Induction of MTHFD2 in Macrophages Inhibits Reactive Oxygen Species-mediated NF-κB Activation and Protects against Inflammatory Responses.

The one-carbon metabolism enzyme methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) is critical for cancer cell proliferation and immune cell phenotypes, but whether it can contribute to macrophage inflammatory responses remains unclear. In this study, we show that MTHFD2 was upregulated by LPS in murine macrophages upon activation of the TLR4-MyD88-IKKα/ß-NF-κB signaling pathway. MTHFD2 significantly attenuated LPS-induced macrophage proinflammatory cytokine production through its enzymatic activity. Notably, ablation of myeloid MTHFD2 rendered mice more sensitive to septic shock and CCl4-induced acute hepatitis. Mechanistically, MTHFD2 restrained IKKα/ß-NF-κB activation and macrophage inflammatory phenotype by scavenging reactive oxygen species through the generation of NADPH. Our study reveals MTHFD2 as a "self-control" mechanism in macrophage-mediated inflammatory responses.

Development of an Ultrasensitive Competitive Double-Enzyme Cascade Fluorescence Signal Amplification Method for Factor XIa Inhibitor Screening.

Coagulation factor XIa (FXIa) is associated with a low risk of bleeding and has been identified as an effective and safe target for the development of novel anticoagulant drugs. In this study, we established an ultrasensitive competitive dual-enzyme cascade signal amplification method for the quantitative analysis and screening of FXIa inhibitors. Due to the specific recognition of FXIa's active site by the aptamer AptE40, the AptE40-QDs-EK recognition probe modified with enterokinase (EK) and the aptamer AptE40, was attached to the MNPs-FXIa capture probe. When FXIa inhibitor was present, it competed with AptE40 for binding to FXIa, resulting in the detachment of AptE40-QDs-EK from MNPs-FXIa. After magnetic separation, the enterokinase of AptE40-QDs-EK in the supernatant hydrolyzed N-terminal hexapeptide of trypsinogen, leading to the production of a large amount of trypsin as part of the first-stage signal cascade amplification. Next, trypsin could hydrolyze the hexameric arginine peptide (RRRRRR, R6), leading to the dissociation of RQDs from the R6-RQDs signal probe; this resulted in a dramatic increase in the fluorescence intensity of the supernatant as the second-stage signal cascade was amplified. The feasibility of the method was investigated using the FXIa inhibitor aptamer FELIAP as a positive model drug. Furthermore, the method was applied to screen the FXIa inhibitors in Eupolyphaga sinensis Walker. Two fractions with more active anticoagulated ingredients were successfully identified and validated via the conventional method, and the results were consistent. The established method provides a key technique for the sensitive detection, high-throughput analysis, and screening of the FXIa inhibitors.

Core-Shell Reactor Partitioning Enzyme and Prodrug by ZIF-8 for NADPH-Sensitive In Situ Prodrug Activation.

Enzyme-prodrug therapies have shown unique advantages in efficiency, selectivity, and specificity of in vivo prodrug activation. However, precise spatiotemporal control of both the enzyme and its substrate at the target site, preservation of enzyme activity, and in situ substrate depletion due to low prodrug delivery efficiency continue to be great challenges. Here, we propose a novel core-shell reactor partitioning enzyme and prodrug by ZIF-8, which integrates an enzyme with its substrate and increases the drug loading capacity (DLC) using a prodrug as the building ligand to form a Zn-prodrug shell. Cytochrome P450 (CYP450) is immobilized in ZIF-8, and the antitumor drug dacarbazine (DTIC) is coordinated and deposited in its outer layer with a high DLC of 43.6±0.8 %. With this configuration, a much higher prodrug conversion efficiency of CYP450 (36.5±1.5 %) and lower IC50 value (26.3±2.6 µg/mL) are measured for B16-F10 cells with a higher NADPH concentration than those of L02 cells and HUVECs. With the tumor targeting ability of hyaluronic acid, this core-shell enzyme reactor shows a high tumor suppression rate of 96.6±1.9 % and provides a simple and versatile strategy for enabling in vivo biocatalysis to be more efficient, selective, and safer.

Laminaria japonica Peptides Suppress Liver Cancer by Inducing Apoptosis: Possible Signaling Pathways and Mechanism.

