Investigation into the photochemical relationship between the pterin and PABA portions of folic acid.

摘要

Folic acid is an essential vitamin and is involved in the biosynthesis of various mammalian metabolic pathways. Deficiency of folic acid causes gastro intestinal disorders, loss of appetite, anemia, vitamin B12 deficiency, and premature grey hair. FA is effective in prevention of birth defects of the brain and spinal cord called neural tube defects (NTDs). NTDs happen when a neural tube fails to close properly. Most common NTDs include spina bifida and anencephaly. FA undergoes photo-degradation when exposed to light. Therefore, understanding the photochemical behavior of FA may aid in the preservation of this vitamin in food and food supplements.;The chemist performed fluorescence quenching experiments of pterins such as 6-carboxy pterin, 6-methyl pterin, 6-formyl pterin, and 6-hydroxy methyl pterin using various N-methyl anilines and constructed Stern Volmer plots for each of the fluorescence quenching experiments to understand the quenching mechanism. The electron donating N-methyl anilines were most efficient in fluorescence quenching. Comparison of Stern Volmer slopes with the Hammett sigma values revealed a probable electron transfer from the N-methyl aniline to pterin resulting in the formation of radical anion and cation of the pterin and N-methyl aniline which would eventually be responsible for photodecomposition of folic acid.