DL-Cystine is a racemic mixture of the proteinogenic amino acids L-cystine and the non-proteinogenic D-cystine. Cystine is the oxidized dimer form of the amino acid cysteine. L-Cystine serves two biological functions, a site of redox reactions and a mechanical linkage that allows proteins to retain their 3-dimensional structure. DL-cystine is used in the preparation of sulfur-containing dimeric and monomeric surfactants.

Hypoxanthine is a naturally occurring purine derivative and a reaction intermediate in the metabolism of adenosine and in the formation of nucleic acids by the salvage pathway. Hypoxanthine is a necessary additive in the certain cell, bacteria, and parasite cultures as a substrate and nitrogen source. For example, it is commonly a required reagent in malaria parasite cultures, since Plasmodium falciparum requires a source of hypoxanthine for nucleic acid synthesis and energy metabolism.

β-phenylethylamine (2-phenylethylamine) is a small amine containing alkaloid synonymous with phenethylamine and the acronym PEA; in the human body it has a neuromodulator/neurotransmitter role and is known as a trace amine due to its low quantity relative to other bioactive amino acids. PEA was characterized as a substrate for type B monoamine oxidase. PEA functions by activating trace amine receptors (including TAAR1 and TAAR2) thereby regulating monoamine turnover. Ring-substituted phenethylamines, commonly known as 2Cs, are designer drugs that are emerging as new drugs of abuse. PEA administration may be therapeutic in selected depressed patients.

β-phenylethylamine (2-phenylethylamine) is a small amine containing alkaloid synonymous with phenethylamine and the acronym PEA; in the human body it has a neuromodulator/neurotransmitter role and is known as a trace amine due to its low quantity relative to other bioactive amino acids. PEA was characterized as a substrate for type B monoamine oxidase. PEA functions by activating trace amine receptors (including TAAR1 and TAAR2) thereby regulating monoamine turnover. Ring-substituted phenethylamines, commonly known as 2Cs, are designer drugs that are emerging as new drugs of abuse. PEA administration may be therapeutic in selected depressed patients.

β-phenylethylamine (2-phenylethylamine) is a small amine containing alkaloid synonymous with phenethylamine and the acronym PEA; in the human body it has a neuromodulator/neurotransmitter role and is known as a trace amine due to its low quantity relative to other bioactive amino acids. PEA was characterized as a substrate for type B monoamine oxidase. PEA functions by activating trace amine receptors (including TAAR1 and TAAR2) thereby regulating monoamine turnover. Ring-substituted phenethylamines, commonly known as 2Cs, are designer drugs that are emerging as new drugs of abuse. PEA administration may be therapeutic in selected depressed patients.