Synthesis,characterization and antimicrobial evaluation of novel halopyrazole derivatives

Two novel halopyrazole derivatives (3, 5) were synthesized from 5-chloro-3-methyl-1-phenylpyrazole-4-carboxaldehyde (1) using appropriate synthetic routes. Newly synthesized compounds were characterized using elemental analysis, spectral data (IR, ¹H NMR, ¹³C NMR and mass spectrometry) and were evaluated for their in vitro antimicrobial activity. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) were determined for the test compounds as well as for reference standards. The investigation of antimicrobial screening revealed that compounds (3, 5) showed good antibacterial and antifungal activities, respectively.     

An efficient synthesis of new thiazolidin-4-one fused s-triazines as potential antimicrobial and anticancer agents

As a part of our endeavor toward the synthesis of new heterocyclic bioactive agents, two series of thiazolidin-4-one fused s-triazines were synthesized by applying an efficient palladium catalyzed C–C Suzuki coupling using catalyst system Pd(OAC)₂, Xphos and K₃PO₄ as a base in toluene solvent. Moreover, the synthesized analogs were further screened for their in vitro antimicrobial as well as anticancer efficacy against prostate cancer PC3 cells. Some compounds displayed remarkable antimicrobial activity and noticeable anticancer activity. It was observed that, both benzonitrile and nicotinonitrile are essential to increase the different pharmacological activities. The newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR and MS analysis.     

Elucidation of potential anticancer,antioxidant and antimicrobial properties of some new triazole compounds bearing pyridine-4-yl moiety and cyclobutane ring

Thiosemicarbazides (2a–e) were obtained by the interaction of pyridine-4-carboxylic acid hydrazide (1) with five different isothiocyanate (RNCS) derivatives. By addition of KOH to the reaction medium, ethyl, allyl, phenyl and benzyl, p-tolyl substituted 1,2,4-triazoles (3a–e) were obtained. 3a–e were dissolved in dry acetone containing K₂CO₃ in the presence of 2-chloro-1-(3-methyl-3- mesitylcyclobutyl) ethanone (4) to give 3,4,5-trisubstituted 1,2,4-triazole sulfanyl compounds containing a cyclobutane ring (5a–e). The structures of the final compounds were confirmed by elemental analyses, FT-IR, ¹H NMR and ¹³C NMR. Due to many activities regarding pharmacology, Compounds such as 1,2,4-triazole attract high attention in the fields of chemistry, pharmacology, and biology. All the newly synthesised compounds were screened for their Antioxidant, antimicrobial, anti-cancer activities. The measurement of the antioxidant feature of the compounds was performed by DPPH radical scavenging activity technique. It was observed that the activity of some of the compounds was close to the standard antioxidant BHT. Furthermore, the anticancer effects of compounds were investigated against HT29 human colon adenocarcinoma cells. It has been noted that all -compounds inhibited cancerous cells in a statistically significant compared to the control. For the measurement of antimicrobial activity Agar well diffusion method was preferred. For the antimicrobial study, S. aureus, E. faecalis, P. aeruginosa, E. coli, and a single fungi C. albicans have been used. They could also be stated as ATCC 29213, 29212, 27853, 2592, and 10231 respectively. The resulting range of MIC values for the chemicals was between 15.625 - >125 µM. In conclusion; all compounds have shown various and important bioactivities at different levels, such as being antioxidant, antimicrobial, and anticancer.     

Synthesis,anticancer and antimicrobial evaluation of new pyridyl and thiazolyl clubbed hydrazone scaffolds

Abstract

A series of new hydrazones bearing pyridyl and thiazolyl scaffolds have been synthesized and evaluated for their in vitro anticancer and antimicrobial activities. The anticancer activity was evaluated against the A549 lung cancer cell line. The eight hydrazone derivatives have shown better anticancer activity than positive control doxorubicin against the A549 lung cancer cell line. The antimicrobial activity was evaluated against bacterial and fungal pathogens by using well diffusion method. The four hydrazone derivatives have displayed good antimicrobial activities. Molecular docking studies of the synthesized hydrazone derivatives revealed good binding via hydrogen bond interactions with key residues on active sites as well as neighboring residues with an active site of Focal adhesion kinase (PDB ID 2JKO). A computational study for the prediction of absorption, distribution, metabolism, and excretion (ADME) properties of all compounds has also been performed.     