The anticancer properties of Laminaria japonica peptides (LJPs) have never been studied. Here, we extracted LJPs from fresh seaweed and explored their anti-liver cancer activity (in vivo and in vitro). LJPs were isolated/purified by HPLC-ESI-MS. HepG2 cell apoptosis and cell cycle were evaluated. MTT assays were used to examine the cytotoxicity of LJPs. Caspase activation of caspases 3 and 9, cleaved caspases 3 and 9, and cleaved PARP was examined by Western blotting. The PI3K/AKT pathway and the phosphorylation states of MAPKs (p38 and JNK) were examined. We found that the LJP-1 peptide had the most antiproliferative activity in H22 cells in vitro. LJP-1 blocked H22 cells in the G0/G1 phase, accompanied by inhibition of cyclin expression. LJP-1 induced apoptosis through caspase activation and regulation of the ASK1/MAPK pathway. Concurrent in vivo studies demonstrated that LJP-1 significantly inhibited tumor growth and induced tumor cell apoptosis/necrosis. In conclusion, LJPs, particularly LJP-1, exert strong inhibitory effects on liver cancer growth in vivo and in vitro. LJP-1 induces HCC cell apoptosis through the caspase-dependent pathway and G0/G1 arrest. LJP-1 induces caspase-dependent apoptosis, in part by inhibiting PI3K, MAPK signaling pathways, and cell cycle proteins. LJP-1 has the potential to be a novel candidate for human liver cancer therapeutics.

How parental socioeconomic status contribute to children's sports participation in China: A cross-sectional study.

Socioeconomic status (SES) is an important factor contributing to health inequality. This study aimed to investigate factors that predict junior school students' sports participation, identify the mechanisms underlying transmission of social resources and assess the mediating effects of classmate support and parental involvement on the relationship between parental SES and children's sports participation. 4829 males and 4536 females (mean age = 13.56 years, standard deviation = 0.686 years) participated in the study. Multivariate regression was adopted to analyze the determinants of junior school students' sports participation and multiple mediation analyses were used to analyze the hypothesized model. The results indicated that parental SES is significantly and directly correlated with junior school students' sports participation. In addition, parental SES has a significant indirect effect on sports participation through classmate support and parental involvement. Furthermore, the mediation effect of classmate support on the association between parental SES and sports participation is stronger than that of parental involvement. To promote and facilitate the participation of junior school students', strategies should be developed by government and social workers to strengthen classmate support and parental involvement.

Discovery of five new species of Allacta from Yunnan and Hainan, China (Blattodea, Pseudophyllodromiidae).

We examined new Allacta materials from Yunnan and Hainan Province, China, and discovered new species using both morphological and molecular species delimitation (ABGD) methods. Five new species are described: A.bifolium Li & Wang, sp. nov., A.hemiptera Li & Wang, sp. nov., A.lunulara Li & Wang, sp. nov., A.redacta Li & Wang, sp. nov., and A.unicaudata Li & Wang, sp. nov. All five species are placed under the hamifera species group. An updated key and checklist of Allacta species from China are provided.

Automatic quantitative stroke severity assessment based on Chinese clinical named entity recognition with domain-adaptive pre-trained large language model.

BACKGROUND: Stroke is a prevalent disease with a significant global impact. Effective assessment of stroke severity is vital for an accurate diagnosis, appropriate treatment, and optimal clinical outcomes. The National Institutes of Health Stroke Scale (NIHSS) is a widely used scale for quantitatively assessing stroke severity. However, the current manual scoring of NIHSS is labor-intensive, time-consuming, and sometimes unreliable. Applying artificial intelligence (AI) techniques to automate the quantitative assessment of stroke on vast amounts of electronic health records (EHRs) has attracted much interest. OBJECTIVE: This study aims to develop an automatic, quantitative stroke severity assessment framework through automating the entire NIHSS scoring process on Chinese clinical EHRs. METHODS: Our approach consists of two major parts: Chinese clinical named entity recognition (CNER) with a domain-adaptive pre-trained large language model (LLM) and automated NIHSS scoring. To build a high-performing CNER model, we first construct a stroke-specific, densely annotated dataset "Chinese Stroke Clinical Records" (CSCR) from EHRs provided by our partner hospital, based on a stroke ontology that defines semantically related entities for stroke assessment. We then pre-train a Chinese clinical LLM coined "CliRoberta" through domain-adaptive transfer learning and construct a deep learning-based CNER model that can accurately extract entities directly from Chinese EHRs. Finally, an automated, end-to-end NIHSS scoring pipeline is proposed by mapping the extracted entities to relevant NIHSS items and values, to quantitatively assess the stroke severity. RESULTS: Results obtained on a benchmark dataset CCKS2019 and our newly created CSCR dataset demonstrate the superior performance of our domain-adaptive pre-trained LLM and the CNER model, compared with the existing benchmark LLMs and CNER models. The high F1 score of 0.990 ensures the reliability of our model in accurately extracting the entities for the subsequent automatic NIHSS scoring. Subsequently, our automated, end-to-end NIHSS scoring approach achieved excellent inter-rater agreement (0.823) and intraclass consistency (0.986) with the ground truth and significantly reduced the processing time from minutes to a few seconds. CONCLUSION: Our proposed automatic and quantitative framework for assessing stroke severity demonstrates exceptional performance and reliability through directly scoring the NIHSS from diagnostic notes in Chinese clinical EHRs. Moreover, this study also contributes a new clinical dataset, a pre-trained clinical LLM, and an effective deep learning-based CNER model. The deployment of these advanced algorithms can improve the accuracy and efficiency of clinical assessment, and help improve the quality, affordability and productivity of healthcare services.

