Transition metal complexes produced from dipicolinic acid: synthesis, structural characterization, and anti-microbial investigations

  ABSTRACT. A novel series of mononuclear complexes of the type, [M(L)(H2O)2] [M = Co(II) (1), Ni(II) (2), Zn(II) (3), Cd(II) (4), L = dipicolinate), has been investigated using various techniques, including elemental analyses, FT-IR, 1H- and 13C NMR spectroscopy, powder XRD and thermogravimetric analysis. The results indicate that the coordination of the dipicolinic acid to the metal ions involves two carboxylate O atoms, the pyridine N atom, and two water molecules. The pyridine-2,6-dicarboxylic acid and its studied compounds have been screened against microbial species. The findings show that the complexes have higher activity in comparison to the free pyridine-dicarboxylic acid.   KEY WORDS: Dipicolinic acid, Metal complexes, Antimicrobial activity   Bull. Chem. Soc. Ethiop. 2022, 36(3), 607-615.                                                               DOI: https://dx.doi.org/10.4314/bcse.v36i3.10                                                       &nbsp

Mill Scales Blended Polymer Composites For Electrical Insulation Application

Standalone composite films were prepared using modified polyester as a binder and waste iron oxides (mill scales) collected from a steel plant as inorganic filler. The morphology, structure, composition, strength and electrical insulation properties of polymer-iron composites were studied using various analytical techniques such as X-ray diffraction (XRD), Scanning electron microscope (SEM), Atomic force microscopy (AFM), optical microscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray fluorescence (XRF), Brunauer–Emmett–Teller (BET) test, particle size analysis and electrical insulation test. The mill scales collected from the hot strip rolling mill (HSM) have found to comprise three different phases such as wustite, magnetite and hematite. Composites prepared using mill scales were showing three times higher strength compared to the mother polymer film. Electrical insulation of these composites were found to increase in the range of 55-230 MV/mm with increasing iron oxide content from 0.0125 g to 0.25 g in 2.5 g polymer. These results show a potential research field on the mill scales based composites for various advanced applications in improving insulation behaviour of materials which can withstand at higher temperatures and electrical stresses

Evaluation of medicinal potential and antibacterial activity of selected plants against Streptococcus mutans

Article Details: Received: 2020-06-15 | Accepted: 2020-09-28 | Available online: 2021-03-31 https://doi.org/10.15414/afz.2021.24.01.9-15The aim of the study is to screen the bioactive compounds (saponin, tannin, phenolic compounds, terpenoid & steroid) present in selected ethnomedicinal plants, Terminalia bellirica (fruits), Smilax zeylanica (leaves) and Dioscorea oppositifolia (fruits) from Odisha state, India. The single formulation was prepared using the selected plants parts in the ratio 1 : 6 : 3 respectively for quantitative analysis of tannin & total phenol, antioxidant activity and analysis of MIC (Minimum Inhibitory Concentration) against Streptococcus mutans causing bacteria of tooth decay. Results revealed that selected plant parts are rich source of bioactive compounds like tannin, phenolic compounds and saponin. The quantitative analysis of secondary metabolites showed highest concentration of tannin. It was noted that antioxidant activity is highest in methanol extract as compared to aqueous and acetone. MIC analysis also revealed that formulated powder had excellent antibacterial activity against S. mutans and it was observed the lowest values (450 µg ml-1) showed aqueous & methanol followed by acetone. The herbal formulation might be used to formulate new herbal products against tooth decay in near future.Keywords: antibacterial activity, antioxidant activity, ethnomedicinal plants, secondary metabolites, tooth decay ReferencesANDERSON, T. (2004). Dental treatment in medieval England. British Dental Journal, 197(7), 419–425.DESHMUKH, M.A. and THENG, M.A. (2018). Phytochemical screening, quantitative analysis of primary secondary metabolites of Acacia aeabica bark. International Journal of Current Pharmaceutical Research, 10(2), 35–37.DHANYA, S.V.S., et al. (2018). Preliminary phytochemical activity of Smilax zeylanica L. (Smilaceaceae). 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Chapman and Hall Ltd, 49–188.HAZRA, K. (2019). Phytochemical investigation of Terminalia bellirica fruit inside. Asian Journal of Pharmaceutical and Clinical Research, 12(8), 191–194.JYOTHI, T., et al. (2012). Phytochemical evaluation of Smilax zeylanica Linn. Soushrutam, 1(1), 1–14.KANDUTI, D. (2016). Fluoride: a review of use and effects on health. Mater Sociomed, 28, 133–137.MAST, P. et al. (2013). Understanding MIH: definition, epidemiology, differential diagnosis and new treatment guidelines. European Journal of Paediatrics Dent, 14(3), 204–8.MEJÁRE, I. and MJÖR, I.A. (2003). Dental caries: The Disease and its Clinical Management. Wiley-Blackwell.MOORE, W.J. (1983). The role of sugar in the aetiology of dental caries. 1. Sugar and the antiquity of dental caries. Journal of Dentist,11(3), 189–190.NATIONS, M.K. and NUTO, S.D.A.S. (2002). 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Photodegradation of rhodamine B over g-C3N4-FeVO4 hetero-structured nanocomposite under solar light irradiation

