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A series of five benzimidazole-based compounds were identified using a machine learning algorithm as potential inhibitors of the respiratory syncytial virus (RSV) fusion protein. These compounds were synthesized, and compound 2 in particular exhibited excellent in vitro potency with an EC(50) value of 5 nM. This new scaffold was then further refined leading to the identification of compound 44, which exhibited a 10-fold improvement in activity with an EC(50) value of 0.5 nM.

Our first-generation CXCR4 antagonist TIQ15 was rationally modified to improve drug-like properties. Introducing a nitrogen atom into the aromatic portion of the tetrahydroisoquinoline ring led to several heterocyclic variants including the 5,6,7,8-tetrahydro-1,6-naphthyridine series, greatly reducing the inhibition of the CYP 2D6 enzyme. Compound

[Image: see text] This work surveys a variety of diamino-heterocycles as an isosteric replacement for the piperazine substructure of our previously disclosed piperarinyl-tetrahydroisoquinoline containing CXCR4 antagonists. A late-stage Buchwald coupling route was developed for rapid access to final compounds from commercial building blocks. Among 13 analogs in this study, compound 31 embodying an aza-piperazine linkage was found to have the best overall profile with potent CXCR4 inhibitory activity and favorable in vitro absorption, distribution, metabolism, and excretion (ADME) properties. An analysis of the calculated physiochemical parameters (ROF, cLogD) and the experimental ADME attributes of the analogs lead to the selection of 31 for pharmacokinetic studies in mice. Compared with the clinical compound AMD11070, compound 31 has no CYP450 3A4 or 2D6 inhibition, higher metabolic stability and PAMPA permeability, greatly improved physiochemical parameters, and superior oral bioavailability (%F = 24). A binding rationale for 31 within CXCR4 was elucidated from docking and molecular simulation studies.

Purpose: Pro-angiogenic and immune cells expressing chemokine receptor CXCR4 traffic along concentration gradients of the chemokine ligand CXCL12, which disseminates from stromal niches. The CXCR4/CXCL12 axis is hijacked by various cancer types characterized by dramatic CXCR4 and/or CXCL12 upregulation. This chemokine network misregulation causes hyperactivation of CXCR4-mediated processes, leading to (1) excessive stimulation of protective tumor-stromal interactions, (2) metastatic expansion of CXCR4+ cancer cells to CXCL12-rich sites, and (3) intratumoral infiltration of CXCR4+ immunosuppressive cells. Accordingly, CXCR4 antagonists have significant therapeutic potential against cancer. While clinical CXCR4 inhibitors are severely limited by suboptimal pharmacokinetic (PK) properties and off-target activities, several of our tetrahydroisoquinoline-based CXCR4 antagonists exhibit superior selectivity and PK profiles to these clinical comparators (e.g., X4P-001). Methods: To test the hypothesis that improved PK profiles would translate to enhanced efficacy, our lead CXCR4 antagonist EMU-116 was compared to X4P-001 head-to-head in three mouse models of genitourinary cancers. First, human 786.0 renal cell carcinoma (RCC) xenograft-bearing female nude mice were treated p.o., q.d. with vehicle, axitinib (30 mg/kg), X4P-001 (100 mg/kg), EMU-116 (3, 10, or 30 mg/kg), X4P + axitinib, or EMU-116 + axitinib. Subcutaneous tumor volume was monitored using calipers. Second, nude male mice bearing intratibial, luciferase-expressing human PC-3 prostate cancer xenografts were treated with vehicle (p.o., q.d.), docetaxel (10 mg/kg i.p. weekly), X4P-001 (10 or 30 mg/kg p.o., q.d.), EMU-116 (10 or 30 mg/kg p.o., q.d.), X4P + axitinib, or EMU + axitinib. Intratibial tumor volume was monitored via luminescence imaging. Third, syngeneic RENCA RCC tumor-bearing female Balb/c mice were treated p.o., q.d. with vehicle, X4P-001 (30 mg/kg), or EMU-116 (30 mg/kg). Subcutaneous tumor volume was monitored using calipers, and immune cell subsets in bone marrow, blood, tumor, and tumor-draining lymph nodes were quantified via flow cytometry. Results: In the RCC xenograft model in combination with axitinib, EMU-116 (3 or 10 mg/kg) was equally effective at decreasing tumor burden compared to X4P-001 (100 mg/kg), whereas EMU-116 (30 mg/kg) was more effective. In the bone metastatic prostate cancer xenograft model, EMU-116 was as or more effective than X4P-001 when paired with docetaxel. In the syngeneic RCC model, EMU-116 mobilized T cells more effectively than X4P-001. Conclusion: EMU-116, at the same or lower dose, was more efficacious than X4P-001 in these models. These results highlight EMU-116 as a clinical candidate with significant therapeutic potential to synergize with chemotherapeutics, targeted therapies, and immuno-oncology agents. Citation Format: Eric J. Miller, Carrie Q. Sun, Petra Gregorova, Edgars Jecs, Yesim Altas Tahirovic, Robert J. Wilson, Huy H. Nguyen, Savita K. Sharma, Perry Bartsch, Zachary Sticher, Levi Moellering, Priscilla Davidson, Ryan Jajosky, Michael D'Erasmo, Manohar Saindane, Zafer Sahin, Nicholas S. Akins, Alexander A. Kolykhalov, Lawrence Wilson, Rebecca S. Arnold, John A. Petros, Haydn Kissick, Lingjie Xu, Yi Jiang, Dennis C. Liotta. Orally bioavailable small molecule CXCR4 antagonists with enhanced efficacy in mouse models of genitourinary cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2649.

