AlgU mediates hyperosmotic tolerance in Pseudomonas protegens SN15-2 by regulating membrane stability, ROS scavenging, and osmolyte synthesis.

Pseudomonas protegens can serve as an agricultural biocontrol agent. P. protegens often encounters hyperosmotic stress during industrial production and field application. The ability of P. protegens to withstand hyperosmotic stress is important for its application as a biocontrol agent. AlgU is a global regulator responsible for stress response and biocontrol ability. However, the specific regulatory role of AlgU in the hyperosmotic adaptation of P. protegens is poorly understood. In this study, we found that the AlgU mutation disrupted the hyperosmotic tolerance of P. protegens. Many genes and metabolites related to cell envelope formation were significantly downregulated in ΔalgU compared with that in the wild-type (WT) strain under hyperosmotic conditions, and we found that the algU mutation caused membrane integrity to be compromised and increased membrane permeability. Further experiments revealed that the cell envelope integrity protein TolA, which is regulated by AlgU, contributes to cell membrane stability and osmotic tolerance in P. protegens. In addition, several genes related to oxidative stress response were significantly downregulated in ΔalgU, and higher levels of intracellular reactive oxygen species were found in ΔalgU. Furthermore, we found that the synthesis of N-acetyl glutaminyl glutamine amide is directly regulated by AlgU and contributes to the hyperosmotic adaptation of P. protegens. This study revealed the mechanisms of AlgU's participation in osmotic tolerance in P. protegens, and it provides potential molecular targets for research on the hyperosmotic adaptation of P. protegens.IMPORTANCEIn this study, we found that the extracytoplasmic function sigma factor AlgU is essential for the survival of P. protegens under hyperosmotic conditions. We provided evidence supporting the roles of AlgU in influencing cell membrane stability, intracellular reactive oxygen species (ROS) accumulation, and dipeptide N-acetylglutaminylglutamine amide (NAGGN) synthesis in P. protegens under hyperosmotic conditions. Our findings revealed the mechanisms of AlgU's participation in hyperosmotic stress tolerance in P. protegens, and they provide potential molecular targets for research on the hyperosmotic adaptation of P. protegens, which is of value in improving the biocontrol ability of P. protegens.

Revitalizing gut barrier integrity: miR-192-5p's role in enhancing autophagy via Rictor in enteritis.

BACKGROUND: Intestinal inflammation and compromised barrier function are critical factors in the pathogenesis of gastrointestinal disorders. This study aimed to investigate the role of miR-192-5p in modulating intestinal epithelial barrier (IEB) integrity and its association with autophagy. METHODS: A DSS-induced colitis model was used to assess the effects of miR-192-5p on intestinal inflammation. In vitro experiments involved cell culture and transient transfection techniques. Various assays, including dual-luciferase reporter gene assays, quantitative real-time PCR, western blotting, and measurements of transepithelial electrical resistance, were performed to evaluate changes in miR-192-5p expression, Rictor levels, and autophagy flux. Immunofluorescence staining, H&E staining, TEER measurements, and FITC-dextran analysis were also employed. RESULTS: Our findings revealed a reduced expression of miR-192-5p in inflamed intestinal tissues, correlating with impaired IEB function. Overexpression of miR-192-5p alleviated TNF-induced IEB dysfunction by targeting Rictor, resulting in enhanced autophagy flux in enterocytes (ECs). Moreover, the therapeutic potential of miR-192-5p was substantiated in colitis mice, wherein increased miR-192-5p expression ameliorated intestinal inflammatory injury by enhancing autophagy flux in ECs through the modulation of Rictor. CONCLUSION: Our study highlights the therapeutic potential of miR-192-5p in enteritis by demonstrating its role in regulating autophagy and preserving IEB function. Targeting the miR-192-5p/Rictor axis is a promising approach for mitigating gut inflammatory injury and improving barrier integrity in enteritis patients.

Interfacial Crosslinking for Efficient and Stable Planar TiO2 Perovskite Solar Cells.