A sensitive analytical strategy of oligonucleotide functionalized fluorescent probes for detection of nusinersen sodium in human serum.

Spinal muscular atrophy (SMA) is a rare autosomal recessive neuromuscular disease. Nusinersen sodium (NS) is the world's first antisense oligonucleotide (ASO) drug for SMA precise targeted therapy. However, the limited half-life of oligonucleotides and their tendency to accumulate in hepatic and renal tissues presented significant challenges for clinical investigation and therapeutic drug monitoring. In this study, we proposed an analytical strategy based on the specific capture of oligonucleotide functionalized fluorescent probes by single stranded binding proteins (SSB) for ultra-sensitive and high-throughput detection of nusinersen sodium in human serum. The magnetic nanoparticles modified with single-strand binding protein (MNPs-SSB) selectively bonded to the red fluorescent quantum dots functionalized with oligonucleotides (RQDs-ssDNA) that were complementary to nusinersen sodium. Upon interaction with nusinersen sodium, RQDs-ssDNA formed a double-stranded complex (RQDs-ssDNA-NS), resulting in enhanced red fluorescence after magnetic separation as it was no longer captured by MNPs-SSB but remained in the supernatant. A quantitative analysis of nusinersen sodium in biological samples was successfully achieved by establishing a relationship between fluorescence intensity and its concentration. The detection signal F/F0 exhibited a linear correlation (R2 = 0.9871) over a wide range from 0.1 nM to 200 nM, with a limit of detection (LOD) of 0.03 nM, demonstrating the high specificity and rapid analysis time (only 30 min). This method provided a novel approach for sensitive, high-throughput, and specific analysis of nusinersen sodium and similar ASO drugs.

A novel and sensitive ratiometric fluorescent quantum dot-based biosensor for alkaline phosphatase detection in biological samples via the inner-filter effect.

Alkaline phosphatase (ALP) is an important biomarker whose abnormal level in activity is associated with hepatobiliary, skeletal, and renal diseases as well as cancer. Herein, we synthesized ZnSe@ZnS quantum dots (ZnSe@ZnS QDs) and Mn-doped ZnS quantum dots (Mn:ZnS QDs) as fluorophores to establish the ratiometric fluorescent assay for ALP activity detection in biological samples. p-Nitrophenyl phosphate (PNPP) was used as a substrate for ALP, and the overlaps between absorption spectra of PNPP and excitation spectra of QDs resulted in sharp fluorescence quenching. Under the catalysis of ALP, PNPP was hydrolyzed into p-nitrophenol (PNP), which caused a red shift of absorption band of PNPP and fluorescence recovery of Mn:ZnS QDs (585 nm). However, the overlaps between absorption spectra of PNP and emission spectra of ZnSe@ZnS QDs led a further quenching of ZnSe@ZnS QDs (405 nm). Therefore, the ratiometric fluorescent signals (F 585/F 405) were associated with activity of ALP based on bidirectional responses of QDs to the concentration of PNPP. Under the optimum conditions, the method exhibited a good linear relationship from 4 to 96 U per L (R 2 = 0.9969) with the detection limit of 0.57 U per L. Moreover, the method was successfully applied for detecting the ALP activity in a complex biological matrix (human serum and HepG2 cells) with impressive specificity. In particular, the complicated chemical modifications of QDs and pretreatments of biological samples were not required in the whole detection procedures. Therefore, it not only provided a sensitive, specific and simple approach to clinical ALP activity detection, but it also provided support for early diagnosis of diseases.

