(6R,9R,14R,17S,23S,25aR)-9-(acetylamino)-23-[4-(aminomethyl)benzyl]-6-(2-amino-2-oxoethyl)-17-(carboxymethyl)-1,1-dimethyl-5,8,16,19,22,25-hexaoxoicosahydro-1H-[1,3]thiazolo[4,3-p][1,2,5,8,11,14,17,20]dithiahexaazacyclotricosine-14-carboxylic acid