The buried interface between the electron transport layer (ETL) and the perovskite layer plays a crucial role in enhancing the power conversion efficiency (PCE) and stability of n-i-p type perovskite solar cells (PSCs). In this study, the interface between the chemical bath deposited (CBD) titanium oxide (TiO2) ETL and the perovskite layer using multi-functional potassium trifluoromethyl sulfonate (SK) is modified. Structural and elemental analyses reveal that the trifluoromethyl sulfonate serves as a crosslinker between the TiO2 and the perovskite layer, thus improving the adhesion of the perovskite to the TiO2 ETL through strong bonding of the ─CF3 and ─SO3 - terminal groups. Furthermore, the multi-functional modifiers reduced interface defects and suppressed carrier recombination in the PSCs. Consequently, devices with a champion PCE of 25.22% and a fill factor (FF) close to 85% is achieved, marking the highest PCE and FF observed for PSCs based on CBD TiO2. The unencapsulated device maintained 81.3% of its initial PCE after operating for 1000 h.

Allogeneic CD19-targeted CAR-T therapy in patients with severe myositis and systemic sclerosis.

Allogeneic chimeric antigen receptor (CAR)-T cells hold great promise for expanding the accessibility of CAR-T therapy, whereas the risks of allograft rejection have hampered its application. Here, we genetically engineered healthy-donor-derived, CD19-targeting CAR-T cells using CRISPR-Cas9 to address the issue of immune rejection and treated one patient with refractory immune-mediated necrotizing myopathy and two patients with diffuse cutaneous systemic sclerosis with these cells. This study was registered at ClinicalTrials.gov (NCT05859997). The infused cells persisted for over 3 months, achieving complete B cell depletion within 2 weeks of treatment. During the 6-month follow-up, we observed deep remission without cytokine release syndrome or other serious adverse events in all three patients, primarily shown by the significant improvement in the clinical response index scores for the two diseases, respectively, and supported by the observations of reversal of inflammation and fibrosis. Our results demonstrate the high safety and promising immune modulatory effect of the off-the-shelf CAR-T cells in treating severe refractory autoimmune diseases.

Vascular endothelial cells of Mongolian gerbils are resistant to cholesterol-induced mitochondrial dysfunction and oxidative damage.

Atherosclerosis is essentially the leading factor behind occurrences of cardiovascular diseases (CVDs)-associated incidents, while mitochondrial dysfunction is also the main cause of atherosclerosis. The present study conducted a comparative analysis of mitochondrial function-related indicators in cholesterol-induced vascular endothelial cells (VECs) from Mongolian gerbils, Sprague-Dawley (SD) rats and humans. It reported that the inhibitory effect of cholesterol treatment on the viability of Mongolian gerbil VECs was markedly lower than the other two types of VECs at the same concentration. Following cholesterol treatment, mitochondrial DNA copy numbers, reactive oxygen species level, calcium concentration and mitochondrial membrane potential of Mongolian gerbil VECs did not change markedly. These results suggested that the function of mitochondria in the VECs of Mongolian gerbil is normal. Additionally, cholesterol treatment also did not alter the levels of superoxide dismutase, glutathione peroxidase, ATP, NADH-CoQ reductase and cytochrome c oxidase in Mongolian gerbil VECs. It was hypothesized that the VECs of Mongolian gerbils have certain resistance to oxidative damage induced by cholesterol. In brief, the present study demonstrated that VECs of Mongolian gerbils are resistant to cholesterol-induced mitochondrial dysfunction and oxidative damage. The aforementioned findings establish a theoretical foundation for the advancement of innovative strategies in the prevention and treatment of atherosclerosis.

Rehmmannia glutinosa polysaccharide exerts antiviral activity against pseudorabies virus and antioxidant activity.

Pseudorabies virus (PRV) is an important pathogen harming the global pig industry. Vaccines available for swine cannot protect against PRV completely. Furthermore, no antiviral drugs are available to treat PRV infections. Rehmmannia glutinosa polysaccharide (RGP) possesses several medicinal properties. However, its antiviral activity is not reported. In the present study, we found that RGP can inhibit PRV/XJ5 infection by western blotting, immunofluorescent assay (IFA), and TCID50 assay quantitative polymerase chain reaction (qPCR). We revealed RGP can inhibit virus adsorption and invasion into PK-15 cells in a dose-dependent manner via western blotting, IFA, TCID50 assay, and quantitative polymerase chain reaction (qPCR), and suppressed PRV/XJ5 replication through western blotting, and qPCR. Additionally, it also reduced PRV/XJ5-induced ROS, lipid oxidation, and improved SOD levels in PK-15 cells, which was observed by using corresponding test kits. To conclude, our findings suggest that RGP might be a novel therapeutic agent for preventing and controlling PRV infection and antioxidant agent.

