Pteridine derivatives play important roles in biological systems and have several practical applications. They serve as structural backbones for essential cofactors such as tetrahydrobiopterin and flavin mononucleotide (FMN), which are involved in redox reactions, neurotransmitter synthesis, and cellular metabolism. In medicine, synthetic pteridine analogs are explored for their potential in treating metabolic disorders and certain genetic diseases related to cofactor deficiencies. Some derivatives show promise in photodynamic therapy due to their ability to generate reactive oxygen species when exposed to light, making them candidates for targeted cancer treatments. Additionally, pteridines are used in research as fluorescent probes to study enzyme activity and molecular interactions in cells. Their unique electronic properties also make them of interest in the development of organic semiconductors and optoelectronic materials.