1-Propanesulfonic acid, 3-[(aminoiminomethyl)amino]-2-hydroxy- 1-Propanesulfonic acid, 3-guanidino-2-hydroxy- 3-(Guanylamino)-2-hydroxypropanesulfonic acid 3-[(Aminoiminomethyl)amino]-2-hydroxy-1-propanesulfonic acid 3-[(Diaminomethylidene)amino]-2-hydroxypropane-1-sulfonic acid 3-Carbamimidamido-2-hydroxypropane-1-sulfonic acid 3-Guanidino-2-hydroxy-propane-1-sulfonic acid 3-Guanidino-2-hydroxypropanesulfonic acid