79925-67-0Relevant academic research and scientific papers
Mechanism for different fluorescence response of a coumarin-amide- dipicolylamine linkage to Zn(II) and Cd(II) in water
Sumiya, Shigehiro,Shiraishi, Yasuhiro,Hirai, Takayuki
, p. 1474 - 1482 (2013)
A coumarin-amide-dipicolylamine linkage (L) was synthesized and used as a fluorescent receptor for metal cations in water. The receptor dissolved in water with neutral pH shows almost no fluorescence due to the photoinduced electron transfer (PET) from the amide and amine nitrogens to the excited state coumarin moiety. Coordination of Zn2+ or Cd2+ with L creates strong fluorescence at 437 or 386 nm, respectively, due to the suppression of PET. In contrast, other metal cations scarcely show fluorescence enhancement. IR, NMR, and potentiometric analysis revealed that both Zn2+ and Cd 2+ are coordinated with two pyridine N, amine N, and amide O; however, the Zn2+ center is also coordinated with a hydroxide anion (OH-). The structure difference for Zn and Cd complexes results in longer- and shorter-wavelength fluorescence. Ab initio calculations revealed that π electrons on the excited state Cd complex are delocalized over the molecules and the Cd complex shows shorter-wavelength emission. In contrast, π electrons of OH--coordinated Zn complex are localized on the coumarin moiety. This increases the electron density of coumarin moiety and shows longer-wavelength fluorescence.
Discovery of unique thiazolidinone-conjugated coumarins as novel broad spectrum antibacterial agents
Geng, Rong-Xia,Kumar, Kannekanti Vijaya,Li, Shuo,Yang, Xun-Cai,Zhang, Peng-Li,Zhou, Cheng-He
, (2022/02/16)
Unique coumarin conjugates with thiazolidinone as novel structural antibacterial modulators were exploited to combat the lethal multidrug-resistant bacterial infections. Bioactivity evaluation identified that indole-incorporated coumarin thiazolidinone conjugate 14a with low cytotoxicity to mammalian cells showed a broad antibacterial spectrum and exerted potent inhibition efficiencies to the tested germs at low concentrations (0.25–2 μg/mL). Moreover, the favorable performance of 14a in eradicating bacterial biofilm was beneficial to avert developing drug resistance. Mechanistic explorations revealed that molecule 14a was able to destroy cell membrane, leading to the leakage of intracellular materials and metabolism inhibition. The accumulation of excess reactive oxygen species (ROS) mediated by compound 14a could impede glutathione (GSH) activity and induce lipid peroxidation to suppress bacteria growth. Furthermore, compound 14a could not only intercalate into DNA base pair but also take part in non-covalent interaction with DNA gyrase B to hinder their biological function. Quantum chemical study indicated that molecule 14a had low HOMO-LUMO energy gap, which resulted in more stabilizing interactions and was conducive to displaying better antibacterial activity. ADMET analysis manifested that 14a possessed promising pharmacokinetic properties.
Synthesis of fluorescent probe - carbohydrate conjugates
Yalpani, Mansur,Hall, Laurence D.
, p. 2934 - 2939 (2007/10/02)
A new type of luminescent label has been synthesized and a range of carbohydrates has been derivatized with various fluorescent probes.Amine-containing labels were readily transformed with chloroacetylchloride into the corresponding fluorescent chloroacet