Tea saponin co-ball milled commercial micro zero-valent iron for boosting Cr(VI) removal.

Tea saponins (TS), a natural biosurfactant extracted from tea trees, were co-ball milled with commercial micro zero-valent iron (mZVI) to produce TS modified mZVI (TS-BZVI) for efficient hexavalent chromium (Cr(VI)) removal. The findings demonstrated that TS-BZVI could nearly remove 100% of Cr(VI) within 2 h, which was 1.43 times higher than that by ball milled mZVI (BZVI) (70%). Kinetics analysis demonstrated a high degree of compatibility with the pseudo-second-order (PSO), revealing that TS-BZVI exhibited a 2.83 times faster Cr(VI) removal rate involved primarily chemisorption. Further, X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure (XANES) measurements indicated that the TS co-ball milling process improved the exposure of Fe(II) and Fe(0) on mZVI, which further promoted the Cr(VI) reduction process. Impressively, the introduction of TS increased the hydrophobicity of ZVI, effectively inhibiting the H2 evolution by 95%, thus improved electron selectivity for efficient Cr(VI) removal. Ultimately, after operating for 10 days, a simulated permeable reactive barrier (PRB) column experiment revealed that TS-BZVI had a higher Cr(VI) elimination efficiency than BZVI, indicating that TS-BZVI was promising for practical environment remediation.

New insights into the milk quality at varying altitudes in China.

Introducing Holstein cows on Qinghai-Tibetan Plateau is a potential solution to enhance local milk production. However, the relationship between milk quality and altitude in China remains unknown. Therefore, the components and plasmin (PL) system of raw milk from different altitudes (sea level, 1600, 2700, and 3800 m) were investigated. The daily milk production of Holstein cows and PL activity decreased as the altitude increased. However, the components content of raw milk, plasminogen (PLG)/PL ratio, activities of PLG and plasmin activator (PA) increased with altitude. The pasteurization resulted a significant decrease in PA activity of all milk and a significant increase in PL activity in milk collected at higher altitudes (2700 and 3800 m), suggesting the pasteurization was unsuitable for preserving milk at higher altitudes. This study offered references for the production and storage of milk after introducing Holstein cows on Qinghai-Tibetan Plateau.

KIAA1429 regulates lung adenocarcinoma proliferation and metastasis through the PI3K/AKT pathway by modulating ARHGAP30 expression.

BACKGROUND: Alterations in epigenetic factors are recognized as key contributors to the emergence of human cancer. The active and reversible alteration of N6-methyladenosine (m6A) RNA is crucial for controlling gene activity and determining cellular destiny. Even with these insights, the triggering of KIAA1429 (also called VIRMA) and its role in lung adenocarcinoma (LUAD) is mostly unclear. As a result, the objective of this study was to elucidate how KIAA1429 contributes to cancer development in LUAD. METHODS: This study utilized multiple methods for investigation, encompassing the in vitro functional examination of KIAA1429 in lung adenocarcinoma cells, transcriptome sequencing, methylation RNA immunoprecipitation sequencing (MeRIP-seq), as well as RNA stability tests to ascertain the half-life and stability of the target genes. RESULTS: The results indicated that modifying the expression of KIAA1429 regulated the proliferation and metastasis of LUAD. By employing transcriptome sequencing alongside MeRIP-seq analysis, the research pinpointed genes affected by m6A alterations triggered by KIAA1429. In a more detailed manner, it was discovered that KIAA1429 plays a regulatory role in the expression of ARHGAP30. Suppressing KIAA1429 results in reduced m6A levels in the mRNA of the target gene ARHGAP30, boosting its stability and expression, thus inhibiting tumor proliferation and metastasis. CONCLUSION: This study revealed the activation mechanism and pivotal function of KIAA1429 in LUAD tumor development, paving the way for molecular-based interventions for LUAD.

Guild-level signature of gut microbiome for diabetic kidney disease.

