Publications by authors named "Pedro M Garcia-Barrantes"

VPS34 has attracted attention in oncology as a target to modulate autophagy. However, the generation of selective VPS34 inhibitors with suitable PK properties has been a difficult task. The discovery of compound provides lessons in hit prioritization and achieving kinase selectivity while maintaining a good pharmacokinetic profile.

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Recent clinical and preclinical studies suggest that selective activators of the M muscarinic acetylcholine receptor have potential as a novel treatment for schizophrenia. M activation inhibits striatal dopamine release by mobilizing endocannabinoids, providing a mechanism for local effects on dopamine signaling in the striatum but not in extrastriatal areas. G protein-coupled receptors (GPCRs) typically induce endocannabinoid release through activation of Gα-type G proteins whereas M transduction occurs through Gα-type G proteins.

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  • - The letter discusses the development of new M positive allosteric modulators (PAMs) using a unique benzomorpholine structure, created through a parallel synthesis approach.
  • - It highlights the optimization process that led to the discovery of the rodent tool compound VU0486846 (7), which has no adverse effects.
  • - The report outlines the challenges encountered in the optimization campaign, including structure-activity relationship (SAR) and drug metabolism and pharmacokinetics (DMPK) profiling, focusing on the impact of small structural changes on properties like CNS penetration.
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  • The selective activation of the M subtype of muscarinic acetylcholine receptor through positive allosteric modulation (PAM) is a promising approach for improving cognition in patients with schizophrenia and Alzheimer's disease, but existing potent PAMs can cause harmful cognitive impairments and seizures due to excessive receptor activation.
  • The newly developed compound VU0486846 shows weak agonist activity in lab settings but avoids the harmful effects seen with previous PAMs, such as MK-7622 and PF-06764427, while effectively enhancing cognitive function in specific tests.
  • Importantly, VU0486846 is able to counteract cognitive deficits caused by atypical antipsychotics like risperidone, highlighting that
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  • Recent studies indicate that the M muscarinic acetylcholine receptor could be a promising target for treating Alzheimer's and schizophrenia, but initial drug discovery attempts were unsuccessful in achieving selectivity for M activation.
  • Researchers are now focusing on allosteric modulators, known as positive allosteric modulators (PAMs), to selectively activate M receptors, although some PAMs can cause adverse effects that limit their use.
  • The study reveals that within a series of indole-based M PAMs, a novel compound was discovered that does not induce adverse effects, despite having a similar molecular profile to another PAM that does, emphasizing the need for in vivo testing to identify effective and safe treatments.
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The first total synthesis of Gombamide A (1), a cytotoxic cyclic thiopeptide from the sponge Clathria gombawuiensis, has been achieved. Highlights of the convergent synthesis feature a disulfide bond forming cascade to close the 17-membered macrocycle and a selenoazidylation procedure to access the unusual para-hydroxystyrlyamide (pHSA) moiety. The synthesis required 18 steps, 11 steps in its longest linear sequence, and proceeded in 9.

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  • The letter details the ongoing chemical optimization of the VU0453595 series, which are M1 positive allosteric modulators (PAMs) used for central nervous system (CNS) targets.
  • Researchers explored new 5,6- and 6,6-heterobicyclic structures to replace the original core in VU453595, which led to compounds with improved potency and better CNS distribution.
  • This research introduced a variety of new chemical structures for M1 PAMs that lack hydrogen-bond donors, significantly enhancing the structural diversity available for further CNS studies.
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This letter describes the further chemical optimization of the picolinamide-derived family of mGlu4 PAMs wherein we identified a 3-amino substituent to the picolinamide warhead that engendered potency, CNS penetration and in vivo efficacy. From this optimization campaign, VU0477886 emerged as a potent (EC50=95nM, 89% Glu Max) mGlu4 PAM with an attractive DMPK profile (brain:plasma Kp=1.3), rat CLp=4.

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The efficacy of positive allosteric modulators (PAMs) of the metabotropic glutamate receptor 4 (mGlu4) in preclinical rodent models of Parkinson's disease has been established by a number of groups. Here, we report an advanced preclinically characterized mGlu4 PAM, N-(3-chloro-4-fluorophenyl)-1H-pyrazolo[4,3-b]pyridin-3-amine (VU0418506). We detail the discovery of VU0418506 starting from a common picolinamide core scaffold and evaluation of a number of amide bioisosteres leading to the novel pyrazolo[4,3-b]pyridine head group.

