Anti-microbial Perspective of a Chalcone, (E)-1-(1-methoxy-9H-carbazol-3-yl)-3-(4-(methylsulfonyl)phenyl)prop-2-en-1-one: Fabrication of a Hybrid by Unification of a Natural Product with a Synthetic Component

Murraya koenigii L. has been explored exhaustively and is known to possess more than 20 different carbazole-based alkaloids having multifarious therapeutic perception. Of this class of alkaloids, murrayanine is the highest explored alkaloid and is known to have (ethno)-pharmacological perspectives of purgative, astringent, febrifuge, anti-helminthic, anti-oxidant, anti-ulcerogenic, immunomodulation, etc. As murrayanine possess multiple sites for substituting wide-range of electron-donating / -withdrawing groups by semi-synthetic approach, in the present research, a chalcone; (E)-1-(1-methoxy-9H-carbazol-3-yl)-3-(4-(methylsulfonyl)phenyl)prop-2-en-1-one was fabricated rationally by incorporating a natural portion (murrayanine) in the A-ring and a synthetic component (4-methylsulfonyl group) in the B-ring and screened against two bacterial species (Escherichia coli and Staphylococcus aureus) and two fungal species (Candida albicans and Aspergillus niger). The rationally designed chalcone demonstrated noteworthy anti-microbial activity. The fabricated chalcone was observed to be a better anti-bacterial agent as compared to its anti-fungal potentials. As compared to the standard drugs, the experimental molecule does hold well against pathogenic challenges. The present research therefore opened new avenues of judiciously developing a natural scaffold having an active methylsulfonyl group, which will inspire life science researchers across the globe in developing inhibitors with pronounced biological activity as compared with the parent compounds

Anti-microbial Perspective of a Chalcone, (E)-1-(1-methoxy-9H-carbazol-3-yl)-3-(4-(methylsulfonyl)phenyl)prop-2-en-1-one: Fabrication of a Hybrid by Unification of a Natural Product with a Synthetic Component

Murraya koenigii L. has been explored exhaustively and is known to possess more than 20 different carbazole-based alkaloids having multifarious therapeutic perception. Of this class of alkaloids, murrayanine is the highest explored alkaloid and is known to have (ethno)-pharmacological perspectives of purgative, astringent, febrifuge, anti-helminthic, anti-oxidant, anti-ulcerogenic, immunomodulation, etc. As murrayanine possess multiple sites for substituting wide-range of electron-donating / -withdrawing groups by semi-synthetic approach, in the present research, a chalcone; (E)-1-(1-methoxy-9H-carbazol-3-yl)-3-(4-(methylsulfonyl)phenyl)prop-2-en-1-one was fabricated rationally by incorporating a natural portion (murrayanine) in the A-ring and a synthetic component (4-methylsulfonyl group) in the B-ring and screened against two bacterial species (Escherichia coli and Staphylococcus aureus) and two fungal species (Candida albicans and Aspergillus niger). The rationally designed chalcone demonstrated noteworthy anti-microbial activity. The fabricated chalcone was observed to be a better anti-bacterial agent as compared to its anti-fungal potentials. As compared to the standard drugs, the experimental molecule does hold well against pathogenic challenges. The present research therefore opened new avenues of judiciously developing a natural scaffold having an active methylsulfonyl group, which will inspire life science researchers across the globe in developing inhibitors with pronounced biological activity as compared with the parent compounds

Exact solutions in two-dimensional string cosmology with back reaction

We present analytic cosmological solutions in a model of two-dimensional dilaton gravity with back reaction. One of these solutions exhibits a graceful exit from the inflationary to the FRW phase and is nonsingular everywhere. A duality related second solution is found to exist only in the ``pre-big-bang'' epoch and is singular at $\tau = 0$. In either case back reaction is shown to play a crucial role in determining the specific nature of these geometries.Comment: Shortened slightly, references added, to appear in Physical Review D (Rapid Communications). 16 pages, RevTex, 3 PostScript figure

Planetoid strings : solutions and perturbations

A novel ansatz for solving the string equations of motion and constraints in generic curved backgrounds, namely the planetoid ansatz, was proposed recently by some authors. We construct several specific examples of planetoid strings in curved backgrounds which include Lorentzian wormholes, spherical Rindler spacetime and the 2+1 dimensional black hole. A semiclassical quantisation is performed and the Regge relations for the planetoids are obtained. The general equations for the study of small perturbations about these solutions are written down using the standard, manifestly covariant formalism. Applications to special cases such as those of planetoid strings in Minkowski and spherical Rindler spacetimes are also presented.Comment: 24 pages (including two figures), RevTex, expanded and figures adde

