(+)-S-2-Amino-5-iodoacetamidopentanoic acid 2-AIPA 2-Amino-6-iodoacetamidohexanoic acid 90764-56-0 BRN 4744380 L-Lysine, N(sup 6)-(iodoacetyl)- N(sup 6)-(Iodoacetyl)-L-lysine