Amino acids

Arginine

Cysteine

Short Chain amino acids
Peptaibols

Branch chain amino acids
http://en.wikipedia.org/wiki/Branched-chain_amino_acids

Leucine

Isoleucine

Valine

AgriLife scientist: Functional amino acids regulate key metabolic pathways

http://agnews.tamu.edu/showstory.php?id=2253

Other groups
Homocysteine

sources: http://www.healthnews.com/Categories/NaturalHealth/BranchedChainAminoAcids