Gyrase ATPase Domain as an Antitubercular Drug Discovery Platform: Structure‐Based Design and Lead Optimization of Nitrothiazolyl Carboxamide Analogues

In this study, we explored the pharmaceutically underexploited mycobacterial gyrase ATPase (GyrB) domain as a template for a structure‐based virtual screening of our in‐house (BITS Pilani) compound collection to discover new inhibitors targeting Mycobacterium tuberculosis (M.tb.) The hit identified was further customized by using a combination of molecular docking and medicinal chemistry strategies to obtain an optimized analogue displaying considerable in vitro enzyme efficacy and bactericidal properties against the M.tb. H₃₇Rv strain. The binding affinity of the ligand toward the GyrB domain was reascertained by differential scanning fluorimetry experiments. Further evaluation of the hERG toxicity (a major limitation among the previously reported N‐linked aminopiperidine analogues) indicated these molecules to be completely devoid of cardiotoxicity, a significant achievement within this class.     

Determination of biogenic amines and total aflatoxins: Quality index of starter culture soy sauce samples

Food Science and Biotechnology - This study deals with understanding the effects of starter cultures on the safety aspects of soy sauce fermentation and their application to compensate undesirable...     

Study and explanation about the morphological,electrochemical and structural properties of differently synthesized polypyrrole

Polypyrrole (ppy), a conducting polymer was synthesized by four different polymerization methods viz. electrochemical polymerization (EP), interfacial polymerization (IP), chemical oxidative polymerization (COP) and template-assisted polymerization (TAP). The change in morphology that occurred due to the variation of polymerization method used was studied with scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The samples were analyzed by Fourier transform infrared (FT-IR) spectroscopy to confirm the successful polymerization of pyrrole to polypyrrole with the appearance of characteristic bands for N–H stretching, C–N stretching, ppy ring stretching, C–H and C–C bending vibrations. Optical studies were done by UV–Vis absorption spectroscopy that displayed π→π^* and polaronic/bipolaronic transitions of ppy. XRD analysis revealed amorphous nature of ppy. Examination of SEM micrographs disclosed that ppy synthesized by EP had the typical cauliflower structure while ppy formed by IP were in the form of chain like network with a thickness of 250–290 nm, COP resulted in the formation of interlinked microspheres of polypyrrole and TAP formed polypyrrole nanofibers. Electrochemical characterization showed that ppy prepared by EP had the lowest redox activity and the samples were also tested to detect Pb²⁺.     

Identification of invasive vegetation using hyperspectral remote sensing in the California Delta ecosystem

Estuaries are among the most invaded ecosystems on the planet. Such invasions have led in part, to the formation of a massive $1 billion restoration effort in California's Sacramento–San Joaquin River Delta. However, invasions of weeds into riparian, floodplain, and aquatic habitats threaten the success of restoration efforts within the watershed and jeopardize economic activities. The doctrine of early detection and rapid response to invasions has been adopted by land and water resource managers, and remote sensing is the logical tool of choice for identification and detection. However meteorological, physical, and biological heterogeneity in this large system present unique challenges to successfully detecting invasive weeds. We present three hyperspectral case studies which illustrate the challenges, and potential solutions, to mapping invasive weeds in wetland systems: 1) Perennial pepperweed was mapped over one portion of the Delta using a logistic regression model to predict weed occurrence. 2) Water hyacinth and 3) submerged aquatic vegetation (SAV), primarily composed of Brazilian waterweed, were mapped over the entire Delta using a binary decision tree that incorporated spectral mixture analysis (SMA), spectral angle mapping (SAM), band indexes, and continuum removal products. Perennial pepperweed detection was moderately successful; phenological stage influenced detection rates. Water hyacinth was mapped with modest accuracies, and SAV was mapped with high accuracies. Perennial pepperweed and water hyacinth both exhibited significant spectral variation related to plant phenology. Such variation must be accounted for in order to optimally map these species, and this was done for the water hyacinth case study. Submerged aquatic vegetation was not mapped to the species level due to complex non-linear mixing problems between the water column and its constituents, which was beyond the scope of the current study. We discuss our study in the context of providing guidelines for future remote sensing studies of aquatic systems.     

