A novel Recjf Exo signal amplification strategy based on bioinformatics-assisted truncated aptamer for efficient fluorescence detection of AFB1.

Aflatoxin B1 (AFB1) is a typical mycotoxin that signifacntly endangers public health and economy. In this study, we systematically studied the interaction of aptamers with AFB1 using circular dichroism, molecular dynamics, molecular docking, and fluorescence analysis. The truncated sequence aptamers were screened using molecular docking. We successfully obtained the AFB1 aptamer with higher affinity and its truncated form was enhanced by 5.2-fold compared to the initial AFB1 aptamer. In addition, for rapid detection of AFB1, we designed a fluorescent nano-adaptor sensing platform using RecJf exonuclease signal amplification strategy based on the optimal aptamer. The aptasensor showed satisfactory sensitivity towards AFB1 with a linear detection range of 1-400 ng/mL and a detection limit of 0.57 ng/mL. The aptasensor was successfully applied to the determination of AFB1 in soybean oil and corn oil with recoveries of 91.02 %-106.59 % and 87.39 %-110.61 %, respectively. The successful application of the AFB1 aptasensor, developed through bioinformatics truncation of the aptamer, provides a novel approach to creating a cost-effective, eco-friendly, and rapid aptamer sensing platform.

Single-Walled Carbon Nanohorn-Based Fluorescence Energy Resonance Transfer Aptasensor Platform for the Detection of Aflatoxin B1.

Aflatoxin B1 (AFB1) is one of the most contaminated fungal toxins worldwide and is prone to cause serious economic losses, food insecurity, and health hazards to humans. The rapid, on-site, and economical method for AFB1 detection is need of the day. In this study, an AFB1 aptamer (AFB1-Apt) sensing platform was established for the detection of AFB1. Fluorescent moiety (FAM)-modified aptamers were used for fluorescence response and quenching, based on the adsorption quenching function of single-walled carbon nanohorns (SWCNHs). Basically, in our constructed sensing platform, the AFB1 specifically binds to AFB1-Apt, making a stable complex. This complex with fluorophore resists to be adsorbed by SWCNHs, thus prevent SWCNHs from quenching of fluorscence, resulting in a fluorescence response. This designed sensing strategy was highly selective with a good linear response in the range of 10-100 ng/mL and a low detection limit of 4.1 ng/mL. The practicality of this sensing strategy was verified by using successful spiking experiments on real samples of soybean oil and comparison with the enzyme-linked immunosorbent assay (ELISA) method.

Insoluble Dietary Fiber from Okara Combined with Intermittent Fasting Treatment Synergistically Confers Antiobesity Effects by Regulating Gut Microbiota and Its Metabolites.

Insoluble dietary fiber (IDF) was recently revealed to have an antiobesity impact. However, the impact and potential mechanism of high-purity IDF derived from okara (HPSIDF) on obesity caused by a high-fat diet (HFD) remain unclear. Except for dietary supplementation, intermittent fasting (IF) has attracted extensive interest as a new dietary strategy against obesity. Thus, we hypothesize that HPSIDF combined with IF treatment may be more effective in preventing obesity. In this study, HPSIDF combined with IF treatment synergistically alleviated HFD-induced dyslipidemia, impaired glucose homeostasis, systemic inflammation, and fat accumulation. Furthermore, gut microbiota dysbiosis and lowered short-chain fatty acid synthesis were recovered by HPSIDF combined with IF treatment. Meanwhile, metabolomic analysis of feces revealed that HPSIDF combined with IF treatment obviously reversed the alterations of metabolic pathways and differential metabolites induced by HFD, which were linked to the modulations of the gut microbiota. Collectively, our findings indicated that HPSIDF combined with IF treatment has great potential to substantially enhance antiobesity efficacy by modulating the gut microbiota and its metabolites.

Isolation and Extraction of Monomers from Insoluble Dietary Fiber.

Insoluble dietary fiber is a macromolecular polysaccharide aggregate composed of pectin, glycoproteins, lignin, cellulose, and hemicellulose. All agricultural by-products contain significant levels of insoluble dietary fiber. With the recognition of the increasing scarcity of non-renewable energy sources, the conversion of single components of dietary fiber into renewable energy sources and their use has become an ongoing concern. The isolation and extraction of single fractions from insoluble dietary fiber is one of the most important recent research directions. The continuous development of technologies for the separation and extraction of single components is aimed at expanding the use of cellulose, hemicellulose, and lignin for food, industrial, cosmetic, biomedical, and other applications. Here, to expand the use of single components to meet the new needs of future development, separation and extraction methods for single components are summarized, in addition to the prospects of new raw materials in the future.

