Synthesis, spectral characterization, computational studies, antifungal, DNA interaction, antioxidant and fluorescence property of novel Schiff base ligand and its metal chelates.

Cobalt, Copper, Nickel and Zinc coordinated metal complexes were synthesized by novel thiazole Schiff base ligand 2-ethoxy-4-((5-methylthiazol-2-ylimino)methyl) phenol derived from 3-ethoxy-4-hydroxybenzaldehyde and 2-amino- 5-methylthiazol. The synthesized compounds were spectrochemically characterized by elemental analysis, molar conductance, FT-IR, UV-Vis, Mass spectral analysis, Powdered-XRD and cyclic voltammetry. The thermal stability of synthesized complexes were investigated by using thermogravimetric analysis (TGA). Theoretical computational study were performed for all the synthesized compounds utilizing the DFT/B3LYP method at the 6-31G basic set for Schiff base ligand whereas LANL2DZ basis set for metal complexes. Molecular Electrostatic Potential (MEP), HOMO-LUMO, Mulliken charges and global reactivity descriptors, including chemical potential (µ), global softness (S), chemical hardness (η), and electrophilicity index (ω) were measured and correlated with antimicrobial activity. The synthesized thiazole Schiff base ligand and its coordinated metal complexes shows good antifungal agreement against Fusarium Oxysporum and Aspergillus Niger species. These compounds also exhibit DNA binding, DNA cleaving and antioxidant activity. All the synthesized molecules indicate potential fluorescence property.

Theoretical and experimental studies on three new coordination complexes of Co(II), Ni(II), and Cu(II) with 2,4-dichloro-6-{(E)-[(5-chloro-2 sulfanylphenyl)imino]methyl}phenol Schiff base ligand.

Three mononuclear coordination complexes of Co(II), Ni(II), and Cu(II) have been synthesized from 2,4-dichloro-6-{(E)-[(5-chloro-2-sulfanylphenyl)imino]methyl}phenol ligand (H 2 L) obtained by simple condensation reaction of 3,5-dichloro-2-hydroxybenzaldehyde and 2-amino-4-chlorobenzenethiol and characterized by elemental analysis, spectral (FT-IR, electronic, and (1)H-NMR), molar conductance, thermal, SEM, PXRD, and fluorescence studies. The PXRD analysis and SEM-EDX micrographs show the crystalline nature of complexes. The domain size and the lattice strain of synthesized compounds have been determined according to Williamson-Hall plot. TG of the synthesized complexes illustrates the general decomposition pattern of the complexes. The ligand exhibits an interesting fluorescence property which is suppressed after complex formation. The Co(II) complex adopted a distorted octahedral configuration while Ni(II) and Cu(II) complexes showed square planar geometry around metal center. The geometry optimization, HOMO-LUMO, molecular electrostatic potential map (MEP), and spin density of synthesized compounds have been performed by density functional theory (DFT) method using B3LYP/6-31G and B3LYP/LANL2DZ as basis set. Graphical abstract Three new coordination complexes of Co(II), Ni(II) and Cu(II) with 2,4-dichloro-6-{(E)-[(5-chloro-2 sulfanylphenyl)imino]methyl}phenol Schiff base ligand.

Preparation and characterization of mercury-based traditional herbomineral formulation: Shwas kuthar rasa.

BACKGROUND: Shwas kuthar rasa is a prestigious and potential herbomineral formulation of Ayurveda tested on 100 years of time scale for the treatment of asthma, allergy, and other respiratory problems. However, there is a lack of scientific work on Shwas kuthar rasa. OBJECTIVE: To prepare and physicochemically evaluate mercury-based Shwas kuthar rasa herbomineral formulation of Ayurveda for asthma and allergy. MATERIALS AND METHODS: Shwas kuthar rasa was prepared as per Ayurvedic text and characterized by various modern analytical techniques, viz., transmission electron microscopy (TEM), X-ray diffraction (XRD), far infrared (IR) spectroscopy, fourier transform IR spectroscopy, energy dispersive X-ray analysis, and inductively coupled plasma-mass spectroscopy. RESULTS: Study clearly revealed that prepared Shwas kuthar rasa formulation shows several crystallites agglomerate into a single particle. It yields submicron size particle structure (1.22 µ) with TEM analysis. The usage of mercury in the formulation found in the form of mercuric sulfide (HgS) and reaching to nanocrystalline (31-56 nm) size by XRD analysis. CONCLUSION: The present study indicates Shwas kuthar rasa is nanocrystallite with submicron size particle. Trituration of Kajjali helps in the formation of HgS and increases the crystallinity in the formulation.

Exploring fiber optic approach to sense humid environment over nano-crystalline zinc oxide film.

A novel humidity sensor made up of nano-crystalline zinc oxide (ZnO) film, coated onto the U-shaped typical glass substrate as a wave guide, conjugated with an optical fiber and He-Ne un-polarized laser source. The nano-crystalline zinc oxide (ZnO) was synthesized using single molecular precursor method. The resulting material was characterized with Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), thermogravimetric-differential thermal analysis (TG-DTA) and scanning electron microscopy (SEM). In the thin film, ZnO particles exhibited the wurtzite phase structure with the particle size in a diameter range of 70-80 nm. The humidity sensing characteristic has been estimated by measuring the optical permeability (OP) as a function of percentage relative humidity (%RH) in the ranging from 5 to 90 inside a closed chamber. The OP decreases linearly with increase in %RH with a respond time of about 30 and recovery time of 35s. The sensor exhibits the sensitivity of 0.45 in the %RH range 5-50 and 0.30 from 50 to 90.

Synthesis, structural, and biological studies of some schiff bases and their metal complexes.

New bidentate or tridentate Schiff bases and their VO(II) and Co(II) complexes formed by the condensation of methyl isobutyl ketone with nicotinamide (mna)/2-amino-4-chlorophenol (map) and 2-hydroxy acetophenone with nicotinamide (han)/isoniazide (hai). Physicochemical characterization has been carried out to determine the structure of the complexes. The FAB mass and thermal data show degradation pattern of the complexes. XRD analysis reveals that all the studied complexes crystallize as tetragonal crystal system. Some of the complexes have been screened for their antimicrobial activity by the well diffusion technique using DMSO as solvent on different species of pathogenic bacteria/fungi, that is, E. coli, S. aureus, S. fecalis, A. niger, T. polysporum, and their antimicrobial potency have been discussed. It has been found that all the complexes are antimicrobially active and show higher activity than the free ligand. Metal chelation affects significantly the antimicrobial/bioactive behavior of the organic ligands.

Development of the neo-morphic air breathing organs in three genera of estuarine gobies.

The rudiment of the neo-morphic organ for O2 uptake arises in the form of a gill mass formed by the gill material of the embryonic 5th gill arch. Ectodermal induction to the gill mass takes place in the post-embryonic stage of development to produce a respiratory epithelium of the neo-morphic air breathing organ. The respiratory epithelium of the opercular chamber and the buccal cavity is formed by the cells of the gill mass alone. The respiratory epithelium of the suprabranchial chamber is formed by the cells of the gill mass as well as the gill lamellae derived from the dorsal aspects of the functional gill arches (1 to 4). Extension of the suprabranchial chamber into the buccal region anteriorly is a device to increase the respiratory surface area available for O2 uptake by air. The epithelial position of the blood capillaries in the suprabranchial chamber of Periophthalmodon schlosseri signifies terrestrial nature of the fish.