Herein, a cost-effective and nontoxic method was employed for the synthesis of g-C3N4-FeVO4 heterojunction nanocomposite photocatalyst. In this method, first g-C3N4 was synthesized from urea by chemical free thermal treatment method. Then FeVO4 nanomaterial was introduced on its surface by co-precipitation method. The prepared nanocomposite was characterized by XRD, Raman, FTIR, XPS, FESEM, and UV-DRS to determine the crystalline phase, functionality, bonding, morphology and band gap. The synthesized nanomaterial was used for the photocatalytic degradation of highly carcinogenic rhodamine B (Rh B) dye from aqueous solution using solar-light irradiation. The composite has remarkably higher photocatalytic behavior compared to pure g-C3N4 and FeVO4. Again, the degradation rate constant of Rh B for g-C3N4-FeVO4 is remarkably more compare to its parent materials. The pattern of the heterojunction formation between g-C3N4 and FeVO4 helps to separate the electron pair thereby increased the photoactivity properties of the composite. Scavenger studies were also performed in order to understand the mechanism of photodegradation. It was observed that along with the electron and hole pairs generated by light photons, hydroxide radicals play an important role in the degradation mechanism

Mill Scales Blended Polymer Composites For Electrical Insulation Application

Standalone composite films were prepared using modified polyester as a binder and waste iron oxides (mill scales) collected from a steel plant as inorganic filler. The morphology, structure, composition, strength and electrical insulation properties of polymer-iron composites were studied using various analytical techniques such as X-ray diffraction (XRD), Scanning electron microscope (SEM), Atomic force microscopy (AFM), optical microscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray fluorescence (XRF), Brunauer–Emmett–Teller (BET) test, particle size analysis and electrical insulation test. The mill scales collected from the hot strip rolling mill (HSM) have found to comprise three different phases such as wustite, magnetite and hematite. Composites prepared using mill scales were showing three times higher strength compared to the mother polymer film. Electrical insulation of these composites were found to increase in the range of 55-230 MV/mm with increasing iron oxide content from 0.0125 g to 0.25 g in 2.5 g polymer. These results show a potential research field on the mill scales based composites for various advanced applications in improving insulation behaviour of materials which can withstand at higher temperatures and electrical stresses

Evaluation of Antihelminthic Activity of Bixa orellana

Intestinal worms are common problems in remote and rural areas of India. The communities of remote areas use some wild plants to treat intestinal worms. Among them, Bixa orellana is a monogenic plant of family Bixaceae, popularly known as lipstick tree or Annatto and locally called as Sinduri. It is traditionally used to kill the intestinal worms, results revealed that seeds of B. orellana possess diverse secondary metabolites such as tannin and phenolic compounds which might be responsible to kill the worms. Antihelminthic activity showed that seed extracts (aqueous, acetone, methanol, and ethanol) were effective against Eisenia fetida. Keeping the traditional uses of Sinduri against stomach worm and to reduce the side effects of synthetic drugs, the present experiment has been designed

Structural investigations, Hirsfeld surface analyses, and molecular docking studies of a phenoxo-bridged binuclear Zinc(II) complex

A novel phenoxo-bridged zinc complex, [Zn2(L)μ(O-O)2H2OCl2] [L= deprotonated salen ligand, 2,2'-((1E,1'E)-((2,2-dimethylpropane-1,3- diyl)bis(azaneylylidene))bis(methaneylylidene))diphenol), was reported. The title complex was characterized by elemental analyses, single crystal X-ray crystallography, spectroscopic studies, and thermogravimetric analysis. The X-ray structure analysis reveals the coordination of Zn1 atom to two imine nitrogen atoms, two phenolic oxygen atoms, and the oxygen atom of aqua ligand, giving it a distorted square pyramidal geometry, whereas the Zn2 atom is bonded to the same phenoxide anions, and two chloride ions, resulting in a distorted tetrahedral geometry. In addition, TD-DFT and NBO analyses were investigated to obtain bonding information insights into the structure. Furthermore, Hirshfeld surface analysis was used to determine various intermolecular interactions in the complex. Furthermore, a docking analysis was performed on the B- DNA [sequence d (CGCGAATTCGCG)2dodecamer] (PDB ID:1BNA) using the AutoDockvina (scripps) software package. The fluorescence property of the title complex was also carried out, and revealed it to be excellent photoluminescent material