Current microbiome signatures for chronic diseases such as diabetic kidney disease (DKD) are mainly based on low-resolution taxa such as genus or phyla and are often inconsistent among studies. In microbial ecosystems, bacterial functions are strain specific, and taxonomically different bacteria tend to form co-abundance functional groups called guilds. Here, we identified guild-level signatures for DKD by performing in-depth metagenomic sequencing and conducting genome-centric and guild-based analysis on fecal samples from 116 DKD patients and 91 healthy subjects. Redundancy analysis on 1,543 high-quality metagenome-assembled genomes (HQMAGs) identified 54 HQMAGs that were differentially distributed among the young healthy control group, elderly healthy control group, early-stage DKD patients (EDG), and late-stage DKD patients (LDG). Co-abundance network analysis classified the 54 HQMAGs into two guilds. Compared to guild 2, guild 1 contained more short-chain fatty acid biosynthesis genes and fewer genes encoding uremic toxin indole biosynthesis, antibiotic resistance, and virulence factors. Guild indices, derived from the total abundance of guild members and their diversity, delineated DKD patients from healthy subjects and between different severities of DKD. Age-adjusted partial Spearman correlation analysis showed that the guild indices were correlated with DKD disease progression and with risk indicators of poor prognosis. We further validated that the random forest classification model established with the 54 HQMAGs was also applicable for classifying patients with end-stage renal disease and healthy subjects in an independent data set. Therefore, this genome-level, guild-based microbial analysis strategy may identify DKD patients with different severity at an earlier stage to guide clinical interventions. IMPORTANCE: Traditionally, microbiome research has been constrained by the reliance on taxonomic classifications that may not reflect the functional dynamics or the ecological interactions within microbial communities. By transcending these limitations with a genome-centric and guild-based analysis, our study sheds light on the intricate and specific interactions between microbial strains and diabetic kidney disease (DKD). We have unveiled two distinct microbial guilds with opposite influences on host health, which may redefine our understanding of microbial contributions to disease progression. The implications of our findings extend beyond mere association, providing potential pathways for intervention and opening new avenues for patient stratification in clinical settings. This work paves the way for a paradigm shift in microbiome research in DKD and potentially other chronic kidney diseases, from a focus on taxonomy to a more nuanced view of microbial ecology and function that is more closely aligned with clinical outcomes.

How is work-family conflict linked to nurse-assessed patient safety among intensive care unit nurses? A serial multiple mediation analysis.

AIM: The aim of this study was to test whether rumination and negative affectivity mediate the relationship between work-family conflict and nurse-assessed patient safety among intensive care unit nurses. BACKGROUND: Most intensive care unit nurses experience work-family conflicts that jeopardise patient safety. Although prior studies have explored the effect of work-family conflict on patient safety, few have investigated whether work-family conflict is associated with patient safety through rumination and negative affectivity among intensive care unit nurses. DESIGN: Cross-sectional study. METHODS: This study included 209 intensive care unit nurses from five general hospitals. The Work-Family Conflict Scale, the Ruminative Response Scale, the Positive and Negative Affect Schedule-Negative Affectivity, and three items indicating nurses' perception of overall patient safety were used to gather data. Associations between work-family conflict, rumination, negative affectivity, and nurse-assessed patient safety were assessed using correlation and serial multiple mediation analysis. RESULTS: Work-family conflict, rumination, negative affectivity, and nurse-assessed patient safety were significantly correlated (p < 0.01). Work-family conflict can have not only a direct negative impact on the nurse-assessed patient safety (effect = -0.0234; standard error [SE] = 0.0116; 95% confidence interval [CI]: lower limit [LL] = -0.0464, upper limit [UL] = -0.0005) but also an indirect impact on nurse-assessed patient safety through three paths: the independent mediating role of rumination (effect = -0.0118; SE = 0.0063; 95% CI: LL = -0.0251, UL = -0.0006), the independent mediating role of negative affectivity (effect = -0.0055; SE = 0.0039; 95% CI: LL = -0.0153, UL = -0.0001), and the chain-mediating role of rumination and negative affectivity (effect = -0.0078; SE = 0.0031; 95% CI: LL = -0.0152, UL = -0.0027). CONCLUSION: Our findings indicated that work-family conflict could influence nurse-assessed patient safety through increasing rumination and negative affectivity among intensive care unit nurses. Based on the results, interventions aimed at decreasing work-family conflict would be beneficial for intensive care unit nurses' emotional stability and patient safety.

Minimal residual disease profiling predicts pathological complete response in esophageal squamous cell carcinoma.

