A Fluorescence Study of Novel Styrylindoles in Homogenous and Microhetrogeneous Media

Abstract

In this paper are presented absorption and fluorescence emission properties of 3-styrylindoles viz. 3-(2-phenylethenyl-E)-NH-indole (1), 3-[2-(4-nitrophenyl)ethenyl-E)-NH-indole (2), 3-[2-(4-cyanophenyl)ethenyl-E]-N-ethylindole (3) and 3-[2-(4-cyanophenyl)ethenyl-E]-NH-indole (4) in organic solvents, 1,4-dioxane-water binary mixtures and micelles (SDS, CTAB and Triton-X-100). The fluorescence properties of 2-4 have been utilized to probe the microenvironment (binding constant, CMC, micropolarity and solubilization site) of the micelles.

A fluorescence study of differently substituted 3‐styrylindoles and their interaction with bovine serum albumin

“…(7), and 5-methoxy-3-[2-(4-chlorophenyl)ethenyl-E ]-NH-indole (8). This is because the absorption and fluorescence properties of 3-(2-phenylethenyl- (6) in organic solvents have already been reported (16). However, the absorption and fluorescence properties of all eight compounds (1-8) have been examined in BSA and are reported herein.…”

“…The fluorescence spectra were recorded on a Perkin Elmer LS-55 luminescence spectrometer by exciting the samples at their absorption maximum (λ ab max ). The Φ f relative to quinine sulfate in 0.05 mol L −1 H 2 SO 4 (Φ f = 0.51) (18) and rhodamin B (for compounds 2-4) in ethanol (Φ f = 0.69) (19) were measured at room temperature by following the procedure described earlier (16,20 ) were taken in a 5 mL volumetric flask. Since the 3-styrylindoles are sparingly soluble in water, their stock solutions were prepared in DMSO, which is used as solvent for interaction studies of serum albumins (21).…”

“…All the solutions were prepared and handled under dim light conditions. (6) were prepared as reported earlier (15,16). (8) were prepared by the condensation of either 5-bromoindole-3-carboxaldehyde or 5-methoxyindole-3-carboxaldehyde with p-nitrophenylacetic acid or p-chlorophenylacetic acid in the presence of piperidine in pyridine at 90°C (15).…”

“…Diphenylpolyenes capable of fluorescing from their charge transfer excited states have been considered as useful and further employed to study the microenvironment of micelles and proteins (7)(8)(9)(10)(11)(12)(13)(14). 3-Styrylindoles with push-pull characteristics have also been found to exhibit solvent polarity-sensitive fluorescence emission from the ICTexcited state (15,16). It has been observed that the fluorescence quantum yield (Φ f ) of 3-styrylindoles is higher, especially in the medium polar organic solvents, as compared with the diphenylpolyenes, which do not contain the indole moiety.…”

“…It has been observed that the fluorescence quantum yield (Φ f ) of 3-styrylindoles is higher, especially in the medium polar organic solvents, as compared with the diphenylpolyenes, which do not contain the indole moiety. The efficacy of some of the 3-styrylindoles as neutral hydrophobic fluorescence probes for studying the microenvironment of organized assembly of micelles (16) and proteins (17) has been evaluated. In these investigations, the fluorescence probe studies of bovine serum albumin (BSA) have been done by using mainly the acceptoracceptor system of 3-styrylindoles.…”