Small-molecule caspase-1 inhibitor CZL80 terminates refractory status epilepticus via inhibition of glutamatergic transmission.

Status epilepticus (SE), a serious and often life-threatening medical emergency, is characterized by abnormally prolonged seizures. It is not effectively managed by present first-line anti-seizure medications and could readily develop into drug resistance without timely treatment. In this study, we highlight the therapeutic potential of CZL80, a small molecule that inhibits caspase-1, in SE termination and its related mechanisms. We found that delayed treatment of diazepam (0.5 h) easily induces resistance in kainic acid (KA)-induced SE. CZL80 dose-dependently terminated diazepam-resistant SE, extending the therapeutic time window to 3 h following SE, and also protected against neuronal damage. Interestingly, the effect of CZL80 on SE termination was model-dependent, as evidenced by ineffectiveness in the pilocarpine-induced SE. Further, we found that CZL80 did not terminate KA-induced SE in Caspase-1-/- mice but partially terminated SE in IL1R1-/- mice, suggesting the SE termination effect of CZL80 was dependent on the caspase-1, but not entirely through the downstream IL-1ß pathway. Furthermore, in vivo calcium fiber photometry revealed that CZL80 completely reversed the neuroinflammation-augmented glutamatergic transmission in SE. Together, our results demonstrate that caspase-1 inhibitor CZL80 terminates diazepam-resistant SE by blocking glutamatergic transmission. This may be of great therapeutic significance for the clinical treatment of refractory SE.

Multicomponent Reactions for Expeditious Construction of ß-Indole Carboxamide Amino Amides.

A multicomponent reaction of N-indole carboxylic acids, aldehydes, amines, and C2 building blocks can be transformed to structurally diverse ß-indole carboxamide amino amides. In this multicomponent reaction, the ynamides and triazenyl alkynes act as the C2 building block, and this protocol features readily available starting materials, high atom economy, and mild reaction conditions. Besides, the acyl triazene group in the product can be easily transformed to differential groups to expand the structural diversity.

Subicular Caspase-1 Contributes to Pharmacoresistance in Temporal Lobe Epilepsy.

OBJECTIVE: Unidentified mechanisms largely restrict the viability of effective therapies in pharmacoresistant epilepsy. Our previous study revealed that hyperactivity of the subiculum is crucial for the genesis of pharmacoresistance in temporal lobe epilepsy (TLE), but the underlying molecular mechanism is not clear. METHODS: Here, we examined the role of subicular caspase-1, a key neural pro-inflammatory enzyme, in pharmacoresistant TLE. RESULTS: We found that the expression of activated caspase-1 in the subiculum, but not the CA1, was upregulated in pharmacoresistant amygdaloid-kindled rats. Early overexpression of caspase-1 in the subiculum was sufficient to induce pharmacoresistant TLE in rats, whereas genetic ablation of caspase-1 interfered with the genesis of pharmacoresistant TLE in both kindled rats and kainic acid-treated mice. The pro-pharmacoresistance effect of subicular caspase-1 was mediated by its downstream inflammasome-dependent interleukin-1ß. Further electrophysiological results showed that inhibiting caspase-1 decreased the excitability of subicular pyramidal neurons through influencing the excitation/inhibition balance of presynaptic input. Importantly, a small molecular caspase-1 inhibitor CZL80 attenuated seizures in pharmacoresistant TLE models, and decreased the neuronal excitability in the brain slices obtained from patients with pharmacoresistant TLE. INTERPRETATION: These results support the subicular caspase-1-interleukin-1ß inflammatory pathway as a novel alternative mechanism hypothesis for pharmacoresistant TLE, and present caspase-1 as a potential target. ANN NEUROL 2021;90:377-390.

Facile Synthesis of γ-Butenolides and Maleic Anhydrides via Annulation of α-Keto Acids and Triazenyl Alkynes.

A facile synthesis of γ-butenolides and maleic anhydrides via annulation of α-keto acids and triazenyl alkynes is described. In this process, α-keto acids and triazenyl alkynes could undergo a self-catalyzed annulation at room temperature to deliver γ-butenolides efficiently, while the further addition of BF3-Et2O furnished maleic anhydrides. Overall, these processes have mild reaction conditions, broad scope, and high efficiency.

