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A series of organophosphorous compounds (3a - 3m) containning phosphonate functional group have been synthesized efficiently with high speed and good yield. All the compounds were correctly characterized using different spectroscopic techniques (IR, Mass, 1H, 13C and 31P-NMR). These compounds were screened for their antibacterial activity. All the synthesized derivatives showed good antibacterial activities. 3g compound showed the best activity against one Gram-positive (Staphylococas aureus) and two Gramnegative (Escherichia coli and Klebsiella pneumoniae) species. In order to predict binding interaction between active site of bacterial enzyme and 3g, molecular docking was performed, into the crystal structures of DNA-gyrase cleavage complex of S. aureus (Gram+ve) with PDB_ID:5CDQ and the cleavage complex of topoisomerase Top. IV of K. pneumoniae (Gram-ve) with PDB_ID:5EIX using autodock/vina, an open source software. The molecule showed strong interaction due to H bonding, pi- pi interaction and hydrophobic interaction with active site amino acids. The synthesized compounds were also submitted to drug likeness model programs e.g molinspiration and osiris to predict bioavailability and toxicity profiles which are important for selection of the best drug candidate among all synthesized compounds. With these results we conclusively demonstrated the selected structural analogues can act as potential antibacterial agents.

A new set of 15 compounds containing etodolac moiety and triazole ring were prepared by CuAAC reaction in moderate to high yield. All the synthesized compounds were purified by chromatographic techniques and characterized by spectral data IR, 1H and 13C NMR and mass spectrometry. The newly derived compounds were screened for their anti-bacterial activities against one gram-positive (S. aureus) and two gram-negative (E. coli, K. pneumoniae) bacteria using an agar-well diffusion method. Most of the compounds showed good to moderate antibacterial activities. Especially compound 4e having good activities against all the strains. The compound 4e displayed significant inhibitory potential with MIC 25 µg/mL against all the strains. The potential DNA gyrase inhibitory activity of this compound was investigated by using molecular docking studies carried out using Autodock Vina software. The compound 4e showed the lowest ΔGbind results (-7.7 Kcal/mol, -7.9Kcal/mol). The cytotoxic activity of the obtained compounds was determined using A549 cancer cell line by a MTT assay. They displayed promising activity against the human lung cancer cell line. Especially 4o, 4b, 4d shown lowest IC50 values.

Background: Benzothiazine derivatives, because of their various biological activities have attracted particular attention in Med Chem and drug discovery efforts. The synthetic modifications of 1,2-benzothiazine 1,1-dioxides have been undertaken in order to explore and identify novel compounds or new analogues possessing promising biological activities. In our effort we have designed -oxicam derived bezothiazine-1,2,3-triazole derivatives as potential antibacterial agents. Methods: These compounds were synthesized via a multi-step sequence involving the Cu catalyzed azide- alkyne cycloaddition (CuAAC) as a key step. The CuAAC proceeded at room temperature in DMF to afford 26 novel molecules in good (70-90%) yields. Results: All these compounds were tested for their antibacterial properties against four strains of bacterial microorganisms and subsequently cytotoxic properties against lung and colon cancer cell lines. The compound 4e showed activities against majority of the bacterial species used (nearly comparable to amoxicillin, ciprofloxacin and ofloxacin against P. vulgaris) whereas 4d and 4f showed cytotoxicities selective towards cancer cells. Conclusion: The present bezothiazine-1,2,3-triazole framework represents a new template for the identification of novel and potent antibacterial/anticancer agents.

Ligands containing benzothiazole moiety upon reaction with arene platinum group metal precursors in dry methanol yielded cationic complexes 1–9 having N∩N bonding mode. The general formulation of t...

