The active ingredients of natural products represent a critical source for innovative drug discovery. However, the poor stereochemical stability and transformation of stereoisomers during storage directly influence therapeutic efficacy and safety. Therefore, the development of new chiral stationary phases (CSPs) with high chiral and structural selectivity is imperative for reliable quality control of natural products. Here, a star phenylalanine cyclodextrin (CD) polymer, Star-Phe-CD, was designed and synthesized. It features a CD parent nucleus, with Phe-derivatized CD as the sidechain monomers. Subsequently, a mixed-mode Sil-Star-Phe-CD CSP was fabricated with Star-Phe-CD as the chiral ligand, which exhibited significant fluorescence enhancement effects and multiple mixed-mode chromatographic retention mechanisms. The Sil-Star-Phe-CD CSP exhibits exceptional shape selectivity and stereoselectivity towards structurally similar analytes, demonstrating outstanding stereoseparation selectivity for analytes with rigid structures or multiple benzene rings with αlansoprazole = 1.90 and αatropine = 1.55, respectively. Coupled with LC-MS analysis, an online approach was established to simultaneously separate two pairs of catechin epimers and monitor their epimerization process. Molecular docking studies revealed the mechanism of chiral recognition, which relies on the cooperative effects of diverse intermolecular interactions, including hydrogen bonding, π-π interactions, and hydrophobic interactions. These interactions are crucial for recognizing structurally similar stereoisomers in complex systems.

Long-chain polyunsaturated fatty acids (LC-PUFAs), including docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and arachidonic acid (ARA), are high-value biomolecules with broad applications in nutrition and pharmaceuticals; however, their concurrent high-level production in Schizochytrium remains constrained by an incomplete understanding of their biosynthetic coordination. By integrating dynamic fatty acid profiling with time-series transcriptomic analysis, three genes-ks, mat, and act-were identified, as they were upregulated during the late-stage of PUFA accumulation. Phylogenetic analysis revealed that MAT is distinct from previously characterized acyltransferase domains embedded within PUFA synthases. Overexpression of mat increased ARA and EPA but reduced DHA, whereas co- expression with ks restored DHA levels. A conventional push-pull metabolic engineering strategy failed to further enhance LC-PUFA production. Chemical modulation further reshaped PUFA accumulation in engineered strains. In the MAT-overexpressing strain, fluridone or gingerol significantly enhanced fatty acid synthesis, with gingerol exhibiting stronger promotion of ARA and EPA, weaker growth inhibition, and restoration of DHA to parental levels. In the CT-MAT-KS strain, fluridone decreased DHA levels but selectively increased ARA and EPA, whereas gingerol moderately increased most fatty acids. Among all conditions tested, MAT overexpression combined with gingerol supplementation yielded the highest ARA and EPA levels, reaching 0.85% and 2.07% of dry cell weight (2.59% and 6.32% of total fatty acids), representing 1.83- and 1.81-fold improvements, respectively, compared with the parental strain. This study provides a targeted engineering strategy for enhancing ARA and EPA production in Schizochytrium and establishes a platform for coordinated biosynthesis of nutritionally important LC-PUFAs.

The single crossover occurring via homologous recombination is a common phenomenon existing among microbes like Escherichia coli, Bacillus subtilis, Vibrio natriegens, Gluconobacter oxydans and most cyanobacteria species, threatening the stability of engineered strains and challenging iterative genetic engineering. Among them, we take the fast-growing cyanobacterium Synechococcus elongatus UTEX 2973 (Syn2973) as a representative study due to its promising roles for CO2 fixation and bioconversion. We established three marker-free platforms to achieve stable genome recombination: (i) T4CROSS, which employs two plasmids and four rounds of single crossover; (ii) TRIPLEARM, which uses a single plasmid containing three homologous arms for three rounds of single crossover; and (iii) CRISPRARM, which integrates CRISPR/Cpf1-mediated genome editing with homologous recombination. As proof of concept, we employed the CRISPRARM platform for a three-step sequential engineering of the sucrose biosynthetic pathway. The final engineered strain produced 7.12 g L-1 of sucrose within 4 days.