Discovery of (2-phenylthiazol-4-yl)urea derivatives that induce neuronal differentiation from mesenchymal stem cells.

The success of stem cells therapy to treat neurodegenerative diseases is currently restricted by the lack of suitable stem cells. Mesenchymal stem cells (MSCs) have demonstrated several advantages as seed-cells for the stem cells therapy. In particular, the low immunogenicity and multiple lineages differentiation capability enables the possibility of using MSCs to treat neurodegenerative diseases. However, a more potent neuronal differentiation capacity of MSCs is required during a success treatment against neurodegenerative diseases. Bioengineering using small molecules to boost the neuronal differentiation of MSCs has been proposed as a promising strategy. Herein, we developed a new series of (2-phenylthiazol-4-yl)urea derivatives and one of them, 18g were observed to successfully promote neuronal differentiation of MSCs after culturing MSCs with 18g for 4 days. In addition, neither significant cytotoxicity nor cell cycle altering were found after the incubation. Interestingly, the osteogenic differentiation potential of MSCs was not affected after 18g treatment. The present study provides a promising small molecule to boost the innate neuronal differentiation capacity of MSCs with no serious detrimental effects.

Discovery of triazenyl triazoles as Nav1.1 channel blockers for treatment of epilepsy.

The voltage-gated sodium (Nav) channel is one of most important targets for treatment of epilepsy, and rufinamide is an approved third-generation anti-seizure drug as Nav1.1 channel blocker. Herein, by triazenylation of rufinamide, we reported the triazenyl triazoles as new Nav1.1 channel blocker for treatment of epilepsy. Through the electrophysiological activity assay, compound 6a and 6e were found to modulate the inactivation voltage of Nav 1.1 channel with shift of -10.07 mv and -11.28 mV, respectively. In the pentylenetetrazole (PTZ) mouse model, 6a and 6e reduced the seizure level, prolonged seizure latency and improved the survival rate of epileptic mice at an intragastric administration of 50 mg/kg dosage. In addition, 6a also exhibited promising effectiveness in the maximal electroshock (MES) mouse model and possessed moderate pharmacokinetic profiles. These results demonstrated that 6a was a novel Nav1.1 channel blocker for treatment of epilepsy.

Novel Caspase-1 inhibitor CZL80 improves neurological function in mice after progressive ischemic stroke within a long therapeutic time-window.

Progressive ischemic stroke (PIS) is featured by progressive neurological dysfunction after ischemia. Ischemia-evoked neuroinflammation is implicated in the progressive brain injury after cerebral ischemia, while Caspase-1, an active component of inflammasome, exaggerates ischemic brain injury. Current Caspase-1 inhibitors are inadequate in safety and druggability. Here, we investigated the efficacy of CZL80, a novel Caspase-1 inhibitor, in mice with PIS. Mice and Caspase-1-/- mice were subjected to photothrombotic (PT)-induced cerebral ischemia. CZL80 (10, 30 mg·kg-1·d-1, i.p.) was administered for one week after PT onset. The transient and the progressive neurological dysfunction (as foot faults in the grid-walking task and forelimb symmetry in the cylinder task) was assessed on Day1 and Day4-7, respectively, after PT onset. Treatment with CZL80 (30 mg/kg) during Day1-7 significantly reduced the progressive, but not the transient neurological dysfunction. Furthermore, we showed that CZL80 administered on Day4-7, when the progressive neurological dysfunction occurred, produced significant beneficial effects against PIS, suggesting an extended therapeutic time-window. CZL80 administration could improve the neurological function even as late as Day43 after PT. In Caspase-1-/- mice with PIS, the beneficial effects of CZL80 were abolished. We found that Caspase-1 was upregulated during Day4-7 after PT and predominantly located in activated microglia, which was coincided with the progressive neurological deficits, and attenuated by CZL80. We showed that CZL80 administration did not reduce the infarct volume, but significantly suppressed microglia activation in the peri-infarct cortex, suggesting the involvement of microglial inflammasome in the pathology of PIS. Taken together, this study demonstrates that Caspase-1 is required for the progressive neurological dysfunction in PIS. CZL80 is a promising drug to promote the neurological recovery in PIS by inhibiting Caspase-1 within a long therapeutic time-window.

