Latest ArticlesConverting CO2 into methanol (CH3OH), a high-value-added liquid-phase product, through efficient and highly selective photocatalysis remains a significant challenge. Herein, we present a straightforward cation exchange strategy for the in-situ growth of BiVO4 on an InVO4 substrate to generate a Z-scheme heterojunction of InVO4/BiVO4. This in-situ partial transformation approach endows the InVO4/BiVO4 heterojunction with a tightly connected interface, resulting in a significant improvement in charge separation efficiency between InVO4 and BiVO4. Moreover, the construction of the heterojunction reduces the formation energy barrier of the *COOH intermediate during the photoreduction of CO2 and increases the desorption energy barrier of the *CO intermediate, facilitating the deep reduction of *CO. Consequently, the InVO4/BiVO4 heterojunction is capable of photocatalytic CO2 reduction to CH3OH with high efficiency and selectivity. Under conditions where water serves as the electron source and a light intensity of 100 mW/cm2, the yield of CH3OH reaches 130.5 µmol g−1 h−1 with a selectivity of 92 %, outperforming photocatalysts reported under similar conditions.
Many labdane-related diterpenoids (LRDs) exhibit high values in drug development. Their diversity in structure and bioactivity, to a large extent, arise from oxidative modifications which are mainly catalyzed by cytochrome P450s (CYPs). The medicinal plant Euphorbia fischeriana Steud. is rich in LRDs with distinct scaffolds. Herein, we characterized three cytochrome P450s involved in LRD biosynthesis from this plant. Notably, CYP71D450 and CYP701A148 are two substrate-promiscuity CYPs. The former is the first example of CYPs which can oxidize C-3 of ent–atisane skeleton and ent–isopimara-7(8),15-diene, and the latter is the first example of CYPs which can oxidize C-19 of ent–abietane and ent–pimarane skeletons. This study expands the toolkit for bioproduction of diverse LRDs.
Owing to their intricate molecular frameworks and copious chiral centers, the structural identification and configurational assignment of natural products are challenging tasks. Comprehensive spectral data analysis is crucial for the confirmation of absolute configurations. Ignoring critical parameters will lead to false structure, which may confuse the total synthesis and drug development. Herein, the configurations of seven heterogeneous Pallavicinia diterpenoids (PDs) isolated from Pallavicinia liverworts are revised using a combination of single-crystal X-ray diffraction and electronic circular dichroism (ECD) calculations. Meanwhile, identification of five unprecedented PD heterodimers PD-dimers A–E (18–22) along with eleven previously undescribed PDs (5–9, 13–17, 23) obtained by the reinvestigation of the Chinese liverwort Pallavicinia subciliata have resulted in corrections and support the revised conclusions.
Overproduction of reactive oxygen species (ROS) following ischemic injury triggers an inflammatory response, significantly impeding neurological functional recovery. Nanozymes with potent antioxidative and anti-inflammatory effects thus offer great potential for ischemic stroke treatment. In this study, we developed an ischemia-homing nanozyme by combining melatonin (MT)-loaded honeycomb manganese dioxide (MnO2) nanoflowers with M2-type microglia membranes to rescue the ischemic penumbra. The surface-engineered M2-type microglia membranes provided intrinsic ischemia-homing and blood-brain barrier (BBB)-crossing properties to the biomimetic nanozymes. This nanozyme can not only transforms harmfulsuperoxide anion radicals (•O2–) and hydrogen peroxide (H2O2) into harmless water and oxygen but also scavenges highly toxic hydroxyl radicals (•OH), dramatically lowering intracellular ROS levels. More importantly, the biomimetic nanoparticles reduce cerebral infarct areas and provide significant neuroprotection against ischemic stroke by lowering oxidative stress, inhibiting cell apoptosis, and decreasing inflammation. This study may offer a viable approach for the use of nanozymes in treating ischemic stroke.
Metal ion homeostasis plays a pivotal role in maintaining cellular functions, and its disruption can initiate regulated cell death pathways. Despite its therapeutic potential, metal ion therapy for breast cancer has been hampered by inefficient ion delivery and the intrinsic resistance mechanisms of cancer cells. In this work, a cuproptosis amplifier of copper-telaglenastat coordinate (denoted as Cu-CB) is developed to trigger cell ferroptosis for synergistic breast cancer treatment. Telaglenastat (CB-839), a glutaminase inhibitor, is identified as an effective copper ionophore that facilitates the formation of Cu-CB. Specially, Cu-CB can promote the aggregation of lipoylated proteins to initiate cuproptosis, while also inhibiting glutathione (GSH) synthesis and downregulating glutathione peroxidase 4 (GPX4) to trigger ferroptosis. The interplay between these cuproptosis and apoptosis pathways, mediated by Cu-CB, significantly amplifies reactive oxygen species (ROS) production and lipid peroxidation, culminating in the synergistic suppression of breast cancer. Both in vitro and in vivo studies validate the superior antitumor effects of Cu-CB through the induction of cuproptosis and ferroptosis, which may provide a new insight for metal ion delivery systems and metal ion-based tumor therapies.