Here, we demonstrate that sub-stoichiometric amounts of alkali cations (Na+ and K+) critically govern defect formation during the synthesis of Silicalite-1 (MFI), enabling precise control over framework integrity and surface properties after calcination. Combining systematic synthesis studies with density functional theory (DFT) calculations and high-resolution microscopy, we reveal a defect-healing mechanism in which in situ generated NaOH or KOH species promote Si-O-Si bond rearrangement and enhance the mobility of Si(OH)4 units. This process facilitates the effective healing of T-site vacancies, yielding highly ordered, defect-free MFI frameworks. The resulting Silicalite-1 exhibits markedly enhanced hydrophobicity and superior selectivity in butanol/water separation, underscoring the decisive role of defect control in modulating adsorption and interfacial properties. Importantly, these insights are successfully extended to the synthesis of defect-free TS-1, affording highly hydrophobic Lewis acid catalysts with improved activity and selectivity in the epoxidation of 1-hexene. This environmentally friendly, straightforward, scalable approach offers a versatile pathway to produce defect-free zeolites with precisely tuned physicochemical properties, enabling the development of advanced catalytic and separation materials, especially for applications involving water or polar compounds.

The inherent presence of structurally similar stereoisomers in natural products poses great challenges for chiral quality control in pharmaceutical and botanical industries, particularly in differentiating the pharmacological activity of high-purity enantiomers. Multi-column methods are commonly used to separate multiple pairs of enantiomeric components, serious impact on the separation efficiency. To address this issue, a star hydroxypropyl cyclodextrin polymer (Star-HPCD) mixed-mode ligand with higher selectivity was designed to achieve both chiral recognition and structural selectivity. Sil-Star-HPCD chiral stationary phase (Sil-Star-HPCD CSP) enabled the simultaneous separation of three pairs of quinoline alkaloid stereoisomers during a single chromatographic run with a separation factor (α) greater than 1.5, significantly improving the analytical efficiency. Compared with the linear polymer structures, the supramolecular structure formed by star-shaped polymer significantly reduces the steric hindrance and improves the ligand density, which provides a prerequisite for adequate chiral recognition. Complementary evidence from molecular simulations and chiral NMR revealed multiple interactions at the molecular level for this single-column separation results. This work establishes a new strategy for the preparation of functionalized chiral ligands through structural design, which facilitates efficient stereoisomer analysis and chiral quality control in natural products.

Natural bioactive peptides (NBPs) possess diverse physiological and pharmacological activities but face challenges in separation and detection due to weak ultraviolet absorption, similar structures, and coexisting chiral and achiral components. A new chiral stationary phase (CSP), Sil-Star-multi-CD CSP, was constructed by synthesizing a multi-terminal star cyclodextrin polymer (Star-multi-CD) with a full 2,3,6-derived CD as the parent nucleus. Sil-Star-multi-CD CSP has multiple interaction sites and altered spectral properties of guests, enabling the simultaneous separation and quantification of chiral and achiral physiological indicators, including endogenous peptides and common metabolites in serum. A simplified strategy was established for analyzing structurally similar NBPs in chicken breast. The limits of detection and quantitation of carnosine analogues ranged from 1.50 to 6.88 μg mL-1 and 5.00 to 22.9 μg mL-1, respectively. Achieving highly selective separations and sensitive detection in a single column for complex biological matrices provides a convenient strategy in the analysis of functional NBPs.

UiO-66(Ce) was prepared from cerium metal, which could trigger Fenton-like reactions. A system DOX@UiO-66(Ce)@TA-Fe was constructed by coating a metal polyphenol layer (TA-Fe) on the surface of DOX@UiO-66(Ce), which was loaded with the anticancer drug doxorubicin hydrochloride (DOX). It could produce reactive oxygen species to realize chemodynamic therapy and show stimuli-responsive drug release behaviors to realize chemotherapy. In addition, the system displayed biocompatibility to normal cells (L929 cells) and toxicity to cancer cells (MCF-7 cells), implying an ideal effect for multimodal cancer therapy.

