Pyrene Excimer-Based Peptidyl Chemosensors for the Sensitive Detection of Low Levels of Heparin in 100% Aqueous Solutions and Serum Samples.

Fluorescent chemosensors (1 and 2, Py-(Arg)nGlyGlyGly(Arg)nLys(Py)-NH2, n = 2 and 3) bearing two pyrene (Py) labeled heparin-binding peptides were synthesized for the sensitive ratiometric detection of heparin. The peptidyl chemosensors (1 and 2) sensitively detected nanomolar concentrations of heparin in aqueous solutions and in serum samples via a ratiometric response. In 100% aqueous solutions at pH 7.

Fluorescent peptide-based sensors for the ratiometric detection of nanomolar concentration of heparin in aqueous solutions and in serum.

New fluorescent peptide-based sensors (1-3) for monitoring heparin in serum sample were synthesized using short peptides (1∼3mer) as a receptor. The peptide-based sensors (2 and 3) showed a sensitive ratiometric response to heparin both in aqueous buffered solution (10 mM HEPES, pH 7.4) and in 2% human serum sample by increase of excimer emission of pyrene at 480 nm and concomitant decrease of monomer emission of pyrene at 376 nm, whereas the peptide-based sensor 1 showed a turn off response only by decrease of monomer emission at 376 nm.

Ratiometric fluorescence chemosensor based on tyrosine derivatives for monitoring mercury ions in aqueous solutions.

Ratiometric fluorescent chemosensors 1 and 2 were synthesized based on tyrosine amino acid derivatives with a pyrene fluorophore. 1 and 2 showed high selectivity for Hg(II) ions among 13 metal ions in aqueous solutions. Both 1 and 2 sensitively detected Hg(II) ions in aqueous solutions by ratiometric response without interference of any of the other tested metal ions including Cu(II), Cd(II), Pb(II), and Ag(I) ions.

A ratiometric fluorescent detection of Zn(II) in aqueous solutions using pyrene-appended histidine.

A fluorescent chemosensor, Py-His, based on histidine was easily synthesized in solid phase synthesis. Py-His displayed a highly sensitive ratiometric response to Zn(II) with potent binding affinity (Ka = 1.17 × 10(13)M(-2)) in aqueous solutions.

A new peptidyl fluorescent chemosensors for the selective detection of mercury ions based on tetrapeptide.

A novel peptidyl chemosensor (PySO2-His-Gly-Gly-Lys(PySO2)-NH2, 1) was synthesized by incorporation of two pyrene (Py) fluorophores into the tetrapeptide using sulfonamide group. Compound 1 exhibited selective fluorescence response towards Hg(II) over the other metal ions in aqueous buffered solutions. Furthermore, 1 with the potent binding affinity (Kd=120 nM) for Hg(II) detected Hg(II) without interference of other metal ions such as Ag(I), Cu(II), Cd(II), and Pb(II).

Highly sensitive ratiometric fluorescent chemosensor for silver ion and silver nanoparticles in aqueous solution.

A pyrene derivative chemosensor (Pyr-WH) based on a dipeptide shows a highly sensitive ratiometric response to Ag(I) as well as silver nanoparticles in aqueous solution at physiological pH. Pyr-WH penetrated live HeLa cells and exhibits a ratiometric response to intracellular Ag(I). The binding mode of Pyr-WH with Ag(I) was characterized based on fluorescence changes in different pH, NMR, and ESI mass spectrometer experiments.

Selective and sensitive ratiometric detection of Hg(II) ions using a simple amino acid based sensor.

Synthesis of a novel pyrene derivative sensor (Py-Met) based on amino acid and its fluorescent behavior for Hg(II) in water was investigated. Upon Hg(II) binding, the Py-Met-bearing sulfonamide group exhibited a considerable excimer emission at 480 nm along with a decrease of monomer emission at 383 nm. Py-Met allows a selective and sensitive ratiometric detection of Hg(II) without any interference from other metal ions.

