Toxoflavin is a

toxin A toxin is a naturally occurring organic poison produced by metabolic activities of living cells or organisms. Toxins occur especially as a protein or conjugated protein. The term toxin was first used by organic chemist Ludwig Brieger (1849– ...

produced by a variety of bacteria including ''

Burkholderia gladioli ''Burkholderia gladioli'' is a species of aerobic gram-negative rod-shaped bacteria that causes disease in both humans and plants. It can also live in symbiosis with plants and fungi and is found in soil, water, the rhizosphere, and in many anima ...

''. It also has antibiotic properties. Toxoflavin acts as a

pH indicator A pH indicator is a halochromic chemical compound added in small amounts to a solution so the pH (acidity or basicity) of the solution can be determined visually or spectroscopically by changes in absorption and/or emission properties. Hence, ...

, changing between yellow and colorless at pH 10.5.

References

Bacterial toxins Lactams Pyrimidinediones Triazines {{heterocyclic-stub es:Reumitsina#Derivados