Chemiluminescence of 6-aryl-2-methylimidazo[1,2-a]pyrazin-3(7H)-ones in DMSO/TMG and in diglyme/acetate buffer: support for the chemiexcitation process to generate the singlet-excited state of neutral oxyluciferin in a high quantum yield in the Cypridina (Vargula) bioluminescence mechanism

Takahashi, Yuto; Kondo, Hiroyuki; Maki, Shôjirô; Niwa, Haruki; Ikeda, Hiroshi; Hirano, Takashi

doi:10.1016/j.tetlet.2006.06.101

Cited by 37 publications

(56 citation statements)

References 25 publications

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“…) were from both the neutral (466 nm) and anionic (548 nm) products, respectively. Hirano extended the chemiluminescence model studies and revealed the influence of R 2 substituents (Fig. ) on the acidity of the amide N. This substitution position influences the acidity of the N‐1, and therefore, the extent of protonation of the dioxetanone, and whether or not in the bioluminescence of imidazopyrazinone luciferins, the neutral or anionic excited product is dominant.…”

Section: Firefly and Coelenterazinementioning

confidence: 93%

Perspectives on Bioluminescence Mechanisms

Lee

2016

Photochem & Photobiology

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The molecular mechanisms of the bioluminescence systems of the firefly, bacteria and those utilizing imidazopyrazinone luciferins such as coelenterazine are gradually being uncovered using modern biophysical methods such as dynamic (ns-ps) fluorescence spectroscopy, NMR, X-ray crystallography and computational chemistry. The chemical structures of all reactants are well defined, and the spatial structures of the luciferases are providing important insight into interactions within the active cavity. It is generally accepted that the firefly and coelenterazine systems, although proceeding by different chemistries, both generate a dioxetanone high-energy species that undergoes decarboxylation to form directly the product in its S 1 state, the bioluminescence emitter. More work is still needed to establish the structure of the products completely. In spite of the bacterial system receiving the most research attention, the chemical pathway for excitation remains mysterious except that it is clearly not by a decarboxylation. Both the coelenterazine and bacterial systems have in common of being able to employ "antenna proteins," lumazine protein and the greenfluorescent protein, for tuning the color of the bioluminescence. Spatial structure information has been most valuable in informing the mechanism of the Ca 2+ -regulated photoproteins and the antenna protein interactions.

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Section: Firefly and Coelenterazinementioning

confidence: 93%

Perspectives on Bioluminescence Mechanisms

Lee

2016

Photochem & Photobiology

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“…DFT calculations often give more satisfactory results. Indeed our experience has shown that charge and spin densities ( q and ρ , respectively) calculated by using the B3LYP method are of sufficiently high quality to explain the reactivity of 2,2′,3,3′‐tetraphenylbicyclopropenyl radical cations [restricted B3LYP/6‐31G(p)], the molecular geometries and electronic structure of the geminally diphenyl‐substituted trimethylenemethane radical cation and 1,4‐diphenylcyclohexane‐1,4‐diyl radical cation ( 5 •+ ) (UB3LYP/cc‐pVDZ), and the classical and nonclassical radical ions derived from 7‐benzhydrylidenenorbornene analogs, in addition to other reactive intermediates of this type …”

Section: Methodsmentioning

confidence: 99%

Density functional theory study of silole‐fused tetramethyleneethane biradicals with orbital interactions

Kano

Mizuno

Ikeda

2011

J of Physical Organic Chem

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The geometries, energy gap between singlet and triplet states (S–T gap), electronic transitions, and molecular orbitals of the diphenyl derivative of the silole‐fused tetramethyleneethane (TME) (3,4‐dimethylenesilole) biradical 7•• were determined by using the density functional theory method at the unrestricted Becke, three‐parameter, Lee–Yang–Parr/cc‐pVDZ level. In a manner similar to that of the parent TME biradical, the S–T gap of 7•• is small. The wavelengths of electronic transitions of 37•• (λET = 450 nm) are calculated to be different from that of 17•• (λET = 673 nm). These differences are attributed to interactions between orbitals of the two allyl radical moieties, especially, the existence of double σ*–π* conjugation, that is, π*–σ*–π* conjugation, that takes place in the silole subunit. Copyright © 2011 John Wiley & Sons, Ltd.

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“…When stressed mechanically, chemically, or electrically in seawater, the animal simultaneously ejects an enzyme (Cypridina luciferase) and a small‐molecular substrate (Cypridina luciferin), which react in the presence of triplet oxygen (Scheme ). The ground‐state reactants generate a product (oxyluciferin) in the first excited state, which subsequently emits bright blue light that is used by the ostracod for camouflage while it escapes from predators . The high quantum yield of this reaction has been considered for the potential it may hold for bioanalytical applications .…”

Section: Figurementioning

confidence: 99%

Mechanically Assisted Bioluminescence with Natural Luciferase

et al. 2020

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Mechanochemical analogues have recently been established for several enzymatic reactions, but they require periodic interruption of the reaction for sampling, dissolution, and (bio)chemical analysis to monitor their progress. By applying a mechanochemical procedure to induce bioluminescence analogous to that used by the marine ostracod Cypridina (Vargula) hilgendorfii, here we demonstrate that the light emitted by a bioluminescent reaction can be used to directly monitor the progress of a mechanoenzymatic reaction without sampling. Mechanical treatment of Cypridina luciferase with luciferin generates bright blue light which can be readily detected and analyzed spectroscopically. This mechanically assisted bioluminescence proceeds through a mechanism identical to that of bioluminescence in solution, but has higher activation energy due to being diffusion‐controlled in the viscous matrix. The results suggest that luciferases could be used as light‐emissive reporters of mechanoenzymatic reactions.

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Chemiluminescence of 6-aryl-2-methylimidazo[1,2-a]pyrazin-3(7H)-ones in DMSO/TMG and in diglyme/acetate buffer: support for the chemiexcitation process to generate the singlet-excited state of neutral oxyluciferin in a high quantum yield in the Cypridina (Vargula) bioluminescence mechanism

Cited by 37 publications

References 25 publications

Perspectives on Bioluminescence Mechanisms

Perspectives on Bioluminescence Mechanisms

Density functional theory study of silole‐fused tetramethyleneethane biradicals with orbital interactions

Mechanically Assisted Bioluminescence with Natural Luciferase

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