MTHFD2 reprograms macrophage polarization by inhibiting PTEN.

The one-carbon metabolism enzyme methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) is involved in the regulation of tumor oncogenesis and immune cell functions, but whether it can contribute to macrophage polarization remains elusive. Here, we show that MTHFD2 suppresses polarization of interferon-γ-activated macrophages (M(IFN-γ)) but enhances that of interleukin-4-activated macrophages (M(IL-4)) both in vitro and in vivo. Mechanistically, MTHFD2 interacts with phosphatase and tensin homolog (PTEN) to suppress PTEN's phosphatidylinositol 3,4,5-trisphosphate (PIP3) phosphatase activity and enhance downstream Akt activation, independent of the N-terminal mitochondria-targeting signal of MTHFD2. MTHFD2-PTEN interaction is promoted by IL-4 but not IFN-γ. Furthermore, amino acid residues (aa 215-225) of MTHFD2 directly target PTEN catalytic center (aa 118-141). Residue D168 of MTHFD2 is also critical for regulating PTEN's PIP3 phosphatase activity by affecting MTHFD2-PTEN interaction. Our study suggests a non-metabolic function of MTHFD2 by which MTHFD2 inhibits PTEN activity, orchestrates macrophage polarization, and alters macrophage-mediated immune responses.

A monoclonal antibody against basic fibroblast growth factor attenuates cisplatin resistance in lung cancer by suppressing the epithelial-mesenchymal transition.

Objectives: To investigate the underlying mechanisms of how the basic fibroblast growth factor monoclonal antibody (bFGFmAb) attenuates cisplatin (DDP) resistance in lung cancer using A549 cells and cisplatin-resistant A549 cells (A549/DDP). Methods: Cancer cell proliferation, cell viability, and 50% inhibitory concentration (IC50) of cisplatin were assessed. Transwell assays were utilized to evaluate the invasion activity of tumor cells in response to treatment. Epithelial-to-mesenchymal transition markers and drug resistance proteins were analysed using Western blots. Results: We demonstrate that the bFGFmAb inhibits the proliferation and invasion of both A549 and A549/DDP cells. The bFGFmAb increases cisplatin sensitivity of both A549 and A549/DDP cells as evidenced by an increase in the IC50 of cisplatin in A549 and A549/DDP cells. Furthermore, bFGFmAb significantly increases the expression of E-cadherin, whilst decreasing the expression of N-cadherin and bFGF in both cell lines, thereby showing inhibition of epithelial-to-mesenchymal transition. In addition, we demonstrate that bFGFmAb significantly reduces the expression of the lung resistance protein. Conclusions: Our data suggests that the humanized bFGFmAb is a promising agent to attenuate cisplatin resistance in NSCLC. The underlying mechanism for this effect of bFGFmAb may be associated with the inhibition of epithelial-to-mesenchymal transition and reduced expression of lung resistance protein.

Development and validation of a simple and sensitive HPLC method for the determination of related substances in regorafenib tablets.

Regorafenib as an oral multi-kinase inhibitor has displayed a promising future in the anticancer drug market. However, there are no articles reporting the method for the determination of related substances in regorafenib tablets. A quality standard was first included in the Ph. Eur. 10.4 until April 2021 but could not detect seven known impurities A, C, D, E, FP-A, FP-B, and FP-C simultaneously. In this paper, a simple and sensitive HPLC method was established for the determination of related substances in regorafenib tablets. The determination was performed on a Polar-RP column with dual wavelength detection set at 230 nm and 260 nm. This method was validated according to the ICH guidelines. Furthermore, the possible sources of impurities were analyzed and forced degradation tests were performed, which provided guidance for formulation development and storage conditions. The established method is simple, sensitive and accurate for the determination of related substances in regorafenib tablets. A specified and sensitive HPLC method for the determination of related substances in regorafenib tablets.

Serine metabolism orchestrates macrophage polarization by regulating the IGF1-p38 axis.