Design and synthesis of some novel pyridothienopyrimidine derivatives and their biological evaluation as antimicrobial and anticancer agents targeting EGFR enzyme

A new series of pyridothienopyrimidine derivatives was designed and evaluated as antimicrobial and anticancer agents. The target compounds were synthesized starting with 3-aminothieno[2,3-b]pyridine-2-carboxamide derivative 1 which underwent cyclocondensation reaction with aromatic aldehydes to give the key intermediates 2a,b. By further treatment of 2a,b with various reagents, the target 2,4-disubstituted-pyrido[3′,2′:4,5]thieno[2,3-d]pyrimidines 3a,b–11a,b were obtained. To evaluate the antimicrobial activity of the new compounds, they were tested against five bacterial and five fungal strains. Compounds 6c, 8b, 9a and 9b revealed the most significant antimicrobial activity against the tested microorganisms with MIC values range (4–16 μg/mL). Also, compounds 2a,b–11a,b were screened for their in vitro cytotoxic activity against HepG-2 and MCF-7 cancer cell lines compared with doxorubicin and cisplatin as references drugs. Moreover, compounds (2b, 4a, 6a, 7b, 7c and 9a) which exhibited the most potent anticancer activity, were further subjected to EGFR^WT enzyme inhibition assay utilizing erlotinib as a standard drug. The compounds 6a, 7b, 7c and 9a which showed the most promising suppression effects were also evaluated as inhibitors against the mutant forms EGFR^L858R and EGFR^T790M. The 4-aminopyrazolone analogue 9a showed superior anticancer activity against both HepG-2 and MCF-7 cell lines (IC50 = 1.27, 10.80 μM, respectively) and more potent enzymatic inhibition activity against EGFR^WT and its mutant forms EGFR^L858R and EGFR^T790M than that obtained by erlotinib (IC₅₀ = 0.021, 0.053, 0.081 µM, respectively, IC_50erlotinib; 0.027, 0.069, 0.550 µM, respectively). Finally, the molecular docking study showed good binding patterns of the most active compounds with the prospective target EGFR^WT.     

Synthesis,Characterization, Biological Evaluation and DNA Interaction Studies of 4-Aminophenol Derivatives: Theoretical and Experimental Approach

In the present study, five 4-aminophenol derivatives (4-chloro-2-(((4-hydroxyphenyl)imino)methyl)phenol(S-1), 4-((4-(dimethylamino)benzylidene)amino)phenol(S-2), 4-((3-nitrobenzylidene)amino)phenol(S-3), 4-((thiophen-2-ylmethylene)amino)phenol(S-4) and 4-(((E)-3-phenylallylidene)amino)phenol(S-5)) were synthesized and characterized by FT-IR, ¹H-NMR, ¹³C-NMR and elemental analyses. The synthesized compounds were tested for their antimicrobial (Gram-positive and Gram-negative bacteria and Saccharomyces cervesea fungus) and antidiabetic (α-amylase and α-glucosidase inhibitory) activities. All the compounds showed broad-spectrum activities against the Staphylococcus aureus (ATCC 6538), Micrococcus luteus (ATCC 4698), Staphylococcus epidermidis (ATCC 12228), Bacillus subtilis sub. sp spizizenii (ATCC 6633), Bordetella bronchiseptica (ATCC 4617) and Saccharomyces cerevisiae (ATCC 9763) strains. The newly synthesized compounds showed a significant inhibition of amylase (93.2%) and glucosidase (73.7%) in a concentration-dependent manner. Interaction studies of Human DNA with the synthesized Schiff bases were also performed. The spectral bands of S-1, S-2, S-3 and S-5 all showed hyperchromism, whereas the spectral band of S-4 showed a hypochromic effect. Moreover, the spectral bands of the S-2, S-3 and S-4 compounds were also found to exhibit a bathochromic shift (red shift). The present studies delineate broad-spectrum antimicrobial and antidiabetic activities of the synthesized compounds. Additionally, DNA interaction studies highlight the potential of synthetic compounds as anticancer agents. The DNA interaction studies, as well as the antidiabetic activities articulated by the molecular docking methods, showed the promising aspects of synthetic compounds.     

