Low-temperature photooxygenation of coelenterate luciferin analog synthesis and proof of 1,2-dioxetanone as luminescence intermediate

In vitro and in vivo studies of 6,8-(diaryl)imidazo[1,2-a]pyrazin-3(7H)-ones as new antioxidants

“…15 However, the formation of aminopyrazines (3) is occasionally mentioned. 29,30 The main questions concern the outcome of the imidazole moiety (which bears the substituent R 2 ) from precursors 1 and the production of 2 and 3 via parallel routes or via consecutive reactions (i.e., formation of 2 and subsequent transformation into 3).…”

N-(Alkyl)-2-amino-1,4-pyrazine Derivatives: Synthesis and Antioxidative Properties of 3- and 3,5-p-Hydroxyphenyl-Substituted Compounds

“…1 3 ], 26.6 (2 CH 2 ), 27.5 (2 CH 2 ), 31.6 (2 CH 2 ), 48.5 (2 NHCH 2 C 5 H 11 ), 120.3 (2 CH arom ), 126.2 (2 CH arom ), 128.4 (C 3 ), 130.8 (C arom ), 138.4 (C 6 ), 139.1 (C 5 ), 152.1 (C 2 ), 155.6 (COH). 1 3 ], 26.6 (2 CH 2 ), 27.5 (2 CH 2 ), 31.6 (2 CH 2 ), 48.5 (2 NHCH 2 C 5 H 11 ), 120.3 (2 CH arom ), 126.2 (2 CH arom ), 128.4 (C 3 ), 130.8 (C arom ), 138.4 (C 6 ), 139.1 (C 5 ), 152.1 (C 2 ), 155.6 (COH).…”

“…Therefore, alkylaminopyrazine derivatives should be prepared from the corresponding aminopyrazines. In our hands, this procedure was found to be also suitable for the one-step alkylation of aminopyrazine 2 (method B, Table 1, entries 3-7); moderate to good yields of N-alkylamino-1,4-pyrazines 3ad,g were collected by reacting 2 with respectively benzaldehyde, phenylacetaldehyde, butyraldehyde, isobutyraldehyde and dodecylaldehyde (THF,20°C,(1)(2)(3)(4)(5)(6)(7). In our hands, this procedure was found to be also suitable for the one-step alkylation of aminopyrazine 2 (method B, Table 1, entries 3-7); moderate to good yields of N-alkylamino-1,4-pyrazines 3ad,g were collected by reacting 2 with respectively benzaldehyde, phenylacetaldehyde, butyraldehyde, isobutyraldehyde and dodecylaldehyde (THF,20°C,(1)(2)(3)(4)(5)(6)(7).…”

Discovery and Validation of a New Family of Antioxidants: The Aminopyrazine Derivatives

“…established that coelenteramide (CLD) represents a major metabolite of the oxidative degradation of CLZn, and that this compound, initially formed as an anionic species in the excited state, is responsible for the emission of light under deactivation [22,[34][35][36] (Fig. (1)).…”

“…Luciferins are the natural substrates of luciferases, the enzymes that catalyse reactions emitting visible light. In all the bioluminescent organisms, light is always produced through oxidation reactions [21][22]. Thus, bioluminescence substrates are naturally designed to react with oxygen and its derived reactive species.…”