Tetramethylpyrazine Nitrone Reduces Oxidative Stress to Alleviate Cerebral Vasospasm in Experimental Subarachnoid Hemorrhage Models

Palladium-Catalyzed Synthesis of Nitrones Via Redox Cross-Coupling of Nitro Compounds and Alcohols

A novel methodology for the synthesis of nitrones via palladium-catalyzed redox cross-coupling of nitro compounds and alcohols is established. The protocol is a mild, convenient, ligand-free, and scalable synthesis method that can be compatible with various nitro compounds and alcohols. Nitrone is a significant multifunctional platform synthon which can be synthesized directly and efficiently via this tactic from commercially available and cheap raw materials.

Pharmacokinetics, Safety Profile, and Tolerability of Tetramethylpyrazine Nitrone Tablets After Single and Multiple Ascending Doses in Healthy Chinese Volunteers

BACKGROUND AND OBJECTIVES

Tetramethylpyrazine nitrone (TBN) is a novel tetramethylpyrazine derivative armed with a strong free radical scavenging nitrone moiety. This study aims to evaluate the pharmacokinetics, safety profile, and tolerability of TBN tablets after a single ascending dose (SAD) and multiple ascending doses (MAD) in healthy Chinese volunteers.

METHODS

This phase I, single-center, open-label study was conducted in China. The SAD portion consisted of four cohorts with dose levels of 400-1800 mg. The MAD portion included three cohorts in which subjects received doses of 600-1800 mg twice daily for 7 days (13 consecutive doses). The third portion was a randomized, two-period, crossover design to assess the influence of food with a single dose of TBN tablets (1200 mg). The safety profile was evaluated by monitoring adverse events (AEs), vital signs, electrocardiograms, physical examinations, and laboratory test results.

RESULTS

Fifty-two healthy subjects aged 18 to 45 years with a body mass index between 19.0 and 26.0 kg/m2 were enrolled. After a single dose of TBN, the median time to maximum plasma concentration (Tmax) was 2.48-3.24 h and the mean half-life (t1/2) was 1.28 to 2.10 h across all doses. In the MAD study, the median Tmax was 2.48 to 3.48 h. In the 400-1800 mg dose range, there was a tendency for less than proportional increases in the maximum plasma concentration (Cmax), the area under the concentration-time curve from 0 to time of last measurable concentration (AUC0-t), and the area under the concentration-time curve from 0 to infinity (AUC0-inf) in both single- and multiple-dose periods. A significantly higher TBN exposure was observed in females than males in both a single and multiple doses of the 600 mg and 1200 mg groups, with a geometric mean female-to-male ratio of 138.69-203.18%. Food decreased the Cmax and AUC0-t of TBN to 45.19% and 59.73%, respectively. Each dose group reached a steady state after 4 days. No drug accumulation was observed. Two subjects had drug-related AEs. A decreased neutrophil count and drug eruption in the SAD portion (1200 mg group) and an increased alanine aminotransferase level in the food effect group were found. All AEs were mild and tolerable (CTCAE grade 1) and resolved without any medical intervention.

CONCLUSION

TBN tablets had a good safety profile and were well tolerated in healthy Chinese volunteers. Steady-state concentrations were reached after 4 consecutive days of oral administration. The results of this phase I study will provide guidance for the design of future TBN clinical studies.

CHINESE CLINICAL TRIAL REGISTRY

ChiCTR1900022092.

Neuroprotection by tetramethylpyrazine and its synthesized analogues for central nervous system diseases: a review

BACKGROUND

Due to the global increase in aging populations and changes in modern lifestyles, the prevalence of neurodegenerative diseases, cerebrovascular disorders, neuropsychiatrcic conditions, and related ailments is rising, placing an increasing burden on the global public health system.

MATERIALS AND METHODS

All studies on tetramethylpyrazine (TMP) and its derivatives were obtained from reputable sources such as PubMed, Elsevier, Library Genesis, and Google Scholar. Comprehensive data on TMP and its derivatives was meticulously compiled.

RESULTS

This comprehensive analysis explains the neuroprotective effects demonstrated by TMP and its derivatives in diseases of the central nervous system. These compounds exert their influence on various targets and signaling pathways, playing crucial roles in the development of various central nervous system diseases. Their multifaceted mechanisms include inhibiting oxidative damage, inflammation, cell apoptosis, calcium overload, glutamate excitotoxicity, and acetylcholinesterase activity.

