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Photocatalytic carboxylation of alkenes with CO2 is a promising and sustainable strategy to synthesize high value-added carboxylic acids. However, it is challenging and rarely investigated for unactivated alkenes due to their low reactivities. Herein, we report a visible-light photoredox-catalyzed arylcarboxylation of unactivated alkenes with CO2, delivering a variety of tetrahydronaphthalen-1-ylacetic acids, indan-1-ylacetic acids, indolin-3-ylacetic acids, chroman-4-ylacetic acids and thiochroman-4-ylacetic acids in moderate-to-good yields. This reaction features high chemo- and regio-selectivities, mild reaction conditions (1 atm, room temperature), broad substrate scope, good functional group compatibility, easy scalability and facile derivatization of products. Mechanistic studies indicate that in situ generation of carbon dioxide radical anion and following radical addition to unactivated alkenes might be involved in the process. Despite the importance of polycyclic carboxylic acids and derivatives in various fields, general methods for the arylcarboxylation of alkenes with CO2 remain elusive. Here, the authors transform unactivated alkenes into high value-added polycyclic carboxylic acids and derivatives via visible-light photoredox-catalysis, using CO2 as the one-carbon feedstock. [ABSTRACT FROM AUTHOR]

The carboxylation of cyclic oxime esters with carbon dioxide via visible‐light photoredox catalysis is demonstrated for the first time. A variety of cyclic oxime esters undergo ring‐opening C−C bond cleavage and carboxylation to give cyanoalkyl‐containing carboxylic acids in moderate to good yields. Moreover, this methodology features mild reaction conditions (room temperature, 1 atm), wide substrate scope, good functional group tolerance as well as facile derivations of products. Mechanistic studies indicate that the benzylic radicals and anions might be the key intermediates. [ABSTRACT FROM AUTHOR]

Remote difunctionalization of unactivated alkenes is challenging but a highly attractive tactic to install two functional groups across long distances. Reported herein is the first remote difunctionalization of alkenes with CO2. This visible‐light photoredox catalysis strategy provides a facile method to synthesize a series of carboxylic acids bearing valuable fluorine‐ or phosphorus‐containing functional groups. Moreover, this versatile protocol shows mild reaction conditions, broad substrate scope, and good functional‐group tolerance. Based on DFT calculations, a radical adds to an unactivated alkene to smoothly form a new carbon radical, followed by a 1,5‐hydrogen atom‐transfer process, the rate‐limiting step, generating a more stable benzylic radical. The reduction of the benzylic radicals by an IrII species generates the corresponding benzylic carbanions as the key intermediates, which further undergo nucleophilic attack with CO2 to generate carboxylates. [ABSTRACT FROM AUTHOR]

Remote difunctionalization of unactivated alkenes is challenging but a highly attractive tactic to install two functional groups across long distances. Reported herein is the first remote difunctionalization of alkenes with CO2. This visible‐light photoredox catalysis strategy provides a facile method to synthesize a series of carboxylic acids bearing valuable fluorine‐ or phosphorus‐containing functional groups. Moreover, this versatile protocol shows mild reaction conditions, broad substrate scope, and good functional‐group tolerance. Based on DFT calculations, a radical adds to an unactivated alkene to smoothly form a new carbon radical, followed by a 1,5‐hydrogen atom‐transfer process, the rate‐limiting step, generating a more stable benzylic radical. The reduction of the benzylic radicals by an IrII species generates the corresponding benzylic carbanions as the key intermediates, which further undergo nucleophilic attack with CO2 to generate carboxylates. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) is an ideal one-carbon source owing to its nontoxicity, abundance, availability, and recyclability. Although the thermodynamic stability and kinetic inertness of CO2 bring its utilization challenges, many groups have achieved significant progress in the utilization of CO2 to synthesize valuable carbonyl-containing compounds, which could be also generated via oxidative carbonylation of C–H bonds with CO. As CO2 has a higher oxidation state than CO, it could be considered as a combination of CO and oxidant (CO2 = CO + [O]), thus providing a safe, redox-neutral and economic strategy. In this Feature Article, we have summarized the recent advances in carbonylation of C–H bonds with CO2 based on this concept. The plausible mechanisms of such reactions and future of this field are also discussed. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) is an ideal one-carbon source owing to its nontoxicity, abundance, availability, and recyclability. Although the thermodynamic stability and kinetic inertness of CO2 bring its utilization challenges, many groups have achieved significant progress in the utilization of CO2 to synthesize valuable carbonyl-containing compounds, which could be also generated via oxidative carbonylation of C–H bonds with CO. As CO2 has a higher oxidation state than CO, it could be considered as a combination of CO and oxidant (CO2 = CO + [O]), thus providing a safe, redox-neutral and economic strategy. In this Feature Article, we have summarized the recent advances in carbonylation of C–H bonds with CO2 based on this concept. The plausible mechanisms of such reactions and future of this field are also discussed. [ABSTRACT FROM AUTHOR]

