Inducing Social Self-Sorting in Organic Cages To Tune The Shape of The Internal Cavity

Many interesting target guest molecules have low symmetry, yet most methods for synthesising hosts result in highly symmetrical capsules. Methods of generating lower symmetry pores are thus required to maximise the binding affinity in host-guest complexes. Herein, we use mixtures of tetraaldehyde building blocks with cyclohexanediamine to access low-symmetry imine cages. Whether a low-energy cage is isolated can be correctly predicted from the thermodynamic preference observed in computational models. The stability of the observed structures depends on the geometrical match of the aldehyde building blocks. One bent aldehyde stands out as unable to assemble into high-symmetry cages-and the same aldehyde generates low-symmetry socially self-sorted cages when combined with a linear aldehyde. We exploit this finding to synthesise a family of low-symmetry cages containing heteroatoms, illustrating that pores of varying geometries and surface chemistries may be reliably accessed through computational prediction and self-sorting.

A novel pipeline of 2-(benzenesulfonamide)-N-(4-hydroxyphenyl) acetamide analgesics that lack hepatotoxicity and retain antipyresis

Although acetaminophen (ApAP) is one of the most commonly used medicines worldwide, hepatotoxicity is a risk with overdose or in patients with compromised liver function. ApAP overdose is the most common cause of acute fulminant hepatic failure. Oxidation of ApAP to N-acetyl-p-benzoquinone imine (NAPQI) is the mechanism for hepatotoxicity. 1 is a non-hepatotoxic, metabolically unstable lipophilic ApAP analog that is not antipyretic. The newly synthesized 3 is a non-hepatotoxic ApAP analog that is stable, lipophilic, and retains analgesia and antipyresis. Intraperitoneal or po administration of the new chemical entities (NCEs), 3b and 3r, in concentrations equal to a toxic dose of ApAP did not result in the formation of NAPQI. Unlike livers from NCE-treated mice, the livers from ApAP-treated mice demonstrated large amounts of nitrotyrosine, a marker of mitochondrial free radical formation, and loss of hepatic tight junction integrity. Given the widespread use of ApAP, hepatotoxicity risk with overuse, and the ongoing opioid epidemic, these NCEs represent a novel, non-narcotic therapeutic pipeline.

Prodrug approach: An overview of recent cases

In this review we highlight the most modern trends in the prodrug strategy. In drug research and development, the prodrug concept has found a number of useful applications. Selected examples of this approach are provided in this paper and they are classified according to the aim of their design.

Abstract 4795: Development of novel, selective, reversible inhibitors equipotent against wild-type and C481S Bruton's tyrosine kinase (BTK)

Redx Oncology has developed novel, differentiated, reversible small molecule inhibitors of BTK, combining current best-in-class potency with improved selectivity profiles, which are suitable for oral, once daily dosing, designed to be equipotent against wild-type and C481S BTK.

BTK is a member of the src-related Tec family of cytoplasmic tyrosine kinases. BTK plays a key role in the BCR signaling pathway, which is required for the development, activation and survival of B-cells. BTK inhibitors have therefore been developed with the aim of treating B-cell malignancies that are dependent on BCR signaling, such as CLL and NHL. Ibrutinib is an irreversible BTK inhibitor that has been approved for the treatment of CLL, MCL and WM.

Irreversible and covalent reversible BTK inhibitors specifically target a cysteine residue C481 within BTK. Following treatment with ibrutinib, cases of secondary resistance have emerged in both CLL and MCL patients. Acquired mutations within BTK such as C481S, C481Y, C481R, C481F have been reported in the literature and clearly interfere with covalent drug binding. It has been predicted that the incidence of observed resistance will increase as clinical use outside clinical trials expands over time. Here, we present our reversible BTK inhibitor series demonstrating subnanomolar binding affinity for WT and C481S forms of BTK, that inhibits formation of pBTK in both WT and C481S BTK expressing cells. In addition, the compound demonstrated significant in vitro potency against a number of lymphoma cell lines including inhibition of BCR signaling and proliferation in OCI-Ly10 cells at nanomolar concentrations. To further investigate the binding nature of these compounds, PBMC wash out studies, measuring CD69 as a marker of B-cell activation, were used to highlight the reversible activity of these compounds.

Some BTK inhibitors also inhibit ITK, which plays a critical role in FcR-stimulated NK cell function that is required for ADCC. ADCC is the mechanism that anti-CD20 antibodies, such as rituximab, are believed to activate, and ibrutinib has been shown to antagonize this mechanism in vitro. As rituximab-combination chemotherapy is today's standard of care in B-cell malignancies, it would be desirable to have a BTK inhibitor with high selectivity for BTK over ITK.

At 1 μM, our lead compound is highly selective when tested against 469 kinase and did not show significant inhibition against other kinases involved in BCR signaling (e.g. Syk, Lyn). Furthermore, the compound has high selectivity versus structurally related cysteine-containing kinases (including EGFR and ITK) both in enzyme and cellular assays.

Our lead compound has a favorable in vitro safety profile and drug-like properties, displaying an improved CYP profile to competitor compounds. In vivo PK demonstrated good oral bioavailability and in vivo efficacy has been demonstrated.

Citation Format: Nicolas E S Guisot, Victoria Walker, Stuart A. Best, Valentina Abet, Rose Chappell, Juliette Emmerich, Kelvin Ho, James R. Kelly, Kristina Lyons, Melanie Müller, Julienne Refuerzo, Louise Sargent, Fatima Talab, Madelene Waldron, Matilda Bingham, Mary-Ann Campbell, Caroline Phillips, Richard Armer. Development of novel, selective, reversible inhibitors equipotent against wild-type and C481S Bruton's tyrosine kinase (BTK). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4795.

State-of-the-art of small molecule inhibitors of the TAM family: the point of view of the chemist

The TAM family of tyrosine kinases receptors (Tyro3, Axl and Mer) is implicated in cancer development, autoimmune reactions and viral infection and is therefore emerging as an effective and attractive therapeutic target. To date, only a few small molecules have been intentionally designed to block the TAM kinases, while most of the inhibitors were developed for blocking different protein kinases and then identified through selectivity profile studies. This minireview will examine in terms of chemical structure the different compounds able to act on either one, two or three TAM kinases with details about structure-activity relationships, drug-metabolism and pharmacokinetics properties where they exist.

N-(4-[(18)F]-fluoropyridin-2-yl)-N-{2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl}carboxamides as analogs of WAY100635. New PET tracers of serotonin 5-HT(1A) receptors

N-(4-[(18)F]-Fluoropyridin-2-yl)-N-{2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl}-carboxamides were prepared by labeling their 4-nitropyridin-2-yl precursors through nitro substitution by the (18)F anion. In vitro and in vivo tests showed that the cyclohexanecarboxamide derivative is a reversible, selective and high affinity 5-HT1A receptor antagonist (IC50 = 0.29 nM, ki = 0.18 nM) with high brain uptake, slow brain clearance and stability to defluorination when compared with conventional standards. This PET radioligand is a promising candidate for an improved in vivo quantification of 5-HT1A receptors in neuropsychiatric disorders.

Guanosine and isoguanosine derivatives for supramolecular devices

Guanosine (G) and isoguanosine (isoG) derivatives can self-assemble, yielding supramolecules that have found broad applications in diverse fields.