Latest ArticlesDeoximation is an important transformation in synthetic industry. It can be employed in protection, characterization and purification of the carbonyls, and in the synthesis of ketones from non-carbonyl molecules. In the field, oxidative deoximation reaction can utilize the driving force caused by the oxidation process so that the reaction can occur under relatively mild conditions. Recently, we designed and prepared polyaniline-supported molybdenum (Mo@PANI) just by immersing PANI into the EtOH/H2O solution of MoCl5. The material was successfully applied as the efficient catalyst for oxidative deoximation reactions, which were performed in ethanol using H2O2 as the clean oxidant. The substrate scope of the reaction was wide. It could be applied on heterocycle-containing substrates, making this protocol preferable for pharmaceutical intermediate synthesis. Since Mo is a necessary trace element for both animals and plants, this method is environment-friendly and is suitable for large-scale preparation. This work as the first example of Mo-catalyzed oxidative deoximation reaction may inspire novel ideas for both catalyst design and synthetic process development.
Prostate cancer (PC) biomarker-citrate detection is clinically important to diagnose PC in early stages. Methylquinolinium iodide (Q) conjugated indole-phenylboronic acid (IB) was designed as a red-emissive QIB probe for the detection of citrate through Lewis acid–base reaction and intramolecular charge transfer (ICT) sensing mechanisms. Boronic acid acts as Lewis acid as well as citrate (Lewis base) recognition unit. The probe reacted with citrate, showing enhanced red emissions. Since the probe has excellent water solubility and great biocompatibility, practical application in biological systems is possible. Citrate was monitored precisely in the mitochondria organelle (in vitro) of living cells with a positive charge on QIB. Also, endogenous (in situ) citrate was detected quantitatively to discriminate non-cancerous and PC mice, observed strong and lower (negligible) emission intensity on non-cancerous and cancerous prostate tissues, respectively. Because, the concentration of citrate is higher in healthy prostate compared with PC prostate. Furthermore, the analysis of sliced prostate tissues can give PC-related information for clinical diagnosis to prevent and treat PC in the initial stages. Therefore, we believe that the present probe is a promising biochemical reagent in diagnosing PC.
The unique properties of metal oxide surfaces, crystal surfaces and defects play vital roles in biomass upgrading reactions. In this work, hierarchical porous bowl-shaped ZrO2 (HB-ZrO2) with mixed crystal phase was designed and employed as the support for loading AuPd bimetal with different proportions to synthesize AuPd/HB-ZrO2 catalysts. The effects of surface chemistry, oxygen defects, bimetal interaction and metal-support interaction of AuPd/HB-ZrO2 on catalytic performance for the selective oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) were systematically investigated. The Au2Pd1/HB-ZrO2 catalyst afforded a satisfactory FDCA yield of 99.9% from HMF oxidation using O2 as the oxidant in water, accompanied with an excellent FDCA productivity at 97.6 mmol g−1 h−1. This work offers fresh insights into rationally designing efficient catalysts with oxygen-rich defects for the catalytic upgrading of biomass platform chemicals.
Colorectal cancer causes the third most common type of malignant tumors with high morbidity and mortality. Chemotherapy is currently one of the most effective and common treatments for colorectal cancer. However, the poor water solubility of some chemotherapeutics, untargeted drug delivery, and the undesirable systemic side effects of conventional treatment remain the major issues for colorectal cancer chemotherapy. Fortunately, drug delivery systems (DDS) based on biomaterials have been widely investigated and found to be capable of resolving those issues with good performance. Therefore, the main goal of this review is to summarize and discuss the progress and potential advantages of different DDS for colorectal cancer chemotherapy. We not only reviewed the nanocarriers used to improve the solubility of chemotherapeutics, including liposomes, micelles, and nanoparticles, but also discussed targeted DDS based on specific ligand-receptor recognition and tumor microenvironmental stimulus responses. Furthermore, locally administered systems based on hydrogels and microspheres, which have been shown to increase drug accumulation at the tumor site while decreasing systemic toxicity, were also emphasized. DDS provides a good option for improving the efficacy of chemotherapy in the treatment of colorectal cancer.
Diversity-oriented synthesis is a powerful and interesting synthetic tool for the rapid construction of structurally complex and privileged scaffolds from readily accessible starting materials. To date, diversity-oriented synthesis mostly relies on the employment of versatile reagents. Versatile reagents can be regulated as controllable and flexible building blocks for multipurpose utilizations. Over the past decade, a variety of multifunctional reagents have been developed. However, most versatile reagents usually need multi-step synthesis, thus restricting their wide application to a large extent. In terms of the practicalities and universalities, we prefer to pay more attention to the utilization of simple and practical versatile reagents with multiple reactivities, mainly including atropaldehyde acetals, aryl methyl ketones, vinylene carbonate, vinyl azides, aryldiazonium salts, rongalite, halodifluoromethyl compounds. Most importantly, these versatile reagents can also play different roles simultaneously in the same reaction, in which their different reactivities are converged into the final target products. Such strategy can not only offer more possibilities for the synthesis of several active pharmaceutical ingredients, but also minimize the occurrence of some side reactions by lessening the varieties of materials. Also, a perspective is given at the end of this review.