Plants are prone to encounter some environmental stresses that include both biotic and abiotic. Plants in response to these stress conditions alter their metabolism at the genetic level with consequential effects at the metabolite production. Phenolic compounds, which are secondary metabolites are one such chemical entity which plays a significant role in various physiological processes of the plant. They are mainly formed by three different types of metabolic pathways that produce phenyl propanoid derivatives, flavonoids, terpenoids based on the needs of the plant and the rate of their production is solely dictated by the type of stress condition. A number of phenolic compounds like phytoalexins, phytoanticipins and nematicides exhibit negative response to biotic stress against several soil borne pathogens and nematodes. But some of the phenolic compounds like acetosyringone, umbelliferone, vanillyl alcohol, p-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid, apigenin and luteolin are found to exhibit beneficial effects to plants by encouraging rhizosphere formation particularly in Leguminosae family. Some of the ROS produced in various stress conditions are effectively dealt by various phenolics with antioxidant activity like hydroxyl benzoic acids and hydroxyl cinnamic acids. As the in vivo production of phenolics in plants is influenced by external factors it can certainly provide information for the adoption of agronomic practices to yield the full befits of commercial exploitation. As the in vivo production of phenolics in plants is influenced by external factors it can certainly provide information for the adoption of agronomic practices to yield the full befits of commercial exploitation.

In this paper, we report a one-step, sunlight-irradiated synthesis of ZnO nanostructures (NSs) covered with Ag nanoparticles (NPs) using Tamarindus indica pulp extract (TPE) and their applications to photocatalytic and antibacterial activity. TPE contains phytochemicals that act as reducing and stabilizing agents for the distribution of uniform Ag NPs of approximately 5 nm on the surface of ZnO NSs. The photocatalysis of the synthesized bare ZnO and ZnO/Ag (0.5 wt%) NSs was evaluated under UVA light and dye degradation results for methylene blue (MB) are 68% for ZnO and 94% for ZnO/Ag after 120 min. For methylene orange (MO), bare ZnO and ZnO/Ag NSs were degraded 40% and 81%, respectively, after 150 min. Moreover, the photocatalyst also showed good recycling stability even after five cycles. In addition to dye degradation, the ZnO/Ag NSs were able to show antibacterial activity against E. coli, P. aeruginosa, S. aureus, and B. subtilis at a concentration of 2 mg/ml. They showed higher activity against Gram-positive than gram-negative bacteria, which showed the influence of Ag metal on the enhanced photocatalytic and antibacterial activity of ZnO NSs. Our findings suggested that ZnO/Ag NSs can be synthesized by a facile and ecofriendly method using TPE and showed superior performance for UVA photocatalysis and antibacterial activity compared to bare ZnO.

Arene metal precursors on treatment with thiosemicarbazone ligands (L1, L2, and L3) yielded a series of cationic mono- and binuclear complexes (1–9) with N∩S bonding mode. In general, the complexes have been formulated as [(p-cymene)Ru(L)Cl]+ and [Cp*2M2(L)2]4+ where L = L1, L2, L3, M = Rh/Ir. Contrary to previous results [1], ruthenium complexes portrayed mononuclear bidentate chelation while rhodium and iridium complexes revealed dinuclear bridging coordination through sulfur and imine nitrogen atoms. All these complexes have been characterized by various spectroscopic techniques and antibacterial studies have been carried out for the complexes as well as the ligands, where 5 and 8 showed good inhibitory antibacterial activity.

Synthesis, characterization and antibacterial activity of p-cymene ruthenium, Cp*rhodium and Cp*iridium metal complexes containing pyridyl azine Schiff base ligands have been described. All the complexes have been characterized by various spectroscopic techniques. Molecular structure of complexes 1, 2, 5, 6 and 8 have been obtained by single crystal X-ray diffraction analyses. Spectral studies revealed that ligand L1 bound to metals as neutral mono dentate N donor whereas ligand L2 and L3 revealed the formation of bi dentate NN′ cationic complexes. In vitro antibacterial activity of the complexes was evaluated by the agar well diffusion method using human pathogenic Gram positive bacteria Staphylococcus aureus and Gram-negative bacteria viz., Escherichia coli and Klebsiella pneumonia. Complexes 2–4 does not show any activity against the selected bacteria whereas complexes 1, 5–9 possesses moderate antimicrobial activity and they are more active than the free ligands. The potent activities of the complexes may arise from the coordination, which tends to make metal complexes act as more controlling and potent antimicrobial agents, thus hindering the growth of microorganisms.

