A Rare Natural Benzo[k,l]xanthene as a Turn-Off Fluorescent Sensor for Cu2+ Ion

Abstract

Rapid and efficient analyses of copper ions are crucial to providing key information for Cu2+ in living cells because of their biological importance. In this study, we reported one new turn-off fluorescent sensor for Cu2+ with a benzo[k,l]xanthene core, which served as an efficient cation sensor for copper ion over a wide range of other cations (Na+, K+, Ag+, Hg2+, Cd2+, Co2+, Ni2+, Zn2+, Mg2+, and Fe3+) owing to the catechol group in the aromatic core. The sensor showed selectivity for Cu2+ over other ions; the logKβ for Cu2+ binding to compound 1 had a value of 13.265. In the presence of Cu2+, sensor 1 provided significant fluorescence decrement; Co2+, and Ni2+ caused a fluorescence decrement when employed at a higher concentration than Cu2+, while Na+, K+, Hg2+, Cd2+, Zn2+, and Mg2+ metal ions produced only minor changes in fluorescence intensity. Fluorescence experiments demonstrate that compound 1 may have an application as a fluorescent probe for detecting Cu2+ with a limit of detection of 0.574 µM.

Microwave-Assisted, Copper-Catalyzed Domino O–H/C–H Arylation Reaction toward the Synthesis of Oxygen-Doped Polyaromatic Molecules

“…On a different note, benzoxanthenes are a class of oxygen-containing heterocyclic compounds rarely found in nature. − Multiple biological properties of benzoxanthenes as antiviral, , anticancer, − and anti-inflammatory , agents are well documented. In addition, their derivatives, which are strongly fluorescent, find uses in laser technologies, solar cells, or are used as dyes for the visualization of biomolecules. ,− A well-known synthetic methodology toward benzoxanthenes is the one-pot multicomponent reaction between naphthol and aryl halides in the presence of palladium (Scheme a) .…”

Characterization and Interaction with Biomembrane Model of Benzo[k,l]xanthene Lignan Loaded Solid Lipid Nanoparticles

“…Because of their limited availability in nature, the biological activities of natural BXLs have been almost unexplored for years. In 2009, a simple and biomimetic methodology for the synthesis of BXLs was published [7], and a variety of synthetic benzoxanthenes have since been obtained and evaluated as antioxidant [8], anti-inflammatory [9], selective copper-chelators [10], antifungal [11], antibacterial [12], antiproliferative agents [13,14]. Additionally, BXLs are reported to induce autophagy towards tumor cells [15] and act as antiangiogenic [16], pro-apoptotic agents [17], DNA-binders [12,17], proteasome inhibitors [18], all targets involved in tumorigenesis, and which are useful for the development of anticancer drugs.…”