Serine metabolism is reportedly involved in immune cell functions, but whether and how serine metabolism regulates macrophage polarization remain largely unknown. Here, we show that suppressing serine metabolism, either by inhibiting the activity of the key enzyme phosphoglycerate dehydrogenase in the serine biosynthesis pathway or by exogenous serine and glycine restriction, robustly enhances the polarization of interferon-γ-activated macrophages (M(IFN-γ)) but suppresses that of interleukin-4-activated macrophages (M(IL-4)) both in vitro and in vivo. Mechanistically, serine metabolism deficiency increases the expression of IGF1 by reducing the promoter abundance of S-adenosyl methionine-dependent histone H3 lysine 27 trimethylation. IGF1 then activates the p38-dependent JAK-STAT1 axis to promote M(IFN-γ) polarization and suppress STAT6-mediated M(IL-4) activation. This study reveals a new mechanism by which serine metabolism orchestrates macrophage polarization and suggests the manipulation of serine metabolism as a therapeutic strategy for macrophage-mediated immune diseases.

Correction: Hierarchical microgroove/nanopore topography regulated cell adhesion to enhance osseointegration around intraosseous implants in vivo.

Correction for 'Hierarchical microgroove/nanopore topography regulated cell adhesion to enhance osseointegration around intraosseous implants in vivo' by Yujuan Tian et al., Biomater. Sci., 2022, 10, 560-580. DOI: 10.1039/D1BM01657A.

Hierarchical microgroove/nanopore topography regulated cell adhesion to enhance osseointegration around intraosseous implants in vivo.

Implant surface topography plays a crucial role in achieving successful implantation. Simple and controllable surface topographical modifications are considered a promising method to accelerate bone osseointegration for biomedical applications. Moreover, comprehension of the mechanism between surface topography and cell osteogenic differentiation is vital for the manipulation of these processes to promote bone tissue regeneration. In this study, we investigated the effects of implant surfaces with various sized hierarchical microgroove/nanopore topographies on cell adhesion, osteogenesis, and their underlying mechanism both in vitro and in vivo. Our findings reveal that a titanium surface with an appropriately sized microgroove/nanopore topography (SLM-1MAH) exhibits the more satisfactory adhesive and osteogenic efficiency than the clinically used sand-blasted, large-grit, and acid-etched (SLA) surface. The underlying molecular mechanism lies in the activation of the integrin α2-PI3K-Akt signaling pathway, where the SLM-1MAH surface increased the protein expressions of integrin α2 (Itga2), phosphatidylinositol 3-kinase (PI3K), and phosphorylated serine/threonine kinase Akt (p-Akt) to enhance osteogenesis and osseointegration. Furthermore, the SLM-1MAH surface also displays better osseointegration efficiency with stronger bonding strength than that on the SLA surface. This work provides a novel strategy for implant surface topography design to improve bone-implant osseointegration.

In vitro and in vivo evaluation of virus-induced innate immunity in mouse.

Innate immunity is the first line of host defense against viral infection. As one of the innate immune cell types, antigen-presenting cells play an important role in the process of antiviral immunity. This protocol describes the analysis of innate immunity induced by vesicular stomatitis virus infection of peritoneal macrophages in vitro and in vivo detection of IFN-ß production and lung injury. For complete details on the use and execution of this protocol, please refer to Shen et al. (2021).

The Role and Activation Mechanism of TAZ in Hierarchical Microgroove/Nanopore Topography-Mediated Regulation of Stem Cell Differentiation.

PURPOSE: To investigate the role and activation mechanism of TAZ in periodontal ligament stem cells (PDLSCs) perceiving hierarchical microgroove/nanopore topography. MATERIALS AND METHODS: Titanium surface with hierarchical microgroove/nanopore topography fabricated by selective laser melting combined with alkali heat treatment (SLM-AHT) was used as experimental group, smooth titanium surface (Ti) and sandblasted, large-grit, acid-etched (SLA) titanium surface were employed as control groups. Alkaline phosphatase (ALP) activity assays, qRT-PCR, Western blotting, and immunofluorescence were carried out to evaluate the effect of SLM-AHT surface on PDLSC differentiation. Moreover, TAZ activation was investigated from the perspective of nuclear localization to transcriptional activity. TAZ knockdown PDLSCs were seeded on three titanium surfaces to detect osteogenesis- and adipogenesis-related gene expression levels. Immunofluorescence and Western blotting were employed to investigate the effect of the SLM-AHT surface on actin cytoskeletal polymerization and MAPK signaling pathway. Cytochalasin D and MAPK signaling pathway inhibitors were used to determine whether actin cytoskeletal polymerization and the MAPK signaling pathway were indispensable for TAZ activation. RESULTS: Our results showed that SLM-AHT surface had a greater potential to promote PDLSC osteogenic differentiation while inhibiting adipogenic differentiation than the other two groups. The nuclear localization and transcriptional activity of TAZ were strongly enhanced on the SLM-AHT surface. Moreover, after TAZ knockdown, the enhanced osteogenesis and decreased adipogenesis in SLM-AHT group could not be observed. In addition, SLM-AHT surface could promote actin cytoskeletal polymerization and upregulate p-ERK and p-p38 protein levels. After treatment with cytochalasin D and MAPK signaling pathway inhibitors, differences in the TAZ subcellular localization and transcriptional activity were no longer observed among the different titanium surfaces. CONCLUSION: Our results demonstrated that actin cytoskeletal polymerization and MAPK signaling pathway activation triggered by SLM-AHT surface were essential for TAZ activation, which played a dominant role in SLM-AHT surface-induced stem cell fate decision.

