Fmoc-Val-Cit-PAB-MMAE is a type of small molecule drug that can selectively target cancer cells while minimizing damage to healthy cells. The Fmoc group is a commonly used protective group in peptide synthesis and is often used to protect N-terminal amino groups. Val and Cit groups are common amino acids in peptides and proteins. The Fmoc group protects the amino group and helps to ensure that the drug is delivered intact to its target, while the Val and Cit amino acids provide a binding site for the drug to target specific cancer cells. The PAB linker (a para-aminobenzoic acid group) ensures that the MMAE cytotoxic drug is delivered specifically to cancer cells, where it can exert its toxic effects and inhibit the growth of cancer cells.
Fmoc-Val-Cit-PAB-MMAE is a precursor of antibody drug conjugate containing a cleavable Val-Cit peptide, a PABC linker and a MMAE payload. It can be attached to a monoclonal antibody (MAB) which directs it toward cancer cells.
Fmoc-Val-Cit-PAB-PNP (388.4 mg,0.507 mmol) was dissolved in DMF (40 ml) at 0 ℃ under nitrogen protection and then HOBt (68.4 mg,0.507 mmol) and MMAE (400.0 mg,0.558 mmol) were added. After 15 min, pyridine (8 ml) and DIPEA (106.2 mL, 0.608 mmol) were added and reached 0 ℃ for 30 min. Then warmed to room temperature and stirred for 3 hours. DIPEA (106.2. mL, 0.608 mmol) was added and the reaction was continued for 24 h. After the reaction was complete, the mixture was concentrated in vacuo. The crude product was purified by column chromatography to give Fmoc-Val-Cit-PAB-MMAE as a white solid.