Synthesis,characterization and antimicrobial activities of new bis-hydrazonothioxothiazolidinone derivatives

New bis-hydrazonothioxothiazolidinone derivatives based on 2-thioxothiazolidin-4-one were synthesized in good yields using a simplified experimental condition. The structure of synthesized compounds was established with the help of common physico-chemical analysis and various spectroscopic techniques like FT-IR, mass and ¹H NMR. The results of characterizations are in good agreement with the proposed structure of all the synthesized compounds. Further, the antimicrobial (antibacterial and antifungal) activities of all the synthesized derivatives were carried out against various species like Bacillus subtilis, Escherichia coli, Aspergillous niger and Aspergillous flavus by using agar-cup method. The results of antimicrobial screening showed that all the compounds have mild to moderate activity. However, some of the compounds (3a, 3b, 3d, 3e, 3f, 3g, 3i and 3j) have shown better activity than the other.     

4-(1-Aryl-5-chloro-2-oxo-1,2-dihydro-indol-3-ylideneamino)-N-substituted benzene sulfonamides: Synthesis,antimicrobial, anticancer evaluation and QSAR studies

A series of 4-(1-aryl-5-chloro-2-oxo-1,2-dihydro-indol-3-ylideneamino)-N-substituted benzenesulfonamide derivatives (1–20) was synthesized and evaluated for its in vitro antimicrobial and anticancer activities. Antimicrobial results indicated that compounds N-(4-(1-benzoyl-5-chloro-2-oxoindolin-3-ylideneamino) phenylsulfonyl)-4-isopropoxy benzamide (9) and N-(4-(5-chloro-1-(2-chlorobenzoyl)-2-oxoindolin-3-ylideneamino) phenylsulfonyl)-4-isopropoxybenzamide (19) were found to be the most effective ones. The anticancer results indicated that almost all the synthesized compounds were more active than the standard drug carboplatin but less active than the standard drug 5-fluorouracil (5-FU) against both the cell lines (HCT116 and RAW 264.7). 4-(1-Benzoyl-5-chloro-2-oxoindolin-3-ylideneamino)-N-(pyrimidin-2-yl) benzenesulfonamide (3) was found to be most potent and exhibited selectivity toward HCT 116. QSAR studies indicated that antimicrobial activity of isatin derivatives against different microbial strains was governed by lipophilic parameter, log P and topological parameters valance zero and third order molecular connectivity indices (⁰χ^v and ³χ^v).     

Isolation,Structure Elucidation and Antimicrobial Evaluation of Natural Pentacyclic Triterpenoids and Phytochemical Investigation of Different Fractions of Ziziphus spina-christi (L.) Stem Bark Using LCHRMS Analysis

Ziziphus spina-christi L. (ZSC-L) is a tree with thorny branches, belongs to the family Rhamnaceae and grows in the sub-tropics. The purpose of this research is to isolate and partially purify bioactive components from the crude ethanol extract of the stem bark of ZSC-L. Besides, bioassay-guided fractionation of ZSC-L stem bark was conducted using different solvents. The solvents were reutilized to minimize the production cost and environmental harm. In addition, the antimicrobial activities of the fractions were analyzed, followed by metabolic profiling using LC-HRMS. The n-butanol fraction showed the highest antimicrobial efficacy, so it was subjected to further purification. For the first time, two major compounds were isolated from the stem bark of ZSC-L and identified as lupane-type pentacyclic triterpenoids betulinic acid and betulin. Both compounds were used as antibacterial and anticancer agents and considered as a green product as the extraction procedure reduced the use of hazardous chemicals. Metabolic characterization of ZSC-L and its bioactive fractions were performed using LC-HR-ESI-MS and the results revealed the dereplication of 36 compounds belonging to different chemical classes. Flavonoids and triterpenes were the most prominent metabolite classes in the different fractions. The molecular docking results were obtained by studying the interaction of betulin and betulinic acid with antimicrobial receptors (4UYM, 1IYL, 1AJ2, 6J7L, 1AD4, 2VEG) to support the in vitro results. Our study highlights that Ziziphus spina-christi and its phytoconstituents, especially triterpenoids, act as a promising antimicrobial candidate in pharmaceutical and clinical applications.     

