Design and Discovery of a Potent and Selective Inhibitor of Integrin αvß1.

Selective inhibition of the RGD (Arg-Gly-Asp) integrin αvß1 has been recently identified as an attractive therapeutic approach for the treatment of liver fibrosis given its function, target expression, and safety profile. Our identification of a non-RGD small molecule lead followed by focused, systematic changes to the core structure utilizing a crystal structure, in silico modeling, and a tractable synthetic approach resulted in the identification of a potent small molecule exhibiting a remarkable affinity for αvß1 relative to several other integrin isoforms measured. Azabenzimidazolone 25 demonstrated antifibrotic efficacy in an in vivo rat liver fibrosis model and represents a tool compound capable of further exploring the biological consequences of selective αvß1 inhibition.

A Novel Agonist of the Type 1 Lysophosphatidic Acid Receptor (LPA1), UCM-05194, Shows Efficacy in Neuropathic Pain Amelioration.

Neuropathic pain (NP) is a complex chronic pain state with a prevalence of almost 10% in the general population. Pharmacological options for NP are limited and weakly effective, so there is a need to develop more efficacious NP attenuating drugs. Activation of the type 1 lysophosphatidic acid (LPA1) receptor is a crucial factor in the initiation of NP. Hence, it is conceivable that a functional antagonism strategy could lead to NP mitigation. Here we describe a new series of LPA1 agonists among which derivative (S)-17 (UCM-05194) stands out as the most potent and selective LPA1 receptor agonist described so far (Emax = 118%, EC50 = 0.24 µM, KD = 19.6 nM; inactive at autotaxin and LPA2-6 receptors). This compound induces characteristic LPA1-mediated cellular effects and prompts the internalization of the receptor leading to its functional inactivation in primary sensory neurons and to an efficacious attenuation of the pain perception in an in vivo model of NP.

Updates in the correlation of electroneuromyographic findings in diabetic polyneuropathy / Actualidades en la correlación de hallazgos electroneuromiográficos en polineuropatía diabética

Background: The diabetic neuropathy is the most common microvascular complication of diabetes mellitus. The reported prevalence ranges from 10-90%. Electrophysiological alterations can be demonstrated in nearly 100% of diabetics. Objective: To know the current profile of the patient with diabetic polyneuropathy. Methods: Retrospective and descriptive study from 2015 to 2016. Reports of electroneuromyography with diabetic polyneuropathy result were analyzed, evaluating neuroconduction parameters of motor and sensory nerves, late F responses and myography. Descriptive statistics, Student's t-test and Pearson's correlation coefficient were used. Results: The sample included 72 men (65.5%) and 38 women (34.5%), mean age 61.2 years, mean duration of diabetes of 9.9 years. The most affected nerve was superficial peroneus, absent in 70% of the population.A positive correlation was found (p < 0.001) for the affection of all the nerves symmetrically and predominantly in neuroconduction velocities of the lower and upper limbs. Conclusion: The most frequent electrophysiological finding in diabetic polyneuropathy was sensory affection, being more severe in lower limbs. A finding in patients with recent diagnosis is the prolongation of proximal latencies in the lower extremities.

Introducción: la neuropatía diabética es la complicación microvascular más frecuente de la diabetes mellitus. Las prevalencias reportadas oscilan del 10 al 90%. Se pueden demostrar alteraciones electrofisiológicas en casi el 100% de los diabéticos. Objetivo: conocer el perfil actual del paciente con polineuropatía diabética. Métodos: estudio retrospectivo y descriptivo del año 2015 a 2016. Se analizaron reportes de electroneuromiografía con resultado de polineuropatía diabética, evaluando parámetros de neuroconducción de nervios motores y sensoriales, respuestas tardías F y miografía. Se utilizó estadística descriptiva, la prueba de t de Student y el coeficiente de correlación de Pearson. Resultados: la muestra incluyó a 72 hombres (65.5%) y 38 mujeres (34.5%), con edad media de 61.2 años, todos con diagnóstico de diabetes mellitus tipo 2, con duración media de la diabetes de 9.9 años. El nervio más afectado fue el peroneo superficial, ausente en el 70% de la población. Se encontró una correlación positiva(p < 0.001) para la afección de todos los nervios de forma simétrica y de predominio en velocidades de neuroconducción de miembros inferiores y superiores. Conclusión: el hallazgo electrofisiológico más frecuente en polineuropatía diabética fue la afección sensorial, siendo más severa en miembros inferiores. Un hallazgo en pacientes con reciente diagnóstico es la prolongación de latencias proximales en extremidades inferiores.

