X-ray structure analysis of 3-chloro-7-hydroxy-4- methyl-chroman-2-one

The title compound crystallizes in the monoclinic space group P21/c, with unit cell parameters a=7.7203(3), b=14.0481(4), c=8.9066(3) Å, â=112.858(5)º, V= 890.11(5) Å3 and Z = 4. The structure has been solved by direct methods and the final R-factor is 0.0433 for 2832 unique reflections. The molecule, as such, is planar and the planarity is confirmed by the magnitude of dihedral angles between the two rings. Extensive Hydrogen-bonding has been observed and chlorine atom is responsible for the formation of trifurcated hydrogen-bond. Trifurcated hydrogen-bond plays a significant role in the design and synthesis of molecules having drug implications

Routing Unmanned Vehicles in GPS-Denied Environments

Most of the routing algorithms for unmanned vehicles, that arise in data gathering and monitoring applications in the literature, rely on the Global Positioning System (GPS) information for localization. However, disruption of GPS signals either intentionally or unintentionally could potentially render these algorithms not applicable. In this article, we present a novel method to address this difficulty by combining methods from cooperative localization and routing. In particular, the article formulates a fundamental combinatorial optimization problem to plan routes for an unmanned vehicle in a GPS-restricted environment while enabling localization for the vehicle. We also develop algorithms to compute optimal paths for the vehicle using the proposed formulation. Extensive simulation results are also presented to corroborate the effectiveness and performance of the proposed formulation and algorithms.Comment: Publised in International Conference on Umanned Aerial System

Molecular structure elucidation and hydrogen bonding analysis of a pyrazolone derivative

The title compound crystallizes in the monoclinic crystal system with space group P21/c having unit cell parameters: a=7.6329(4), b=7.8137(4), c=28.0651(14) Å, ? =95.995o. The structure converges to a final R-value of 0.0563. The two C-N bonds in Ring B are puckered as the torsion around these bonds is 29.67(2)o and -18.49(2)o , respectively. The two methyl carbons as well as the oxygen atom of the central N-containing five-membered ring (B) are significantly deviated from their mean positions. The magnitude of dihedral angle between the phenyl ring A and B is 133.09(1)o while it is 170.43(1)o between ring B and the phenyl ring C. This indicates that the molecule adopts a non-planar configuration. The crystal structure is stabilized by few C-H…O and C-H…N inter and intramolecular hydrogen interactions

COMPARATIVE STUDY OF DIFFERENT ANAND-BHAIRAV RASA AND ITS STANDARIZATION (W.S.R. TO BHAISHAJYA RATNAVALI)

Introduction: Standardization of Ayurvedic drug is an important criteria for selection, processing, efficacy & safety wise, to meet the WHO guidelines for the world wide acceptability of Ayurvedic formulations. Therefore different preparations of Anandbhairav rasa from classic Bhaishajya Ratnavali has been selected and studied for standariztion.Materials & Methods: Three samples of Anand Bhairav Rasa were prepared according to Jwaratisar prakaran of Bhaishajya Ratnavaliand three samples according to Atisar Prakaran of Bhaishajya Ratnavali were made and subjected to various physico-chemical analyses so that their physical as well as chemical changes can be analyzed.Conclusion: Both formulations showed the difference in pharmaceutically, organoleptic examination as well as in chemical analysis. However, the results obtained from physico chemical analysis of all the three samples are very close together and within fixed physico-chemical norms as described in pharmacopeial standards for Ayurvedic formulations

Bioactive flavanoids from Glycosmis arborea

BACKGROUND: Glycosmis is a genus of evergreen glabrous shrub and distributed all over India. It possesses various medicinal properties and is used in indigenous medicine for cough, rheumatism, anemia, and jaundice. Glycosmis arborea is a rich source of alkaloids, terpenoids, coumarins, as well as flavonoids. RESULTS: The chemical investigation of methanol fraction of the leaves of G. arborea led to the isolation of one new flavone C-glycoside along with three known flavanoids, named as 5,7-dihydroxy-2-[4-hydroxy-3-(methoxy methyl) phenyl]-6-C-β-d-glucopyranosyl flavone (4), 5,7,4(′)-trihydroxy-3(′)-methoxy flavone (1), 5,4(′)-dihydroxy-3(′)-methoxy-7-O-β-d-glucupyranosyl flavanone (2), and 5,4(′)-dihydroxy-3(′)-methoxy-7-O-(α-l-rhamnosyl-(1‴→6‴)-β-d-glucopyranosyl) flavanone (3), respectively. The structures of all compounds were elucidated with the help of nuclear magnetic resonance spectrometry. Pure compounds and fractions were evaluated for pest antifeedant and antimicrobial activity. CONCLUSION: Four compounds were isolated from the leaves of G. arborea. Among them, compound 4 showed significant antimicrobial activity

Polymyxin B in Combination with Rifampin and Meropenem against Polymyxin B-Resistant KPC-Producing Klebsiella pneumoniae

Safe and effective therapies are urgently needed to treat polymyxin-resistant KPC-producing K. pneumoniae and suppress the emergence of resistance. We investigated the pharmacodynamics of polymyxin B, rifampin, and meropenem alone and as polymyxin B-based double and triple combinations against KPC-producing K. pneumoniae . The rate and extent of killing with polymyxin B (1-128mg/L), rifampin (2-16mg/L), and meropenem (10-120mg/L) were evaluated against polymyxin B-susceptible (PB S ) and -resistant (PB R ) clinical isolates using 48h static time-kills. Additionally, humanized triple drug regimens of polymyxin B (C ss : 0.5, 1, 2mg/L), rifampin 600mg every 12 or 8h, and meropenem 1 or 2g every 8h dosed as an extended 3h infusion were simulated over 48h using a one-compartment in vitro dynamic infection model. Serial bacterial counts were measured to quantify pharmacodynamic effect. Population analysis profiles (PAPs) were used to assess the emergence of polymyxin B resistance. Monotherapy was ineffective against both isolates. Polymyxin B with rifampin demonstrated early bactericidal activity against the PB S isolate followed by regrowth by 48h. Bactericidal activity was sustained at all polymyxin B concentrations ≥2 mg/L in combination with meropenem. No two-drug combinations were effective against the PB R isolate, but all simulated triple-drug regimens showed early bactericidal activity by 8h that was sustained over 48h against both strains. PAPs did not reveal the emergence of resistant subpopulations. The triple drug combination of polymyxin B, rifampin, and meropenem may be a viable consideration for the treatment of PB R KPC-producing K. pneumoniae . Further investigation is warranted to optimize triple combination therapy