Isoxanthopterin is a natural intermediate in the pteridine pathway, which has roles in pigmentation and cell division. It can be produced naturally from 7-oxobiopterin or in vitro by the oxidation of pterin by xanthine oxidase. Isoxanthopterin is a guanine analog that interferes with RNA and DNA synthesis and can inhibit cell proliferation. Methylated derivatives of isoxanthopterin are fluorescent guanine analogs that are used to study DNA structure.
