Sulfur amino acids

Lanthionine ketimine (3,4-dihydro-2H-1,3-thiazine-3,5-dicarboxylic acid) is a naturally occurring sulfur amino acid metabolite found in the mammalian brain and central nervous system (CNS).

Felinine, also known as (R)-2-amino-3-(4-hydroxy-2-methylbutan-2-ylthio)propanoic acid, is a chemical compound and amino acid found in cat urine and a precursor via microbial lyase of the putative cat pheromone and thiol called 3-mercapto-3-methylbutan-1-ol (MMB).

Methionine is an essential amino acid in humans.

Cysteine (abbreviated as Cys or C) is a semi-essential proteinogenic amino acid with the formula HO2CCH(NH2)CH2SH.

Ethionine is a non-proteinogenic amino acid structurally related to methionine, with an ethyl group in place of the methyl group.

S-Methylmethionine (SMM) is a derivative of methionine with the chemical formula (CH3)2S+CH2CH2CH(NH3+)CO2−.

Homocysteine /ˌhoʊmoʊˈsɪstiːn/ is a non-protein α-amino acid.

Cysteic acid is an intermediate in cysteine metabolism.

Cysteine sulfinic acid is an amino acid containing a sulfinic acid functional group.

Alliin /ˈæli.ɪn/ is a sulfoxide that is a natural constituent of fresh garlic.

Cystine is the oxidized dimer form of the amino acid cysteine and has formula (SCH2CH(NH2)CO2H)2.

Lanthionine is a nonproteinogenic amino acid with the chemical formula (HOOC-CH(NH2)-CH2-S-CH2-CH(NH2)-COOH).

Cysteinyldopa is a catecholamine.

Cystathionine is an intermediate in the synthesis of cysteine.

Hawkinsin is an amino acid.

N-Formylmethionine (fMet) is a derivative of the amino acid methionine in which a formyl group has been added to the amino group.

Djenkolic acid (or sometimes jengkolic acid) is a sulfur-containing non-protein amino acid naturally found in djenkol beans of the South-East Asian legumes jengkol (Archidendron jiringa).

S-Allyl cysteine (SAC) is an organic compound that is a natural constituent of fresh garlic.

S-Aminoethyl-L-cysteine, also known as thialysine, is a toxic analog of the amino acid lysine in which the second carbon of the amino acid's R-group (side chain) has been replaced with a sulfur atom.