Modular Synthesis of Diverse Natural Product-like Macrocycles: Discovery of Hits with Antimycobacterial Activity

A modular synthetic approach was developed in which variation of the triplets of building blocks used enabled systematic variation of the macrocyclic scaffolds prepared. The approach was demonstrated in the synthesis of 17 diverse natural product-like macrocyclic scaffolds of varied (12-20-membered) ring size. The biological relevance of the chemical space explored was demonstrated through the discovery of a series of macrocycles with significant antimycobacterial activity

Divergent Approach to Building a Latrunculin Family Derived Hybrid Macrocyclic Toolbox

A divergent approach to obtain a latrunculin family based hybrid macrocyclic toolbox is developed. A practical, stereoselective synthesis of a common substructure present in latrunculin A and latrunculol A was achieved. This was further utilized in the macrocyclic diversity synthesis. The amino acid moiety embedded in the 15-membered macrocyclic ring allows for the exploration of various chiral side chains as one of the diversity sites

Macrocyclic toolbox from epothilone fragment identifies a compound showing molecular interactions with actin and novel promoters of apoptosis in patient-derived brain tumor cells

A simple, practical stereoselective synthesis of the epothilone fragment is developed to obtain a diverse set of expanded 18-membered macrocyclic compounds. These macrocycles contain the C5–C8 sub-unit of epothilone and an additional amino acid moiety incorporated in the 18-membered macrocycle, which allows the synthesis of several analogs with a variation in the chiral side chain. The epothilone fragment was obtained by using an enantiopure epoxide, which was subjected to a regioselective opening, giving the key derivative. Finally, the synthesis of the 18-membered macrocyclic ring was achieved by employing two key steps: (i) acylation with an N-allylated amino acid moiety, and (ii) a ring-closing metathesis (RCM) approach. Computational studies of the macrocyclic compounds obtained from this study with actin give rise to the proposed molecular interactions with the target protein. Further, the screening of our chemical toolbox from this program (i.e., the final products and several intermediates) identified several compounds as promoters of apoptosis in patient-derived brain tumor glioma cells

Phenotypic Screen Identifies a Small Molecule Modulating ERK2 and Promoting Stem Cell Proliferation

Stem cells display a fundamentally different mechanism of proliferation control when compared to somatic cells. Uncovering these mechanisms would maximize the impact in drug discovery with a higher translational applicability. The unbiased approach used in phenotype-based drug discovery (PDD) programs can offer a unique opportunity to identify such novel biological phenomenon. Here, we describe an integrated phenotypic screening approach, employing a combination of in vitro and in vivo PDD models to identify a small molecule increasing stem cell proliferation. We demonstrate that a combination of both in vitro and in vivo screening models improves hit identification and reproducibility of effects across various PDD models. Using cell viability and colony size phenotype measurement we characterize the structure activity relationship of the lead molecule, and identify that the small molecule inhibits phosphorylation of ERK2 and promotes stem cell proliferation. This study demonstrates a PDD approach that employs combinatorial models to identify compounds promoting stem cell proliferation

14-Membered Macrocyclic Ring-Derived Toolbox: The Identification of Small Molecule Inhibitors of Angiogenesis and Early Embryo Development in Zebrafish Assay

A highly practical and modular synthesis to obtain a diverse 14-membered ring-based macrocyclic toolbox is achieved. These compounds were further tested in zebrafish assays related to early embryonic development, angiogenesis, and neurogenesis, respectively. <b>1.4c</b> was identified as an antiangiogenesis agent

Synthesis and Evaluation of a 2,11-Cembranoid-Inspired Library

The 2,11-cembranoid family of natural products has been used as inspiration for the synthesis of a structurally simplified, functionally diverse library of octahydroisobenzofuran-based compounds designed to augment a typical medicinal chemistry library screen. Ring-closing metathesis, lactonisation and SmI2-mediated methods were exemplified and applied to the installation of a third ring to mimic the nine-membered ring of the 2,11-cembranoids. The library was assessed for aqueous solubility and permeability, with a chemical-space analysis performed for comparison to the family of cembranoid natural products and a sample set of a screening library. Preliminary investigations in cancer cells showed that the simpler scaffolds could recapitulate the reported anti-migratory activity of the natural products