Cyanobacteria offer a direct route for converting solar energy and CO 2 into valuable chemicals, yet the metabolic burden of complex heterologous pathways often limits their productivity and stability. Here, we present a modular co-culture strategy that uses glycerol as an efficient mediator metabolite to link cyanobacterial carbon fixation with downstream bioconversion. We first engineered Synechococcus elongatus UTEX 2973 (Syn2973) for high-level glycerol biosynthesis by optimizing synthase selection, eliminating competing pathways, and improving CO 2 -supply conditions, achieving a production of 14.53 g·L -1 . In parallel, we constructed glycerol conversion modules in Syn2973 and Gluconobacter oxydans enabling production of 1,3-propanediol (1,3-PDO), 3-hydroxypropionic acid, and dihydroxyacetone, with exogenous glycerol yielding up to 30.07 g·L -1 1,3-PDO. Integrating the two modules resulted in a fully autotrophic co-culture that produced all three target chemicals directly from CO 2 , including semi-continuous 1,3-PDO production at 6.02 g·L -1 ·day -1 , corresponding to a net carbon fixation efficiency of 3.43 kg CO 2 eq/kg 1,3-PDO.

With the widespread application of mixed-mode chromatography in separation analysis, it is becoming increasingly important to study its retention mechanism. The retention behavior of acidic compounds on mixed-mode octyl-quaternary ammonium (Sil-C8-QA) columns was investigated by computer simulation. Firstly, the benzoic acid homologues were used as the analytes, and the simulation model was constructed by the Materials Studio. Geometric optimization, annealing and molecular dynamics (MD) simulation of these complexes resulted in optimized conformations. The binding energy, mean square displacement (MSD) and torsion angle distribution generated by MD simulation were then analyzed. The results showed that the more negative binding energy, the greater the MSD and the narrower the torsion angle distribution, indicating that the stationary phase behaves with stronger interaction and retention. The retention behavior of five acidic drugs on the Sil-C8-QA column was then successfully explained by simulation. Acidic drugs are more retentive on the mixed-mode column due to the more substantial interaction brought by the reversed-phase/ion-exchange mixed-mode mechanism compared to other single-mode columns. This simulation method is expected to provide ideas for studying the separation mechanism and predicting the retention behavior of more complex samples.

Background As the derivatives of cyclodextrin (CD), cyclodextrin polymers (CDPs) effectively increase the concentration of CD units and construct supramolecular structures with unique stereoselectivity by the structure design. CDPs have shown significant potential in chiral separation, however, the process of stereoselective interactions on chiral stationary phases (CSPs) and the specific contribution of intermolecular forces are still a challenge issue. A comprehensive understanding of the chiral recognition mechanism of CDPs will help to optimize chiral separation conditions and design new CSPs. Results The star CDP with a supermolecular structure was synthesized by grafting β-CD onto the external 6-position hydroxyl groups using β-CD as the parent nucleus. The enhanced host-guest recognition ability of CD supramolecular polymer structure provided better inclusion interaction and increased chiral recognition of the isomers. The Star-CD CSP with star CDP as a chiral ligand performed satisfactory stereoisomer separation ability with the separation factor (α) up to 2.0 for various quinoline alkaloid isomers and 1.89 for catechins. To elucidate its chiral separation mechanism, molecular docking was used to construct the three-dimensional visual models of the binding sites and the contribution of non-covalent interactions between Star-CD CSP and quinoline alkaloid isomers. In addition, the formation sites of non-covalent interactions on the CD monomers of the polymer side chains were confirmed from the actual geometric structure by analyzing the NMR chemical shift changes before and after the formation of complexes between Star-CD polymers and isomers. Combined with the mutual evidence of molecular simulation and chiral NMR, the specific recognition mechanism of selector-selectand complexes was comprehensively expounded. Significance The multi-mode CSP based on cyclodextrin supramolecular structure provides new ideas for the stereoisomeric separation of complex chiral components with multiple chiral centers in natural products. Not limited to the macroscopic performance of the chromatographic separation, molecular docking explored the theoretical model of chiral recognition from the molecular level. The chiral NMR analysis confirmed the credibility of the model from the geometry structure, and then the recognition mechanism of multi-mode CSP was fully elaborated combining the above three aspects.

