Peramivir

(1S,2S,3R,4R)-3-(1-acetaMido-2-ethylbutyl)-4-guanidino-2-hydroxycyclopentanecarboxylic acid

3(R)-[1(S)-AcetaMido-2-ethylbutyl]-4(R)-guanidino-2(S)- hydroxycyclopentane-1(S)-carboxylic acid

(1S,2S,3S,4R)-3-[(1S)-1-AcetaMido-2-ethylbutyl]-4-[(diaMinoMethylene)aMino]-2-hydroxycyclopentanecarboxylic acid