Synthesis,antimicrobial, anticancer,antiviral evaluation and QSAR studies of 4-(1-aryl-2-oxo-1,2-dihydro-indol-3-ylideneamino)-N-substituted benzene sulfonamides

A series of 4-(1-aryl-2-oxo-1,2-dihydro-indol-3-ylideneamino)-N-substituted benzenesulfonamide derivatives (1–32) was synthesized and evaluated for its in vitro antimicrobial, antiviral and cytotoxic activities. Antimicrobial results indicated that compounds (11) and (18) were found to be the most effective ones. In general, the synthesized compounds were bacteriostatic and fungistatic in their action. The cytotoxic screening results indicated that the compounds were less active than the standard drug 5-fluorouracil (5-FU). None of the compounds inhibited viral replication at subtoxic concentrations. In general, the presence of a pyrimidine ring with electron releasing groups and an ortho- and para-substituted benzoyl moiety favored antimicrobial activities. The results of QSAR studies demonstrated the importance of topological parameters, valence zero order molecular connectivity index (⁰χ^v) and valence first order molecular connectivity index (¹χ^v) in describing the antimicrobial activity of synthesized compounds.     

Synthesis,characterization and biological activities of some azo derivatives of aminothiadiazole derived from nicotinic and isonicotinic acids

In this study we synthesized the new compounds containing bis-1,3,4-thiadiazole 3(A–D)_n from many reaction steps (cyclization, diazotization and etherification respectively). The compounds have been characterized by melting point, FT-IR and ¹H NMR data. All the synthesized compounds have been evaluated in vitro for their antimicrobial activities against several microbes like: Escherichia coli, Klebsiellia pneumonia, Pseudomonas aeruginosa, Serratia marscens and Staphylococcus aureus and show that some of these compounds have very good antibacterial activity.     

Synthesis,characterization and catalytic,cytotoxic and antimicrobial activities of two novel cyclotriphosphazene‐based multisite ligands and their Ru(II) complexes

Two novel cyclotriphosphazene ligands ( 2 and 3 ) bearing 3‐oxypyridine groups and their corresponding Ru(II) complexes ( 4 and 5 ) were synthesized and their structures were characterized using Fourier transform infrared, ¹H NMR and ³¹P NMR spectroscopic data and elemental analysis. The Ru(II) complexes were used as catalysts for catalytic transfer hydrogenation of p‐substituted acetophenone derivatives in the presence of KOH. Additionally, the cytotoxic activities of compounds 2 , 3 , 4 , 5 were evaluated against PC3 (human prostate cancer), DLD‐1 (human colorectal cancer), HeLa (human cervical cancer) and PNT1A (normal human prostate) cell lines. Finally the antimicrobial activities of compounds 2 , 3 , 4 , 5 were evaluated against a panel of Gram‐positive and Gram‐negative bacteria and yeast cultures. The complexes showed efficient catalytic activity towards transfer hydrogenation of acetophenone derivatives, especially those bearing electron‐withdrawing substituents on the para‐position of the aryl ring. The compounds were found to have moderate to high cytotoxic and antimicrobial activities, and Ru(II) complexation enhanced both cytotoxic and antimicrobial activities in comparison with the parent compounds. Copyright © 2015 John Wiley & Sons, Ltd.     

Synthesis,antibacterial, anticancer and molecular docking studies of macrocyclic metal complexes of dihydrazide and diketone

The complexes of Co(II), Ni(II), Cu(II) and Zn(II) metal ions has been synthesized through template method by the condensation of succinic acid dihydrazide with 5-chloroisatin in alcoholic medium. Complexes were characterized by C H N analysis, molar conductance, thermal analysis, magnetic susceptibility, mass spectrometry, FTIR, EPR, ¹H NMR, UV–Visible spectroscopy. These studies suggest an octahedral geometry for all the complexes. The compounds were found active against B. subtilis and S. aureus and P. aeruginosa and E. coli bacteria. The Zn(II) complex showed significant anticancer activity against Squamous Cell Carcinoma cells tested by the MTT assay method. Molecular docking studies with EGFR tyrosine kinase were also carried out. All these results show that some of the synthesized compounds have remarkable antibacterial and anticancer property.     