CONCLUSION

This review provides a brief summary of the most recent advancements in research on TMP and its derivatives in the context of central nervous system diseases. It involves synthesizing analogs of TMP and evaluating their effectiveness in models of central nervous system diseases. The ultimate goal is to facilitate the practical application of TMP and its derivatives in the future treatment of central nervous system diseases.

Hydrogen sulfide and its donors for the treatment of cerebral ischaemia-reperfusion injury: A comprehensive review

As an endogenous gas signalling molecule, hydrogen sulfide (H₂S) is frequently present in a variety of mammals and plays a significant role in the cardiovascular and nervous systems. Reactive oxygen species (ROS) are produced in large quantities as a result of cerebral ischaemia-reperfusion, which is a very serious class of cerebrovascular diseases. ROS cause oxidative stress and induce specific gene expression that results in apoptosis. H₂S reduces cerebral ischaemia-reperfusion-induced secondary injury via anti-oxidative stress injury, suppression of the inflammatory response, inhibition of apoptosis, attenuation of cerebrovascular endothelial cell injury, modulation of autophagy, and antagonism of P2X7 receptors, and it plays an important biological role in other cerebral ischaemic injury events. Despite the many limitations of the hydrogen sulfide therapy delivery strategy and the difficulty in controlling the ideal concentration, relevant experimental evidence demonstrating that H₂S plays an excellent neuroprotective role in cerebral ischaemia-reperfusion injury (CIRI). This paper examines the synthesis and metabolism of the gas molecule H₂S in the brain as well as the molecular mechanisms of H₂S donors in cerebral ischaemia-reperfusion injury and possibly other unknown biological functions. With the active development in this field, it is expected that this review will assist researchers in their search for the potential value of hydrogen sulfide and provide new ideas for preclinical trials of exogenous H₂S.

Peroxiredoxin-3 plays a neuroprotective role in early brain injury after experimental subarachnoid hemorrhage in rats

Subarachnoid hemorrhage (SAH), a type of hemorrhagic stroke, is a neurological emergency associated with a high morbidity and mortality rate. After SAH, early brain injury (EBI) is the leading cause of poor prognosis in SAH patients. Peroxiredoxins (PRDXs) are a family of sulphhydryl-dependent peroxidases. Peroxiredoxin-3 (PRDX3) is mainly located in the mitochondria of neurons, which can remove hydrogen peroxide (H2O2); however, the effect of PRDX3 on EBI after SAH remains unclear. In this study, an endovascular perforation model was used to mimic SAH in Sprague Dawley rats in vivo. The results revealed that after SAH, PRDX3 levels decreased in the neurons. PRDX3 overexpression by neuron-specific adeno-associated viruses upregulated PRDX3 levels. Furthermore, PRDX3 overexpression improved long- and short-term behavioral outcomes and alleviated neuronal impairment in rats. Nissl staining revealed that the upregulation of PRDX3 promoted cortical neuron survival. PRDX3 overexpression decreased the H2O2 content and downregulated caspase-9 expression. In conclusion, PRDX3 participates in neuronal protection by inhibiting the neuronal mitochondria-mediated death pathway; PRDX3 may be an important target for EBI intervention after SAH.

Genetic variation in NFE2L2 is associated with outcome following aneurysmal subarachnoid haemorrhage

BACKGROUND AND PURPOSE

Nuclear factor erythroid 2-related factor 2 (NRF2; encoded by the NFE2L2 gene) has been implicated in outcome following aneurysmal subarachnoid haemorrhage (aSAH) through its activity as a regulator of inflammation, oxidative injury and blood breakdown product clearance. The aim of this study was to identify whether genetic variation in NFE2L2 is associated with clinical outcome following aSAH.

METHODS

Ten tagging single nucleotide polymorphisms (SNPs) in NFE2L2 were genotyped and tested for association with dichotomized clinical outcome, assessed by the modified Rankin scale, in both a discovery and a validation cohort. In silico functional analysis was performed using a range of bioinformatic tools.

