Inhibition of Vesicular Glutamate Uptake by Rose Bengal-Related Compounds: Structure–Activity Relationship

Synaptic vesicular accumulation of glutamate is a vital initial step in glutamate transmission. We have previously shown that Rose Bengal, a polyhalogenated fluorescein analog, is a potent inhibitor of glutamate uptake into synaptic vesicles. Here, we report the structural features of Rose Bengal required for this inhibition. Various Rose Bengal-related compounds, with systematic structural variations, were tested. Results indicate that the four iodo groups and the phenyl group attached to the xanthene moiety are critical for potent inhibitory activity. Replacement of these groups with two iodo groups and an alkyl group, respectively, results in substantial reduction in potency. Of further interest in creating high potency is the critical nature of the oxygen atom which links the two benzene rings of xanthene. Thus, the phenyl group and multiple iodo groups, as well as the bridging oxygen of xanthene, are crucial elements of Rose Bengal required for its potent inhibitory action.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45424/1/11064_2005_Article_2610.pd

New fluorescent octadecapentaenoic acids as probes of lipid membranes and protein-lipid interactions.

The chemical and spectroscopic properties of the new fluorescent acids all(E)-8, 10, 12, 14, 16-octadecapentaenoic acid (t-COPA) and its (8Z)-isomer (c-COPA) have been characterized in solvents of different polarity, synthetic lipid bilayers, and lipid/protein systems. These compounds are reasonably photostable in solution, present an intense UV absorption band (epsilon(350 nm) approximately 10(5) M(-1) cm(-1)) strongly overlapped by tryptophan fluorescence and their emission, centered at 470 nm, is strongly polarized (r(O) = 0.385 +/- 0.005) and decays with a major component (85%) of lifetime 23 ns and a faster minor one of lifetime 2 ns (D,L-alpha-dimyristoylphosphatidylcholine (DMPC), 15 degrees C). Both COPA isomers incorporate readily into vesicles and membranes (K(p) approximately 10(6)) and align parallel to the lipids. t-COPA distributes homogeneously between gel and fluid lipid domains and the changes in polarization accurately reflect the lipid T(m) values. From the decay of the fluorescence anisotropy in spherical bilayers of DMPC and POPC it is shown that t-COPA also correctly reflects the lipid order parameters, determined by 2H NMR techniques. Resonance energy transfer from tryptophan to the bound pentaenoic acid in serum albumin in solution, and from the tryptophan residues of gramicidin in lipid bilayers also containing the pentaenoic acid, show that this probe is a useful acceptor of protein tryptophan excitation, with R(O) values of 30-34 A

Matrices poliméricas sólidas conteniendo derivados de 2-(2'-hidroxifenil)benzazoles y su utilización en láseres por transferencia protónica

Referencia OEPM: P9300157.-- Fecha de solicitud: 28/01/1993.-- Titular: Consejo Superior de Investigaciones Científicas (CSIC).La presente patente de invención describe la obtención de láseres de estado sólido de colorantes de las familias de los derivados de 2-(2'-hidroxifenil)- benzazoles (bencimidazol, benzoxazol y benzotiazol) que emiten luz láser por un mecanismo de transferencia de protón en el estado excitado. Más en concreto, describe láseres en los que el mencionado colorante o cromóforo se encuentra anclado covalentemente a, o disperso en, una matriz sólida, consistente en un polímero orgánico transparente a la radiación de bombeo.Peer reviewe