Synthesis of novel naphtho[1,2-e][1,3]oxazines bearing an arylsulfonamide moiety and their anticancer and antifungal activity evaluations

A series of novel naphtho[1,2-e][1,3]oxazines bearing arylsulfonamide moiety have been synthesized via a one-pot approach and in a green reaction medium. These new naphtho[1,2-e][1,3]oxazine derivatives have been characterized by their ¹H NMR, ¹³C NMR and the X-ray single crystallography method for compound 7a. All the newly synthesized compounds were examined for their in vitro anticancer activity against breast (MCF-7), colon (HCT116), and B-CLL (Waco3-CD5) cancers. Some of these compounds such as 7j and 7l showed remarkable activities against MCF-7 (breast) and HCT116 (colon) cancers with comparable IC₅₀ (The half maximal inhibitory concentration) values as that of known drugs such as 5-fluorouracil (5-FU). In vitro antimicrobial activities of all compounds were also evaluated against five human pathogenic fungi strains and two bacteria (one gram positive and one gram negative). The best MICs (Minimum Inhibitory Concentrations) were found against the C. albicans.     

Diethylmethyl chitosan as an antimicrobial agent: Synthesis, characterization and antibacterial effects

Chitosan with excellent biodegradable and biocompatible characteristics has received attention as an oral drug delivery vehicle. A quaternized chitosan (i.e., N-diethylmethyl chitosan, DEMC) was prepared based on a modified two-step process via a 2² factorial design to optimize the preparative conditions. DEMC was fully characterized using FTIR and ¹H-NMR spectroscopies. As calculated using NMR-based data, high degree of quaternization was achieved through the optimized two-step process. The highly quaternized biopolymeric derivative was subjected to microbial experiments. The antimicrobial activities of chitosan and DEMC against Escherchia coli were compared by calculation of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Our data indicates that although the antimicrobial activity of DEMC is higher than that of chitosan in acetic acid medium, the both compounds are pH dependent and an increase in concentration of acetic acid results in a significant decrease in both MIC and MBC.     

Synthesis and Bioactivity Evaluation of New 6-Aryl-5-cyano Thiouracils as Potential Antimicrobial and Anticancer Agents

Several novel 6-aryl-5-cyano thiouracil derivatives were synthesized and explored for their activities as antibacterial, antifungal and anticancer agents. The antimicrobial evaluation revealed that compounds 7b and 7c possessed superior antibacterial activity against the Gram positive bacteria S. aureus and B. subtilis compared to the reference drug amoxicillin. Moreover, compound 4i was found to be a broad spectrum antimicrobial agent and it also exhibited the highest antifungal activity against C. albicans, even higher than the reference drug amphotericin B (MIC = 2.34, 3.00 μg/mL respectively). Selected compounds were tested for in vitro cytotoxicity at a single 10^-5 M concentration in accordance to the NCI (USA) protocol. The preliminary screening results showed that most of the compounds had limited cytotoxic activity against renal cancer UO-31 and/or A498 cell lines. Nevertheless, compounds 6d and 6i displayed potent growth inhibitory effect toward non-small cell lung cancer HOP-92 and leukemia MOLT-4 cell lines, respectively.     

Synthesis,antimicrobial, and antioxidant activities of new pyridyl‐ and thiazolyl‐bearing carbohydrazides

A series of novel substituted (E)‐N′‐benzylidene‐4‐methyl‐2‐(2‐propylpyridin‐4‐yl)thiazole‐5‐carbohydrazide derivatives ( 6a‐l ) have been synthesized by following the multistep synthetic route starting from prothionamide. The resulting compounds were characterized via ¹H, ¹³C NMR, and HRMS spectral data. The synthesized carbohydrazides were evaluated for their in vitro antimicrobial and antioxidant activities. Tested molecules have displayed moderate to good growth inhibition activity. Among the screened compounds, 6b , 6e , 6j, and 6k are found to be the more promising antimicrobial agents. A 2,2‐diphenyl‐1‐picrylhydrazyl assay was used to test the antioxidant activity of the carbohydrazides. The carbohydrazide derivatives 6b and 6i have shown better free‐radical scavenging ability than the other investigated compounds.     

