flavins

https://doi.org/10.1351/goldbook.F02423
Derivatives of the dimethylisoalloxazine (7,8-dimethylbenzo[g]pteridine- 2,4(3H,10H)-dione) skeleton, with a substituent on the 10 position. (Riboflavin, having a 10-d-ribityl group, is the most prominent member).
F02423.png
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1335 [Terms] [Paper]