bacteria use a chemical language to communicate with each other which enables them to synchronize gene expression as a result of cell density. this special language which is called quorum sensing (qs) is based on producing and sensing the small signals and eventually leads them to perceive when a minimum population unit is reached. on the contrary, quorum sensing blockade (quorum quenching) has...

spiro-4- thiazolidinones have been synthesized by the cyclocondensation of phthalazinyl hydrazones with cyclic ketones and substituted mercapto acetic acids. compounds were screened for their antibacterial, antifungal and antihypertensive activity. the combined elemental analyses and spectroscopic data prove the authenticity of the synthesized compounds

An efficient and practical approach for the synthesis of all four stereoisomers of the MT(2) melatonin receptor ligand 4-phenyl-2-propionamidotetralin (4-P-PDOT), each in enantiomerically pure form (ee > 99.9%), was developed. The strategy involved an optical resolution procedure of the key precursor (±)-4-phenyl-2-tetralone with the unusual resolving agent (S)-mandelamide, through the formatio...

In this paper, the pore filling of spiro-OMeTAD (2,2(,7,7(-tetrakis-(N,N-di-pmethoxyphenylamine)9,9(-spirobifluorene) in mesoporous TiO2 films is quantified for the first time using XPS depth profiling and UV–Vis absorption spectroscopy. It is shown that spiro-OMeTAD can penetrate the entire depth of the film, and its concentration is constant throughout the film. We determine that in a 2.5-mm-...

This Focus Review highlights the exciting results obtained in the area of asymmetric catalysis using spirobiindane- or spirobifluorene-based chiral ligands. The spiro, mono, and bidentate ligands have been successfully applied in a wide range of transition-metal-catalyzed asymmetric reactions, including hydrogenations, carbon-carbon and carbon-heteroatom coupling reactions, with superior or com...

Baeyer-Villiger oxidation of racemic bicyclic cyclobutanones with Zr[bis(salicylidene)ethylenediaminato] (salen) complex 1 as catalyst in the presence of a urea-hydrogen peroxide adduct was found to proceed enantiospecifically. The enantiotopos selection in the oxidation was governed primarily by the Zr(salen) catalyst, although migratory aptitude (methine > methylene > methyl) in Baeyer-Villig...

A series of twenty new N-[(4-arylpiperazin-1-yl)-propyl]-2-aza-spiro[4.4]nonane- and [4.5]decane-1,3-dione derivatives were synthesized and their anticonvulsant activity was evaluated in maximal electroshock (MES) and sc pentertazole (sc PTZ) tests. Their neurotoxicity was examined as well. Although no antiseizure properties of the investigated compounds were found in the MES model, eight of th...

Sulfonic acid functionalized SBA-15 (SBA-Pr-SO3H) with pore size 6 nm as an efficient heterogeneous nanoporous solid acid catalyst exhibited good catalytic activity in the Biginelli-like reaction in the synthesis of spiroheterobicyclic rings with good yield and good recyclability. Spiro-pyrimidinethiones/spiro-pyrimidinones-barbituric acid derivatives were synthesized in a simple and efficient ...

9-aminocamptothecin glucuronide (9ACG) is a new water-soluble prodrug of 9-aminocamptothecin (9AC) that is a substrate for beta-glucuronidase and displays potent antitumor activity against human tumor xenografts. The lactone ring of camptothecins (CPTs) is required for antitumor activity but spontaneously opens under physiological conditions to an inactive carboxy form. The carboxy form of many...

background: n-acyl homoserine lactone (ahl) is found to be the main component of quorum sensing (qs) in gram-negative bacteria and plays an important role in biofilm formation. little information is available regarding the role of ahl in biofilm formation in escherichia coli (e. coli). the purpose of this investigation was to biochemically detect and characterize ahl activity in biofilm-forming...