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Here, we describe a novel mycovirus, tentatively designated as "Botryosphaeria dothidea mitovirus 3" (BdMV3), isolated from Botryosphaeria dothidea strain FJ, which causes pear ring rot disease in Fujian Province, China. The complete genome nucleotide sequence of BdMV3 is 2538 nt in length and contains a single 2070-nt open reading frame (ORF) encoding a putative RNA-dependent RNA polymerase (RdRp) of 689 amino acids (aa) using the fungal mitochondrial genetic code. BLASTp analysis revealed that the RdRp of BdMV3 shares 28.91%-69.36% sequence identity (query sequence coverage more than 90%) with those of members of the genus Mitovirus, with the highest sequence identity of 69.36% and 68.79% to the corresponding RdRp aa sequences of Rhizoctonia solani mitovirus 10 and Macrophomina phaseolina mitovirus 4, respectively. Phylogenetic analysis based on RdRp aa sequences indicated that BdMV3 is a new member of the genus Mitovirus in the family Mitoviridae.

In this study, the characteristic of the designed porphyrin sensitizer was studied by density functional theory (DFT) and time-dependent density functional theory (TDDFT). D-π-A sequence of seven donor-acceptor dyes A-F in the organic dye-sensitized solar cell (DSSCs) was analyzed. Firstly, the structure and frequency of porphyrin dyestuffs with different substituents were optimized by DFT method, and the structure and properties of the ground state of porphyrin dyes were studied by comparing the energy differences of different orbitals. Then, the TDDFT method was used to study the porphyrin molecules with different π bridge. The structure and properties of the excited state are discussed in terms of the energy and charge separation state of the molecular orbital of the porphyrin sensitizer. According to the absorption spectrum, the characteristic of the light absorption for the sensitizer molecule is investigated. The results shown that the key characteristic parameters closely related to the open circuit photovoltage (VOC) and the short circuit current density (JSC) of the porphyrin sensitizers helped to clarify different π bridges. The change of VOC and JSC affected the energy level change of the porphyrin sensitizers with different π bridge. Finally, a suitable π bridge was selected as a porphyrin sensitizer candidate with higher conversion efficiency.

We provide evidence of oxygen-involved electrochemiluminescence (ECL) of metal-free porphyrins and metalloporphyrins first. O2•– and OH•, which are oxygen intermediates, are indispensable for the formation of excited porphyrins, which has been proven by trapping free radical strategies. The wide differences regarding emission location and mechanism between metal-free porphyrins [including meso-tetra(4-methoxyphenyl)porphine (H2TMPP), meso-tetraphenylporphyrin (H2TPP), and meso-tetra(4-carboxyphenyl)porphine (H2TCPP)] and metalloporphyrins (MTPP) depend on whether protons are present in the center of the porphin ring. Besides, the oxygen-involved ECL of porphyrins can be controlled regularly by peripheral substituents with different polarities. Because of the stretched molecular structure and the decrease in electron density around the protons located at porphin ring, electron-withdrawing groups are more conducive to protons being attacked by O2•–, as well as the enhancement of porphyrins ECL. The ECL effi...

Here, we describe a novel mycovirus, Botryosphaeria dothidea mitovirus 2 (tentatively designated as BdMV2), isolated from Botryosphaeria dothidea FJ strain causing pear ring rot disease in Fujian Province, China. The complete genome nucleotide sequence of BdMV2 is 2538 nt in length and contains a single 2070 nt open reading frame (ORF) encoding a putative RNA-dependent RNA polymerase (RdRp) of 689 amino acid (aa) using fungal mitochondrial genetic code. BLASTp analysis revealed that the RdRp of BdMV2 shares 28.91%–69.36% (query sequence coverage more than 90%) sequence identity to those of members in the genus Mitovirus, and the closest similarity is 69.36% and 68.79% with the corresponding protein aa sequences of Rhizoctonia solani mitovirus 10 and Macrophomina phaseolina mitovirus 4, respectively. Phylogenetic analysis based on the RdRp aa sequences further revealed that BdMV2 is a newly member in the genus Mitovirus of the family Narnaviridae. To our knowledge, BdMV2 is thus a novel mitovirus from the causal agent B. dothidea of pear ring rot disease.

In the present work, the classical synthesis method of 5,10,15,20-(4-sulphonatophenyl) porphyrin (TPPS4) was improved. The synthesis process became more environmentally friendly, and the yield was increased by 10%. We constructed a sensitive fluorescent sensor for detection hydrogen peroxide (H2O2) and glucose (C6H12O6) by using the hyperfluorescence of TPPS4. The TPPS4-Fe3+ complex system of the sensor could generate electron transfer process (ET) in the process of hydrogen peroxide (H2O2) and glucose oxidation, which quenched the TPPS4 fluorescence. The system had a linear range of 0–42 μM for hydrogen peroxide, and the minimum detectable limit (LOD) was 1.24 nM (S/N = 3). Compared with other detection methods, the proposed method had the advantages of higher sensitivity, lower detection limit and more simple operation.

