Macrocycle synthesis strategy based on step-wise “adding and reacting” three components enables screening of large combinatorial libraries

Abstract

<p>Combination of three efficient chemical reactions allows for solution-phase synthesis of 3780 macrocycles and identification of potent thrombin inhibitor.</p>

Picomole‐Scale Synthesis and Screening of Macrocyclic Compound Libraries by Acoustic Liquid Transfer

“…We tested the acoustic dispensing strategy using a recently developed approach for macrocycle synthesis (Figure 1 d) in which m N α ‐bromoacetyl‐activated linear peptides were reacted with n primary amines, followed by a cyclization with o linkers to yield m × n × o macrocycles [17] . We had previously used this approach to affinity mature a macrocyclic thrombin inhibitor (P2, K i =42 n m ) through combinatorial synthesis of thousands of variants of it.…”

Strategies to expand peptide functionality through hybridisation with a small molecule component

“…In a follow up study, it was found that the simultaneous substitution of L-b-homoproline with D-b-homoproline, and hydroxymethyl-benzyl with furfuryl resulted in a 5.5-fold improvement in potency over P2. 77 Many cyclisation chemistries are currently available to add functionalisation in a diversity orientated fashion. [78][79][80][81][82] In a recent example, Waldmann and co-workers developed a strategy to add natural product inspired small molecule structures via the cyclisation linkage.…”

“…In a follow up study, it was found that the simultaneous substitution of l -β-homoproline with d -β-homoproline, and hydroxymethyl-benzyl with furfuryl resulted in a 5.5-fold improvement in potency over P2 . 77 …”

Synthesis and direct assay of large macrocycle diversities by combinatorial late-stage modification at picomole scale

“…Inspired by studies using mosquito liquid handling 20 , 21 or contactless acoustic droplet ejection (ADE) technology 22 – 25 for synthesizing and screening small molecule libraries, we recently applied ADE for miniaturizing chemical reactions and screening of macrocycles at smaller scale 26 . However, the reaction yields varied substantially due to the challenging nature of the macrocyclization reactions we applied, and the small number of commercially available linker reagents (<20) limited the diversities of these libraries 19 , 26 , 27 . While the approach allowed identification of nanomolar binders to targets with defined binding pockets such as trypsin-like serine proteases 19 , 27 , we struggled to generate high-affinity binders to more challenging targets such as protein-protein interactions, the best ones obtained being PPI inhibitors of p53:MDM2 PPI with rather weak potency in the low micromolar range 26 .…”