Stepwise energy transfer is ubiquitous in natural photosynthesis, which greatly promotes the widespread use of solar energy. Herein, we constructed a supramolecular light harvesting system based on sequential energy transfer through the hierarchical self-assembly of M, which contains a cyanostilbene core flanked by two ureidopyrimidinone motifs, endowing itself with both aggregation-induced emission behavior and quadruple hydrogen bonding ability. The monomer M can self-assemble into hydrogen bonded polymers and then form supramolecular polymeric nanoparticles in water through a mini-emulsion process. The nanoparticles were further utilized to encapsulate the relay acceptor ESY and the final acceptor NDI to form a two-step FRET system. Tunable fluorescence including a white-light emission was successfully achieved. Our work not only shows a desirable way for the fabrication of efficient two-step light harvesting systems, but also shows great potential in tunable photoluminescent nanomaterials.
The construction of hydrogels with good mechanical properties and phosphorescent properties is full of challenges. Herein, we report a supramolecular phosphorescent hydrogel with long lifetime, high tensile strength and self-healing property, which can be easily constructed through in-situ thermal-initiated polymerization of isocyanatoethyl acrylate-modified β-cyclodextrin (β-CD-DA) and acrylate-modified adamantane (Ad-DA), acrylic acid (AA), followed by the non-covalent association with carbon dots (CNDs). The lifetime of phosphorescent hydrogel can reach 1261 ms at room temperature, and the quantum yield is 11%. Importantly, through the efficient triplet to singlet Förster resonance energy transfer (TS-FRET), the phosphorescent hydrogel shows the good phosphorescence energy transfer property for organic dyes Rhodamine B and Eosin Y with the delayed fluorescence lifetime up to 730 ms and 585 ms as well as the energy transfer efficiency (ΦET) up to 99.9% and 99.3%, respectively. Moreover, owing to the host-guest interactions between β-CD-DA and Ad-DA, the three-dimensional cross-linked network phosphorescent hydrogel can be easily stretched to 18 times of its original length, and can achieve self-healing of the cut surfaces within 30 min. These results will expand the scope of phosphorescent materials and provide new ideas and opportunities for materials science.
Artificial photocatalytic energy conversion is considered as the most potential strategy for solving the increasingly serious energy crisis and environmental pollution problems by directly capturing solar energy. Therefore, high efficiency photocatalyst has drawn significant research attention in recent years. Due to the excellent electronic, optical, structural, and physicochemical performances, silver-based g-C3N4 have become promising photocatalysts. This review emphasizes the recent progresses and challenges on g-C3N4 decorated with silver for photocatalytic energy conversion. The extensive use of g-C3N4 decorated with silver in diverse photocatalytic reactions, including hydrogen evolution, pollutant degradation and carbon dioxide reduction, is also fully introduced. In addition, we propose the perspectives of g-C3N4 decorated with silver on photocatalytic applications. We hope that this review will shed some light on the photocatalytic energy conversion of g-C3N4 decorated with silver.
Accurate and sensitive strategies for Concanavalin A (Con A) sensing are conducive to the better cognition of various important biological and physiological processes. Here, by designing dextran-functionalized fluorescent microspheres (DxFMs) and boric acid-modified carbon dots (BCDs) as recognition unit and built-in signal reference respectively, a ratiometric fluorescent detection platform was proposed for Con A detection with high reliability. In this protocol, the BCDs/DxFMs precipitation was formed due to the covalent interactions between cis-diol of DxFMs and boronic acid groups of BCDs, thus only fluorescence of BCDs could be detected in the supernatant. When Con A was presented, it could bind to DxFMs through its carbohydrate recognition ability and suppress the subsequent assembly between DxFMs and BCDs, leading to the simultaneous capture of DxFMs and BCDs fluorescence in the supernatant. Since the BCDs content was superfluous, their fluorescence intensities were basically constant in all cases. Based on the unchanged BCDs fluorescence signal and target-dependent DxFMs fluorescence signal in supernatant, the ratiometric detection of Con A was realized. Under optimized conditions, this ratiometric fluorescent platform displayed a linear detection range from 0.125 µg/mL to 12.5 µg/mL with a detection limit of 0.089 µg/mL. Moreover, satisfied analytical outcomes for Con A detection in serum samples were obtained, manifesting huge application potential of this ratiometric fluorescent platform in clinical diagnosis.
Exosomes are membrane-bound nanoscale extracellular vesicles, which produced by almost all organisms. Due to the excellent biocompatibility, long circulation time as well as low immunogenicity, exosomes as naturally-derived drug delivery carriers have experienced explosive growth over the past decades. However, issues such as insufficient loading efficiency, heterogeneous delivery efficiency, uncontrollable targeting ability, and low production limit their wide application. Recently, the emerging exosome–liposome fusion strategy has become a potential approach to solve such issues. Thus, this review mainly focuses on the currently developed exosome–liposome fusion strategy and their application in drug delivery as well as disease treatment. This review aims to shed light on the advantages of fusion strategy in drug delivery and provides a better understanding for more rational design. The current challenge and future perspective regarding their clinical translation and application will also be discussed.