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This letter describes the re-exploration of the mGlu1 PAM Ro 07-11401 scaffold through a multi-dimensional, iterative parallel synthesis approach. Unlike recent series of mGlu1 PAMs with robust SAR, the SAR around the Ro 07-11401 structure was incredibly steep (only ∼6 of 200 analogs displayed mGlu1 PAM activity), and reminiscent of the CPPHA mGlu5 PAM scaffold. Despite the steep SAR, two new thiazole derivatives were discovered with improved in vitro DMPK profiles and ∼3- to 4-fold improvement in CNS exposure (Kps 1.

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This Letter describes the further lead optimization of the VU0486321 series of mGlu1 positive allosteric modulators (PAMs), focused on addressing the recurrent issue of plasma instability of the phthalimide moiety. Here, we evaluated a number of phthalimide bioisosteres, and ultimately identified isoindolinones as the ideal replacement that effectively address plasma instability, while maintaining acceptable mGlu1 PAM potency, DMPK profile, CNS penetration and mGluR selectivity.

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This Letter describes the further lead optimization of the VU0486321 series of mGlu1 positive allosteric modulators (PAMs), driven by recent genetic data linking loss of function GRM1 to schizophrenia. Steep and caveat-laden SAR plagues the series, but ultimately potent mGlu1 PAMs (EC50s ∼5 nM) have resulted with good DMPK properties (low intrinsic clearance, clean CYP profile, modest Fu) and CNS penetration (Kps 0.25-0.

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This Letter describes the lead optimization of the VU0486321 series of mGlu1 positive allosteric modulators (PAMs). While first generation PAMs from Roche were reported in the late 1990s, little effort has focused on the development of mGlu1 PAMs since. New genetic data linking loss-of-function mutant mGlu1 receptors to schizophrenia, bipolar disorder and other neuropsychiatric disorders has rekindled interest in the target, but the ideal in vivo probe, for example, with good PK, brain penetration and low plasma protein binding, for robust target validation has been lacking.

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The therapeutic potential of selective mGlu1 activation is vastly unexplored relative to the other group I mGlu receptor, mGlu5; therefore, our lab has focused considerable effort toward developing mGlu1 positive allosteric modulators (PAMs) suitable as in vivo proof of concept tool compounds. Optimization of a series of mGlu1 PAMs based on an N-(3-chloro-4-(1,3-dioxoisoindolin-2-yl)phenyl)-3-methylfuran-2-carboxamide scaffold provided 17e, a potent (mGlu1 EC50 = 31.8 nM) and highly CNS penetrant (brain to plasma ratio (Kp) of 1.

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Herein, we report the structure-activity relationship of a novel series of (2(phenoxymethyl)-6,7-dihydrooxazolo[5,4-c]pyridine-5(4H)-yl(aryl)methanones as potent, selective, and orally bioavailable metabotropic glutamate receptor subtype 5 (mGlu5) positive allosteric modulators (PAMs). On the basis of its robust in vitro potency and in vivo efficacy in multiple preclinical models of multiple domains of schizophrenia, coupled with a good DMPK profile and an acceptable therapeutic window, 17a (VU0409551/JNJ-46778212) was selected as a candidate for further development.

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Schizophrenia is a complex and highly heterogeneous psychiatric disorder whose precise etiology remains elusive. While genome-wide association studies (GWAS) have identified risk genes, they have failed to determine if rare coding single nucleotide polymorphisms (nsSNPs) contribute in schizophrenia. Recently, two independent studies identified 12 rare, deleterious nsSNPS in the GRM1 gene, which encodes the metabotropic glutamate receptor subtype 1 (mGlu1), in schizophrenic patients.

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This work deals with the synthesis and evaluation of new compounds designed by combination of 1,4-naphthoquinone and ferrocene fragments in a 3-ferrocenylmethyl-2-hydroxy-1,4-naphthoquinone arrangement. A practical coupling reaction between 2-hydroxy-1,4-naphthoquinone and ferrocenemethanol derivatives has been developed. This procedure can be carried out "on-water", at moderate temperatures and without auxiliaries or catalysts, with moderate to high yields.

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Myeloid cell leukemia 1 (Mcl-1), a member of the Bcl-2 family of proteins, is overexpressed and amplified in various cancers and promotes the aberrant survival of tumor cells that otherwise would undergo apoptosis. Here we describe the discovery of potent and selective Mcl-1 inhibitors using fragment-based methods and structure-based design. NMR-based screening of a large fragment library identified two chemically distinct hit series that bind to different sites on Mcl-1.

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Aim Of The Study: Quassia amara L. is commonly used in Costarican folk medicine. It has been used for the treatment of a broad range of gastrointestinal symptoms such as dyspepsia, gastritis and constipation.

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Aim Of The Study: Witheringia solanacea is a small shrub that belongs to the Solanaceae family. The plant is used as an antidiabetic in Costa Rican herbal medicine. The aim of this study was to evaluate the hypoglycemic and antihyperglycemic activity of the aqueous extract of W.

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