Triphenyltin (TPT) is a one of the most commercially-important organotin compounds. The major use of TPT is in agriculture in fungicides to protect crops. It can detrimentally impact the environment. Reaction A is non-enzymic, catalyzed by a microbially-associated low-molecular-weight compound called TPT-Degrading Factor (TPT-DF). TPT-DF is most likely a pyoverdine, which is a yellow-green chromopeptide siderophore with a molecular mass of 1,000 to 1,500 Da, or a pyoverdine analog ([http://www.ncbi.nlm.nih.gov/pubmed/10919812|Inoue et al., 2000]).