Development of a Fluorescent Bodipy Probe for Visualization of the Serotonin 5-HT1A Receptor in Native Cells of the Immune System.

Serotonin (5-HT) modulates key aspects of the immune system. However, its precise function and the receptors involved in the observed effects have remained elusive. Among the different serotonin receptors, 5-HT1A plays an important role in the immune system given its presence in cells involved in both the innate and adaptive immune responses, but its actual levels of expression under different conditions have not been comprehensively studied due to the lack of suitable tools. To further clarify the role of 5-HT1A receptor in the immune system, we have developed a fluorescent small molecule probe that enables the direct study of the receptor levels in native cells. This probe allows direct profiling of the receptor expression in immune cells using flow cytometry. Our results show that important subsets of immune cells including human monocytes and dendritic cells express functional 5-HT1A and that its activation is associated with anti-inflammatory signaling. Furthermore, application of the probe to the experimental autoimmune encephalomyelitis model of multiple sclerosis demonstrates its potential to detect the specific overexpression of the 5-HT1A receptor in CD4+ T cells. Accordingly, the probe reported herein represents a useful tool whose use can be extended to study the levels of 5-HT1A receptor in ex vivo samples of different immune system conditions.

2-AG limits Theiler's virus induced acute neuroinflammation by modulating microglia and promoting MDSCs.

The innate immune response is mediated by primary immune modulators such as cytokines and chemokines that together with immune cells and resident glia orchestrate CNS immunity and inflammation. Growing evidence supports that the endocannabinoid 2-arachidonoylglycerol (2-AG) exerts protective actions in CNS injury models. Here, we used the acute phase of Theiler's virus induced demyelination disease (TMEV-IDD) as a model of acute neuroinflammation to investigate whether 2-AG modifies the brain innate immune responses to TMEV and CNS leukocyte trafficking. 2-AG or the inhibition of its hydrolysis diminished the reactivity and number of microglia at the TMEV injection site reducing their morphological complexity and modulating them towards an anti-inflammatory state via CB2 receptors. Indeed, 2-AG dampened the infiltration of immune cells into the CNS and inhibited their egress from the spleen, resulting in long-term beneficial effects at the chronic phase of the disease. Intriguingly, it is not a generalized action over leukocytes since 2-AG increased the presence and suppressive potency of myeloid derived suppressor cells (MDSCs) in the brain resulting in higher apoptotic CD4+ T cells at the injection site. Together, these data suggest a robust modulatory effect in the peripheral and central immunity by 2-AG and highlight the interest of modulating endogenous cannabinoids to regulate CNS inflammatory conditions.

2-Arachidonoylglycerol Reduces Proteoglycans and Enhances Remyelination in a Progressive Model of Demyelination.

The failure to undergo remyelination is a critical impediment to recovery in multiple sclerosis. Chondroitin sulfate proteoglycans (CSPGs) accumulate at demyelinating lesions creating a nonpermissive environment that impairs axon regeneration and remyelination. Here, we reveal a new role for 2-arachidonoylglycerol (2-AG), the major CNS endocannabinoid, in the modulation of CSPGs deposition in a progressive model of multiple sclerosis, the Theiler's murine encephalomyelitis virus-induced demyelinating disease. Treatment with a potent reversible inhibitor of the enzyme monoacylglycerol lipase, which accounts for 85% of the 2-AG degradation in the mouse CNS, modulates neuroinflammation and reduces CSPGs accumulation and astrogliosis around demyelinated lesions in the spinal cord of Theiler's murine encephalomyelitis virus-infected mice. Inhibition of 2-AG hydrolysis augments the number of mature oligodendrocytes and increases MBP, leading to remyelination and functional recovery of mice. Our findings establish a mechanism for 2-AG promotion of remyelination with implications in axonal repair in CNS demyelinating pathologies.SIGNIFICANCE STATEMENT The deposition of chondroitin sulfate proteoglycans contributes to the failure in remyelination associated with multiple sclerosis. Here we unveil a new role for 2-arachidonoylglycerol, the major CNS endocannabinoid, in the modulation of chondroitin sulfate proteoglycan accumulation in Theiler's murine encephalomyelitis virus-induced demyelinating disease. The treatment during the chronic phase with a potent reversible inhibitor of the enzyme monoacylglycerol lipase, which accounts for 85% of the 2-arachidonoylglycerol degradation in the mouse CNS, modulates neuroinflammation and reduces chondroitin sulfate proteoglycan deposition around demyelinated lesions in the spinal cord of Theiler's murine encephalomyelitis virus-infected mice. The increased 2-arachidonoylglycerol tone promotes remyelination in a model of progressive multiple sclerosis ameliorating motor dysfunction.