RESULTS

One SNP, rs10183914, was significantly associated with outcome following aSAH in both the discovery (n = 1007) and validation cohorts (n = 466). The risk of poor outcome was estimated to be 1.33-fold (95% confidence interval 1.12-1.58) higher in individuals with the T allele of rs10183914 (p_{meta-analysis}  = 0.001). In silico functional analysis identified rs10183914 as a potentially regulatory variant with effects on transcription factor binding in addition to alternative splicing with the T allele, associated with a significant reduction in the NFE2L2 intron excision ratio (p_sQTL  = 1.3 × 10^-7 ).

CONCLUSIONS

The NFE2L2 SNP, rs10183914, is significantly associated with outcome following aSAH. This is consistent with a clinically relevant pathophysiological role for oxidative and inflammatory brain injury due to blood and its breakdown products in aSAH. Furthermore, our findings support NRF2 as a potential therapeutic target following aSAH and other forms of intracranial haemorrhage.

Tetramethylpyrazine nitrone activates hypoxia-inducible factor and regulates iron homeostasis to improve renal anemia

Renal anemia is one of the most common complications of chronic kidney disease and diabetic kidney disease. Despite the progress made in recent years, there is still an urgent unmet clinical need for renal anemia treatment. In this research, we investigated the efficacy and mechanism of action of the novel tetramethylpyrazine nitrone (TBN). Animal models of anemia including the streptozotocin (STZ)-induced spontaneously hypertensive rats (SHR) and the cisplatin (CDDP)-induced C57BL/6J mice are established to study the TBN's effects on expression of hypoxia-inducible factor and erythropoietin. To explore the mechanism of TBN's therapeutic effect on renal anemia, cobalt chloride (CoCl2) is used in Hep3B/HepG2 cells to simulate a hypoxic environment. TBN is found to increase the expression of hypoxia-inducible factor HIF-1α and HIF-2α under hypoxic conditions and reverse the reduction of HIFs expression caused by saccharate ferric oxide (SFO). TBN also positively regulates the AMPK pathway. TBN stimulates nuclear transcription and translation of erythropoietin by enhancing the stability of HIF-1α expression. TBN has a significant regulatory effect on several major biomarkers of iron homeostasis, including ferritin, ferroportin (FPN), and divalent metal transporter-1 (DMT1). In conclusion, TBN regulates the AMPK/mTOR/4E-BP1/HIFs pathway, and activates the hypoxia-inducible factor and regulates iron homeostasis to improve renal anemia.

Targeting Oxidative Stress in Intracerebral Hemorrhage: Prospects of the Natural Products Approach

Intracerebral hemorrhage (ICH), the second most common subtype of stroke, remains a significant cause of morbidity and mortality worldwide. The pathological mechanism of ICH is very complex, and it has been demonstrated that oxidative stress (OS) plays an important role in the pathogenesis of ICH. Previous studies have shown that OS is a therapeutic target after ICH, and antioxidants have also achieved some benefits in the treatment of ICH. This review aimed to explore the promise of natural products therapy to target OS in ICH. We searched PubMed using the keywords “oxidative stress in intracerebral hemorrhage” and “natural products in intracerebral hemorrhage”. Numerous animal and cell studies on ICH have demonstrated the potent antioxidant properties of natural products, including polyphenols and phenolic compounds, terpenoids, alkaloids, etc. In summary, natural products such as antioxidants offer the possibility of treatment of OS after ICH. However, researchers still have a long way to go to apply these natural products for the treatment of ICH more widely in the clinic.

Admission Serum Iron as an Independent Risk Factor for Postoperative Delayed Cerebral Ischemia Following Aneurysmal Subarachnoid Hemorrhage: A Propensity-Matched Analysis

