Cell binding agent-drug conjugates comprising phosphinate-based charged linkers and methods of using such linkers and conjugates are provided.

Disclosed are novel conjugates and methods for the preparation thereof. One of the methods for the preparation of a conjugate comprises a step of: acting a compound of formula (I), with a thiol-containing molecule of formula (II), wherein represents an amino acid, a peptide, a protein, an antibody, a nucleotide, an oligonucleotide, a saccharide, a polysaccharide, a polymer, a small molecule, an optionally substituted C.sub.1-C.sub.8-alkyl, an optionally substituted phenyl, or an optionally substituted aromatic 5- or 6-membered heterocyclic system; resulting in a compound of formula (III).

Cell binding agent-drug conjugates comprising phosphinate-based charged linkers and methods of using such linkers and conjugates are provided.