Mild access to planar-chiral ortho-condensed aromatic ferrocenes via gold(i)-catalyzed cycloisomerization of ortho-alkynylaryl ferrocenes.

An efficient approach to (Rp) planar-chiral tri- and tetracyclic ortho-condensed aromatic ferrocenes was developed through the enantioselective cationic Au(i)-catalyzed cycloisomerization, in the presence of bidentate phosphine ligand (R)-DTBM-Segphos, from readily available ortho-alkynylaryl ferrocenes under very mild conditions (11 examples, up to 92% yield and 93% ee).

A reversible and selective inhibitor of monoacylglycerol lipase ameliorates multiple sclerosis.

Monoacylglycerol lipase (MAGL) is the enzyme responsible for the inactivation of the endocannabinoid 2-arachidonoylglycerol (2-AG). MAGL inhibitors show analgesic and tissue-protecting effects in several disease models. However, the few efficient and selective MAGL inhibitors described to date block the enzyme irreversibly, and this can lead to pharmacological tolerance. Hence, additional classes of MAGL inhibitors are needed to validate this enzyme as a therapeutic target. Here we report a potent, selective, and reversible MAGL inhibitor (IC50=0.18 µM) which is active in vivo and ameliorates the clinical progression of a multiple sclerosis (MS) mouse model without inducing undesirable CB1 -mediated side effects. These results support the interest in MAGL as a target for the treatment of MS.

Total synthesis of natural p-quinol cochinchinenone.

Cochinchinenone has been synthesized in only five steps and four pots and in 58% overall yield from commercially available 2,3-dimethoxy-4-hydroxy-benzaldehyde and OPMB-protected p-hydroxy acetophenone, the key step being the oxone-mediated oxidative dearomatization of the corresponding ketone-containing p-substituted phenol.

Organocatalysis as a safe practical method for the stereospecific dibromination of unsaturated compounds.

Organocatalytic stereospecific dibromination of a wide variety of functionalized alkenes was achieved using a stable, inexpensive halogen source, 1,3-dibromo 5,5-dimethylhydantoin, and a simple thiourea catalyst at room temperature. The presence of a tertiary amine enhanced the rate of the dibromination reaction, and yields were good in various solvents, including aqueous solvents. The procedure was extended to alkynes and aromatic rings and to dichlorination reactions by using the 1,3-dichloro hydantoin derivative.

Highly efficient hydrogen-bonding catalysis of the Diels-Alder reaction of 3-vinylindoles and methyleneindolinones provides carbazolespirooxindole skeletons.

Carbazolespirooxindole derivatives were synthesized in a high-yielding, atypically rapid, stereocontrolled Diels-Alder reaction catalyzed by a C(2)-symmetric bisthiourea organocatalyst. Simple precursors and mild conditions were used to construct carbazolespirooxindole derivatives with high enantiopurity and structural diversity under H-bonding catalysis. The practical approach recycles the organocatalyst and solvent. This simple and efficient operational procedure will allow diversity-oriented syntheses of this intriguing class of compounds.

The effect of sulfoxides on the stereoselective construction of tetrahydrofurans: total synthesis of (+)-goniothalesdiol.

Good to excellent stereoselectivities were achieved in the reductive cyclization (with Et(3)SiH/trimethylsilyl trifluoromethanesulfonate (TMSOTf)) of enantiopure hydroxy sulfinyl ketones en route to 2,5-cis-disubstituted tetrahydrofuran skeletons. Electrostatic effects of the exocyclic sulfoxide, which stabilized the reactive intermediate oxocarbenium conformations, were responsible for the observed stereocontrol. A model is proposed to explain the results. The use of this reaction and the asymmetric ß-ketosulfoxide reduction as key steps facilitated the total enantioselective synthesis of the natural ß-C-aryl glycoside (+)-goniothalesdiol.

Highly enantioselective organocatalytic α-amination reactions of aryl oxindoles: developing designer multifunctional alkaloid catalysts.