This study aimed to investigate the association between serum iron (SI) and postoperative delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH). We retrospectively analyzed 985 consecutive adult patients diagnosed with aSAH. Demographic, clinical, and laboratory data were recorded. Univariate and multivariate analyses were employed to assess the association between SI and DCI. Propensity-score matching (PSM) analysis was implemented to reduce confounding. Postoperative DCI developed in 14.38% of patients. Lower SI upon admission was detected in aSAH patients with severe clinical conditions and severe aSAH. SI was negatively correlated with WFNS grade (r = −0.3744, p < 0.001) and modified Fisher (mFisher) grade (r = −0.2520, p < 0.001). Multivariable analysis revealed lower SI was independently associated with DCI [odds ratios (OR) 0.281, 95% confidence interval (CI) 0.177−0.448, p < 0.001], while WFNS grade and mFisher grade were not. The receiver-operating characteristics (ROC) curve analysis of SI for DCI gave an area under the curve (AUC) of 0.7 and an optimal cut-off of 7.5 μmol/L (95% CI 0.665 to 0.733, p < 0.0001). PSM demonstrated the DCI group had a significantly lower SI than the non-DCI group (10.91 ± 6.86 vs. 20.34 ± 8.01 μmol/L, p < 0.001). Lower SI remained a significant independent predictor for DCI and an independent poor prognostic factor of aSAH in multivariate analysis (OR 0.363, 95% CI 0.209−0.630, p < 0.001). The predictive performance of SI for poor outcome had a corresponding AUC of 0.718 after PSM. Lower SI upon admission is significantly associated with WFNS grade, mFisher grade, and predicts postoperative DCI and poor outcome at 90 days following aSAH.

Tetramethylpyrazine nitrone TBN extends the lifespan of C. elegans by activating the Nrf2/SKN-1 signaling pathway

SKN-1, the ortholog of mammalian Nrf2 proteins, is a transcription factor that plays an important role in oxidative stress resistance and longevity. Similar to other defense systems, the Nrf2-mediated stress response is compromised in aging and neurodegenerative diseases. Our previous studies demonstrated that tetramethylpyrazine nitrone (TBN), a derivative of tetramethylpyrazine armed with a potent free radical-scavenging nitrone moiety, exerted multifunctional neuroprotection in neurological and other diseases. However, the ability of TBN to extend a healthy lifespan and its underlying mechanisms of action are not yet clear. C. elegans have become a popular animal model in aging research. Herein, we demonstrate that TBN can extend the lifespan, promote age-associated health indicators, and restore mitochondrial function in C. elegans. TBN also significantly reduced ROS levels and superoxide accumulation in C. elegans. We show that TBN-mediated lifespan extension is SKN-1dependent. The present study provides valuable insights into the mechanisms by which TBN inhibits aging via the Nrf2/SKN-1 pathway in C. elegans.

New Mechanisms and Targets of Subarachnoid Hemorrhage: A Focus on Mitochondria

Spontaneous subarachnoid hemorrhage (SAH) accounts for 5-10% of all strokes and is a subtype of hemorrhagic stroke that places a heavy burden on health care. Despite great progress in surgical clipping and endovascular treatment for ruptured aneurysms, cerebral vasospasm (CVS) and delayed cerebral ischemia (DCI) threaten the long-term outcomes of patients with SAH. Moreover, there are limited drugs available to reduce the risk of DCI and adverse outcomes in SAH patients. New insight suggests that early brain injury (EBI), which occurs within 72 h after the onset of SAH, may lay the foundation for further DCI development and poor outcomes. The mechanisms of EBI mainly include excitotoxicity, oxidative stress, neuroinflammation, blood-brain barrier (BBB) destruction, and cellular death. Mitochondria are a double-membrane organelle, and they play an important role in energy production, cell growth, differentiation, apoptosis, and survival. Mitochondrial dysfunction, which can lead to mitochondrial membrane potential (Δψm) collapse, overproduction of reactive oxygen species (ROS), release of apoptogenic proteins, disorders of mitochondrial dynamics, and activation of mitochondria-related inflammation, is considered a novel mechanism of EBI related to DCI as well as post-SAH outcomes. In addition, mitophagy is activated after SAH. In this review, we discuss the latest perspectives on the role of mitochondria in EBI and DCI after SAH. We emphasize the potential of mitochondria as therapeutic targets and summarize the promising therapeutic strategies targeting mitochondria for SAH.

The blood-brain barrier and the neurovascular unit in subarachnoid hemorrhage: molecular events and potential treatments

The response of the blood-brain barrier (BBB) following a stroke, including subarachnoid hemorrhage (SAH), has been studied extensively. The main components of this reaction are endothelial cells, pericytes, and astrocytes that affect microglia, neurons, and vascular smooth muscle cells. SAH induces alterations in individual BBB cells, leading to brain homeostasis disruption. Recent experiments have uncovered many pathophysiological cascades affecting the BBB following SAH. Targeting some of these pathways is important for restoring brain function following SAH. BBB injury occurs immediately after SAH and has long-lasting consequences, but most changes in the pathophysiological cascades occur in the first few days following SAH. These changes determine the development of early brain injury as well as delayed cerebral ischemia. SAH-induced neuroprotection also plays an important role and weakens the negative impact of SAH. Supporting some of these beneficial cascades while attenuating the major pathophysiological pathways might be decisive in inhibiting the negative impact of bleeding in the subarachnoid space. In this review, we attempt a comprehensive overview of the current knowledge on the molecular and cellular changes in the BBB following SAH and their possible modulation by various drugs and substances.

