A New Class of Organic Luminophores With a Stilbene Chromophore: 3-Phenylmethylene-1(3H)-Isobenzofuranones

A new class of luminophores with a stilbene chromophore, 3-phenylmethylene-1(3H)-iso-benzofuranones (BPH's), has been investigated. The fluorescence occurs in the region 26000-16000 cm-1, the maximal quantum yield being about 0.6. As a result of substitution or higher polarity of the solvent the ππ* state of the BPH's separates from the fluorescently inactive nπ* state.

The S0-S2 absorption transition of the BPH's results from an excitation which is practically localized in the stilbene fragment. The good linear correlation of the fluorescence and absorption maxima and O-O transitions in ethanol with the σp-Hammett constants has been used for an interpretation of the changes in the potential hyperfaces of S0 and S1 states.

Opiate-like peptides. Part XI. 2-[2-phenyl-1,3-indandionyl]--amides of enkephalin analogs. Synthesis and analgesic activity

Four enkephalin analogs containing C-terminal 2-amino-2-phenyl-1,3-indandione residue were prepared: [Met-NHPID5]--enkephalin (E3), [D-Ala2,Met-NHPID5]--enkephalin (E4), [Leu-NHPID5]--enkephalin (E5), [D-Ala2,Leu-NHPID5]--enkephalin (E6). Their analgesic activities were assayed by three in vivo tests: the "hot plate" method, the reaction to electric painful stimulus and the writhing syndrome test. Neurotoxicity effects were determined by the rota-rod test. The most pronounced analgesic effect was induced by compounds with D-Ala in position 2, particularly in the "hot plate" test.