We report the efficient biogenic synthesis of silver nanoparticles (Ag NPs) using silver nitrate and extracts of different parts of Theobroma cacao: the husk (h-Ag NPs), pulp (p-Ag NPs), and seed (s-Ag NPs). In addition, we have tested the antibacterial and photocatalytic activities of the Ag-NPs. The Ag NPs obtained from husk, pulp, and seed extracts show variation in the particle size, dispersion, and morphology. UV–visible absorbance measurements reveal surface plasmon resonance bands at 425, 438, and 462 nm for the s-Ag, h-Ag, and p-Ag NPs, respectively. Transmission electron microscopy studies revealed the formation of monodisperse spherical Ag NPs with diameter ranging from 6 to 18 nm. Fourier transform infrared measurements of the as-synthesized Ag NPs indicate differences in the phytochemicals decorating the NP surfaces, which led to differences in the zeta potential, hydrodynamic radius, and polydispersity index. The p-Ag, h-Ag, and s-Ag NPs exhibited photocatalytic activity on exposure to sunlight from sun, achieving 35%, 29%, and 24% degradation of methylene blue (MB) within 60 min, respectively. Further, the p-Ag NPs showed 98.3% MB photodegradation after 180 min. The photocatalytic rate constants for the degradation of MB were also calculated. Finally, we found that the biogenic nanoparticles affect bacterial growth, possibly by causing protein leakage and cell death. The p-Ag NPs showed better antibacterial activity against Bacillus subtilis and Escherichia coli than h-Ag and s-Ag. The photocatalytic and antibacterial activities of the Ag NPs synthesized with T. cacao mainly depend on the particle size and the biomolecules on the surface of the NPs.

Complexes 1–9 were prepared by the reaction of [(arene)MCl2]2 (arene = p-cymene, Cp*; M = Ru, Rh and Ir) with thiourea derivative ligands L1, L2 and L3. These complexes have been isolated as cationic bidentate (N, S), neutral bidentate (N, S) as well as neutral mono-dentate (S) complexes. Anti-bacterial activity studies were carried out for these complexes as well as the ligands against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli; Klebsiella pneumoniae) in which all the complexes (except complexes 2 and 6) as well as the ligands (except L3) showed anti-bacterial activity. In addition to the biological studies, colorimetric sensing study using silver nanoparticles was also carried out where, ligands L1 and L3 showed agglomeration effects.

A series of C-7 substituted-2-morpholino-N-(pyridin-2-ylmethyl)quinazolin-4-amine have been synthesized and biochemical assay was examined against α-glucosidase function inhibition activity. A structure activity and structure property relationship study was experimented to surface the new hit compound. This study led to the identification of C-7substituted quinazolines with minimum inhibitory concentrations (MICs) in the preffered micromolar range in addition with interesting physicochemical properties. Biological evaluation yielded eight analogs which rose with significant α-glucosidase inhibition potency (IC50 values < 2 μM, where reference compound (Acarbose) potency value is IC50 = 0.586 uM) and could be promising candidates for further lead optimization.

For the first time the template containing structural features of more than one NSAIDs and the 1,2,3-triazole ring was explored for the identification of potential cytotoxic agents. These new and complex molecules were predicted to be effective inhibitors of PDE4B by molecular modelling studies in silico. The multi-step synthesis of these compounds were carried out starting from the well-known drug nimesulide and involved the use of copper-catalyzed azide-alkyne cycloaddition (CuAAC) approach as the key step. Mainly two types of compounds e.g. 1-aryl-1H-1,2,3-triazoles and N-aryl-2-(1H-1,2,3-triazol-1-yl)acetamide derivatives were synthesized by using this method in good yields. The in vitro screening of these compounds against two cancer cell lines e.g. HCT-15 (human colon cancer cell line) and NCI-H226 (human lung cancer cell line) using a colorimetric MTT assay allowed identification of two preliminary hit molecules i.e. 8a and 8f. The SAR (Structure Activity Relationship) analysis indicated that the presence of an amide linker between the aryl ring and the 1,2,3-triazole moiety was favorable for the activities. The compound 8a and 8f showed significant inhibition of PDE4B in vitro and good interactions with this protein in silico suggesting PDE4B as their potential target. The usefulness and concerns of these molecules in the light of computational ADME prediction were analyzed. Overall, novel molecules were identified as potential cytotoxic agents for further study.

