Design, synthesis, and biological evaluation of acyl sulfonamide derivatives with spiro cycles as NaV1.7 inhibitors for antinociception.

Chronic pain, as an unmet medical need, severely impacts the quality of life. The voltage-gated sodium channel NaV1.7 preferentially expressed in sensory neurons of dorsal root ganglia (DRG) serves a promising target for pain therapy. Here, we report the design, synthesis, and evaluation of a series of acyl sulfonamide derivatives targeting Nav1.7 for their antinociceptive activities. Among the derivatives tested, the compound 36c was identified as a selective and potent NaV1.7 inhibitor in vitro and exhibited antinociceptive effects in vivo. The identification of 36c not only provides a new insight into the discovery of selective NaV1.7 inhibitors, but also may hold premise for pain therapy.

Boosting the K+-adsorption capacity in edge-nitrogen doped hierarchically porous carbon spheres for ultrastable potassium ion battery anodes.

Although carbon materials have great potential for potassium ion battery (KIB) anodes due to their structural stability and abundant carbon-containing resources, the limited K+-intercalated capacity impedes their extensive applications in energy storage devices. Current research studies focus on improving the surface-induced capacitive behavior to boost the potassium storage capacity of carbon materials. Herein, we designed edge-nitrogen (pyridinic-N and pyrrolic-N) doped carbon spheres with a hierarchically porous structure to achieve high potassium storage properties. The electrochemical tests confirmed that the edge-nitrogen induced active sites were conducive for the adsorption of K+, and the hierarchical porous structure promoted the generation of stable solid electrolyte interphase (SEI) films, both of which endow the resulting materials with a high reversible capacity of 381.7 mA h g-1 at 0.1 A g-1 over 200 cycles and an excellent rate capability of 178.2 mA h g-1 at 5 A g-1. Even at 5 A g-1, the long-term cycling stability of 5000 cycles was achieved with a reversible capacity of 190.1 mA h g-1. This work contributes to deeply understand the role of the synergistic effect of edge-nitrogen induced active sites and the hierarchical porous structure in the potassium storage performances of carbon materials.

Inhibition of Nav1.7 channel by a novel blocker QLS-81 for alleviation of neuropathic pain.

Voltage-gated sodium channel Nav1.7 robustly expressed in peripheral nociceptive neurons has been considered as a therapeutic target for chronic pain, but there is no selective Nav1.7 inhibitor available for therapy of chronic pain. Ralfinamide has shown anti-nociceptive activity in animal models of inflammatory and neuropathic pain and is currently under phase III clinical trial for neuropathic pain. Based on ralfinamide, a novel small molecule (S)-2-((3-(4-((2-fluorobenzyl) oxy) phenyl) propyl) amino) propanamide (QLS-81) was synthesized. Here, we report the electrophysiological and pharmacodynamic characterization of QLS-81 as a Nav1.7 channel inhibitor with promising anti-nociceptive activity. In whole-cell recordings of HEK293 cells stably expressing Nav1.7, QLS-81 (IC50 at 3.5 ± 1.5 µM) was ten-fold more potent than its parent compound ralfinamide (37.1 ± 2.9 µM) in inhibiting Nav1.7 current. QLS-81 inhibition on Nav1.7 current was use-dependent. Application of QLS-81 (10 µM) caused a hyperpolarizing shift of the fast and slow inactivation of Nav1.7 channel about 7.9 mV and 26.6 mV, respectively, and also slowed down the channel fast and slow inactivation recovery. In dissociated mouse DRG neurons, QLS-81 (10 µM) inhibited native Nav current and suppressed depolarizing current pulse-elicited neuronal firing. Administration of QLS-81 (2, 5, 10 mg· kg-1· d-1, i.p.) in mice for 10 days dose-dependently alleviated spinal nerve injury-induced neuropathic pain and formalin-induced inflammatory pain. In addition, QLS-81 (10 µM) did not significantly affect ECG in guinea pig heart ex vivo; and administration of QLS-81 (10, 20 mg/kg, i.p.) in mice had no significant effect on spontaneous locomotor activity. Taken together, our results demonstrate that QLS-81, as a novel Nav1.7 inhibitor, is efficacious on chronic pain in mice, and it may hold developmental potential for pain therapy.

Electrophysiological characterization of a small molecule activator on human ether-a-go-go-related gene (hERG) potassium channel.

The human ether-a-go-go-related gene (hERG) encodes the K+ channel that carries the rapid component of the delayed rectifier current in the human heart. Reduction of hERG activity induced by gene mutations or pharmacological inhibition is responsible for the type 2 form of long QT syndrome in patients which can develop into ventricular arrhythmia and sudden cardiac death. Therefore, pharmacological activation of hERG may lead to therapeutic potential for cardiac arrhythmias. In this study we characterized a small and novel compound, N-(2-(tert-butyl)phenyl)-6-(4-chlorophenyl)-4-(trifluoromethyl) nicotinamide, HW-0168, that exhibits potent activation of hERG channel with an EC50 of 0.41 ± 0.2 µM. Using whole-cell patch clamp recording of HEK293 cells stably expressed hERG channels, we found that HW-0168 dramatically increased current amplitude about 2.5 folds and slowed down current inactivation about 4 folds. HW-0168 shifted the voltage-dependent channel activation to hyperpolarizing direction about 3.7 mV and the voltage-dependent channel inactivation to depolarizing direction about 9.4 mV. In addition, recording of guinea-pig ventricular cells confirmed that HW-0168 shortened the action potential duration. In conclusion, we identified a novel hERG channel activator HW-0168 that can be used for studying the physiological role of hERG in cardiac myocytes and may be beneficial for treating long QT syndrome.