As excellent crystalline materials, covalent organic frameworks (COFs) are widely used in drug adsorption. In this work, a defective engineering strategy was proposed for designing and preparing the functionalized end-capping monomer and missing-linker COFs. The missing-linker COF 2,4,6-trihydroxybenzene-1,3,5-tricarbaldehyde compound with glycidyltrimethyl ammonium chloride modified benzene-1,4-diamine (TpPa-GTA) was synthesized through Schiff base reaction with wide pore size distribution for adsorption of four nonsteroidal anti-inflammatory drugs (NSAIDs). The adsorption process follows pseudo-second-order kinetics, and the four drugs reached adsorption equilibrium within 10 min. The sunflower-like structure helps to promote intraparticle diffusion during the adsorption process, thereby realizing the rapid adsorption of TpPa-GTA. The equilibrium isotherms fit well with both the Freundlich and Langmuir models, with a maximum adsorption capacity of 83.3–315 mg g−1 calculated from the Langmuir model. Based on the detection results of Zeta potential and XPS, the adsorption mechanism was inferred, and the rapid capture of NSAIDs in the wide pH range of 4.0 to 7.5 was realized under electrostatic interaction, hydrogen bonding, and π-π interaction. The detection of lake and river samples using the missing adapter TpPa-GTA has a recovery rate of 84.2–117

Proteins are the material basis of life and the primary carriers of life activities, containing various impurities that must be removed before use. To keep pace with the increasing complexity of protein samples, it is essential to constantly work on developing new purification technologies for downstream processes. While traditional downstream purification methods rely heavily on protein A affinity chromatography, there is still a lot of interest in finding safer and more cost-effective alternatives to protein A. Many non-affinity ligands and technologies have also been developed in biological purification recently. Here, the current status of biotechnology and the progress of protein separation technology from 2018 to 2023 are reviewed from the aspects of new preparation methods and new composite materials of commonly used separation media. The research status of new ligands with different mechanisms of action was reviewed, including the expanded application of affinity ligands, the development prospect of biotechnology such as polymer grafting, continuous column technology, and its new applications.

Schematic illustration of the formation of energy band bending and interface electric field (IEF) from Bi5O7I (+) to WO3 (−) before and after the contact of WO3 and Bi5O7I, and the possible S-scheme carrier transfer mechanism.

Photodynamic therapy (PDT) has emerged as a highly efficacious therapeutic modality for malignant tumors owing to its non-invasive property and minimal adverse effects. However, the pervasive hypoxic microenvironment within tumors significantly compromises the efficacy of oxygen-dependent PDT, posing a formidable challenge to the advancement of high-efficiency PDT. Here, we developed a nanostructured photosensitizer (PS) assembled by cationic and anionic zinc phthalocyanines to load oxygen-throttling drug atovaquone (ATO), which was subsequently coated with polydopamine to obtain the final product ATO/ZnPc-CA@DA. ATO/ZnPc-CA@DA exhibited excellent stability, particularly in the blood milieu. Interestingly, the acidic microenvironment can trigger drug release from ATO/ZnPc-CA@DA, leading to a significant enhancement in fluorescence and an augmented generation of reactive oxygen species (ROS). ATO/ZnPc-CA@DA can induce synergistic cytotoxicity of PS and ATO, and significantly enhance the killing ability against tumor cells under hypoxic conditions. The mechanism underlying cytotoxicity of ATO/ZnPc-CA@DA was demonstrated to be associated with augmented cell apoptosis, disruption of mitochondrial membrane potential, diminished ATP production, heightened intracellular ROS generation, and reduced intracellular oxygen consumption. The animal experiments indicated that ATO/ZnPc-CA@DA possessed enhanced tumor targeting capability, along with a reduction in PS distribution within normal organs. Furthermore, ATO/ZnPc-CA@DA exhibited enhanced inhibitory effect on tumor growth and caused aggravated damage to tumor tissue. The construction strategy of nanostructured PS and the synergistic antitumor principle of combined oxygen-throttling drugs can be applied to other PSs, thereby advancing the development of photodynamic antitumor therapy and promoting the clinical translation.

