Propargyl-Gly(m-PEG4)-Gly-Gly-Phe-Gly-PAB(m-PEG4)-Exatecan tmr CC(C)(C)C(=O)OC1=CC2=C(C=C1)C1(OC(=O)C3=CC=C(C=C13)C(=O)NCCOCCOCCOCCN=[N]#N)C1=CC=C(OC(=O)C(C)(C)C)C=C1O2 Purity (HPLC): ≥ 95%

CC(C)(C)C(=O)OC1=CC2=C(C=C1)C1(OC(=O)C3=CC=C(C=C13)C(=O)NCCOCCOCCOCCN=[N]#N)C1=CC=C(OC(=O)C(C)(C)C)C=C1O2 Purity (HPLC): ≥ 95% Shipping Conditions: room temperature Storage Conditions: Refrigerated Regulatory Statement: For Research Use Only

313 SMILES OCCCC1=CC=C2C(=O)N(C3CCC(=O)NC3=O)C(=O)C2=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

7 SMILES CC1=C(SC=N1)C1=CC=C(CNC(=O)[C@@H]2C[C@@H](O)CN2C(=O)[C@@H](NC(=O)CCOCCN=[N+]=[N-])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 Azide-Lys(m-PEG4)-Val-Ala-PAB(m-PEG4)-PNP Synonyms CAS Number Related CAS Molecular Formula C48H73N9O18 Molecular Weight 1064

77 Purity (HPLC) >= 95% Solubility DMSO

Propargyl-Gly(m-PEG4)-Gly-Gly-Phe-Gly-PAB(m-PEG4)-Exatecan tmr CC(C)(C)C(=O)OC1=CC2=C(C=C1)C1(OC(=O)C3=CC=C(C=C13)C(=O)NCCOCCOCCOCCN=[N]#N)C1=CC=C(OC(=O)C(C)(C)C)C=C1O2 Purity (HPLC): ≥ 95%SOLU KNEX cleavable linker features a Gly Gly Phe Gly (GGFG) peptide. In this product, a Propargyl Gly(m PEG4) moiety replaces the conventional maleimidocaproyl (MC) unit to enhance aqueous solubility. The propargyl functional group is widely employed in click chemistry to undergo selective cycloaddition with azides. Additionally, m PEG4 is attached to the commonly used self immolative para aminobenzyl (PAB) moiety to further increase aqueous