Influence of Extraction Solvent on the Phenolic Profile and Bioactivity of Two Achillea Species

The phenolic composition, as well as the antioxidant and antimicrobial activities of two poorly investigated Achillea species, Achillea lingulata Waldst. and the endemic Achillea abrotanoides Vis., were studied. To obtain a more detailed phytochemical profile, four solvents with different polarities were used for the preparation of the plant extracts whose phenolic composition was analyzed using UHPLC-MS/MS (ultra-high performance liquid chromatography-tandem mass spectrometry). The results indicate that both of the investigated Achillea species are very rich in both phenolic acids and flavonoids, but that their profiles differ significantly. Chloroform extracts from both species had the highest yields and were the most chemically versatile. The majority of the examined extracts showed antimicrobial activity, while ethanolic extracts from both species were potent against all tested microorganisms. Furthermore, the antioxidant activity of the extracts was evaluated. It was found that the ethanolic extracts possessed the strongest antioxidant activities, although these extracts did not contain the highest amounts of detected phenolic compounds. In addition, several representatives of phenolic compounds were also assayed for these biological activities. Results suggest that ethanol is a sufficient solvent for the isolation of biologically active compounds from both Achillea species. Moreover, it was shown that the flavonoids naringenin and morin are mainly responsible for these antimicrobial activities, while caffeic, salicylic, chlorogenic, p-coumaric, p-hydroxybenzoic, and rosmarinic acid are responsible for the antioxidant activities of the Achillea extracts.     

Synthesis,biological evaluation,and docking study of a series of 1,4-disubstituted 1,2,3-triazole derivatives with an indole-triazole-peptide conjugate

A series of new compounds containing an indole-triazole - peptide conjugate were designed as potential agents possessing the dual anti-bacterial and anticancer activities. Accordingly, 20 compounds were prepared via a multi-step synthesis involving the copper-catalyzed azide-alkyne cycloaddition (CuAAC) as a key step in moderate to high yield. All the synthesized compounds were purified by chromatographic techniques and characterized by IR, ¹H and ¹³C NMR and mass spectral data. The synthesized derivatives were screened for their antimicrobial activities against one gram-positive (Staphylococcus aureus) and three gram-negative (Escherichia coli, Klebsiella pneumonia, and Proteus vulgaris) bacteria using an agar-well diffusion method. Most of the compounds showed moderate to reasonable antibacterial activities especially the compound 9e that showed good activities against all the strains. The potential of DNA gyrase inhibitory activity of this compound was assessed by using molecular docking studies in silico carried out using Autodock Vina software. The low ΔG_bind value (−9.4 Kcal/mol) of compound 9e suggested its good interactions with the target protein in silico. The cytotoxic activities of some of the compounds synthesized were evaluated via a MTT assay using the human lung cancer cell line A549. Several compounds showed promising activities among which compound 9b , 9k, and 9e showed low IC₅₀ values.     

Synthesis and structural elucidation of bioactive triorganotin(IV) derivatives of sodium deoxycholate

Trimethyl (1), tributyl (2), and triphenyl tin (3) derivatives of sodium (R)-4-((3R,5R,8R,9S,10S,12S,13R,14S,17R)-3,12-dihydroxy-10,13-dimethyl-hexadecahydro-1H-cyclopenta[a]phenanthren-17-yl)pentanoate (sodium deoxycholate) were synthesized by refluxing sodium deoxycholate with the corresponding triorganotin(IV) chloride in 1?:?1?M ratio. All the three compounds were characterized by elemental analysis, infrared spectroscopy, ¹H, ¹³C, ¹¹⁹Sn NMR, and X-ray diffraction studies. From FT-IR spectra, Δν values proposed bridging or chelating behavior of the ligand. The three compounds gave a trigonal bipyramidal geometry in the solid state and tetrahedral geometry in solution. Single crystal of 1 showed polymeric trigonal bipyramidal geometry. Synthesized compounds obtained were screened for their antimicrobial and antitumor activities against A2780 cell line. Results revealed that only 2 showed significant antibacterial activity. However, all the three compounds exhibited promising antifungal and anticancer activities.