CXCR4 is a G-protein-coupled receptor that interacts with its cognate ligand, CXCL12, to synchronize many physiological responses and pathological processes. Disruption of the CXCL12-CXCR4 circuitry by small-molecule antagonists has emerged as a promising strategy for cancer intervention. We previously disclosed a hit-to-lead effort that led to the discovery of a series of tetrahydroisoquinoline-based CXCR4 antagonists exemplified by the lead compound TIQ15. Herein, we describe our medicinal-chemistry efforts toward the redesign of TIQ15 as a result of high mouse-microsomal clearance, potent CYP2D6 inhibition, and poor membrane permeability. Guided by the in vitro ADME data of TIQ15, structural modifications were executed to provide compound 12a, which demonstrated a reduced potential for first-pass metabolism while maintaining CXCR4 potency. Subsequent SAR studies and multiparameter optimization of 12a resulted in the identification of compound 25o, a highly potent, selective, and metabolically stable CXCR4 antagonist possessing good intestinal permeability and low risk of CYP-mediated drug-drug interactions.

[Image: see text] A novel series of CXCR4 antagonists with piperidinyl and piperazinyl alkylamine side chains designed as butyl amine replacements are described. Several of these compounds showed similar activity to the parent compound TIQ-15 (5) in a SDF-1 induced calcium flux assay. Preliminary structure–activity relationship investigations led us to identify a series containing N-propyl piperazine side chain analogs exemplified by 16 with improved off-target effects as measured in a muscarinic acetylcholine receptor (mAChR) calcium flux assay and in a limited drug safety panel screen. Further efforts to explore SAR and optimize drug properties led to the identification of the N′-ethyl-N-propyl-piperazine tetrahydroisoquinoline derivative 44 and the N-propyl-piperazine benzimidazole compound 37, which gave the best overall profiles with no mAChR or CYP450 inhibition, good permeability in PAMPA assays, and metabolic stability in human liver microsomes.

A structure–activity relationship study of potent TIQ15-derived CXCR4 antagonists is reported. In this investigation, the TIQ15 side-chain was constrained to improve its drug properties. The cyclohexylamino congener 15a was found to be a potent CXCR4 inhibitor (IC50 = 33 nM in CXCL12-mediated Ca2+ flux) with enhanced stability in liver microsomes and reduced inhibition of CYP450 (2D6). The improved CXCR4 antagonist 15a has potential therapeutic application as a single agent or combinatory anticancer therapy.

CXCR4 is the most common chemokine receptor expressed on the surface of many cancer cell types. In comparison to normal cells, cancer cells overexpress CXCR4, which correlates with cancer cell metastasis, angiogenesis, and tumor growth. CXCR4 antagonists can potentially diminish the viability of cancer cells by interfering with CXCL12-mediated pro-survival signaling and by inhibiting chemotaxis. Herein, we describe a series of CXCR4 antagonists that are derived from (S)-5,6,7,8-tetrahydroquinolin-8-amine that has prevailed in the literature. This series removes the rigidity and chirality of the tetrahydroquinoline providing 2-(aminomethyl)pyridine analogs, which are more readily accessible and exhibit improved liver microsomal stability. The medicinal chemistry strategy and biological properties are described.

Introduction: The chemokine receptor CXCR4 has been under intense study due to the central role it plays in immune system regulation and the pathology of many human diseases. The FDA approval of the first CXCR4 antagonist drug Plerixafor (i.e. AMD3100, Mozobil®) ushered in an increase in patent activity covering CXCR4 based therapeutic agents over the past decade.Areas covered: This article describes patent documents published during the period of 2010 through 2018 for both small molecules and peptide-based CXCR4 modulators as therapeutic agents. There is an expansion of intellectual property (IP) around existing and new small molecules of clinical interest, including new chemotypes featuring aromatic and aliphatic heterocycles. There is also significant IP covering peptide-based therapeutics, although about half as many in number as those covering small molecules.Expert opinion: In the last decade there has been significant interest in modulators of the CXCR4 receptor, as gauged by the number of patent filings and clinical investigations targeting this receptor for human disease intervention. Seven of the many CXCR4 modulators described herein, that are currently in human clinical trials, are likely to spur the creation of other FDA approved therapeutics in the near future, most likely as immune and oncology drugs.

The total synthesis of amphidinolide P was achieved through two different ene-yne metathesis approaches. In each approach, the metathesis step was performed at late stages in the synthesis with all other functionality present. By forging two successful pathways to the synthesis of 1, some of the strengths and weaknesses of metathesis-intensive synthetic strategies were identified.