Remote difunctionalization of unactivated alkenes is challenging but a highly attractive tactic to install two functional groups across long distances. Reported herein is the first remote difunctionalization of alkenes with CO2. This visible‐light photoredox catalysis strategy provides a facile method to synthesize a series of carboxylic acids bearing valuable fluorine‐ or phosphorus‐containing functional groups. Moreover, this versatile protocol shows mild reaction conditions, broad substrate scope, and good functional‐group tolerance. Based on DFT calculations, a radical adds to an unactivated alkene to smoothly form a new carbon radical, followed by a 1,5‐hydrogen atom‐transfer process, the rate‐limiting step, generating a more stable benzylic radical. The reduction of the benzylic radicals by an IrII species generates the corresponding benzylic carbanions as the key intermediates, which further undergo nucleophilic attack with CO2 to generate carboxylates. [ABSTRACT FROM AUTHOR]

Remote difunctionalization of unactivated alkenes is challenging but a highly attractive tactic to install two functional groups across long distances. Reported herein is the first remote difunctionalization of alkenes with CO2. This visible‐light photoredox catalysis strategy provides a facile method to synthesize a series of carboxylic acids bearing valuable fluorine‐ or phosphorus‐containing functional groups. Moreover, this versatile protocol shows mild reaction conditions, broad substrate scope, and good functional‐group tolerance. Based on DFT calculations, a radical adds to an unactivated alkene to smoothly form a new carbon radical, followed by a 1,5‐hydrogen atom‐transfer process, the rate‐limiting step, generating a more stable benzylic radical. The reduction of the benzylic radicals by an IrII species generates the corresponding benzylic carbanions as the key intermediates, which further undergo nucleophilic attack with CO2 to generate carboxylates. [ABSTRACT FROM AUTHOR]

Remote difunctionalization of unactivated alkenes is challenging but a highly attractive tactic to install two functional groups across long distances. Reported herein is the first remote difunctionalization of alkenes with CO2. This visible‐light photoredox catalysis strategy provides a facile method to synthesize a series of carboxylic acids bearing valuable fluorine‐ or phosphorus‐containing functional groups. Moreover, this versatile protocol shows mild reaction conditions, broad substrate scope, and good functional‐group tolerance. Based on DFT calculations, a radical adds to an unactivated alkene to smoothly form a new carbon radical, followed by a 1,5‐hydrogen atom‐transfer process, the rate‐limiting step, generating a more stable benzylic radical. The reduction of the benzylic radicals by an IrII species generates the corresponding benzylic carbanions as the key intermediates, which further undergo nucleophilic attack with CO2 to generate carboxylates. [ABSTRACT FROM AUTHOR]

Photocatalytic carboxylation of alkenes with CO 2 is a promising and sustainable strategy to synthesize high value-added carboxylic acids. However, it is challenging and rarely investigated for unactivated alkenes due to their low reactivities. Herein, we report a visible-light photoredox-catalyzed arylcarboxylation of unactivated alkenes with CO 2 , delivering a variety of tetrahydronaphthalen-1-ylacetic acids, indan-1-ylacetic acids, indolin-3-ylacetic acids, chroman-4-ylacetic acids and thiochroman-4-ylacetic acids in moderate-to-good yields. This reaction features high chemo- and regio-selectivities, mild reaction conditions (1 atm, room temperature), broad substrate scope, good functional group compatibility, easy scalability and facile derivatization of products. Mechanistic studies indicate that in situ generation of carbon dioxide radical anion and following radical addition to unactivated alkenes might be involved in the process., (© 2023. The Author(s).)

Objectives: Previous studies have shown that ulinastatin (UTI) alleviates pulmonary edema in acute lung injury (ALI) caused by lipopolysaccharide (LPS), although the mechanism behind this action is uncertain. This research aimed to identify the fundamental mechanism by which UTI alleviates pulmonary edema., Materials and Methods: We established a model of acute lung injury (ALI) in rats by using LPS as the inciting agent.The control, LPS, and LPS+UTI groups were each comprised of a specific number of randomly selected Wistar rats. We evaluated lung injury and determined pulmonary edema. The concentrations of TNF-α, IL-1β and IL-6 in BALF and the expression levels of α1Na, k-ATPase, β1Na, K-AtPase, α-ENaC, β-ENaC, γ-ENaC, Zonula occludens (ZO)-1, Occludin, Caludin-5, PI3K, Akt, TLR4, MyD88 and NF-ƘBwere identified in lung tissues., Results: The presence of UTI was associated with a reduction in lung pathological alterations, lung injury scores, the lung W/D ratio, and MPO activity, in addition to the improved gas exchange (P<0.01). Furthermore, UTI alleviated EB leakage and stimulated AFC ( P <0.01). Importantly, UTI increased the expression of ZO-1, Occludin, Caludin-5, α1Na, K-ATPase, β1Na, K-AtPase, α-ENaC, β-ENaC, and γ-ENaC ( P <0.01). Furthermore, UTI inhibited the inflammatory response, enhanced the expression of PI3K and Akt and hindered TLR4, MyD88, and NF-ƘB expression ( P <0.01) in lung tissues., Conclusion: Our results demonstrated that UTI attenuated pulmonary edema by reducing pulmonary permeability and promoting AFC through inhibiting the inflammatory response, and the mechanism is related to promoting PI3K/Akt signaling pathways and suppressing TLR4/MyD88/NF-ƘB signaling pathways., Competing Interests: The authors declare that they have no competing interests.

