"chemical precursors" refers to substances that are used to make or produce other chemicals. These substances serve as important building blocks in the process of creating various products or substances. Full definition
The pineal gland abounds both in chemical precursors of DMT, such as tryptophan, and in beta - carbolines, the same compounds that render DMT orally active in the South American brew ayahuasca by counteracting the enzyme in the gut that breaks down DMT. (discovermagazine.com)
Syria possesses about 1,000 metric tons of chemicals for weapons, Walker said, with nearly all of it in the form of chemical precursors for sarin and mustard gas. (aaas.org)
This compound is a metabolic intermediate and chemical precursor in the biosynthesis of melatonin and serotonin. (aminoacidstudies.org)