In this work, a double shell material chitosan (CS)-recombinant soybean seed H-2 ferritin (H-2F) was fabricated to encapsulate epigallocatechin gallate (EGCG) molecules. EGCG-loaded H-2F complex (EHF) was firstly prepared by taking advantages of the reversible self-assembly of the ferritin, and the EHF-CS composite (EHFC) was fabricated by electrostatic interactions with binding number n of (4.1 ± 0.11) and binding constant K of ((5.3 ± 0.2) × 105 M−1), respectively. It was calculated that about 12.6 of EGCG molecules can be encapsulated in one H-2F ferritin cage with an encapsulation efficiency of 9.69% (w/w). SDS-PAGE analysis indicated that the CS binding to H-2F could inhibit ferritin degradation by pepsin and trypsin; the stability of EGCG molecules in EHFC was also significantly improved in simulated gastrointestinal tract. In addition, the chitosan-ferritin double shells were beneficial for the transport of EGCG across the Caco-2 monolayer model based on ferritin uptake. This work demonstrates a novel method to promote stabilization and absorption of food bioactive molecules.

In the present work, we proposed a novel naked-eye and turn-on fluorescence sensor based on the 5,10,15,20-(4-sulphonatophenyl) porphyrin (TPPS4)-Hg2+ system with short assay time and high sensitivity to detect glutathione (GSH) in real samples. The TPPS4 was the first time to detect GSH because of its high fluorescence quantum yield. The initial fluorescence from TPPS4 was quenched by Hg2+ with an electron transfer process. However, when put a certain concentration of GSH into this system, the fluorescence sensor was turned to the “on” state, which was related to a competitive affinity of Hg2+ to GSH and the N atoms of porphyrin ring. Under the optimal conditions, the naked-eye detection limit was 0.43 nM and the limit of detection (LOD) was arrived to 16 fM (S/N = 3) for GSH. The linear regions are obtained by two ranges varying from 0 to 28.5 μM and from 38.15 to 61.87 μM. Furthermore, it was confirmed that the TPPS4-Hg2+ fluorescence probe has excellent selectivity, high sensitivity and quick fluorescence response for GSH.

Rice bran albumin protein (RAP) is sensitive to thermal changes and tends to degrade when exposed to high-temperature processing. In this work, RAP–epigallocatechin-3-gallate (EGCG) complex (RAPE) was prepared and the thermal stability was evaluated. Fluorescence results showed that EGCG could interact with RAP with a binding number n of 0.0885:1 (EGCG:RAP, w/w) and a binding constant Kof 1.02 (± 0.002) ×104/M, suggesting both hydrogen bonding and van der Waals forces played an important role. FTIR analysis demonstrated that EGCG could induce secondary structural changes in RAP above a ratio of 1.6:1 (EGCG:RAP, w/w). Interestingly, the secondary structure changes of RAPE at different temperatures (25, 50, 60, 70, and 80 °C) were inhibited compared with that for RAP, suggesting RAPE was more resistant and stable to the heat treatment. In addition, a dense porous structure of RAPE was achieved due to the EGCG binding after thermal treatment. Furthermore, the Tpeaktemperature of RAPE increased significantly from 64.58 to 74.16 °C and the enthalpy also increased from 85.53 to 138.52 J/g with a mass ratio increasing from 0 to 3.2 (EGCG:RAP, w/w), demonstrating the thermal stability of RAPE. In addition, the valine, methionine, and lysine content in RAPE were significantly higher than RAP following 80 °C treatment for 20 min (P< 0.05), exhibiting enhanced amino acid profiles, which might be due to EGCG–RAP interactions and microenvironment changes around relevant amino acids. These findings demonstrate that EGCG has the potential to improve the thermal stability of sensitive proteins and is beneficial for usage in the food industry. Rice bran albumin protein can be combined with the tea polyphenol-EGCG to achieve an improved thermal stability and amino acid profile. Therefore, tea polyphenols have potential usage in food resource protein stabilization during food processing.

A novel strategy was developed for the fluorescence detection of nitrite (NO2−) in real samples. The method is based on the reaction of water-dispersible graphite-like carbon nitride (w-g-C3N4) with nitrite (NO2−) in an acidic medium to form a new kind of weak fluorescence species. Under optimal conditions, the limit of detection (LOD) for nitrite (NO2−) detection was determined to be 0.16 nM (S/N = 3), and the relative fluorescence intensity versus logarithm concentration of nitrite (NO2−) showed good linearity in the range from 0 to 58.5 μM with R2 = 0.997. This probe displayed several appealing properties including low-cost, simplicity and convenience, high sensitivity, and excellent selectivity.

Surface recombination at the photoanode/electrolyte junction seriously impedes photoelectrochemical (PEC) performance. Through coating of photoanodes with oxygen evolution catalysts, the photocurrent can be enhanced; however, current systems for water splitting still suffer from high recombination. We describe herein a novel charge transfer system designed with BiVO4 as a prototype. In this system, porphyrins act as an interfacial-charge-transfer mediator, like a volleyball setter, to efficiently suppress surface recombination through higher hole-transfer kinetics rather than as a traditional photosensitizer. Furthermore, we found that the introduction of a "setter" can ensure a long lifetime of charge carriers at the photoanode/electrolyte interface. This simple interface charge-modulation system exhibits increased photocurrent density from 0.68 to 4.75 mA cm-2 and provides a promising design strategy for efficient photogenerated charge separation to improve PEC performance.

