Theoretical Study of the Thermolysis Reaction and Chemiexcitation of Coelenterazine Dioxetanes

• Type: Article in International Scientific Journal
• Date: 2022-05-25

Authors

Luís Pinto da Silva (Author) FCUP; Carla M. Magalhães (Author) FCUP; Joaquim C G E Esteves da Silva (Author) FCUP

Journal

Title: Journal of Physical Chemistry A

Vol. 126

Pages: 3486-3494

ISSN: 1089-5639

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 3 Citations

Scopus

Associated Projects

ChemiTumorTher - Quimioluminescência Marinha como uma Terapia Anticancro de Amplo Espectro com uma Selectividade e Actividade Tumoral Melhorada

Other information

Authenticus ID: P-00W-KJQ

DOI: 10.1021/acs.jpca.2c01835

Abstract (EN): Coelenterazine and other imidazopyrazinones are important bioluminescent substrates widespread in marine species and can be found in eight phyla of luminescent organisms. Light emission from these systems is caused by the formation and subsequent thermolysis of a dioxetanone intermediate, whose decomposition allows for efficient chemiexcitation to singlet excited states. Interestingly, some studies have also reported the involvement of unexpected dioxetane intermediates in the chemiand bioluminescent reactions of Coelenterazine, albeit with little information on the underlying mechanisms of these new species. Herein, we have employed a theoretical approach based on density functional theory to study for the first time the thermolysis reaction and chemiexcitation profile of two Coelenterazine dioxetanes. We have found that the thermolysis reactions of these species are feasible but with relevant energetic differences. More importantly, we found that the singlet chemiexcitation profiles of these dioxetanes are significantly less efficient than the corresponding dioxetanones. Furthermore, we identified triplet chemiexcitation pathways for the Coelenterazine dioxetanes. Given this, the chemiexcitation of these dioxetanes should lead only to minimal luminescence. Thus, our theoretical investigation of these systems indicates that the thermolysis of these dioxetanes should only provide dark pathways for the formation of nonluminescent degradation products of the chemi- and bioluminescent reactions of Coelenterazine and other imidazopyrazinones.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9