Toxoflavin (PKF 118-310) is an azapteridine antibiotic produced by some species of Pseudomonas, Streptomyces, and Burkholderia gladioli that has antibiotic and anticancer properties. It is also a yellow pigment that acts as a pH indicator changing between yellow and colorless at a pH of 10.5. Toxoflavin is one of two toxins produced when a fermented coconut drink, Tempe bonkrek, is contaminated with P. cocovenenans.