Carbon dioxide (CO2) is an ideal one-carbon source owing to its nontoxicity, abundance, availability, and recyclability. Although the thermodynamic stability and kinetic inertness of CO2 bring its utilization challenges, many groups have achieved significant progress in the utilization of CO2 to synthesize valuable carbonyl-containing compounds, which could be also generated via oxidative carbonylation of C-H bonds with CO. As CO2 has a higher oxidation state than CO, it could be considered as a combination of CO and oxidant (CO2 = CO + [O]), thus providing a safe, redox-neutral and economic strategy. In this Feature Article, we have summarized the recent advances in carbonylation of C-H bonds with CO2 based on this concept. The plausible mechanisms of such reactions and future of this field are also discussed.

.This study is to investigate the analgesic effect produced by intrathecal injection (ith) of oxysophoridine (OSR) and the mechanism of GABAA receptor. Warm water tail-flick test was used to detect the analgesic effect of OSR (12.5, 6.25, and 3.13 mg.kg-1 ith) and to observe the influence of GABA (gamma aminobutyric acid) agonist or antagonist on the analgesic effect of OSR in mice. Immunohistochemistry method were used to detect the influence of OSR (12.5 mg.kg-1, ith) on the GABAARalpha1 protein expression in spinal cord. The results obtained covers that OSR (12.5 and 6.25 mg.kg-, ith) alleviates pain significantly with the warm water tail-flick test (P<0.05, P<0.01), the rate of pain threshold increases by 68.45%; GABA and muscimol (MUS) produces analgesic synergism together with the OSR, picrotoxin (PTX) and bicuculline (BIC) antagonize the analgesic effect of OSR; OSR (12.5 mg.kg-1, ith) significantly increase the positive number of GABAARalpha1 nerve cell in spinal cord (P<0.01) and significantly decrease the average grey levels (P<0.01). In conclusion, OSR intrathecal injection has significant analgesic effect. And GABAA receptor in spinal cord is involved in the analgesic mechanism.

Background: Treatment with melatonin significantly reduces lung injury induced by bleomycin, paraquat and ischemia reperfusion. In the present study, we investigated the possible protective roles of melatonin in pulmonary inflammation and lung injury during acute endotoxemia., Methods: Thirty-two male Sprague-Dawley rats were randomly assigned to four groups: vehicle + saline group, melatonin + saline group, vehicle + lipopolysaccharide group, melatonin + lipopolysaccharide group. The rats were treated with melatonin (10 mg/kg, intraperitoneal injection (i.p.)) or vehicle (1% ethanol saline), 30 minutes prior to lipopolysaccharide administration (6 mg/kg, intravenous injection). Four hours after lipopolysaccharide injection, samples of pulmonary tissue were collected. Blood gas analysis was carried out. Optical microscopy was performed to examine pathological changes in lungs and lung injury score was assessed. Wet/dry ratios (W/D), myeloperoxidase activity, malondialdehyde concentrations and tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) levels in lungs were measured. The pulmonary expression of nuclear factor-kappa B (NF-kappaB) p65 was evaluated by Western blotting., Results: PaO(2) in the vehicle + lipopolysaccharide group decreased compared with that in the vehicle + saline group. This decrease was significantly reduced in the melatonin + lipopolysaccharide group. The lung tissues from the saline + lipopolysaccharide group were significantly damaged, which were less pronounced in the melatonin + lipopolysaccharide group. The W/D ratio increased significantly in the vehicle + lipopolysaccharide group (6.1 +/- 0.18) as compared with that in the vehicle + saline group (3.61 +/- 0.3) (P < 0.01), which was significantly reduced in the melatonin + lipopolysaccharide group (4.8 +/- 0.25) (P < 0.01). Myeloperoxidase activity and malondialdehyde levels increased significantly in the vehicle + lipopolysaccharide group compared with that in the vehicle + saline group, which was reduced in the melatonin + lipopolysaccharide group. The TNF-alpha level of pulmonary tissue increased significantly in the vehicle + lipopolysaccharide group ((8.7 +/- 0.91) pg/mg protein) compared with that in the vehicle + saline group ((4.3 +/- 0.62) pg/mg protein, P < 0.01). However, the increase of TNF-alpha level of pulmonary tissue was significantly reduced in the melatonin + lipopolysaccharide group ((5.9 +/- 0.56) pg/mg protein, P < 0.01). Pulmonary IL-10 levels were elevated markedly in the vehicle + lipopolysaccharide group in contrast to that in the vehicle + saline group, whereas the elevation was augmented in the melatonin + lipopolysaccharide group. The nuclear localization of p65 increased markedly in the vehicle + lipopolysaccharide group and this enhancement of nuclear p65 expression was much less in the melatonin + lipopolysaccharide group., Conclusion: Melatonin reduces acute lung injury in endotoxemic rats by attenuating pulmonary inflammation and inhibiting NF-kappaB activation.