Rhodium-Catalyzed Atroposelective Click Cycloaddition of Azides and Alkynes.

The cycloaddition of azides and alkynes is the leading click chemistry technology and has been widely used in drug discovery, biology and material sciences. However, the development of a modular and scalable enantioselective click cycloaddition remains a long-standing challenge. Herein, we report a rhodium-catalyzed enantioselective click cycloaddition of azides and alkynes for rapid and modular access to atropisomeric triazoles in excellent yields and enantioselectivities. The process is mild, efficient and scalable, and features broad substrate scope.

Triazenyl Alkynes as Versatile Building Blocks in Multicomponent Reactions: Diastereoselective Synthesis of ß-Amino Amides.

Multicomponent reactions (MCRs) are powerful tool for the construction of polyfunctional molecules in an operationally simple and atom-economic manner, and the discovery of novel MCRs requests various building blocks. Herein, triazenyl alkynes were disclosed as versatile building blocks in a multicomponent reaction with carboxylic acids, aldehydes and anilines to furnish ß-amino amides with the achievement of high diastereoselectivity and structural diversity. In this process, triazenyl alkynes were bifunctional so that the alkyne moiety acts as C2 fragment and triazene serves as directing group to modulate the transition state thus achieving high diastereoselectivity, in consistence with DFT calculations. Furthermore, the triazenyl group also enables diverse late-stage transformation. This protocol opens a new vision for the discovery of building block and rational design of MCRs.

Neohesperidin prevents colorectal tumorigenesis by altering the gut microbiota.

Neohesperidin (NHP), derived from citrus fruits, has attracted considerable interest due to its preventative and therapeutic effects on numerous diseases. However, little progress has been made in determining the exact function of NHP on tumorigenesis. In the current study, we found that NHP inhibited colorectal tumorigenesis in the APC min/+ transgenic mouse model, as well as induced apoptosis and blocked angiogenesis in vivo. Our in-cell study suggested that this tumorigenic preventative effect of NHP is not due to the direct impact on tumor cells. Intriguingly, by utilizing 16 s rRNA gene-based microbiota sequencing, the relative abundance of Bacteroidetes was decreased, while Firmicutes and Proteobacteria were increased in the presence of NHP. Additionally, the fecal microbiota transplantation experiment further revealed that feeding with fecal of NHP-treated mice induced considerable inhibition of tumorigenesis, which indicates that the alteration of gut microbiota is responsible for NHP-mediated prevention of colorectal tumorigenesis. Thus, our study not only suggests the efficacy of NHP as a potent natural product for preventing colorectal cancer but also proposes a compelling model to connect the gut microbiota to the preventative effect of NHP on tumorigenesis.

Iterative Assembly of Nitrile Oxides and Ynamides: Synthesis of Isoxazoles and Pyrroles.

Described is an iterative assembly of nitrile oxides and ynamides for the synthesis of isoxazoles and pyrroles. The nitrile oxides could undergo Cu(I)-free cyclization with terminal ynamides for accessing isoxazoles, which could engage in another cyclization with internal ynamides in the presence of Au(I) catalyst to deliver pyrroles, and the reaction could be carried out in a two-step, one-pot procedure. This process is featured with mild reaction condition and broad substrate scope for the synthesis of heterocycles.

Discovery of 3,6-diaryl-1H-pyrazolo[3,4-b]pyridines as potent anaplastic lymphoma kinase (ALK) inhibitors.

A new series of 3,6-diaryl-1H-pyrazolo[3,4-b]pyridine compounds have been discovered as potent anaplastic lymphoma kinase (ALK) inhibitors. The 4-hydroxyphenyl in the 6-position of 1H-pyrazolo[3,4-b]pyridine were crucial and a fluorine atom substitution could give promising inhibitory activity. The IC50 of compound 9v against ALK was up to 1.58 nM and a binding mechanism was proposed.

One-Pot Reaction of Carboxylic Acids and Ynol Ethers for The Synthesis of ß-Keto Esters.

