Quantitative imaging of glutathione in live cells using a reversible reaction-based ratiometric fluorescent probe.

Glutathione (GSH) plays an important role in maintaining redox homeostasis inside cells. Currently, there are no methods available to quantitatively assess the GSH concentration in live cells. Live cell fluorescence imaging revolutionized the field of cell biology and has become an indispensable tool in current biological studies.

Bufalin is a potent small-molecule inhibitor of the steroid receptor coactivators SRC-3 and SRC-1.

Virtually all transcription factors partner with coactivators that recruit chromatin remodeling factors and interact with the basal transcription machinery. Coactivators have been implicated in cancer cell proliferation, invasion, and metastasis, including the p160 steroid receptor coactivator (SRC) family composed of SRC-1 (NCOA1), SRC-2 (TIF2/GRIP1/NCOA2), and SRC-3 (AIB1/ACTR/NCOA3). Given their broad involvement in many cancers, they represent candidate molecular targets for new chemotherapeutics.

Syntheses and biological activities of 13-substituted avermectin aglycons.

The reactions of sulfonate esters of the allylic/homoallylic 13-alcohol of 5-O-(tert-butyldimethylsilyl)-22,23-dihydroavermectin B1a aglycon (1a) were investigated. Nucleophilic substitution gave 13 beta-chloro and 13 beta-iodo derivatives, while solvolytic reaction conditions yielded 13 alpha-methoxy, 13 alpha-fluoro, and 13 alpha-chloro products. A mixture of 13 alpha- and 13 beta-fluorides was obtained upon reaction with DAST.

Novel analgesic-antiinflammatory salicylates.

5-(2,4-Difluorophenyl)salicylic acid, diflunisal (25), is the best compound, in terms of both efficacy and safety, from over 500 salicylates investigated in our laboratories. It is a chemically distinct, nonacetylating salicylic acid, more active than aspirin as an analgesic and antiinflammatory agent and superior in duration of action and therapeutic index. Some recent clinical and biochemical observations are briefly discussed.

4-amino-6-(trichloroethenyl)-1,3-benzenedisulfonamide, a new, potent fasciolicide.

The synthesis and fasciolicidal activity of 4-amino-6-(trichloroethenyl)-1,3-benzenedisulfonamide are reported. A single dose of 15 mg/kg was effective in removing over 90% of immature Fasciola hepatica from sheep (6 weeks after infection) and calves (8 weeks after infection). A 2.