A series of ruthenium, rhodium and iridium complexes with 4-phenyl-1-(pyridin-4yl)methylene thiosemicarbazide (L1) and 4-phenyl-1-(pyridin-4yl)ethylidene thiosemicarbazide (L2) ligands were synthesized and isolated with hexafluorophosphate as a counter ion. All these complexes were fully characterized with the help of FT-IR, UV-Vis, 1H NMR, 13C NMR and elemental analysis. An agar-well diffusion method was employed for evaluation of antibacterial activities against one Gram-positive bacteria Staphylococcus aureus and two Gram-negative bacteria Escherichia coli, Klebsiella pneumoniae. Antimicrobial activity evaluation revealed that Cp* rhodium complexes has a significant antibacterial activity for all the three strains, Cp* iridium and p-cymene ruthenium complexes have shown moderated activity against the microorganisms but none of the complexes surpass the activity of their reference drugs. Results indicated that all the complexes reported here inhibit the growth of bacteria. Synopsis. A series of ruthenium, rhodium and iridium complexes bearing thiosemicarbazide ligands were synthesized and isolated with hexafluorophosphate as counter ion. Antibacterial potencies of the compounds was reported against Staphylococcus aureus, Escherichia coli, and Klebsiella pneumonia and results shows that all the complexes reported here inhibit the growth of bacteria.

Imino-quinolyl Schiff-base ligands have been prepared by the condensation reaction of substituted 2-aminopyridine and quinoline-2-carbaldehyde. The reaction of [(arene)MCl2]2 with imino-quinolyl Schiff-base ligands leads to the formation of cationic complexes [(arene)M(L)Cl]+ (1–12). Single crystal X-ray diffraction studies were used to confirm the coordination mode and structures of these complexes. The molecular structures of these complexes revealed that they adopt characteristic three-legged piano stool geometry with the metal coordinating through a terminal chloride and imino-quinolyl ligands in a bidentate chelating NN′ fashion. The ligand coordinates to the metal center through the nitrogen of the quinoline and the imine nitrogen forming a five-membered metallacycle. These compounds were evaluated for their in vitro antibacterial activity by the agar well diffusion method against Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae strains. Results show that all the ligands and complexes inhibited the growth of bacteria.

Ligands containing benzothiazole moiety upon reaction with arene platinum group metal precursors in dry methanol yielded cationic complexes 1–9 having N∩N bonding mode. The general formulation of the complexes is presented as [(arene)M(κ2N∩N-L)Cl]+, where L = L1, L2 and L3, M = Ru, Rh and Ir, and arene = p-cymene and pentamethylcyclopentadiene (Cp*). All these complexes were characterized by various spectroscopic techniques and were found to be air-stable. The biological activity studies of these complexes and ligands such as antibacterial and cytotoxicity studies showed that complexes 5, 6 and 9 have the highest antibacterial activity and ligand L1 has the highest cytotoxicity activity.

A new library of pyrido-pyrrolidine hybrid compounds were designed, developed and screened for their antidiabetic property with α-glucosidase. The design is based on preliminary screening of key fragments identified from literature reported α-glucosidase inhibitors and antidiabetic compounds. The most active fragments were stitched to provide a pyrido-pyrrolidine hybrid molecule as a new motif. A library of these compounds were synthesized and screened against a series of α-glycosidases. Subsequently, compound 3k was the most efficacious analog with IC50 of 0.56 μM. Photoluminescence study and circular dichroism experiments indicated that compound 3k modulates the primary and secondary structure of the enzyme. It successfully brings down the fasting blood glucose level for streptozotocin (STZ, 70 mg/kg, Intraperitoneal) induced type I diabetic male Sprague-Dawley rats (250–320 g). At lower concentration, compound 3k slightly stimulates proliferation of BRIN-BD11 (α-glucose responsive beta cells from rat pancreas islets that secretes insulin) cells.