Highly selectively monitoring heavy and transition metal ions by a fluorescent sensor based on dipeptide.

Fluorescent sensor (DMH) based on dipeptide was efficiently synthesized in solid phase synthesis. The dipeptide sensor shows sensitive response to Ag(I), Hg(II), and Cu(II) among 14 metal ions in 100% aqueous solution. The fluorescent sensor differentiates three heavy metal ions by response type; turn on response to Ag(I), ratiometric response to Hg(II), and turn off detection of Cu(II).

Friedel-Crafts arylation reactions of N-sulfonyl aldimines or sulfonamidesulfones with electron-rich arenes catalyzed by FeCl3 x 6 H2O: synthesis of triarylmethanes and bis-heteroarylarylmethanes.

The FeCl(3) x 6H(2)O-catalyzed Friedel-Crafts arylation reactions of N-sulfonyl aldimines or sulfonamidesulfones with electron-rich arenes and heteroarenes, which lead to the formation of triarylmethanes and bis-heteroarylarylmethanes, are developed. The use of mild reaction conditions, low catalytic loading, high yield, and single step synthesis are the advantages of the present procedure.

InBr3: a versatile catalyst for the different types of Friedel-Crafts reactions.

Mild and efficient InBr(3)-catalyzed Friedel-Crafts alkylation of heteroaromatic or electron-rich aromatic compounds with alpha-amido sulfones at room temperature in CH(2)Cl(2) has been developed. The products undergo further Friedel-Crafts alkylation with heteroaromatic or electron-rich aromatic compounds leading to unsymmetrical or bis-symmetrical triaryl methanes in good yield. Alpha-amido sulfones are employed for the synthesis of the unsymmetrical and bis-symmetrical triaryl methanes.

Isolation, synthesis, and bioactivity of homoisoflavonoids from Caesalpinia pulcherrima.

One new homoisoflavonoid, (3E)-2,3-dihydro-6,7-dimethoxy-3[(3-hydroxy-4-methoxyphenyl)methylene]-4H-1-benzopyran-4-one and four naturally new analogues, (3E)-3-(1,3-benzodioxol-5-ylmethylene)-2,3-dihydro-7-hydroxy-4H-1-benzopyran-4-one, (3E)-3-(1,3-benzodioxol-5-ylmethylene)-2,3-dihydro-7-methoxy-4H-1-benzopyran-4-one, (3E)-2,3-dihydro-7-hydroxy-3-[(3-hydroxy-4-methoxyphenyl)methylene]-4H-1-benzopyran-4-one and (3E)-2,3-dihydro-3-[(3,4-dimethoxyphenyl)methylene]-7-methoxy-4H-1-benzopyran-4-one, along with four known homoisoflavonoids, bonducellin, sappanone A, 2'-methoxybonducellin and 7-O-methylbonducellin were isolated from aerial parts of Caesalpinia pulcherrima. The structures of the new compounds were elucidated by interpretation of their 1D and 2D NMR spectra. Syntheses of the naturally new compounds and the known compounds have also been accomplished.

Isolation and synthesis of a new chromenochalcone and a new chromene from Orthosiphon glabratus.

Chemical investigation on Orthosiphon glabratus afforded 10 compounds, among which a chromenochalcone and a chromene are new. The structures of the new constituents were settled from their 1D- and 2D-NMR spectra. The synthesis of these two compounds and some of their analogues have been accomplished.

Diterpenoids from Jatropha multifida.

Chemical investigation on the stems of Jatropha multifida yielded two diterpenoids, multifolone and (4E)-jatrogrossidentadione acetate along with five known diterpenoids, a flavone and a coumarino-lignan. The structures of the compounds were settled by detailed analysis of their 1D and 2D NMR spectra. The X-ray crystallographic analysis of (4E)-jatrogrossidentadione acetate was also accomplished.