One of the main limitations in supporting experimental characterization of Al siting/pairing via modelling is the high computational cost of ab initio calculations. For this reason, most works rely on static or very short dynamical simulations, considering limited Al pairing/siting combinations. As a result, comparison with experiment suffers from a large degree of uncertainty. To alleviate this limitation we have developed neural network potentials (NNPs) which can dynamically sample across broad configurational and chemical spaces of sodium-form aluminosilicate zeolites, preserving the level of accuracy of the ab initio (dispersion-corrected metaGGA) training set. By exploring a wide range of Al/Na arrangements and a combination of experimentally relevant Si/Al ratios, we found that the Na-23 NMR spectra of dehydrated high-silica CHA zeolite offer an opportunity to assess the distribution and pairing of Al atoms. We observed that the Na-23 chemical shift is sensitive not only to the location of sodium in 6- and 8MRs, but also to the Al-Si-n-Al sequence length. Furthermore, neglect of thermal and dynamical contributions was found to lead to errors of several ppm, and has a profound influence on the shape of the spectra and the dipolar coupling constants, thus necessitating the long-term dynamical simulations made feasible by NNPs. Finally, we obtained a predictive regression model for the Na-23 chemical shift in CHA (Si/Al = 35, 17, 11) that circumvents the need for expensive NMR density functional calculations and can be easily extended to other zeolite frameworks. By combining NNPs and regression methods, we can expedite the simulations of NMR properties and capture the effect of dynamics on the spectra, which is often overlooked in computational studies despite its clear manifestation in experimental setups.

Oxygenic photosynthesis in microalgae and cyanobacteria is considered an important chassis to accelerate energy transition and mitigate global warming. Currently, cultivation systems for photosynthetic microbes for large-scale applications encountered excessive light exposure stress. High light stress can: affect photosynthetic efficiency, reduce productivity, limit cell growth, and even cause cell death. Deciphering photoprotection mechanisms and constructing high-light tolerant chassis have been recent research focuses. In this review, we first briefly introduce the self-protection mechanisms of common microalgae and cyanobacteria in response to high light stress. These mechanisms mainly include: avoiding excess light absorption, dissipating excess excitation energy, quenching excessive high-energy electrons, ROS detoxification, and PSII repair. We focus on the species-specific differences in these mechanisms as well as recent advancements. Then, we review engineering strategies for creating high-light tolerant chassis, such as: reducing the size of the light-harvesting antenna, optimizing non-photochemical quenching, optimizing photosynthetic electron transport, and enhancing PSII repair. Finally, we propose a comprehensive exploration of mechanisms: underlying identified high light tolerant chassis, identification of new genes pertinent to high light tolerance using innovative methodologies, harnessing CRISPR systems and artificial intelligence for chassis engineering modification, and introducing plant photoprotection mechanisms as future research directions.

Ecdysone receptor (EcR) and three insect chitinases (OfChtI, OfChtII, and OfChi-h) are considered as attractive targets for the development of novel insect growth regulators (IGRs) since they are closely related to the insect molting. In this study, to develop potent multi-target IGRs, a series of hexacyclic pyrazol-3-amide derivatives were rationally designed by utilizing the scaffold hopping strategy with the previously reported compound 6j (N-(4-bromobenzyl)-2-phenyl-4,5,6,7-tetrahydro-2H-indazole-5-carboxamide) as a lead compound. The bioassay results indicated that most of the target compounds exhibited obvious insecticidal activity. Especially, compounds a5 and a21 displayed excellent insecticidal activities against P. xylostella with LC50 values of 82.29 and 69.45 mg/L, respectively, exceeding that of 6j (263.78 mg/L). Compounds a5 and a21 also dramatically disturbed the growth and development of O. furnacalis larvae, and their LC50 values were 124.71 and 127.54 mg/L, respectively, superior to the lead 6j (267.33 mg/L). The action mechanism study revealed that the most active compound a21 could act simultaneously on EcR (21.4 % binding activity at 8 mg/L), OfChtI (94.9 % inhibitory at 10 μM), OfChtII (23.1 % inhibitory at 10 μM), and OfChi-h (94.3 % inhibitory at 10 μM), significantly higher than that of the lead compound 6j. The result of molecular docking indicated that transferring the carboxamide group from pyrazole position 5 to 3 enhanced the interactions of a21 with the key amino acid residues of the OfChtI, OfChtII, and OfChi-h, resulting in stronger affinity to the three targets than 6j. The present work offers a useful guidance for the further development of novel multi-target IGRs.