Context: Albizia odoratissima (L. f.) Benth has been used in Indian folk medicine to treat numerous inflammatory pathologies, such as leprosy, ulcers, burns and asthma. Objective: To evaluate the antioxidant and antimicrobial properties of A. odoratissima. Materials and methods: Dried leaves of A. odoratissima were extracted in organic solvents (hexane, chloroform, ethyl acetate, and methanol). The total phenolic content (TPC) and total flavonoid content (TFC) were determined using the Folin-Ciocalteu and aluminum chloride colorimetric methods, respectively. The antioxidant activity was examined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide (H2O2), 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), and ferric reducing antioxidant power (FRAP) assays. The antibacterial activity was examined using minimum inhibitory concentration (MIC) and the minimum bacterial concentration (MBC), determined by broth microdilution method against Gram-negative bacteria (Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Proteus vulgaris) and Gram-positive bacterium (Staphylococcus aureus). Results: The TPC ranged from 4.40 ± 1.06 to 1166.66 ± 31.85 mg GAE/g of dry weight (DW), and the TFC ranged from 48.35 ± 3.62 to 109.74 ± 1.84 mg QE/g of DW. The IC50 values of the ethyl acetate extract for DPPH, ABTS, and H2O2 were 10.96 ± 0.40, 4.35 ± 0.07, and 163.82 ± 1.52 μg/mL, respectively. Both methanol and ethyl acetate extracts demonstrated effective antibacterial activity with MICs and MBCs values ranging 136–546 μg/mL and 273–1093 μg/mL, respectively, against the tested pathogenic species. Conclusions: The leaves of A. odoratissima showed potent free radical scavenging property and antimicrobial activity.

Half sandwich ruthenium, rhodium and iridium complexes containing pyridyl chalcone analogues (L1 and L2) are prepared by the reaction of [(arene)M(µ-Cl)Cl]2 (arene = benzene, p-cymene, Cp*) and (M = Ru, Rh/Ir)] with L1 and L2 in 1:2 (M:L) ratio. Eight neutral mononuclear complexes (1–8) were obtained and characterized using FT-IR, 1H NMR, 13C NMR, ESI mass and UV–Vis spectroscopic methods. The molecular structures of complexes 2, 4, 5 and 7 are established by single crystal X-ray diffraction studies. Antibacterial studies were tested against three strains of bacterial microorganisms Staphylococcus aureus (gram +ve), Klebsiella pneumoniae (gram −ve) and Escherichia coli (gram −ve). Further the cytotoxicity study of the pyridyl chalcone derivatives and their complexes were evaluated against the human colorectal cancer cell lines HT-29, HCT-116 p53+/+, HCT-116 p53−/− and ARPE-19 (non-cancer retinal epithelium).

Herein we report the synthesis, characterization, bonding modes, antibacterial and antioxidant studies of half-sandwich ruthenium, rhodium and iridium complexes containing salicylaldehyde based thiosemicarbazone derivatives. All complexes have been prepared by reacting [(arene)MCl2]2 (M = Ru, Rh, Ir) with thiosemicarbazone derivatives (L1, L2, and L3) in 1:2 (M:L) molar ratio respectively. Three mononuclear and six binuclear cationic complexes have been obtained with either chloride or PF6 or both (in the case of binuclear complexes) as their counter ion. The binding modes of the thiosemicarbazone derivatives to the metal center for complexes 1–3, 6 and 8 have been confirmed by single-crystal X-ray diffraction studies. Further, their in-vitro antibacterial activity against gram-positive Staphylococcus aureus and gram-negative Escherichia coli, Klebsiella pneumoniae strains have been tested. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of these complexes have also been evaluated. Antioxidant activity of these compounds have also been tested. DNA binding studies for complexes 1 and 4 have been assessed owing to their good fluorescence intensity and are presented in supplementary information.

Metal precursors [(arene)MCl2]2 (arene = p-cymene, Cp∗; M = Ru, Rh and Ir) on reacting with 9-fluorenone derivative ligands L1, L2 and L3 resulted in the formation of mononuclear bidentate cationic N∩N bonded complexes. The biological studies of these complexes such as antibacterial activity studies (against Gram-positive and Gram-negative bacteria) revealed significant antibacterial activity with complexes 4, 7 and 9 having the highest activity potency (in-vitro). Whilst for DNA-binding studies, the results revealed that complexes 4 and 5 displayed significant changes in their spectral features upon addition of SM-DNA, thus, indicating that these complexes bind to DNA with a significant affinity.

