Red-emitting β-diketonate Eu(III) Complexes With Substituted 1,10-phenanthroline Derivatives: Optoelectronic and Spectroscopic Analysis

Journal of Fluorescence - A series of europium diketonate complexes with 1-phenyl-1,3-butanedione (PBD) and 1,10-phenanthroline derivatives were synthesized and explored spectroscopically....     

On birational Torelli theorems

Archiv der Mathematik - Let G be a simple simply-connected connected linear algebraic group over $${\mathbb {C}}$$ . We prove a 2-birational Torelli theorem for the moduli space of semistable...     

Copper-catalyzed Pummerer type reaction of α-thio aryl/heteroarylacetates: Synthesis of aryl/heteroaryl α-keto esters

A copper catalyzed Pummerer type reaction of α-thio aryl/heteroarylacetates is described for the first time. This transformation represents a new route to synthesize α-keto esters, which are important intermediates for pharmaceuticals and organic synthesis. The reaction proceeds via in situ generation of a thionium ion that undergoes hydrolysis to furnish α-keto esters in synthetically viable yields (up to 82%).     

Anti-inflammatory chromone alkaloids and glycoside from Dysoxylum binectariferum

Herein we report isolation of a new chromone alkaloid chrotacumine K (12) from fruits and a chromone glycoside schumaniofioside A (13) from leaves of Dysoxylum binectariferum Hook f. Schumaniofioside A is reported for the first time from Meliaceae family. Other known alkaloids isolated include rohitukine (1) and chrotacumine E (6). The structure of new alkaloid 12 was elucidated on the basis of extensive 1D and 2D NMR analysis, synthesis and chemical hydrolysis. Chemically, chrotacumine K (12) is a 3′-O-acetyl rohitukine which on chemical or enzymatic hydrolysis produces rohitukine. The new alkaloid 12 is also present in seeds and stem-barks of this plant. The glycoside schumaniofioside A (13) is present only in leaves, and in abundance (～1% w/w of dried leaves). The isolated compounds and extracts were evaluated for in vitro effect on the proinflammatory cytokines (TNF-α and IL-6) in human monocytic THP-1 cells. The alkaloid 12 displayed potent inhibition (57%) of TNF-α at 0.3 µM, and was non-toxic to THP-1 cells up to 40 µM, indicating its excellent therapeutic window. Furthermore, a nitrobenzoyl ester analog 15e showed better inhibition of IL-6 than parent natural product chrotacumine K.     

A Novel Method for Permeability Estimation from Micro-tomographic Images

Transport in Porous Media - A methodology has been developed to create a pore network model (PNM) from the geometrical/topological information extracted from the micro-tomographic images of a...     

Synthesis and formulation of self-immolative PEG-aryl azide block copolymers and click-to-release reactivity with trans-cyclooctene

Self-immolative aryl azides can react with trans-cyclooctenes (TCO), triphenylphosphines or hydrogen sulfide (H₂S) to activate prodrugs, imaging probes and drug delivery systems. To date, the synthesis of polymers containing these aryl azide self-immolative linkers and their reactivity with a strained alkene (i.e., in a bioorthogonal reaction) has not been explored. Also, due to the instability of aryl azides towards light and high temperatures, the polymerization methods compatible with aryl azides are limited. Through systematic investigation of the reversible addition-fragmentation chain transfer (RAFT) and atom transfer radical polymerization (ATRP) methods, a self-immolative PEG-aryl azide block copolymer (PEG₄₅-b-ABOC₂₈ 2 ) and a non-responsive 4-fluoroaryl block copolymer (PEG₄₅-b-FBOC₂₄ 3 ) was prepared. ATRP provided the desired polymers in a highly controlled manner, whereas the RAFT conditions led to higher levels of aryl azide polymer degradation. The ATRP derived polymers 2 and 3 were formulated into nanoparticles of approximately 200 nm diameter, and particle triggering was demonstrated by the [3+2]-cycloaddition reaction of TCO with PEG₄₅-b-ABOC₂₈ 2 in solution (pure polymer) and as a formulated nanoparticle. Preliminary in vitro cell viability studies suggested that the stimuli-responsive aryl azide polymers/nanoparticles are not cytotoxic up to 200 μg/ml concentrations.     

Photoluminescence properties of Gd:ZnO nano phosphor

Journal of Sol-Gel Science and Technology - Gd (0.1, 0.5, 1.0?mol%) doped ZnO nano phosphor, prepared by wet chemical method followed by sintering in air at 700?°C, was...