Biopterin and neopterin in human saliva

Presence of biopterin and neopterin in human saliva was investigated by HPLC after iodine oxidation in acidic medium. Concentrations of biopterin and neopterin (M +/- SEM) were 1.271 +/- 0.254 and 0.358 +/- 0.075 ng per ml, respectively, in saliva of apparently healthy young male adults, ages 20 to 22 years (n = 9). Nearly identical value of the neopterin/biopterin ratio (0.29 +/- 0.07) was obtained for each of these specimens. Monapterin, the L-threo-isomer of neopterin (0.084 +/- 0.022 ng per ml saliva), and other unconjugated pterins such as xanthopterin, 6-hydroxymethylpterin and pterin were also found in the saliva. These pterins were all detectable in saliva of young female adults with similar levels to those of male saliva. Another fluorescent compound which was identical with 7-iso biopterin in retention time on HPLC was observed in all specimens of normal saliva examined.