On the Synthesis and Reactivity of 2,3-Dihydropyrrolo[1,2- a ]quinazolin-5(1 H)-ones

An improved, scalable synthetic route to the quinazolinone natural product 2,3-dihydropyrrolo[1,2-a]quinazolin-5(1H)-one is reported. The applicability of this method to analogue synthesis and the synthesis of related natural products is explored. Finally, reactivity of the scaffold to a variety of electrophilic reagents, generating products stereoselectively, is reported.Charlotte Sutherell was funded by the Cambridge PhD Training Programme in Chemical Biology and Molecular Medicine. We gratefully acknowledge the EPSRC (SVL, Grant Nos. EP/K099494/1 and EP/K039520/1).This is the author accepted manuscript. The final version is available from Georg Thieme via https://doi.org/10.1055/s-0035-1562792

Identification of the first structurally validated covalent ligands of the small GTPase RAB27A

Rab27A is a small GTPase, which mediates transport and docking of secretory vesicles at the plasma membrane via protein–protein interactions (PPIs) with effector proteins. Rab27A promotes the growth and invasion of multiple cancer types such as breast, lung and pancreatic, by enhancing secretion of chemokines, metalloproteases and exosomes. The significant role of Rab27A in multiple cancer types and the minor role in adults suggest that Rab27A may be a suitable target to disrupt cancer metastasis. Similar to many GTPases, the flat topology of the Rab27A-effector PPI interface and the high affinity for GTP make it a challenging target for inhibition by small molecules. Reported co-crystal structures show that several effectors of Rab27A interact with the Rab27A SF4 pocket (‘WF-binding pocket’) via a conserved tryptophan–phenylalanine (WF) dipeptide motif. To obtain structural insight into the ligandability of this pocket, a novel construct was designed fusing Rab27A to part of an effector protein (fRab27A), allowing crystallisation of Rab27A in high throughput. The paradigm of KRas covalent inhibitor development highlights the challenge presented by GTPase proteins as targets. However, taking advantage of two cysteine residues, C123 and C188, that flank the WF pocket and are unique to Rab27A and Rab27B among the >60 Rab family proteins, we used the quantitative Irreversible Tethering (qIT) assay to identify the first covalent ligands for native Rab27A. The binding modes of two hits were elucidated by co-crystallisation with fRab27A, exemplifying a platform for identifying suitable lead fragments for future development of competitive inhibitors of the Rab27A-effector interaction interface, corroborating the use of covalent libraries to tackle challenging targets

Research data supporting "On the Synthesis and Reactivity of 2,3-Dihydropyrrolo[1,2-a]quinazolin- 5(1H)-ones"

NMR and IR data to support characterisation of synthetic compounds in publicationEPSRC [EP/K099494/1 and EP/K039520/1] Cambridge PhD Training Programme in Chemical Biology and Molecular Medicin

Aryl-linked imidazolidin-2-ones as non-peptidic beta-strand mimetics

We describe the design and synthesis of a non-peptidic beta-strand mimetic composed of alternating aryl and imidazolidin-2-one rings that can be adapted to display diverse side-chains. Solid- and solution-phase data together with calculations suggest that the desired conformation for side-chain mimicry is readily accessible and well-populated

Novel fibrillin 1 mutation in a case of neonatal Marfan syndrome: the increasing importance of early recognition.

Neonatal Marfan syndrome (MFS) is a severe form of classic MFS caused by mutations in a specific region of the fibrillin 1 gene (FBN1). We report a case of an infant with neonatal MFS who presented with flexion contractures in utero and severe skeletal and cardiovascular manifestations at birth. A novel de novo missense mutation in exon 26 of FBN1 was demonstrated. Because of potential new therapies, it is increasingly important to recognize neonatal MFS in utero as well as shortly after birth to initiate the appropriate diagnostic work-up and management