An one-pot reaction of carboxylic acids and ynol ethers for the synthesis of ß-keto esters has been developed. Under promotion of Ag2O, various carboxylic acids and ynol ethers could transform to α-acyloxy enol esters, which undergo a following DMAP-catalyzed rearrangement to deliver ß-keto esters rapidly. This method provides a direct approach to ß-keto esters from carboxylic acids without any preactivation. The protocol features mild reaction conditions, broad substrate scope, and the products could be transformed to an array of compounds.

A silver catalyzed domino reaction of N-cyanamide alkenes and 1,3-dicarbonyls for the synthesis of quinazolinones.

A silver catalyzed domino reaction of N-cyanamide alkenes and 1,3-dicarbonyls including 1,3-diketones and ethyl acetoacetate has been developed for the facile synthesis of quinazolinones. In the presence of AgNO3/K2S2O8, the diketones could be converted to radicals and coupled with N-cyanamide alkenes to undergo a cyclization cascade for accessing quinazolinones. This method features mild reaction conditions, readily available starting materials, and valuable synthetic utility. Moreover, the products could be further transformed into various heterocycles.

Metal-free α-alkylation of alcohols with para-quinone methides.

A metal-free α-alkylation of alcohols with para-quinone methides (p-QMs) for accessing alcohol-containing phenols and dihydroisocoumarins has been developed. The alcohols were converted to α-oxy radicals in the presence of di-tert-butyl peroxide (DTBP), which were added to p-QMs for aromatization and C(sp3)-C(sp3) bond formation.

Homologation of Ugi and Passerini reactions using ynamides.

Being important biological and pharmacological units, ß-amino amides and ß-acyloxy amides have a privileged position in both academia and industry. Developing a methods to prepare them has gained attention. Ynamides, which possess dual nucleophilic and electrophilic properties, are similar to isonitriles. In this review, usage of ynamides in the single reactant replacement approach of Ugi and Passerini reactions to develop two new multicomponent reactions to get various ß-amino amides and ß-acyloxy amides is reported.

Synthesis of Amides and Nitriles from Vinyl Azides and p-Quinone Methides.

A divergent synthesis of amides and nitriles from vinyl azides and p-quinone methides (p-QMs) was developed. The p-QMs could be activated by BF3-Et2O and then nucleophilically attacked by vinyl azides, leading to divergent rearrangement toward amides and nitriles.

One-Pot Multicomponent Synthesis of ß-Amino Amides.

Multicomponent reactions are excellent tools for rapid generation of small molecules with broad chemical diversity and molecular complexity. Herein, a novel one-pot multicomponent synthesis of ß-amino amides from aldehydes, anilines, carboxylic acids and ynamides has been successfully developed. This process is practical and efficient to unravel synthetic utility and scalability. Moreover, an isotope labeling reaction was conducted to elucidate a plausible reaction mechanism.

Rh(iii)-catalyzed C-H activation/cyclization of oximes with alkenes for regioselective synthesis of isoquinolines.

A Rh(iii)-catalyzed C-H activation/cyclization of oximes and alkenes for facile and regioselective access to isoquinolines has been developed. This protocol features mild reaction conditions and easily accessible starting materials, and has been applied to the concise synthesis of moxaverine. A kinetic isotope effect study was conducted and a plausible mechanism was proposed.

Rh(III)-catalyzed C-H activation/cyclization of indoles and pyrroles: divergent synthesis of heterocycles.

We report herein a new strategy of the Rh(III)-catalyzed C-H activation/cyclization of indoles and pyrroles, for the divergent synthesis of privileged heterocycles. A simple derivation of indoles and pyrroles to N-carboxamides with oxidative bidentate directing group could enable rhodacycle formation and late-stage redox-neutral cyclization with alkynes, alkenes and diazo compounds, for access to five- and six-membered fused heterocycles, such as pyrimido[1,6-a]indol-1(2H)-one, 3,4-dihydropyrimido[1,6-a]indol-1(2H)-one, and 1H-imidazo[1,5-a]indol-3(2H)-ones. Kinetic isotope effect study was conducted, and a plausible mechanism was proposed. Furthermore, this protocol was applied to concise synthesis of 5-HT3 receptor antagonist in gram-scale.