An Update on Antioxidative Stress Therapy Research for Early Brain Injury After Subarachnoid Hemorrhage

The main reasons for disability and death in aneurysmal subarachnoid hemorrhage (aSAH) may be early brain injury (EBI) and delayed cerebral ischemia (DCI). Despite studies reporting and progressing when DCI is well-treated clinically, the prognosis is not well-improved. According to the present situation, we regard EBI as the main target of future studies, and one of the key phenotype-oxidative stresses may be called for attention in EBI after laboratory subarachnoid hemorrhage (SAH). We summarized the research progress and updated the literature that has been published about the relationship between experimental and clinical SAH-induced EBI and oxidative stress (OS) in PubMed from January 2016 to June 2021. Many signaling pathways are related to the mechanism of OS in EBI after SAH. Several antioxidative stress drugs were studied and showed a protective response against EBI after SAH. The systematical study of antioxidative stress in EBI after laboratory and clinical SAH may supply us with new therapies about SAH.

Metal-Free Solvent Promoted Oxidation of Benzylic Secondary Amines to Nitrones with H2O2

An environmentally benign protocol for the generation of nitrones from benzylic secondary amines via catalyst-free oxidation of secondary amines using H2O2 in MeOH or CH3CN is described. This methodology provides a selective access to a variety of C-aryl nitrones in yields of 60 to 93%. Several studies have been performed to shed light on the reaction mechanism and the role of the solvent.

Preconditioning Exercise in Rats Attenuates Early Brain Injury Resulting from Subarachnoid Hemorrhage by Reducing Oxidative Stress, Inflammation, and Neuronal Apoptosis

Subarachnoid hemorrhage (SAH) is a catastrophic form of stroke responsible for significant morbidity and mortality. Oxidative stress, inflammation, and neuronal apoptosis are important in the pathogenesis of early brain injury (EBI) following SAH. Preconditioning exercise confers neuroprotective effects, mitigating EBI; however, the basis for such protection is unknown. We investigated the effects of preconditioning exercise on brain damage and sensorimotor function after SAH. Male rats were assigned to either a sham-operated (Sham) group, exercise (Ex) group, or no-exercise (No-Ex) group. After a 3-week exercise program, they underwent SAH by endovascular perforation. Consciousness level, neurological score, and sensorimotor function were studied. The expression of nuclear factor erythroid 2 p45-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), 4-hydroxynonenal (4HNE), nitrotyrosine (NT), ionized calcium-binding adaptor molecule 1 (Iba1), tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), interleukin 1β (IL-1β), 14-3-3γ, p-β-catenin Ser37, Bax, and caspase-3 were evaluated by immunohistochemistry or western blotting. The terminal deoxynucleotidyl transferase-mediated biotinylated dUTP nick end labeling (TUNEL) assay was also performed. After SAH, the Ex group had significantly reduced neurological deficits, sensorimotor dysfunction, and consciousness disorder compared with the No-Ex group. Nrf2, HO-1, and 14-3-3γ were significantly higher in the Ex group, while 4HNE, NT, Iba1, TNF-α, IL-6, IL-1β, Bax, caspase-3, and TUNEL-positive cells were significantly lower. Our findings suggest that preconditioning exercise ameliorates EBI after SAH. The expression of 4HNE and NT was reduced by Nrf2/HO-1 pathway activation; additionally, both oxidative stress and inflammation were reduced. Furthermore, preconditioning exercise reduced apoptosis, likely via the 14-3-3γ/p-β-catenin Ser37/Bax/caspase-3 pathway.

