Seven pyrrole alkaloids isolated from Agelas sponges were tested for interactions with the cellular calcium homeostasis. Brominated pyrrole alkaloids reduced voltage dependent calcium elevation in PC12 cells. Dibromosceptrin was the most potent alkaloid with a half maximal concentration of 2.8 microM followed by sceptrin (67.5 microM) and oroidin (75.8 microM). 4,5-Dibromopyrrole-2-carboxylic a...

We report here an enzyme-amplified, sandwich-type immunosensor for detecting the biospecific interaction between an antibody and antigen using redox mediation. We employed biotin/anti-biotin IgG as a model immunosensing pair. Partially ferrocenyl-tethered dendrimer (Fc-D), whose ferrocene moiety acts as a redox mediator, was immobilized to the electrode surface by covalent binding between the d...

1,1 0-Ferrocene dicarboxylic acid pyridin-4-yl ester (1) is prepared from 1,1 0-ferrocene dicarbonyl chloride and 4-hydroxypyridine. This new bidentate ferrocenoyl ligand reacts with the monocationic complex [(g-p-cymene)2Ru2(l-OH)3] + to give the dicationic complex [(g-p-cymene)2Ru2(l-OH)2(1,1 0(NC5H4–OOC)2–Fc)] 2+ (2) (Fc: C5H4–Fe–C5H4), isolated as a tetrafluoroborate salt. The single-crysta...

The activities of the enzymes tyrosinase and thrombin are probed by the association of the ferrocene boronic acid label to the enzyme-generated catechol ligand, and by the cleavage of the ligand-redox complex tethered to a peptide, respectively.

L-Alanine, L-threonine, L-valine, D-cystine and three derivatives of thiazole-4-carboxylic acid (thiostreptin, 1-aminomethylthiazole-4-carboxylic acid and thiostreptoic acid) were isolated from the acid-hydrolysate of thiopeptin B. In addition, the presence of dehydrobutyrine and dehydroalanine residues in the antibiotic was determined. Other components remain unidentified.

2-Aminobenzothiazole-6-carboxylic acid (1), on condensation with chloroacetyl chloride yielded 2-(2-chloroacetylamino)benzothiazole-6-carboxylic acid (2), which on amination with hydrazine hydrate yielded in turn 2-(2-hydrazinoacetylamino)benzo-thiazole-6-carboxylic acid (3). Compound 3, on condensation with various aromatic aldehydes afforded a series of 2-{2-[N'-(arylidene)hydrazino]acetylami...

Multiwalled carbon nanotubes (CNT) of diameters of 10–40 nm are synthesized on Fe and Co coated nm-scale catalyst support in a xylene chemical vapor deposition (CVD) process without the need for ferrocene iron source. Silica ( 40 nm diameter) and nanocrystalline Au ( 10 nm) are coated with a monolayer of amine, sulfonate, or thiol termination to ensure monolayer Fe loading, reduce Fe surface mi...

A number of manganese-based catalysts employing ligands whose structures incorporate pyridyl groups have been reported previously to achieve both high turnover numbers and selectivity in the oxidation of alkenes and alcohols, using H(2)O(2) as terminal oxidant. Here we report our recent finding that these ligands decompose in situ to pyridine-2-carboxylic acid and its derivatives, in the presen...