The complexes of soybean protein isolate and procyanidin B2 have synergistic hypolipidemic activity at the cellular level by activating the AMPKα pathway.

The alkali method was used to prepare soybean protein isolate (SPI) and procyanidin B2 (PCB2) complexes, and the interaction between SPI and PCB2 was studied using multi-spectroscopic methods. The human hepatoma (HepG2) cell hyperlipidemia model was used to explore whether SPI-PCB2 has the potential for synergistic hypolipidemia. According to the findings, PCB2 was primarily linked to SPI via C-S and C-N bonds, and the addition of PCB2 reduced the α-helix structure content of SPI by 4.1%. At the cellular level, the optimal SPI-PCB2 ratio for lowering blood lipids was 1:1. Compared with the model group, the TG content and TC content in the 1:1 group were reduced by 28.7% and 26.3%, respectively. Western blot analysis revealed that SPI-PCB2 = 1:1 exerted synergistic hypolipidemic activity mainly by activating adenosine monophosphate-activated protein kinase α (AMPKα) phosphorylation, inhibiting 3-hydroxy-3-methylglutaryl CoA reductase (HMGCR) and fatty acid synthetase (FAS) protein expression, and upregulating carnitine palmitoyl transferase 1A (CPT1A) protein activity.

Ultrasmall amphiphilic zeolitic nanoreactors for the aerobic oxidation of alcohols in water.

Organic reactors in a green solvent (water) is the goal of sustainable development. Green nanoreactors with excellent amphiphilicity and catalytic activity are strongly desired. Herein, a novel amphiphilic nanoreactor Pd@amZSM-5 with ultrasmall size has been successfully synthesized via a simple one-step oil bath method, subjected to the modification-etching-modification strategy and in situ reduction of Pd2+. Ultrasmall Pd@amZSM-5 nanoreactors (60 nm) with hierarchical structures showed outstanding amphiphilicity for forming Pickering emulsions with fine uniform droplets (50 µm). Fine droplets formed short diffusion distances, which can significantly improve the catalytic activity in biphasic reactions. Moroever, the ultrasmall Pd@amZSM-5 nanoreactors demonstrated excellent catalytic activity for the selective oxidation of alcohols in water using air as the oxidant. Alkali was not present in the reaction system. The hydrophilic aminopropyl groups on the surface of the Pd@amZSM-5 nanoreactors not only changed the affinity of the zeolite surface and provided targeting points for Pd nanoparticles but also provided an alkaline environment for the selective oxidation of alcohols. The ultrasmall Pd@amZSM-5 nanoreactors presented excellent universality for aromatic alcohols (with >90% conversion and >90% selectivity) and allylic alcohols (with 100% conversion and 100% selectivity).

Hemishell Zeolites Synthesized by Asymmetric Modification as Biphasic Nanoreactors with Tunable Amphiphilicity for Catalysis of Cascade Reactions.

It is strongly desired to design and synthesize amphiphilic nanoreactors with tunable compatibility, which are stable at the biphasic interface in both acidic and alkaline environments. Herein, a novel amphiphilic R1-ZSM-5-R2 nanoreactor with adjustable hydrophilic-lipophilic balance (solid) (HLB(S)) values has been successfully synthesized by hydrophilic/lipophilic asymmetric modification of the surface of hemishell zeolites. The hemishell zeolites obtained by alkali etching have different surfaces for this asymmetric modification. Owing to the unique hemishell structures and asymmetric modification, the R1-ZSM-5-R2 nanoreactors with an optimized type and amount of modified organosilanes show excellent stability and emulsifying properties under extreme environments, which is important for cascade reactions in a biphasic system. The modified amino groups on the surface of the nanoreactors not only enhance the hydrophilicity of the hemishell zeolites and stabilize ultrasmall Pt nanoparticles (1.90 nm) but also used for the catalytic synthesis of trans-cinnamaldehyde. The Pt@R1-ZSM-5-R2 amphiphilic catalysts fabricated through a one-step reduction of Pt nanoparticles present outstanding performances in the biphasic cascade synthesis of cinnamic acid, achieving a very high turnover frequency (TOF) of 978 h-1. The TOF values of the catalysts correspond well to the HLB(S) values of the R1-ZSM-5-R2 nanoreactors.