What is "djenkolic acid"

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). This compound consists of two cysteine radicals connected by a methylene group between the sulfurs, or it is 2-amino-3-[(2-amino-3-hydroxy-3-oxopropyl)sulfanylmethylsulfanyl] propanoic acid. It is toxic to humans, especially causing nephrotoxicity.