Interleukin-6: Important Mediator of Vasospasm Following Subarachnoid Hemorrhage

The correlation of neuroinflammation with the development of cerebral vasospasm following subarachnoid hemorrhage has been well documented in the literature; both clinical and preclinical. The exact mechanisms by which this process occurs, however, are poorly elucidated. Recent evidence indicates that interleukin-6 is not only an important prognostic biomarker for subarachnoid hemorrhage and subsequent vasospasm development but also an integral component in the progression of injury following initial insult. In this review, we briefly highlight other pathways under investigation and focus heavily on what has been discovered regarding the role of interleukin 6 and cerebral vasospasm following subarachnoid hemorrhage. A proposed mechanistic pathway is highlighted in written and graphical format. A discussion regarding the human correlative findings and initial pre-clinical mechanistic studies is addressed. Finally, in the future investigation section, innovative developments and a clear description of areas warranting further scientific inquiry are emphasized. This review will catalyze continued discovery in this area of emerging significance and aid in the quest for effective vasospasm treatment where limited clinical therapeutics currently exist.

Tetramethylpyrazine nitrone improves motor dysfunction and pathological manifestations by activating the PGC-1α/Nrf2/HO-1 pathway in ALS mice

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive loss of upper and lower motor neurons that results in skeletal muscle atrophy, weakness and paralysis. Oxidative stress plays a key role in the pathogenesis of ALS, including familial forms of the disease arising from mutation of the gene coding for superoxide dismutase (SOD1). We have used the SOD1^G93A ALS mouse model to investigate the efficacy of 2-[[(1,1-dimethylethyl)oxidoimino]-methyl]-3,5,6-trimethylpyrazine (TBN), a novel tetramethylpyrazine derivative armed with a powerful free-radical scavenging nitrone moiety. TBN was administered to mice by intraperitoneal or intragastric injection after the onset of motor deficits. TBN slowed the progression of motor neuron disease as evidenced by improved motor performance, reduced spinal motor neuron loss and the associated glial response, and decreased skeletal muscle fiber denervation and fibrosis. TBN treatment activated mitochondrial antioxidant activity through the PGC-1α/Nrf2/HO-1 pathway and decreased the expression of human SOD1. These findings suggest that TBN holds promise as a therapeutic agent for ALS.

Targeting Transcription Factor Nrf2 (Nuclear Factor Erythroid 2-Related Factor 2) for the Intervention of Vascular Cognitive Impairment and Dementia

Vascular cognitive impairment and dementia (VCID) is an age-related, mild to severe mental disability due to a broad panel of cerebrovascular disorders. Its pathobiology involves neurovascular dysfunction, blood-brain barrier disruption, white matter damage, microRNAs, oxidative stress, neuroinflammation, and gut microbiota alterations, etc. Nrf2 (Nuclear factor erythroid 2-related factor 2) is the master regulator of redox status and controls the transcription of a panel of antioxidative and anti-inflammatory genes. By interacting with NF-κB (nuclear factor-κB), Nrf2 also fine-tunes the cellular oxidative and inflammatory balance. Aging is associated with Nrf2 dysfunction, and increasing evidence has proved the role of Nrf2 in mitigating the VCID process. Based on VCID pathobiologies and Nrf2 studies from VCID and other brain diseases, we point out several hypothetical Nrf2 targets for VCID management, including restoration of endothelial function and neurovascular coupling, preservation of blood-brain barrier integrity, reduction of amyloidopathy, promoting white matter integrity, and mitigating oxidative stress and neuroinflammation. Collectively, the Nrf2 pathway could be a promising direction for future VCID research. Targeting Nrf2 would shed light on VCID managing strategies.

Recent Advances on Nitrones Design for Stroke Treatment

The recent advances of tetramethylpyrazine nitrones and quinolylnitrones for the treatment of stroke have been reviewed and compared with other agents, showing promising therapeutic applications. As a result of a functional transformation of natural product ligustrazine, (Z)-N-tert-butyl-1-(3,5,6-trimethylpyrazin-2-yl)methanimine oxide (6) is a multitarget small nitrone showing potent thrombolytic activity and free radicals scavenging power, in addition to nontoxicity and blood-brain barrier permeability. Similarly, antioxidant (Z)-N-tert-butyl-1-(2-chloro-6-methoxyquinolin-3-yl)methanimine oxide (17) is a novel agent for cerebral ischemia therapy as it is able to scavenge different types of free radical species, showing strong neuroprotection and reduced infarct size.