Pyridyl benzothiazole hydrazone derivatives containing ruthenium, rhodium and iridium complexes have been synthesized, characterized and evaluated for antimicrobial activity. Metal precursors of the type [(arene)RuCl2]2(arene = p-cymene, benzene), [Cp∗MCl2]2 (M = Rh/Ir) and pyridyl benzothiazole hydrazone ligands (L1 and L2) have been employed in this work. Complexes containing ligands L1 in 1:2 (M:L) ratio yielded only one type of cationic mononuclear complexes whereas ligand L2 in 1:2 (M:L) ratio yielded two types of cationic mononuclear complexes. In same manner ligand L2 in 1:1 (M:L) ratio also yielded two types of binuclear complexes with different modes of binding. All these complexes have been characterized by analytical, spectroscopic and single-crystal X-ray diffraction studies. Antibacterial studies of ligands and complexes have been carried out and were found to exhibit potent activity towards gram-positive and gram-negative bacteria.

The reaction of pyrimidine based electron-rich heterocyclic thiophene pyrazoles and halide bridged arene d6 metal precursors yielded a series of mononuclear and dinuclear half sandwich d6 metal complexes. Mononuclear and dinuclear complexes formed by the ratio-based reaction between ligand and metal precursor. All these cationic complexes have been characterized by IR, UV–Vis, 1H NMR, 13C NMR spectroscopic techniques. Complex 5 has been established by single-crystal analysis. X-ray diffraction studies revealed the formation of mononuclear and dinuclear complexes and suggest that the vicinity around the metal atom is distorted octahedral. An in vitro study to screen the antibacterial potential of these complexes against pathogenic bacteria, S. aureus, K. pneumoniae, and E. coli was addressed. All the complexes display a better zone of inhibitions for both Gram-positive (S. aureus) and Gram-negative strains (K. pneumoniae, and E. coli). The minimum inhibitory concentrations (MICs) for the most active complex ranged from 0.125 to 0.25 mg/ml for S. aureus and Klebsiella Pneumoniae and 0.25–0.5 mg/ml for E. coli.

A number of pre-designed benzoxepine-1,2,3-triazole hybrids were synthesized for the first time using a Cu-catalyzed azide–alkyne cycloaddition (CuAAC) strategy. Thus, a remarkably rapid click reaction of 7,9-disubstituted (Z)-4-(azidomethyl)-5-chloro-2,3-dihydrobenzo[b]oxepine with terminal alkynes at room temperature in DMF afforded twenty novel (Z)-1-((5-chloro-2,3-dihydrobenzo[b]oxepin-4-yl)methyl)-1H-1,2,3-triazole derivatives in good to excellent yields. All these compounds were tested for their antibacterial properties against four strains of bacterial microorganisms including two Gram-positive and two Gram-negative species. Some of them showed better activity against Gram-negative bacteria (Escherichia coli) over the Gram-positive strains, indicating the special effectiveness of the present class of compounds towards Gram-negative species. These compounds also showed cytotoxicity against lung and colon cancer cell lines.

BACKGROUND A library of compounds related to the new benzoxepine-oxime-1,2,3-triazole hybrid was created as probable antibacterial agents. Their synthesis involved a Cu-catalyzed azidealkyne cycloaddition (CuAAC) as a key step to construct the desired 1,2,3-triazole ring. Thus the click reaction between the appropriate alkyne containing the benzoxepine-oxime framework with aryl azides afforded the target compounds in good yields. METHOD To assess their antibacterial properties all the synthesized compounds were tested using four bacterial strains consisting of one Gram-positive and three Gram-negative species. RESULTS & CONCLUSION These compounds were generally found to be effective towards gram -ve species and one of them showed selective cytotoxicity against lung cancer cell line.

The title compound, phenyl-2-(4-{(N-(2,2,4-trimethyl-7-phenoxy-1,2-dihydroquinolin-6-yl)methylsulfonamido) methyl}-1H-1,2,3-triazol-1-yl)acetate was synthesized in a single pot. The compound was fully characterized by spectral (IR, NMR & MS) data and elemental analysis and was evaluated in vitro for antibacterial activity against both gram positive as well as gram negative bacteria.