On the Rotating Charged Black String Solution

A rotating charged black string solution in the low energy effective field theory describing five dimensional heterotic string theory is constructed. The solution is labelled by mass, electric charge, axion charge and angular momentum per unit length. The extremal limit of this solution is also studied.Comment: 12 pages, IMSC-93/6,(Phyzzx macro), January 199

Exact Primordial Black Strings in Four Dimensions

A solution of effective string theory in four dimensions is presented which admits interpretation of a rotating black cosmic string. It is constructed by tensoring the three dimensional black hole, extended with the Kalb-Ramond axion, with a flat direction. The physical interpretation of the solution is discussed, with special attention on the axion, which is found to play a role very similar to a Higgs field. Finally, it is pointed out that the solution represents an exact WZWN $\sigma$ model on the string world sheet, to all orders in the inverse string tension $\alpha'$.Comment: 11 pages plain TeX, Univ. of Alberta preprint Alberta-THY-14-199

String propagation in four-dimensional dyonic black hole background

We study string propagation in an exact, four-dimensional dyonic black hole background. The general solutions describing string configurations are obtained by solving the string equations of motion and constraints. By using the covariant formalism, we also investigate the propagation of physical perturbations along the string in the given curved background.Comment: 19 pages, Tex (macro phyzzx is needed

Antisymmetric tensor coupling and conformal invariance in sigma models corresponding to gauged WZNW theories

String backgrounds associated with gauged $G/H$ WZNW models generically depend on $\alpha'$ or $1/k$. The exact expressions for the corresponding metric G_{\m\n}, antisymmetric tensor B_{\m\n}, and dilaton $\phi$ can be obtained by eliminating the $2d$ gauge field from the local part of the effective action of the gauged WZNW model. We show that there exists a manifestly gauge-invariant prescription for the derivation of the antisymmetric tensor coupling. When the subgroup $H$ is one-dimensional and $G$ is simple the antisymmetric tensor is given by the semiclassical ($\alpha'$-independent) expression. We consider in detail the simplest non-trivial example with non-trivial B_{\m\n} -- the D=3 sigma model corresponding to the $[SL(2,R) x R]/R$ gauged WZNW theory (`charged black string') and show that the exact expressions for G_{\m\n}, B_{\m\n} and $\phi$ solve the Weyl invariance conditions in the two-loop approximation. Similar conclusion is reached for the closely related $SL(2,R)/R$ chiral gauged WZNW model. We find that there exists a scheme in which the semiclassical background is also a solution of the two-loop conformal invariance equations (but the tachyon equation takes a non-canonical form). We discuss in detail the role of field redefinitions (scheme dependence) in establishing a correspondence between the sigma model and conformal field theory results.Comment: 55 pages, harvmac, CERN-TH.6969/93, THU-93/25, Imperial/TP/92-93/59. (Another prescription for extracting the exact antisymmetric tensor is described leading to a purely semiclassical expression for it

Physics Potential of the ICAL detector at the India-based Neutrino Observatory (INO)

The upcoming 50 kt magnetized iron calorimeter (ICAL) detector at the India-based Neutrino Observatory (INO) is designed to study the atmospheric neutrinos and antineutrinos separately over a wide range of energies and path lengths. The primary focus of this experiment is to explore the Earth matter effects by observing the energy and zenith angle dependence of the atmospheric neutrinos in the multi-GeV range. This study will be crucial to address some of the outstanding issues in neutrino oscillation physics, including the fundamental issue of neutrino mass hierarchy. In this document, we present the physics potential of the detector as obtained from realistic detector simulations. We describe the simulation framework, the neutrino interactions in the detector, and the expected response of the detector to particles traversing it. The ICAL detector can determine the energy and direction of the muons to a high precision, and in addition, its sensitivity to multi-GeV hadrons increases its physics reach substantially. Its charge identification capability, and hence its ability to distinguish neutrinos from antineutrinos, makes it an efficient detector for determining the neutrino mass hierarchy. In this report, we outline the analyses carried out for the determination of neutrino mass hierarchy and precision measurements of atmospheric neutrino mixing parameters at ICAL, and give the expected physics reach of the detector with 10 years of runtime. We also explore the potential of ICAL for probing new physics scenarios like CPT violation and the presence of magnetic monopoles.Comment: 139 pages, Physics White Paper of the ICAL (INO) Collaboration, Contents identical with the version published in Pramana - J. Physic