Objective: To study the analgesic effects and sites of oxymatrine-carbenoxolone sodium complex (OCSC)., Method: Adopting formalin test, warm water tail-flick test and intracerebroventricularly (icv) injection to observe the analgesic effects of OCSC in mice., Result: Intraperitoneally injecting (ip) OCSC (75, 150 mg x kg(-1)) remarkedly inhibited the pain of mice in the formalin test and prolonged latent phases of tail-shrinking of mice, icy OCSC (1.875, 3.75, 7.5 mg x kg(-1)) significantly prolonged latent phases of tail-shrinking of mice, it had dose-dependent effect with concentration., Conclusion: The result indicated that OCSC has obvious analgesic effects and its mechanism may be involved in central nervous system (CNS).

Objective: To investigate the ulcer-preventive effect of bismuth glycyrrhizate on experimental gastric ulcer and its mechanisms., Method: Three kinds of model animals with experimental gastric ulcer were established and gastric mucosal injuries were induced by pyloric ligation in rats, applying ethanol in rats and imposing stress in mice, respectively. The rats were divided into experimental groups treated with bismuth glycyrrhizat 700, 350, 175 mg kg(-1), positive control group treated with cimetidine (200 mg kg(-1), and negative control group treated with 0.1% EDTA. The mice were divided into experimental groups treated with bismuth glycyrrhiza 980, 490, 250 mg kg(-1). The gastric ulcer index, gastric juice volume, acidity, pepsin activity, the level of nitric oxide (NO) in serum and the level of prostaglandin E2 in gastric tissue were measured in rats., Result: Bismuth glycyrrhizate was shown to be able to reduce the gastric juice volume, acidity and pepsin activity as well as gastric ulcer index. It could increase the content of NO in serum and the content of prostaglandin E2 in gastric tissue., Conclusion: The bismuth glycyrrhizate has antiulcer effect in rats.

Objective: To study the effect of oxysophoridine (OSR) on glutamate (Glu) and gamma aminobutyric acid (GABA) immuno-reaction positive neurons in the cortex and hippocampus of rats., Method: Immunohistochemistry method (SABC) and the micrographic analysis technique were employed to monitor the effect of OSR in the variations of Glu and GABA immunoreaction positive neurons in the cortex and hippocampus of rats., Result: OSR administrated icv (10 mg) significantly increased the number of GABA immuno-reaction positive neurons while decreasing the number of glu immunoreaction positive neurons in cortex and hippocampus in rats (P < 0.05)., Conclusion: Results showed that the change of Glu and GABA caused by OSR may responsible for its inhibitory effects on the central nervous system.

Objective: To study the action of pseudoephedrine salicylate on the central nervous system of mice., Methods: Following the administration of pseudoephedrine salicylate at various dose levels and schedules, the alterations in general behavior and autonomic activities of the mice were recorded using photoelectric counter Type GJ-1, the changes in hypnotic action indices (sleep latency, sleep-lasting time) for the mice placed on pentobarbital in advance were observed, and the muscular clonic spasm of forefoot and neck muscles as well as the deaths from convulsions induced by previously given pentylenetrazol, nicotin and picrotoxin were observed and recorded respectively., Results: Pseudoephedrine salicylate (12.5, 25.0, 50.0, 100.0 mg/kg) administrated ip significantly inhibited the autonomic activities and the hypnotic action induced by previously given pentobarbital. Pseudoephedrine salicylate (100.0 mg/kg) given ip was noted to have synergistic effect on convulsions of the mice previously given pentylenetrazol and picrotoxin at subthreshold doses respectively, but no synergistic effect of pseudoephedrine salicylate (100 mg/kg) and nicotin (at subthreshold dose 0.018 mg/kg) was observed., Conclusion: Pseudoephedrine salicylate has excited effect on the central nervous system of mice.