The Effects of the Steroids 5-Androstenediol and Dehydroepiandrosterone and Their Synthetic Derivatives on the Viability of K562, HeLa, and Wi-38 Cells and the Luminol-Stimulated Chemiluminescence of Peripheral Blood Mononuclear Cells from Healthy Volunteers.

In order to evaluate the role of substituents at 3-C and 17-C in the cytotoxic and cytoprotective actions of DHEA and 5-AED molecules, their derivatives were synthesized by esterification using the corresponding acid anhydrides or acid chlorides. As a result, seven compounds were obtained: four DHEA derivatives (DHEA 3-propionate, DHEA 3-butanoate, DHEA 3-acetate, DHEA 3-methylsulfonate) and three 5-AED derivatives (5-AED 3-butanoate, 5-AED 3,17-dipropionate, 5-AED 3,17-dibutanoate). All of these compounds showed micromolar cytotoxic activity toward HeLa and K562 human cancer cells.

Photolabile Amphiphiles with Fluorogenic Thioxanthone-Dithiane Functionality: Synthesis and Photoinduced Fragmentation in Micelles.

Novel photolabile amphiphiles containing thioxanthone-based fluorogenic caging groups are developed. Photoinduced fragmentation in dithiane-thioxanthone adducts was demonstrated to occur with 100% quantum efficiency at λ ~ 320 nm and more than 50% at λ ~ 360 nm. A plausible mechanism involves homolytic fission of a carbon-carbon single bond in the excited thioxanthone followed by disproportionation via hydrogen transfer.

Luminescent Zn and Pd tetranaphthaloporphyrins.

Zn and Pd complexes of meso-tetraphenyltetranaphthaloporphyrins (Ph(4)TNP) exhibit strong infrared absorption bands and luminesce in solutions at room temperature. S1 --> S0 fluorescence (lambda(max) = 732 nm, phi = 5.3%) is the predominant emission in the case of ZnPh(4)TNP (1).

Direct amination of 1-substituted 3,5-dinitrobenzenes by 1,1,1-trimethylhydrazinium iodide.

The amination of 1-X-3,5-dinitrobenzenes via the vicarious nucleophilic substitution of hydrogen (VNS) with 1,1,1-trimethylhydrazinium iodide (TMHI) in the presence of t-BuOK or NaOMe in DMSO was studied. It was observed (when X = OMe, OCH(2)CF(3), OCH(2)CF(2)CF(2)H, OPh) that the amination occurs regioselectively (ratio of ortho/para-isomers is approximately 9:1) and with high yield. For X = SPh or SCH(2)Ph, the reaction proceeded with a low yield (less than 20%), with a ratio of ortho/para-isomers approximately 1:1.