Luminescent Gold Nanorods To Enhance the Near-Infrared Emission of a Photosensitizer for Targeted Cancer Imaging and Dual Therapy: Experimental and Theoretical Approach

Strong plasmon absorption in the near-infrared (NIR) region renders gold nanorods (GNRs) amenable for biomedical applications, particularly for photothermal therapy. However, these nanostructures have not been explored for their imaging potential because of their weak emission profile. In this study, the weak fluorescence emission of GNRs is tuned to match that of the absorption of a photosensitizer (PS) molecule, and energy transfer from the GNR to PS enhances the emission profile of the GNR–PS combination. GNR complexes generally quench the fluorescence emission of nearby chromophores. However, herein, the complex retains or rather enhances the fluorescence through competition in energy transfer. Excitation-dependent energy transfer has been explained experimentally and theoretically by using DFT calculations, the CIE chromaticity diagram, and power spectrum. The final GNR–PS complex modified for tumor specificity serves as an excellent organ-specific theranostic probe for bioimaging and dual therapy both in vitro and in vivo. Principal component analysis designates photodynamic therapy a better candidate than that of photothermal therapy for long-term efficacy in vivo.     

Trinuclear lanthanide complexes of a compartmental ligand N,N'-bis(2-pyridinyl)-2,6-pyridinedicarboxamide: a spectroscopic investigation

Trinuclear lanthanide complexes of the formula [Ln(3)(PPDA)(NO(3))(6)(H(2)O)(2)].NO(3).2H(2)O where Ln=La(III), Pr(III), Sm(III), Nd(III), Eu(III) Gd(III) Tb(III), Dy(III) and Y(III); H(2)PPDA=N,N'-bis(2-pyridinyl)-2,6-pyridinedicarboxamide, have been isolated. The complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibility measurements and spectral (IR, NMR, UV-vis, fluorescence, FAB and EPR) and thermal studies.     

N-(salicylidene)nitrosophenylglycine Schiff base as NOOO-donor towards transition metal ions

A new tetradentate NOOO-donor ligand, N-(salicylidene)nitrosophenylglycine (H₂snpg) has been designed, synthesized and structurally characterized. Copper(II), nickel(II), cobalt(II), manganese(II) and zinc(II) complexes of H₂snpg have been prepared for the first time. The authenticities of the ligand and its metal complexes have been established on the basis of elemental analyses, molar conductance measurements, magnetic properties, spectral (i.r., ¹H-n.m.r., u.v.–vis. and mass) studies. The i.r. spectral studies of all the complexes exhibit a similar feature about the ligating nature of the ligand to the metal ions and revealed that the ligand has coordinated through the carbonyl oxygen, azomethine nitrogen, nitroso oxygen and deprotonated hydroxyl oxygen. The molar conductance data suggest them to be non-electrolytes. The antimicrobial activity of all the compounds was studied against Escherichia coli, Bacillus cirroflagellosus, Aspergillus niger and Candida albicans. All the complexes have shown a moderate to high fungal activity compared to the ligand.     

The effect of terminal chain modifications on the mesomorphic properties of 4,4'-disubstituted diphenyldiacetylenes

A variety of terminal chain modifications (Y) were made on the diacetylenes in which X=C_nH_2n+1, C₁₂H₂₅O and F, and Y=CH₂CH(Me)C₂H₅, COCH₃, C≡CC₅H₁₁, C_nF_2n+1C_nH_2n+1 and CH=CHCO₂C₃H₇. Mesomorphic properties were determined by hot stage polarizing microscopy and DSC. These were compared with those for the dialkyl analogues (X=C_mH_2m+1, Y=C_nH_2n+1) and a series of 1- and 2-olefins (Y=CH=CHC_nH_2n+1 and CH₂CH=CHC_nH_2n+1). The 1-olefin series showed wider range nematics than the dialkyl compounds, whereas the above modifications showed either narrow range nematic phases, no mesophase or higher melting temperatures. New transition temperature and enthalpy data are provided for some of the dialkyl and F-alkyl compounds previously reported, for comparisons. Preliminary birefringence data are also included along with the results of some heat and UV stability studies.     

An improved synthesis of latanoprost involving effective control on 15(S) diastereomer

Abstract

An improved process for the synthesis of latanoprost having excellent optical purity (de 99.9%, [α]_D²⁰?=?+35.37° (c?=?0.90, acetonitrile)) without use of preparative HPLC is described. This process involves effective purification of hydroxyl intermediate (5A) through solvent crystallization followed by inhibition of inversion of the chiral center at C-15 position. This was possible due to judicious use of diol intermediate (6) for double bond reduction prior to hydroxyl protection.     

Synthesis,Characterization, and Antimicrobial Studies of Some Quinolines Containing 1,3-Thiazines

6/8-Substituted-2-chloroquinoline-3-carboxylic acids, upon reaction with 3-(p-substituted aryl)-4H-5-mercapto-1,2,4-triazoles in the presence of sodium acetate and an acetic anhydride medium, afforded a novel series of 2-(p-substituted aryl)-s-triazolo[5,1-b]-6/8-substituted quinolino [1,3] thiazin-9(H)-ones. The structures of the new compounds were elucidated by IR, ¹H NMR, and mass spectral studies. All the newly synthesized compounds have been screened for their antibacterial and antifungal activities. Most of them showed significant activity comparable with that of the standards Furacin and Flucanazol.     

A comparative analysis of uranium in potable waters using laser fluorimetry and ICPMS techniques

The main objective of this work is the accurate measurement of uranium in the potable water sources of Muktsar district of Punjab, India. In the present work, a laser fluorimetry technique was used for the analysis of uranium. Inductively coupled plasma mass spectrometry (ICPMS) technique was also applied to verify and compare the uranium content analyzed using laser technique. About 16 samples from waterworks, bore wells, and hand pumps that supply the drinking water to local population were collected for this purpose. An indigenous laser fluorimeter supplied by RRCAT, Indore was employed for the analysis. Uranium concentrations obtained were in the range from 0 to 10???g?L^?1 in ten samples, 11?C30???g?L^?1 in three samples, and more than 100???g?L^?1 in three samples namely Channu ground water, Warning Khera pump, and Killanwale village hand pump. The USEPA guideline value for uranium in safe drinking water is 30???g?L^?1. Also, a data comparison with similar studies carried out in other countries is presented.     

Condensed Heterotricycles. Synthesis and Reactions of b-Fused 1(2H)-Isoquinolinones with unusual enaminic properties

Homophthalic acid ( 1 ) undergoes reaction with 1,2-, 1,3-, and 1,4-diamines to give condensed 1(2H)-isoquinolinones like 2 , 4 , 13 , and 25 , which exhibit marked enamine character. These are attacked by electrophiles at the N or C terminus. Some notable reactions of imidazoisoquinolone 2 are those with maleic and acrylic acids to form the tetracycles 48 and 51 , respectively. With propiolic acid, 5 underwent an interesting reaction to form the benzimidazonaphthyridine 53 . An equally interesting behaviour was elicited from 2 in its reaction with formaldehyde, when in addition to the expected methylene-bridged molecule 59 , the novel spiro derivative 60 was formed by the dimerisation of a presumed azadiene intermediate 63 .