Mal-Propionyl-PEG4-Val-Cit-PAB(m-PEG4)-Exatecan Size:5mg 94 SMILES CC1=C(SC=N1)C1=CC=C(CNC(=O)[C@@H]2C[C@@H](O)CN2C(=O)[C@@H](NC(=O)CCOCCOCCOCCOCCOCCOCC#C)C(C)(C)C)C=C1 Purity (HPLC)

94 SMILES CC1=C(SC=N1)C1=CC=C(CNC(=O)[C@@H]2C[C@@H](O)CN2C(=O)[C@@H](NC(=O)CCOCCOCCOCCOCCOCCOCC#C)C(C)(C)C)C=C1 Purity (HPLC) >= 95% Shipping Conditions Room temperature Storage Conditions Refrigerated Shelf Life 12 months after the date of delivery Regulatory Statement For Research Use Only

15 SMILES CC1=C(SC=N1)C1=CC=C(CNC(=O)[C@@H]2C[C@@H](O)CN2C(=O)[C@@H](NC(=O)COCCOCCCl)C(C)(C)C)C=C1 Purity (HPLC) >= 95% Shipping Conditions Room temperature Storage Conditions Refrigerated Shelf Life 12 months after the date of delivery Regulatory Statement For Research Use Only

Product Name DBCO-Propionyl-Val-Cit-PAB(m-PEG8)-MMAE Synonyms CAS Number Related CAS Molecular Formula C98H147N13O24 Molecular Weight 1891

Pure 5-isomer

Product Name Thalidomide-O-PEG3-C2-azide Synonyms Thalidomide-4'-O-PEG3-C2-azide CAS Number 2758432-01-6 Related CAS Molecular Formula C21H25N5O8 Molecular Weight 475

Mal-Propionyl-PEG4-Val-Cit-PAB(m-PEG4)-Exatecan Size:5mg 94 SMILES CC1=C(SC=N1)C1=CC=C(CNC(=O)[C@@H]2C[C@@H](O)CN2C(=O)[C@@H](NC(=O)CCOCCOCCOCCOCCOCCOCC#C)C(C)(C)C)C=C1 Purity (HPLC)SOLU KNEX cleavable linker features a Val Cit dipeptide. The conventional maleimidocaproyl (MC) unit is replaced by Mal Propionyl PEG4 moiety to enhance aqueous solubility. The Mal Propionyl group may also improve retro Michael addition stability during antibody conjugation. m PEG4 is attached to the commonly used self immolative para aminobenzyl (PAB) moiety to increase aqueous solubility. The payload is Exatecan, a highly potent topoisomerase I