An enantioselective α-amination of aryl oxindoles catalyzed by a dimeric quinidine has been developed. The reaction is general, broad in substrate scope, and affords the desired products in good yields with good to excellent enantioselectivities. This study provides the first examples of a general organocatalytic method for the creation of nitrogen-containing, tetrasubstituted chiral centers at C(3) of various aryl oxindoles. Furthermore, new catalysts and insights into structural elements of the catalysts that significantly influence enantioselectivities are disclosed.

Organocatalytic asymmetric assembly reactions for the syntheses of carbohydrate derivatives by intermolecular Michael-Henry reactions.

Given the significance of carbohydrates in life, medicine, and industry, the development of simple and efficient de novo methods to synthesize carbohydrates are highly desirable. Organocatalytic asymmetric assembly reactions are powerful tools to rapidly construct molecules with stereochemical complexity from simple precursors. Here, we present a simple and robust methodology for the asymmetric synthesis of pyranose derivatives with talo- and manno- configurations from simple achiral precursors through organocatalytic asymmetric intermolecular Michael-Henry reaction sequences. In this process, (tert-butyldimethylsilyloxy)acetaldehyde 1 was successfully utilized in two ways: as a donor in a highly selective anti-Michael reaction and as an acceptor in a consecutive Henry reaction. Varied nitroolefins served as Michael acceptors and varied aldehydes substituted for 1 as Henry acceptors providing for the construction of a wide range of carbohydrates with up to 5 stereocenters. In these reactions, a catalyst-controlled Michael reaction followed by a substrate-controlled Henry reaction provided 3,4-dideoxytalose derivatives 6 in a highly stereoselective manner. The Henry reaction was affected by addition of a simple base such as triethylamine: A complex chiral base was not necessary. 3,4-Dideoxymannose derivatives 7 were produced by simply changing the base from triethylamine to 1,8-diazabicyclo[5.4.0]undec-7-ene. Extension of this methodology to a syn-Michael initiated sequence was also successful. A mechanistic discussion is provided to explain the unusual substrate-induced stereoselectivity of the Henry reaction.

Enantioselective total synthesis of the natural gamma-tocopherol metabolite (S)-gamma-CEHC [(S)-LLU-alpha].

The asymmetric synthesis of the natural gamma-tocopherol metabolite (S)-gamma-CEHC (1) is described in 10 steps and 18.4% overall yield starting from 2,3-dimethylhydroquinone. The key step is a stereoselective TiCl(4)-mediated homochiral sulfoxide-directed allylation of ketal (SS)-3 to efficiently generate the challenging C-2 stereogenic carbon of chroman (SS,S)-2 with the correct absolute configuration.

Enantiopure sulfoxides: recent applications in asymmetric synthesis.

Sulfoxides are nowadays recognised as powerful chiral auxiliaries that may participate in a wide range of asymmetric reactions. Their high configurational stability, the existence of several efficient methods allowing the access to both configurations as well as their synthetic versatility are characteristic features offering a tremendous potential to develop new applications. Significant recent advances leading to high asymmetric inductions in carbon-carbon and carbon-oxygen bond forming reactions, and applications of homochiral sulfoxides to atroposelective synthesis and asymmetric catalysis are discussed. New uses of sulfoxides in the design of chiroptical switches are also shown.

Stereocontrolled generation of the (2R) chroman core of vitamin E: total synthesis of (2R,4'RS,8'RS)-alpha-tocopherol.

(2R,4'RS,8'RS)-alpha-tocopherol (1) was prepared using, as the two key steps, a novel diastereoselective TiCl(4)-promoted (S)-sulfoxide-directed allylation of ketal 2 with allyl trimethyl silane 3 to efficiently generate the challenging (2R) stereocenter of the chroman moiety and a cross-metathesis reaction with olefin 4 to efficiently join the lipophilic alkyl chain present in the final target.

Total stereoselective synthesis of (+)-goniothalesdiol.

[reaction: see text] The stereoselective synthesis of (+)-goniothalesdiol (1) was accomplished in nine steps starting from commercially available (-)-(2S,3S)-dimethyl D-tartrate (3). The key features were a completely diastereoselective reduction of a beta-ketosulfoxide to generate the stereogenic center at C-5 in 7 and formation of the 2,5-cis-substituted tetrahydrofuran ring in 10 from a stereoselective Et(3)SiH/TMSOTf-promoted reductive cyclization/deoxygenation.