We report a trifluoromethyl-labeled copper(I) complex probe that, in combination with 19F NMR spectroscopy, enables rapid and specific detection of alkene and alkyne compounds. The probe operates based on dynamic coordination interactions between the Cu(I) center and unsaturated hydrocarbons, converting recognition events into distinct 19F NMR signal changes, thereby allowing separation-free analysis without requiring complex sample pretreatment. Experimental results demonstrate that the probe can effectively discriminate between terminal and disubstituted alkynes, distinguish structurally similar compounds and regioisomers, and simultaneously identify multiple alkene and alkyne components in mixed samples, showing good anti-interference capability and potential for multiplexed analysis. This method offers a simple, sensitive, and reliable new strategy for the rapid identification and structural analysis of unsaturated compounds in complex matrices.

Construction of a heterojunction to promote exciton dissociation is widely pursued in photocatalyst design, and the interfacial area is one of the critical factors that must be considered. To date, covalent organic framework (COF) photocatalytic heterojunctions mainly rely on their crystal outer surface as an interface, while overlooking the extensive surface area provided by internal pore walls. Here, we report a COF pore wall-based heterojunction design achieved by in situ confinement of linear conjugated polymers (LCPs) within COF pores via concurrent growth in copolymerization of a four-aldehyde-functionalized pyrene monomer, a two-amine-functionalized benzene monomer, and a two-aldehyde-functionalized benzothiadiazole monomer. The optimized COF/LCP hybrid displays enhanced charge carrier generation, lifetime, and transport, resulting in a significant improvement in photocatalytic H2O2 production performance (209%-enhancement vs. COF, 75%-enhancement vs. LCP, and 99%-enhancement vs. COF/LCP physical mixture). The established heterojunction has been proven to efficiently promote electron transfer from COF to LCP, thereby opening new avenues in high-performance photocatalyst design.

S-Adenosyl-l-methionine (SAM)-dependent methyltransferases (MTs) play important roles in many biological processes by catalyzing a methylation reaction. Proteins with a similar MT-fold to enable catalytic abilities rather than methylation were evidenced, but revealing these abilities appears to be a challenge to bioinformatics analysis unless experimental efforts are involved. Based on comprehensive investigations into MitM in the biosynthesis of mitomycins, the clinically important antitumor antibiotics, we report here that this MT catalyzes reactions more than methylation. MitM primarily acts as a C9a-O-MT for methylating the 6/5/5/3-fused aziridinomitosane (AMS) skeleton that is shared by many known mitomycin variables in C9 stereoselectivity and aziridine-N-methylation. Further, this MT can process AMS for C9a-O-methoxy elimination, aziridine hydrolysis/opening, and subsequent C1-O- and C2-N-methylations. Gene inactivation, biochemical characterization, substrate/product cocrystallization, and site-specific mutagenesis rationalized the mechanisms by which the MT-fold of MitM is repurposed to deliver such an extraordinary capability, facilitating the observation of a few new antitumor mitomycins that were not recognized previously in the producing strain. This study attracts attention to uncharacterized MT-fold proteins, which have millions of sequences in databases but remain to be appreciated in catalytic function.

The asymmetric Tsuji-Trost reaction is a basic transformation model in organic synthesis that usually requires the use of special substrates to form terminal or symmetric pi-allyl metal species to avoid resolution issues. The fundamental reason lies in the challenging interconversion deracemization mechanism, which requires the transition metal to function as both the catalyst and nucleophile. This study presents a different mechanistic pathway for efficient allylic deracemization transformations using common unsymmetric internal allyl substrates. By breaking the classical deracemization route, which is restricted to the eta 3-metal center, the proposed 1,3-diene-formation principle enables diverse allyl electrophiles to react with different types of carbon and phosphine nucleophiles with good enantioconvergence efficiency. In addition, the stereoselective migration of the whole allyl unit is established through deracemization, which differs from prior metal walking models that are limited to alkene migration. Convergent synthesis and concise preparations of a couple of natural products highlight the practical value of the method. Mechanistic studies support 1,3-diene formation as the key process for deracemization and that the final allylic substitution is a slow and rate-determining step.

Multiple sclerosis (MS) and neuromyelitis optica (NMO) are distinct autoimmune demyelinating diseases of the central nervous system with overlapping clinical features, complicating early diagnosis. Accurate differentiation is essential to avoid inappropriate treatment and improve outcomes. We conducted a comprehensive proteomic analysis of cerebrospinal fluid (CSF) from MS and NMO patients using both conventional proteomics and a nanoparticle-based low-abundance protein enrichment strategy (LAPE). Deep CSF proteome coverage yielded 3,816 proteins. Proteomic profiling revealed shared and distinct molecular features of MS and NMO. The common downregulation of neuronal adhesion pathways and the activation of immune responses highlight convergent mechanisms of neurodegeneration and inflammation, whereas MS-specific alterations in glycosylation suggest divergent molecular processes. Differential proteomic analysis delineated disease-specific signatures, with MS characterized by enhanced macrophage signaling, chemokine production, and complement activation, while NMO was distinguished by hemostasis-related pathways, Toll-like receptor 4 signaling, and neuroinflammatory responses. LAPE uncovered MS-associated changes in focal adhesion, cognition, and learning, and NMO-associated enrichment of lysosomal and phagocytic processes. Validation in an independent cohort using enzyme-linked immunosorbent assay (ELISA) confirmed CD74 as an MS-specific and CD14 as an NMO-specific biomarker with ROC analyses (AUC 0.75 for CD74; 0.72 for CD14) supporting their robust utility as discriminating biomarkers in clinical practice.