Acetyl Radical Generation in Cigarette Smoke: Quantification and Simulations.

Free radicals are present in cigarette smoke and can have a negative effect on human health. However, little is known about their formation mechanisms. Acetyl radicals were quantified in tobacco smoke and mechanisms for their generation were investigated by computer simulations.

One-pot efficient synthesis of dimeric, trimeric, and tetrameric BODIPY dyes for panchromatic absorption.

One-pot Knoevenagel self-condensation reaction of β-formyl BODIPY dye bearing a formyl group at 2-position offered dimeric, trimeric and tetrameric BODIPY dyes containing a formyl capping end group, exhibiting panchromatic absorption.

Highly water-soluble neutral BODIPY dyes with controllable fluorescence quantum yields.

A series of novel highly water-soluble neutral BODIPY dyes have been obtained by functionalization of BODIPY dyes with branched oligo(ethylene glycol)methyl ether groups at positions 8, 2 and 6 or 4 and 4'. Use of an ortho-substituent group of branched oligo(ethylene glycol)methyl ether on the meso-phenyl ring of BODIPY dyes and replacement of the fluorine atoms of BODIPY dyes at positions 4 and 4' with methyloxy or ethynyl subunits significantly enhance fluorescence quantum yields of BODIPY dyes.

Synthetic oligodeoxynucleotide purification by polymerization of failure sequences.

Synthetic oligodeoxynucleotide is purified by capping failure sequences with an acrylated phosphoramidite followed by polymerization and product extraction. The method is suitable for large scale oligonucleotide drug purification.

Noncovalent functionalization of boron nitride nanotubes with poly(p-phenylene-ethynylene)s and polythiophene.

Boron nitride nanotubes (BNNTs) are functionalized and solubilized in organic solvents such as chloroform, methylene chloride, and tetrahydrofuran by using conjugated poly(p-phenylene ethynylene)s (PPEs) (polymers A and B) and polythiophene (polymer C) via a noncovalent functionalization approach through strong pi-pi stacking interactions between the conjugated polymers and BNNTs. The functionalization of BNNTs with PPEs enhanced planarization of PPEs with red shifts in both absorbance and emission of the composite materials with reference to free PPEs, whereas the functionalization of BNNTs with polythiophene disrupts the pi-conjugation, resulting in blue shifts in both the absorption and emission of the composite material.

Prefluorescent nitroxide probe for the highly sensitive determination of peroxyl and other radical oxidants.

Fluorescamine derivatized 3-amino-2,2,5,5,-tetramethyl-1-pyrrolidinyloxy (I) is shown to undergo an irreversible reaction with peroxyl radicals and other radical oxidants to generate a more highly fluorescent diamagnetic product (II) and thus can be used as a highly sensitive and versatile probe to determine oxidant production optically, either by monitoring the changes in fluorescence intensity, by HPLC analysis with fluorescence detection, or by a combination of both approaches. By changing the [O2]/[I] ratio, we show that peroxyl radicals can be detected and quantified preferentially in the presence of other radical oxidants. Detection of photochemically produced peroxyl radicals is achieved by employing 3-amino-2,2,5,5,-tetramethyl-1-pyrrolidinyloxy (3-ap) alone, followed by derivatization with fluorescamine.

Fractionation and spectroscopic properties of fulvic acid and its extract.

Novel results were obtained when a fulvic acid was isolated from Acros humic acid and fractionated by traditional preparative thin-layer chromatography. Eight colorful bands were directly viewed and analyzed showing very different fluorescence and absorption properties. The fluorescence quantum yield of the bands ranged from 2% to 9.

Protective effect of nitronyl nitroxide-amino acid conjugates on liver ischemia-reperfusion induced injury in rats.

Stable nitroxides are potential antioxidant drugs. In this study, we have linked nitroxide to natural amino acids with the aim to improve therapeutic activity. The radical scavenging activities of two nitronyl nitroxide-amino acid conjugates (NNR and NNK) were evaluated in PC 12 cell survival assays.