Alzheimer’s disease (AD) is a common neurodegenerative disorder among the elderly population. There are currently no effective therapeutic drugs available, the multi-target-directed ligands (MTDLs) strategy has been considered as the promising approach. Given the structural diversity of natural products, Rivastigmine’s pharmacophore was integrated with diverse natural product scaffolds to construct a combinatorial compound library. This library was subsequently screened and optimized to identify a novel butyrylcholinesterase (BuChE) inhibitor, compound 3c. The results showed that compound 3c exhibited favorable BuChE inhibitory activity (half-maximal inhibitory concentration (IC50) = 0.43 µmol/L), potential anti-inflammatory potency, good Aβ1–42 aggregation inhibitory capacity and remarkable neuroprotective effects. The in vivo study exhibited that 3c significantly ameliorated AlCl3-induced zebrafish AD model and scopolamine-induced memory impairment. Collectively, compound 3c was the artificial intelligence (AI)-driven promising multifunctional agent with BuChE inhibition for the treatment of AD.
The study of target proteins is crucial for understanding molecular interactions and developing analytical platforms, therapeutic agents and functional tools. Herein, we present a novel nanoplatform activated by near-infrared (NIR) light for triple-modal proteins study, which enabling target protein labeling, enrichment and visualization. Azido-naphthalimide-coated upconversion nanoparticles (UCNPs) serve as NIR light-responsive nanoplatforms, showing promising applications in studying interactions between various bioactive molecules and proteins in living systems. Under NIR light irradiation, azido-naphthalimides are activated by ultraviolet (UV) and blue light emitted from UCNPs and the resulting amino-naphthalimides intermediate not only crosslink nearby target proteins but also enable imaging performance. We demonstrate that this nanoplatform is capable of selective protein labeling and imaging in complex protein environments, achieving specific labeling and imaging of both intracellular and extracellular proteins in mammalian cells as well as bacteria. Furthermore, in vivo protein labeling has been achieved using this novel NIR light-activatable nanoplatform. This technique will open new avenues for discoveries and mechanistic interrogation in chemical biology.
Detecting biomarkers in body fluids by optical lateral flow immune assay (LFIA) technology provides rapid access to disease information for early diagnosis. LFIA is based on an antigen-antibody reaction and is rapidly becoming the preferred choice of physicians and patients for point-of-care testing due to its simplicity, cost-effectiveness, and rapid detection. Observing the optical signal change from the colloidal gold of the traditional LFIA strip has been widely applied for various biomarkers detection in body fluids. Despite the significant progress, rapid real-time detection of color changes in the colloidal gold by the naked eye still faces many limitations, such as large errors and the inability to quantify and accurately detect. New optical LFIA strip technology has emerged in recent years to extend its application scenarios for achieving quantitative detection such as fluorescence, afterglow, and chemiluminescence. Herein, we summarized the development of optical LFIA technology from single to hyphenated optical signals for biomarkers detection in body fluids from invasive and non-invasive sources. Moreover, the challenge and outlook of optical LFIA strip technology are highlighted to inspire the designing of next-generation diagnostic platforms.
The field of nanomedicine has been revolutionized by the concept of immunogenic cell death (ICD)-enhanced cancer therapy, which holds immense promise for the efficient treatment of cancer. However, precise delivery of ICD inducer is severely hindered by complex biological barriers. How to design and build intelligent nanoplatform for adaptive and dynamic cancer therapy remains a big challenge. Herein, this article presents the design and preparation of CD44-targeting and ZIF-8 gated gold nanocage (Au@ZH) for programmed delivery of the 1,2-diaminocyclohexane-Pt(Ⅱ) (DACHPt) as ICD inducer. After actively targeting the CD44 on the surface of 4T1 tumor cell, this Pt-Au@ZH can be effectively endocytosed by the 4T1 cell and release the DACHPt in tumor acidic environment, resulting in ICD effect and superior antitumor efficacy both in vitro and in vivo in the presence of mild 808 nm laser irradiation. By integration of internal and external stimuli intelligently, this programmed nanoplatform is poised to become a cornerstone in the pursuit of effective and targeted cancer therapy in the foreseeable future.
Fluorescent probes based on intramolecular charge transfer (ICT) have obvious advantages for accurate quantitative analysis. To obtain high-performance ratiometric probes requires distinct photophysical properties during recognition reaction process, which is closely related to their ICT characteristics. 1,8-Naphthalimide is known as a typical fluorophore with desirable ICT property when functionalized with an electron-donating moiety at the para-position of the naphthalene chromophore. Although the photophysical properties of para-substituted 1,8-naphthalimide have been well studied, its meta-substituted counterpart has not been fully evaluated since the meta-position is conventionally thought to be weakly conjugated. Herein, combined experimental and theoretical studies are performed which consistently indicate that stronger charge transfer (CT) is exhibited by the meta-amino substituted 1,8-naphthalimide (m-NH2) compared to the para-amino substituted one (p-NH2). The ratiometric response of fluorescence with significant changes in wavelength and intensity upon acetylation (m-NAc and p-NAc) can be attributed to the larger ICT and stronger -NH2 vibrations. This observation is further demonstrated by deuterium oxide experiments, viscosity experiments and quantum chemical calculations. The practical application of meta-amino-1,8-naphthalimide ICT-based probes is also confirmed. This research is expected to bring an in-depth understanding of π-conjugated systems with ICT characteristics, and facilitates the design of sensitive ICT fluorescent probes with meta-amino substitution.