A process-simplified hard template approach was established to synthesize the monodisperse macroporous silica microspheres with homogeneous structures by twice alkali-thermal treatment and calcination routes. Porous vinyl-functionalized polysesquioxane microspheres (V-PMSQ) were synthesized through a hydrolyzation–polycondensation method and used as templates. The template particles with large aperture and high pore volume were obtained by adjusting the pH value and reaction time of the twice alkali-thermal reaction. After calcination, monodisperse silica microspheres with an average pore size of 30 nm, homogeneous pore structures, and narrow particle size distribution were fabricated, which can be directly used as chromatographic matrices without classification. After that, a new reversed-phase/strong anion-exchange (RP/SAX) mixed-mode stationary phase Sil-S-VOIM was prepared by bonding the 1-vinyl-3-octyl-imidazole ligands to the above silica microspheres through a “thiol-ene” click reaction. The performance of the Sil-S-VOIM column was evaluated by one acidic protein (transferrin) and two basic proteins (lysozyme, α-chymotrypsin) and compared to a single imidazole-modified Sil-S-VIM column and an octyl-modified Sil-C8 column, respectively. Due to the synergistic effect of electrostatic repulsion and hydrophobic interactions, baseline separations of the above proteins were observed only on the Sil-S-VOIM column, with resolutions of 2.55 and 2.01 between lysozyme and transferrin, and between transferrin and α-chymotrypsin, respectively, indicating good selectivity and separation ability compared with single-mode stationary phases. It was applied to the isolation of egg white samples with peaks identified by SDS-PAGE and MALDI-TOF–MS. The results showed that the selective retention and isolation of ovomucoid and ovotransferrin were successfully achieved, with yields of 78.8

While the structures of Brønsted acid sites (BAS) in zeolites are well understood, those of Lewis acid sites (LAS) remain an active area of investigation. Under hydrated conditions, the reversible formation of framework-associated octahedral aluminum has been observed in zeolites in the acidic form. However, the structure and formation mechanisms are currently unknown. In this work, combined experimental 27 Al NMR spectroscopy and computational data reveal for the first time the details of the zeolite framework-associated octahedral aluminium. The octahedral LAS site becomes kinetically allowed and thermodynamically stable under wet conditions in the presence of multiple nearby BAS sites. The critical condition for the existence of such octahedral LAS appears to be the availability of three protons: at lower proton concentration, either by increasing the Si/Al or by ion-exchange to non-acidic form, the tetrahedral BAS becomes thermodynamically more stable. This work resolves the question about the nature and reversibility of framework-associated octahedral aluminium in zeolites.

A multifunctional mixed-mode β-CD polymer adsorbent PNVCD-SIM containing amphoteric ions and multiple functional groups was prepared. Its physicochemical properties were characterized by scanning electron microscope (SEM), 1H nuclear magnetic resonance (1H NMR), 13C NMR, Fourier transform infrared spectroscopy (FT-IR), nitrogen adsorption-desorption test, elemental analysis (EA), and thermogravimetry and differential scanning calorimetry (TGA-DSC). The acidic indomethacin and alkaline promethazine were selected to evaluate the adsorption properties of PNVCD-SIM at different pH. Under optimal neutral pH conditions, the adsorption performance of PNVCD-SIM on acidic NSAIDs, alkaline phenothiazine, and neutral steroid hormone drugs was investigated. The results showed that PNVCD-SIM exhibited excellent diversified adsorption properties for acidic, alkaline, and neutral mixed drug components through the synergistic effects of β-CD inclusion, electrostatic interaction, hydrogen bond, π-π conjugation, and π-cation effect. The adsorption mechanism was consistent with the pseudo-second-order kinetic model and Langmuir isotherm model. Under the optimized conditions, a dispersive solid phase extraction method combined with high-performance liquid chromatography (dSPE-HPLC) using PNVCD-SIM as the adsorbent was established. The simultaneous extraction and detection of acidic-alkaline multi-component drugs in actual urine and lake water samples were successfully realized. This study provides new insight into the design and preparation of mixed-mode adsorption materials suitable for the rapid analysis and detection of multiple analytes.