derives from farnesylated residue modification reporter fragment farnesyl reporter fragment 205.1956329345703125 205.1956329345703125 205.3600006103515625 205.3600006103515625 natural 1+ The farnesyl cation protein modification reporter fragment produced by fragmentation of some farnesyl modified residues. none (2E,6E)-3,7,11-trimethyldodeca-2,6,10-trien-1-ylium MOD:01771 C 15 H 25 C 15 H 25 farnesyl cation X PSI-MOD Farn+