CXCR4 is a seven-transmembrane receptor expressed by hematopoietic stem cells and progeny, as well as by ≥48 different cancers types. CXCL12, the only chemokine ligand of CXCR4, is secreted within the tumor microenvironment, providing sanctuary for CXCR4+ tumor cells from immune surveillance and chemotherapeutic elimination by (1) stimulating prosurvival signaling and (2) recruiting CXCR4+ immunosuppressive leukocytes. Additionally, distant CXCL12-rich niches attract and support CXCR4+ metastatic growths. Accordingly, CXCR4 antagonists can potentially obstruct CXCR4-mediated prosurvival signaling, recondition the CXCR4+ leukocyte infiltrate from immunosuppressive to immunoreactive, and inhibit CXCR4+ cancer cell metastasis. Current small molecule CXCR4 antagonists suffer from poor oral bioavailability and off-target liabilities. Herein, we report a series of novel tetrahydroisoquinoline-containing CXCR4 antagonists designed to improve intestinal absorption and off-target profiles. Structure–activity relat...

Ene–yne cross metathesis was assessed for use as a key fragment coupling in a planned total synthesis of amphidinolide P. A terminal alkyne containing a β,γ-epoxide was synthesized and employed as the alkyne partner in an intermolecular ene–yne metathesis. In the alkene substrate, optimal functionality and reaction conditions were determined. An unprotected allyl alcohol was found to be critical for both high yield and high E-selectivity. Fewer equivalents of the alkene resulted in incomplete reaction and side reactions consumed the terminal alkyne. The best ruthenium carbene precatalysts were found to be the Hoveyda–Grubbs carbene complexes.

A relay strategy was employed to achieve an intermolecular ene-yne metathesis between 1,1-disubstituted alkenes and alkynes. The relay serves to activate an unreactive alkene which will not participate in ene-yne metathesis. The new relay cross ene-yne metathesis gives rise to 1,1,3-trisubstituted-1,3-dienes previously inaccessible by direct ene-yne metathesis methods.

Novel route to obtain EO material is proposed by supramolecular assembly of neutral-ground-state (NGS) and zwitterionic (ZWI) NLO chromophores in binary chromophore organic glass (BCOG) host–guest system. On a basis of our Langeven Dynamics (LD) molecular modeling combined with quantum chemical calculations, we have shown that anticipated enhancement NLO efficiency of BCOG material is possible via electrostatic supramolecular assembly of NGS with ZWI chromophore in antiparallel manner. Binding energy of such complex could be more dependent on molecular compatibility of components and local (atomic) charge distribution, then overall molecular dipole moments. According to our LD simulations these supramolecular bind structures of NGS and ZWI chromophores can sustain thermally assisted electrical field poling. For the one of experimentally investigated systems, build from dimethylaminobenzylidene 1,3-indanedione containing host and zwitterionic indanedione-1,3 pyridinium betaine as a guest, almost twofold enhancement of NLO efficiency was observed.

For the development of electro optical active polyurethanes six new derivatives of 2-{(2-hydroxyethyl)-[4-(4-nitrophenylazo)phenyl]amino}ethanol and two of 2-{(2-hydroxyethyl)-[4-(5-nitropyridin-2-ylazo)phenyl]amino}ethanol were synthesized by azocoupling reaction. Molecular geometry, hyperpolarizability βFF and ground state dipole moment μg were acquired by RHF ab initio (6–31G∗∗) calculations using HyperChem software package. To characterize NLO performance of synthesized azo compounds second order non linear coefficients d31 and d33 were measured as function of chromophore load in guest–host films (PMMA). Eight synthesized compounds can be grouped in four similar gross formula pairs (different position of octyloxy group) with almost equal μg βFF product and different μg values. At low chromophore concentrations higher dipole moment compounds perform better. Lower dipole moment compounds have better NLO efficiency at high chromophore loads. Accurate ranking of all chromophores, based on two-level model corrected zero frequency d33(0) values, was not viable due to overestimation of the dispersion factor.

A practical method has been devised for the synthesis of previously unknown push-pull azochromophores with 5-nitropyridin-2-yl acceptor moiety from 2-amino-5-nitro-1-oxypyridine.

Ene–yne cross metathesis was assessed for use as a key fragment coupling in a planned total synthesis of amphidinolide P. A terminal alkyne containing a β,γ-epoxide was synthesized and employed as the alkyne partner in an intermolecular ene–yne metathesis. In the alkene substrate, optimal functionality and reaction conditions were determined. An unprotected allyl alcohol was found to be critical for both high yield and high E-selectivity. Fewer equivalents of the alkene resulted in incomplete reaction and side reactions consumed the terminal alkyne. The best ruthenium carbene precatalysts were found to be the Hoveyda–Grubbs carbene complexes.

A relay strategy was employed to achieve an intermolecular ene–yne metathesis between 1,1-disubstituted alkenes and alkynes. The relay serves to activate an unreactive alkene which will not participate in ene-yne metathesis. The new relay cross ene–yne metathesis gives rise to 1,1,3-trisubstituted-1,3-dienes previously inaccessible by direct ene–yne metathesis methods.