Serine metabolism antagonizes antiviral innate immunity by preventing ATP6V0d2-mediated YAP lysosomal degradation.

Serine metabolism promotes tumor oncogenesis and regulates immune cell functions, but whether it also contributes to antiviral innate immunity is unknown. Here, we demonstrate that virus-infected macrophages display decreased expression of serine synthesis pathway (SSP) enzymes. Suppressing the SSP key enzyme phosphoglycerate dehydrogenase (PHGDH) by genetic approaches or by treatment with the pharmaceutical inhibitor CBR-5884 and by exogenous serine restriction enhanced IFN-ß-mediated antiviral innate immunity in vitro and in vivo. Mechanistic experiments showed that virus infection or serine metabolism deficiency increased the expression of the V-ATPase subunit ATP6V0d2 by inhibiting S-adenosyl methionine-dependent H3K27me3 occupancy at the promoter. ATP6V0d2 promoted YAP lysosomal degradation to relieve YAP-mediated blockade of the TBK1-IRF3 axis and, thus, enhance IFN-ß production. These findings implicate critical functions of PHGDH and the key immunometabolite serine in blunting antiviral innate immunity and also suggest manipulation of serine metabolism as a therapeutic strategy against virus infection.

Reduced expression of CENP-E contributes to the development of hepatocellular carcinoma and is associated with adverse clinical features.

Human kinesin centromere-associated protein E (CENP-E), one of spindle checkpoint proteins, has been identified as a tumor suppressor in several types of cancer, however, its role in hepatocarcinogenesis remains unknown. Here we investigated the role of CENP-E in human hepatocellular carcinoma (HCC) employing HCC cell lines (Hep3B, SMMC7721, and QGY7701), animal models, and patient's clinical samples and data. We demonstrated that down-regulation of CENP-E by CENP-E-silencing shRNAs significantly promoted HCC proliferation/growth both in vitro and in vivo. Further studies found that CENP-E suppressed the proliferation of HCC cells by halting cell cycle progression at the G1-S phase and accelerating cell apoptosis. Analyses of HCC patient samples and clinical data revealed that CENP-E was significantly down-regulated in HCC tissues and low CENP-E expression was significantly associated with patient's adverse clinicopathological features: poor prognosis, advanced TNM stage, metastasis, and larger tumor size. Multivariate analysis indicated that CENP-E was an independent prognostic factor predicting outcomes of advanced HCC patients. Our data suggest that loss of CENP-E contributes to HCC development and is strongly associated with adverse HCC clinical pathology. Thus, CENP-E could be a novel target for new treatments and a useful prognostic biomarker for HCC patients.

Iron-catalyzed oxidative C-C(vinyl) σ-bond cleavage of allylarenes to aryl aldehydes at room temperature with ambient air.

A general and selective iron-catalyzed allylic C-C(vinyl) σ-bond cleavage of allylarenes without the assistance of heteroatoms to give aryl aldehydes is reported. The unstrained carbon-carbon single bond cleavage reaction uses ambient air as the sole oxidant, proceeds efficiently at room temperature, and allows for exceptional functional-group tolerance, which addresses the long-standing challenges of current C-C bond cleavage/functionalization. Notably, the method enables rapid late-stage oxidation of complex bioactive molecules and can be used to expedite syntheses of natural products (vanillin and glucovanillin) from readily available chemical feedstocks.