Chinese Journal of Chemistry最新文献

Real-time on-site monitoring of resorcinol (RS) concentrations is crucial for detecting hazardous levels, enabling prompt response measures to mitigate potential environmental and health risks. In this study, we developed an innovative method using CoNi@CN-2 nanozymes to activate peroxymonosulfate (PMS) for oxidizing 3,3',5,5'-tetramethylbenzidine (TMB). Our results show that the formation of Ni²⁺ through the oxidation of Ni⁰ on the CoNi@CN-2 surface significantly enhances the electron-donating capacity of Co⁰. The catalytic reaction of TMB is mediated by redox active species (SO₄^•−, •O₂⁻, •OH and ¹O₂). RS drives colorimetry by transferring electrons to the benzene ring and specific nitrogen atoms in ox-TMB, reducing ox-TMB to TMB. Furthermore, the colorimetric assay shows a robust linear correlation between RS concentration and absorbance (Abs), described by Abs = –0.44[RS] + 0.886 (0—200 μmol/L, R² = 0.983). Also, we introduce a novel smartphone-integrated autonomous detection software that can analyze RS concentration and grayscale values (GSV), yielding GSV = 0.327[RS] + 63.601 (0—200 μmol/L, R² = 0.990) with a detection limit of 5.29 μmol/L. Additionally, excess PMS leads to ROS attacking specific sites in ox-TMB, forming secondary oxidation products. This study has enabled rapid and accurate detection of RS, making a significant contribution to environmental safety and protection.

Chiral 1,3-substituted fragments are ubiquitous in pharmaceutical molecules and natural products, prompting the development of numerous methods to access these structures. Nonetheless, devising synthetic routes for complex chiral architectures in practical applications typically demands years of expertise. Herein, we developed a nickel-catalyzed enantioselective migratory arylboration reaction of allylboronic esters using a chiral 1,2-diamine ligand, yielding a range of chiral 1,3-bis(boronates) with high enantioselectivity. The protocol is characterized by its use of commercially available substrates, mild reaction conditions, user-friendly procedures, and a broad substrate compatibility. Moreover, we demonstrate the practicality and application potential of this reaction by synthesizing several key drug intermediates.

Herein, we describe a direct route for the synthesis of 3-gem-difluorovinyl lactams through Zn-mediated reductive hydrodehalogenation. Importantly, by using inexpensive deuterium oxide (D₂O), the high value-added vicinal dideuterated gem-difluoroalkenes with excellent deuterium (D) incorporation were prepared. Mechanism studies indicated a successive single electron transfer process: the reaction initially undergoes hydrodechlorination to give the intermediate α-trifluoromethylidene lactams, which are then activated by the in-situ generated zinc cations and reduced to the desired product via hydrodefluorination.

Six new acorane-type sesquiterpenes, named penijanacoranes A—F (1—6), as well as one known eudesmane sesquiterpenoid 1α,6β,11-eudesm-triol (7) have been isolated from a deep-sea-derived fungus Penicillium janthinellum SH0301. Their structures and absolute configurations were established by the comprehensive spectroscopic analysis, TDDFT-ECD calculations, and X-ray diffraction. Penijanacorane A (1) was identified as a rare acorane-type sesquiterpene lactone featuring a novel 6/5/6 tricyclic system, while penijanacoranes E and F (5 and 6) represented undescribed examples of nor-acorane sesquiterpenes at C-1. Penijanacorane C (3) exhibited significant inhibitory activity against LPS-induced NO production in Raw264.7 macrophages with an IC₅₀ value of 6.23 μM, which was more potent than that of positive control dexamethasone (IC₅₀ = 11.49 μM). This study expanded the chemical diversity of acorane-type sesquiterpenoids and revealed that compound 3 was a potential molecule for anti-inflammatory agents.