Accurate presurgical prediction of pathological complete response (pCR) can guide treatment decisions, potentially avoiding unnecessary surgeries and improving the quality of life for cancer patients. We developed a minimal residual disease (MRD) profiling approach with enhanced sensitivity and specificity for detecting minimal tumor DNA from cell-free DNA (cfDNA). The approach was validated in two independent esophageal squamous cell carcinoma (ESCC) cohorts. In a cohort undergoing neoadjuvant, surgical, and adjuvant therapy (NAT cohort), presurgical MRD status precisely predicted pCR. All MRD-negative cases (10/10) were confirmed as pCR by pathological evaluation on the resected tissues. In contrast, MRD-positive cases included all the 27 non-pCR cases and only one pCR case (10/10 vs 1/28, P < 0.0001, Fisher's exact test). In a definitive radiotherapy cohort (dRT cohort), post-dRT MRD status was closely correlated with patient prognosis. All MRD-negative patients (25/25) remained progression-free during the follow-up period, while 23 of the 26 MRD-positive patients experienced disease progression (25/25 vs 3/26, P < 0.0001, Fisher's exact test; progression-free survival, P < 0.0001, log-rank test). The MRD profiling approach effectively predicted the ESCC patients who would achieve pCR with surgery and those likely to remain progression-free without surgery. This suggests that the cancer cells in these MRD-negative patients have been effectively eliminated and they could be suitable candidates for a watch-and-wait strategy, potentially avoiding unnecessary surgery.

New Insights into the Genetic Basis of Lysine Accumulation in Rice Revealed by Multi-Model GWAS.

Lysine is an essential amino acid that cannot be synthesized in humans. Rice is a global staple food for humans but has a rather low lysine content. Identification of the quantitative trait nucleotides (QTNs) and genes underlying lysine content is crucial to increase lysine accumulation. In this study, five grain and three leaf lysine content datasets and 4,630,367 single nucleotide polymorphisms (SNPs) of 387 rice accessions were used to perform a genome-wide association study (GWAS) by ten statistical models. A total of 248 and 71 common QTNs associated with grain/leaf lysine content were identified. The accuracy of genomic selection/prediction RR-BLUP models was up to 0.85, and the significant correlation between the number of favorable alleles per accession and lysine content was up to 0.71, which validated the reliability and additive effects of these QTNs. Several key genes were uncovered for fine-tuning lysine accumulation. Additionally, 20 and 30 QTN-by-environment interactions (QEIs) were detected in grains/leaves. The QEI-sf0111954416 candidate gene LOC_Os01g21380 putatively accounted for gene-by-environment interaction was identified in grains. These findings suggested the application of multi-model GWAS facilitates a better understanding of lysine accumulation in rice. The identified QTNs and genes hold the potential for lysine-rich rice with a normal phenotype.

Research on prediction of PPV in open-pit mine used RUN-XGBoost model.

The drill-blasting method is a commonly used mining technique in open-pit mines, and the peak particle velocity (PPV) caused by blasting vibrations is an important indicator for evaluating the rationality of blasting mining design parameters. To develop an effective PPV prediction model, a parameter self-optimizing RUN-XGBoost prediction model is implemented using the Runge-Kutta optimization algorithm (RUN) combined with extreme gradient boosting (XGBoost). The factors affecting the prediction of PPV, including maximum explosive (ME), total explosive (TE), blast center distance (BCD), blast hole depth (BHD), and height difference between the measurement location and the blast location (DH), are selected as the influencing indicators. 188 pieces of blasting operation data were measured at the RK open pit copper-cobalt mine. Then, the RUN-XGBoost prediction model for PPV is studied and compared with the Sadovsky empirical formula, traditional XGBoost model, PSO-XGBoost model, and some traditional machine learning models (Ridge, LASSO, SVM, and SVR) using R2, RMSE, VAF, MAE, and MBE as evaluation indicators for model prediction results. Finally, the Shapley Additive Explanations (SHAP) method is used to evaluate the contribution of different influencing indicators to the PPV prediction results. The results show that the RUN-XGBoost prediction model is significantly better than other machine learning models and the Sadovsky empirical formula in the prediction of PPV, further demonstrating that the RUN-XGBoost prediction model can handle the nonlinear features of multiple factors and provide a reliable, simple, and effective PPV prediction model, forming a rapid prediction and evaluation method for blasting vibrations in open-pit mining.

HLA-A+ tertiary lymphoid structures with reactivated tumor infiltrating lymphocytes are associated with a positive immunotherapy response in esophageal squamous cell carcinoma.

