extract Terminalia arjuna stem bark in a better way and evaluate the change in antimicrobial activity of the improved extracts.Objective:The extraction and evaluation of antimicrobial activity of stem bark of Terminalia arjuna were performed, analyzed and compared using different extraction methods viz. RTE, SE and USAE in this article.Methods:The central composite design among the response surface methods was adopted to carry out the optimization of different parameters of ultrasound-assisted extraction. The central composite design was used for optimization and the values of parameters for an optimized batch of ultrasoundassisted extraction were 800 W power, 10 minutes time and 1:80 ratio of solid/solvent ratio. The invitro antimicrobial activity was performed using the tube dilution method taking ciprofloxacin and fluconazole as standard antibacterial and antifungal agents.Results:The value of estimated total percentage yield was 12.8 % which upon experimentation was obtained as 12.7 %. The extraction efficiency of USAE was found better as compared to the RTE and SE in terms of the extraction yield 4.2% and 6.8 % respectively. The extraction time of the conventional RTE and SE (2 days and 7 days) was also reduced to minutes (10 to 20 min.) in USAE hence was found to be better. The antimicrobial activity of the selected extracts was performed using tube dilution method on selected strains of bacteria S. aureus, B. subtilis, E. coli and fungal A. niger and C. albicans. The results obtained suggested that the USAE technique showed best results as compared to the other extraction methods and the standard drugs taken (MIC values of 3.12, 1.56, 3.12, 1.56 and 3.12 µg/mL respectively).Conclusion:Hence, it was concluded that ultrasound is an effective technique of extraction and has enhanced the antimicrobial principles of the Terminalia arjuna stem bark.