A tandem Diels–Alder reaction/Claisen rearrangement/decarboxylation strategy of N-allenamides (or aryloxyallenes) with 3-alkoxycarbonyl-2-pyrones has been developed for the efficient synthesis of diarylmethanes with moderate to good yields. The reaction exhibits good functional group tolerance and can be applied to late-stage modifications of known drug molecules. Mechanistic studies indicate that the ester group at the 3-position of 2-pyrones is essential, and the initial Diels–Alder reaction between the 2-pyrones and the proximal C=C bond of the N-allenamides (or aryloxyallenes) is crucial for the success of the reaction.

Conjugate addition and allylic substitution are two essential chemical transformations, and they could be competitive for substrates with multiple reactive sites. Herein, we report the diversified enantioselective synthesis of cyclobutenes via the functionalization of cyclobutenones. The conjugate addition of cyclobutenones with arylzinc halides provided enantioenriched cyclobutenes with all-carbon quaternary centers. On the other hand, when cyclobutenones with gem-dichloro groups were employed, a chemo- and enantioselective allylic substitution occurred. Further synthetic utility was demonstrated for synthesizing versatile cyclobutane derivatives, together with ring-opening and expansion products.

We report the design and development of a β-glucuronidase (β-Glu)-responsive ManNAz derivative, Glu-AAM, for tumor-selective metabolic glycoengineering. Glu-AAM enables specific labeling of tumor cell surface sialoglycans in the presence of overexpressed β-Glu in cancer cells, including breast, leukemia, and colorectal cancer cells. We demonstrate the high selectivity and efficiency of Glu-AAM-mediated metabolic glycoengineering across multiple cancer cell lines. Furthermore, we synthesized multivalent antibody-recruiting molecules (DBCO-Rha) that can be covalently attached to the azido-modified tumor cell surface, leading to potent antibody-dependent cellular phagocytosis and complement-dependent cytotoxicity. The octameric DBCO-Rha8 construct exhibited the most effective immune response. This integrated strategy of β-Glu-responsive metabolic glycoengineering and antibody-recruiting immunotherapy provides a promising platform for targeted cancer therapies and expands the toolbox of metabolic glycoengineering for cancer immunotherapy.

Photodynamic therapy (PDT) has been attracted a surge of research interest. However, there are several obstacles to limit the efficacy of PDT, such as hypoxic tumor microenvironment (TME), overexpressed glutathione (GSH), inefficient reactive oxygen species (ROS) generation, and so on. Herein, a smart responsive nanosystem was constructed, which was composed of Au₂₅ modified with triphenylphosphine (Au₂₅-TPP), catalase (CAT) and GSH-responsive diselenide-bridged mesoporous silica nanoparticles (Se-MSN). When the nanosystem arrived at tumor site, Se-MSN was degraded by the intracellular overexpressed GSH to release Au₂₅-TPP and CAT. The Au₂₅-TPP was targeted to mitochondria and generated ROS under the 808 nm NIR laser irradiation to kill tumor cells. Simultaneously, CAT could catalyze hydrogen peroxide to provide oxygen for relieving the hypoxia of TME. Besides, GSH was consumed by the diselenide bond to diminish the ROS loss. The above tactics (mitochondria targeting, hypoxia relieving and GSH consuming) jointly enhanced the PDT efficacy. The nanosystem showed distinct in vitro anticancer effect significantly stronger than other groups containing one or two assistance. Moreover, the in vivo results suggested that the tumors could be restrained obviously. The current study provides a new inspiration for constructing novel inorganic nanomedicines with multiple enhancement effect of PDT efficacy.

Traditional protecting groups are often removed under harsh conditions with potentially hazardous reagents, thereby impeding the convenient synthesis of oligosaccharides and glycosides. Herein, we present to utilize the photolabile ortho-nitro-benzyl carbonate (oNBC) as a permanent hydroxyl protecting group for stereocontrolled synthesis of glycosides. The Ph₃PO-modulated glycosylation with strongly disarmed per-O-oNBC-protected glycosyl ynenoates preferred to afford glycosides with excellent α-selectivities via the β-phosphonium transition state. Based on the oNBC-mediated galactosylation, synthesis of the glycolipid digalactosyl diacylglycerol (DGDG) containing six double bonds and two esters was achieved in a straightforward manner.