BACKGROUND: Immune checkpoint blockade (ICB) therapy provides remarkable clinical benefits for multiple cancer types. However, the overall response rate to ICB therapy remains low in esophageal squamous cell carcinoma (ESCC). This study aimed to identify biomarkers of ICB therapy for ESCC and interrogate its potential clinical relevance. METHODS: We investigated gene expression in 42 treatment-naïve ESCC tumor tissues and identified differentially expressed genes, tumor-infiltrating lymphocytes and immune-related genes signatures associated with differential immunotherapy responses. We systematically assessed the tumor microenvironment using the NanoString GeoMx digital spatial profiler, single-cell RNA-seq and multiplex immunohistochemistry in ESCC. Finally, we evaluated the associations between HLA-A-positive tertiary lymphoid structures (TLSs) and patients' responses to ICB in 60 ESCC patients. RESULTS: Tumor infiltrating B lymphocytes and several immune-related gene signatures, such as the antigen presenting machinery (APM) signature, are significantly elevated in ICB treatment responders. Multiplex immunohistochemistry identified the presence of HLA-A+ TLSs and showed that TLS-resident cells increasingly express HLA-A as TLSs mature. Most TLS-resident HLA-A+ cells are tumor-infiltrating T (TIL-T) or tumor-infiltrating B (TIL-B) lymphocytes. Digital spatial profiling of spatially distinct TIL-T lymphocytes and single-cell RNA-seq data from 60 ESCC tumor tissues revealed that CXCL13-expressing exhausted TIL-Ts inside TLSs are reactivated with elevated expression of the APM signature as TLSs mature. Finally, we demonstrated that HLA-A+ TLSs and their major cellular components, TIL-Ts and TIL-Bs, are associated with a clinical benefit from ICB treatment for ESCC. CONCLUSIONS: HLA-A+ TLSs are present in ESCC tumor tissues. TLS-resident TIL-Ts with elevated expression of the APM signature may be reactivated. HLA-A+ TLSs and their major cellular components, TIL-Ts and TIL-Bs, may serve as biomarkers for ICB-treated ESCC patients.

Improving tumor sensitivity by the introduction of an ester chain to triaryl derivatives targeting PD-1/PD-L1.

PD-1/PD-L1 pathway blockade is a promising immunotherapy for the treatment of cancer. In this manuscript, a series of triaryl compounds containing ester chains were designed and synthesized based on the pharmacophore studies of the lead BMS-1. After several SAR iterations, 22 showed the best biochemical activity binding to hPD-L1 with an IC50 of 1.21 nM in HTRF assay, and a KD value of 5.068 nM in SPR analysis. Cell-based experiments showed that 22 effectively promoted A549 cell death by restoring T-cell immune function. 22 showed significant in vivo antitumor activity in a 4T1 mouse model without obvious toxicity, with a TGI rate of 67.8 % (20 mg/kg, ip). Immunohistochemistry data indicated that 22 activates the immune activity in tumors. These results suggest that 22 is a promising compound for further development of PD-1/PD-L1 inhibitor for cancer therapy.

Light and matter co-confined multi-photon lithography.

Mask-free multi-photon lithography enables the fabrication of arbitrary nanostructures low cost and more accessible than conventional lithography. A major challenge for multi-photon lithography is to achieve ultra-high precision and desirable lateral resolution due to the inevitable optical diffraction barrier and proximity effect. Here, we show a strategy, light and matter co-confined multi-photon lithography, to overcome the issues via combining photo-inhibition and chemical quenchers. We deeply explore the quenching mechanism and photoinhibition mechanism for light and matter co-confined multiphoton lithography. Besides, mathematical modeling helps us better understand that the synergy of quencher and photo-inhibition can gain a narrowest distribution of free radicals. By using light and matter co-confined multiphoton lithography, we gain a 30 nm critical dimension and 100 nm lateral resolution, which further decrease the gap with conventional lithography.

Stereoselective Synthesis of ß, γ-Fused Bicyclic γ-Ureasultams via an Intramolecular Mannich and aza-Michael Addition Cascade.

A novel approach has been developed for the synthesis of bicyclic ß, γ-fused bicyclic γ-ureasultams containing two consecutive chiral centers through an intramolecular Mannich and aza-Michael addition cascade of alkenyl sulfamides. The straightforward practical procedure and readily available starting materials enable the synthesis of variously substituted ureasultams. In addition, bicyclic γ-ureasultams is a class of potential biotin analogues.