Photophysical Study and Biological Applications of Synthetic Chalcone-Based Fluorescent Dyes

Abstract

A chalcone series (3a–f) with electron push–pull effect was synthesized via a one-pot Claisen–Schmidt reaction with a simple purification step. The compounds exhibited strong emission, peaking around 512–567 nm with mega-stokes shift (∆λ = 93–139 nm) in polar solvents (DMSO, MeOH, and PBS) and showed good photo-stability. Therefore, 3a–f were applied in cellular imaging. After 3 h of incubation, green fluorescence was clearly brighter in cancer cells (HepG2) compared to normal cells (HEK-293), suggesting preferential accumulation in cancer cells. Moreover, all compounds exhibited higher cytotoxicity within 24 h toward cancer cells (IC50 values ranging from 45 to 100 μM) than normal cells (IC50 value >100 μM). Furthermore, the antimicrobial properties of chalcones 3a–f were investigated. Interestingly, 3a–f exhibited antibacterial activities against Escherichia coli and Staphylococcus aureus, with minimum bactericidal concentrations (MBC) of 0.10–0.60 mg/mL (375–1000 µM), suggesting their potential antibacterial activity against both Gram-negative and Gram-positive bacteria. Thus, this series of chalcone-derived fluorescent dyes with facile synthesis shows great potential for the development of antibiotics and cancer cell staining agents.

On-Strand Aldehyde Capture by an Indanone Building Block: A Modular Aldol Approach for Fluorescent Molecular Rotor Nucleobase Surrogates

“…Chalcones are unexplored as DNA fluorescent probes, but the free dyes exhibit brightness comparable to commercial fluorophores along with FMR character. [33][34][35] Herein, we demonstrate, to the best of our knowledge, the first example of an internal label which is capable of aldehyde capture via a latent enolate to generate a donor-acceptor FMR library (Figure 1). Reactions proceed in high yield when catalyzed by sodium hydroxide, with relative synthetic simplicity.…”

Solvatochromism, Acidochromism and Photochromism of the 2,6-Bis(4-hydroxybenzylidene) Cyclohexanone Derivative

“…Chalcone derivatives containing the ketoethylenic group (-CO-CH=CH-) provide a rich source for the synthesis of optically active compounds [ 3 ]. These derivatives have great potential for applications due to their specific electronic structures (i.e., a completely delocalized electron system) [ 4 ], photophysical properties [ 5 , 6 , 7 ], and biological activities, such as being antimicrobial [ 8 ], antioxidant [ 9 ], anticonvulsant [ 10 ], inhibitors of inflammatory markers [ 11 ], and antifungal agent [ 12 ]. In recent years, dibenzylidene cyclohexanone derivatives have been used as corrosion inhibitors [ 13 ], fluorescent sensors for detecting Hg 2+ [ 14 ], and chromium ions in aqueous media [ 15 ].…”

Unraveling the photophysical characteristics and biological applications of vinyl sulfones as viscosity sensors

“…In this regard, we and others developed small molecule-based uorescent probes for biological applications such as cellular imaging and microorganism targeting. [12][13][14] As a part of our continuing endeavour to develop uorescent probes, we hypothesized that modication of the small molecule vinyl sulfones would affect its photophysical characteristics. Due to the lack of conclusive study on the photophysical and imaging features of vinyl sulfone, we present here the chemical reduction of non-uorescent probes, vinyl sulfone-NO 2 (3), to uorescent probes, vinyl sulfone-NH 2 (4).…”

“…In this regard, we and others developed small molecule-based fluorescent probes for biological applications such as cellular imaging and microorganism targeting. 12–14…”