Ueber die Oxydation des Tolualloxazins

Naturally Occurring Lumazines

“…29,30 No biological testing was conducted on this natural lumazine. Lepteridine (8) was isolated from New Zealand ma ̅ nuka honey (derived from the nectar of Leptospermum scoparium) by Brimble et al, who also confirmed its structure by total synthesis. 31 Speer et al reported the replication of this isolation, along with 6,7-dimethyllumazine (9); the structures of both compounds were assigned using Xray crystallography.…”

“…2,5−7 In 1894, Kuḧling described the first intentional synthesis of lumazine (3) in which benzo[g]pteridine, also known as alloxozine (4), was oxidized to lumazine-6,7-dicarboxylic acid, followed by thermal decarboxylation to generate the product 3. 8,9 Later, in 1901 and 1906, synthesis of the pteridine ring system 1 was also reported by Gabriel and Colman, 10 and Isay, 11 respectively.…”

“…Chemically synthesized pteridines appeared long before they were isolated from Nature. In 1857, Wöhler and Hlasiwetz reported the formation of novel fluorescent compounds upon heating uric acid in water, and it was not until 100 years later that some of these products were recognized as lumazine derivatives. ,− In 1894, Kühling described the first intentional synthesis of lumazine ( 3 ) in which benzo­[ g ]­pteridine, also known as alloxozine ( 4 ), was oxidized to lumazine-6,7-dicarboxylic acid, followed by thermal decarboxylation to generate the product 3 . , Later, in 1901 and 1906, synthesis of the pteridine ring system 1 was also reported by Gabriel and Colman, and Isay, respectively.…”

The Chemistry of the Pteridines.

“…The earliest successful synthesis of this ring system was carried out in 1895 by Kiihling (48) who, having ascertained that the reaction of alloxan with aliphatic 1 ,a-diamines fails (47), was able to degrade "tolualloxazine" (V) by oxidative method5 to 2,6-dihydroxypteridine (VI). is unsuccessful (47,110). Again, the structures of products from unsymmetrical dicarbonyl compounds were not ascertained.…”

Non-classical disproportionation revealed by photo-chemically induced dynamic nuclear polarization NMR

“…The first intentional synthesis of pteridine-2,4(1H,3H)-dione (1; see Scheme 1) was described by Kühling in 1894(Kühling, 1894, 1895. Due to its blueish-green fluorescence even in very dilute aqueous solutions, the compound was named lumazine (Kuhn and Cook, 1937).…”