123437-73-0Relevant articles and documents
Low-temperature photooxygenation of coelenterate luciferin analog synthesis and proof of 1,2-dioxetanone as luminescence intermediate
Usami, Ken,Isobe, Minoru
, p. 12061 - 12090 (2007/10/03)
Coelenterate luciferin analog having bulky tert-butyl group at the 2-position was suitable for studies on chemiluminescence under various conditions. Photooxygenation of the analog(s) at low temperature (-78°C) afforded luminous intermediates which were proved as peroxides by reduction with PPh3 with resultant loss of luminescence ability. In order to clarify these structures of accumulated luminous intermediates by means of 13C NMR, three 13C enriched analogs were synthesized at the 2, 3 and 5 positions of 3,7-dihydroimidazo[1,2-a]pyrazin-3-one skeleton in 99% enrichment with site-specificity. These 13C-enriched coelenterate luciferin analogs were photooxygenated at -78°C to form two peroxidic products as luminescent intermediates. Structures of these unstable intermediates were deduced by means of 13C NMR spectra at low temperature using substrates enriched at three sites by 13C. Photooxygenation in a mixture of CF3CD2OD and CD3OD as highly protic solvents afforded the dioxetanone and 2-hydroperoxide. These two peroxides emitted light independently at different temperatures either at 400 nm (neutral species) and/or 475 nm (anionic species) after diluting to 10-5 M in diglyme (DGM) containing acid or base.
Chemi- and Bio-luminescence of Coelenterazine Analogues with Phenyl Homologues at the C-2 Position
Qi, Chen Feng,Gomi, Yasushiro,Hirano, Takashi,Ohashi, Mamoru,Ohmiya, Yoshihiro,Tsuji, Frederick I.
, p. 1607 - 1612 (2007/10/02)
A series of phenyl homologues of coelenterazine substituted at the C-2 position were synthesized and their bio- and chemi-luminescence properties were investigated including the measurement of chemiluminescence spectra in various media.The light emitting species of each analogue was found to be a neutral form of a coelenteramide derivative in diethylene glycol dimethyl ether (DGM) containing a trace amount of acetate buffer (pH 5.60), while a monoanion was found only in dimethyl sulfoxide (DMSO) and a dianion was observed in DMSO containing a trace amount of aqueous sodium hydroxide.Based on pseudo first-order reaction kinetics, chemiluminescence rate constants were obtained in DGM containing a trace amount of acetate buffer.Each of the synthetic coelenterazine analogues was incorporated into recombinant apoaequorin to obtain a series of semisynthetic aequorins.Measurements of bioluminescence activities of the aequorins revealed that a benzyl group in the C-2 position was essential for efficient luminescence activity.A two-step incubation procedure was used to determine why some analogues gave less luminescence activity than the benzyl analogue and natural coelenterazine.