Aflatoxin Inactivation Using Aqueous Extract of Ajowan (Trachyspermum ammi) Seeds

ABSTRACT: Aqueous extract of ajowan seeds was found to contain an aflatoxin inactivation factor (IF). Thin layer chromatography analysis of the toxins after treatment with IF showed relative reduction of aflatoxin G₁ > G₂ > B₁ > B₂. Quantification of toxin using a fluorotoxin meter as well as the Enzyme Linked Immuno s orb ent Assay (ELISA) confirmed these findings. An approximate 80% reduction in total aflatoxin content over the controls was observed. This observed phenomenon of reduction in total toxin was referred to as toxin inactivation. Temperature was found to influence the rate of toxin inactivation. At 45 °C, it was found to be rapid during the initial 5 h and slowed later. The IF was found to retain considerable activity even after boiling and autoclaving, indicating partial heat stability. The activity was lost below pH 4.0. Above pH 4.0, it increased gradually, reaching the maximum at pH 10.0. IF was found to be stable to gamma irradiation. Toxin decontamination in spiked corn samples could be achieved using IF. This study emphasizes the potential of ajowan IF in aflatoxin removal from contaminated food commodities. However, the biological toxicity, if any, of the IF inactivated aflatoxins needs to be confirmed, and the work in this direction is in progress.     

Perinatal choline supplementation improves cognitive functioning and emotion regulation in the Ts65Dn mouse model of Down syndrome.

In addition to mental retardation, individuals with Down syndrome (DS) also develop the neuropathological changes typical of Alzheimer's disease (AD) and the majority of these individuals exhibit dementia. The Ts65Dn mouse model of DS exhibits key features of these disorders, including early degeneration of cholinergic basal forebrain (CBF) neurons and impairments in functions dependent on the two CBF projection systems; namely, attention and explicit memory. Herein, we demonstrate that supplementing the maternal diet with excess choline during pregnancy and lactation dramatically improved attentional function of the adult trisomic offspring. Specifically, the adult offspring of choline-supplemented Ts65Dn dams performed significantly better than unsupplemented Ts65Dn mice on a series of 5 visual attention tasks, and in fact, on some tasks did not differ from the normosomic (2N) controls. A second area of dysfunction in the trisomic animals, heightened reactivity to committing an error, was partially normalized by the early choline supplementation. The 2N littermates also benefited from increased maternal choline intake on 1 attention task. These findings collectively suggest that perinatal choline supplementation might significantly lessen cognitive dysfunction in DS and reduce cognitive decline in related neurodegenerative disorders such as AD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gallium-containing phosphosilicate glasses: Functionalization and in-vitro bioactivity

A gallium containing glass 45.7SiO₂·24.1Na₂O·26.6CaO·2.6P₂O₅·1.0Ga₂O₃ (referred to as “Ga1.0”) and a parent Ga-free glass 46.2SiO₂·24.3Na₂O·26.9CaO·2.6P₂O₅ (hereinafter represented as “H”), corresponding to Bioglass® 45S5, were functionalized with Tetraethoxysilane (TEOS) and (3-Aminopropyl)triethoxysilane (APTS) in order to improve their ability to bond with biomolecules, such as drugs, proteins, and peptides. Functionalization with TEOS and APTS promoted the increment in OH groups and formation of NH₂ groups on the glass surface, respectively. The presence of OH or NH₂ groups was investigated by means of IR spectroscopy and elemental analysis. Moreover, in vitro study of these functionalized glasses was performed in simulated body fluid (SBF) so as to investigate the effect of functionalization on the bioactive behavior of H and Ga1.0. The results showed that the functionalization was obtained along with maintaining their bioactivity. The surfaces of both functionalized glasses were covered by a layer of apatite within 30 days of SBF immersion. In addition, CaCO₃ was also identified on the surface of APTS functionalized glasses. However, no gallium release was detected during SBF soaking.     

Visual Awareness and the Detection of Fearful Faces.

A commonly held view is that emotional stimuli are processed independently of awareness. Here, the authors parametrically varied the duration of a fearful face target stimulus that was backward masked by a neutral face. The authors evaluated awareness by characterizing behavioral performance using receiver operating characteristic curves from signal detection theory. Their main finding was that no universal objective awareness threshold exists for fear perception. Although several subjects displayed a behavioral pattern consistent with previous reports (i.e., targets masked at 33 ms), a considerable percentage of their subjects (64%) were capable of reliably detecting 33-ms targets. Their findings suggest that considerable information is available even in briefly presented stimuli (possibly as short as 17 ms) to support masked fear detection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)