A small molecule drug conjugate (SMDC) of DUPA and a duocarmycin built on the solid phase

Borylation via iridium catalysed C-H activation: a new concise route to duocarmycin derivatives

The synthesis of the ethyl ester analogue of the ultrapotent antitumour antibiotic seco-duocarmycin SA has been achieved in eleven linear steps from commercially available starting materials. The DSA alkylation subunit can be made in ten linear steps from the same precursor. The route involves C-H activation at the equivalent of the C7 position on indole leading to a borylated intermediate 9 that is stable enough for peptide coupling reactions but can be easily converted to the free hydroxyl analogue.

Small Molecule-Drug Conjugates Emerge as a New Promising Approach for Cancer Treatment

Antibody drug conjugates (ADCs) have emerged as a new promising class of anti- cancer agents. However, limitations such as higher costs and unavoidable immunogenicity due to their relatively large structures cannot be ignored. Therefore, the development of lightweight drugs such as small molecule-drug conjugates (SMDCs) based on the ADC design idea has become a new option for targeted therapy. SMDCs are derived from the coupling of small-molecule targeting ligands with cytotoxic drugs. They are composed of three parts: small-molecule targeting ligands, cytotoxic molecules, and linkers. Compared with ADCs, SMDCs can be more rapidly and evenly dispersed into tumor tissues, with low cost and no immunogenicity. In this article, we will give a comprehensive review of different types of SMDCs currently under clinical trials to provide ideas and inspirations for the development of clinically applicable SMDCs.

How can the potential of the duocarmycins be unlocked for cancer therapy?

The duocarmycins belong to a class of agent that has fascinated scientists for over four decades. Their exquisite potency, unique mechanism of action, and efficacy in multidrug-resistant tumour models makes them attractive to medicinal chemists and drug hunters. However, despite great advances in fine-tuning biological activity through structure-activity relationship studies (SARS), no duocarmycin-based therapeutic has reached clinical approval. In this review, we provide an overview of the most promising strategies currently used and include both tumour-targeted prodrug approaches and antibody-directed technologies.