The application of bioactive lutein in the food industry is limited because of its poor water-solubility, instability, and low bioavailability. Nano-sized ferritin and chitosan provide a platform for fabricating shell–core system to encapsulate lutein. Herein, soybean seed ferritin (Glycine max) and chitosan stabilized lutein composites (FCLs) were fabricated by a unique reversible disassembly-reassembly character of apoferritin and ferritin–chitosan interaction. Results showed that lutein molecules were successfully encapsulated within the apoferritin with a molar ratio of 25.2 to 1 (lutein/ferritin), and the encapsulation efficiency and loading capacity were 16.8% and 2.50% (w/w), respectively. It was calculated that approximately 10 chitosan molecules were bound to a ferritin with a binding constant of 6.3 × 105 M−1, suggesting electrostatic interaction played an important role in ferritin–chitosan interaction. Results also indicated as much as 74.1% (w/w) of lutein was retained in FCLs after storage at 20 °C for 7 days. In addition, the photo- and heat-stability of lutein in FCLs were greatly improved as compared to free lutein. Furthermore, FCLs exhibited prolonged release of lutein in simulated gastrointestinal tract (GI) digestion as a result of ferritin coating and chitosan binding. Interestingly, food components exerted different effects in lutein release, EGCG, grape seed proanthocyanidin, and milk could inhibit while pectin could facilitate the release of lutein from FCLs. This work demonstrates an innovative strategy to solubilize, stabilize and control release of functional food nutrients.

Activating mutations are significant drug targets of diseases. Statistical analysis on the mutated amino acids, the mutation characteristic and the related disease information of activating mutations is of great significance for the diagnosis and treatment of diseases. Study on the protein stability by predicting Gibbs free energy (ΔΔG) change after mutation is very helpful for understanding the relationship between protein structure and function. By combining mCSM and disease datasets, this paper studies the effect of mutation on the protein stability and disease. The results show that the mutations in protein may be the cause of disease for PPI structures, which statistically afford significant information for disease related research and medical diagnosis and treatment.

This paper developed a sensitive method for detecting hydroquinone by combining the unique optical properties of quantum dots and the specificity of enzymatic reactions. The interesting results shown that the fluorescence of graphite phase carbon nitride quantum dot (g-CNQDs) was quenched directly by benzoquinone or indirectly by hydroquinone (H2Q), and the possible quenching mechanism was proposed. Quinone might generate by catalyzing the oxidation of H2Q with horseradish peroxidase (HRP) in the presence of hydrogen peroxide. The intermediate quinone could effectively quench the fluorescence of g-CNQDs quantum dots. Therefore, a novel fluorescence probe based on g-CNQDs Quantum Dots was successfully used to detect H2Q by strongly quenching the fluorescence of g-CNQDs Quantum Dots which mediated by horseradish peroxidase enzymes. The detection limit was as low as 0.04 μM (S/N = 3), and the linear range was 0.5–11.6 μM. This kind of quantum dot-enzyme system has the advantages of simple operation, no modification of quantum dots, low cost, high sensitivity and short detection time.

Rutin is a common dietary flavonoid with important pharmacological activities. However, its application in the food industry is limited mainly because of its poor water-solubility. The nano-scale ferritin cage provides an ideal space for subtle encapsulation of hydrophobic rutin molecules. This study describes the preparation of novel homogeneous soybean seed ferritin stabilized rutin nanodispersions (FRNs) by a unique reversible dissociation and reassembly of the apoferritin. The characteristics including the water-solubility, morphology, leakage kinetics, and stability of the FRNs were investigated. Results indicated that the rutin molecules could be successfully encapsulated within the protein cages with a rutin/protein molar ratio of 30.1 to 1, and the encapsulation and loading efficiency were 25.1% (w/w) and 3.29% (w/w), respectively. In vitro experiments of rutin release demonstrated that the entrapment of rutin was effective, with more than 75% (w/w) still encapsulated in the ferritin cage after storage for 15 days. Furthermore, the thermal and UV radiation stability of ferritin trapped rutin was greatly improved due to the encapsulation as compared to free rutin. Additionally, the antioxidant activity of FRNs was partly retained as compared to free rutin molecules. This study provides a novel strategy for the design and fabrication of nanocarriers providing water-insoluble molecules with protection and stabilization.

Ferritin is a shell-like carrier protein with an 8nm diameter cavity which endows a natural space to encapsulate food and drug components. In this work, phytoferritin was unprecedentedly glycosylated by chitosan to fabricate ferritin-chitosan Maillard reaction products (FCMPs) (grafting degree of 26.17%, 24h, 55°C). Results indicated that the amide I and II bands of ferritin were altered due to the chitosan grafting, whereas the ferritin spherical structure were retained. Simulated digestion analysis showed that the FCMPs were more resistant to pepsin and trypsin digestion as compared with ferritin alone. Furthermore, FCMPs were employed as carrier to encapsulate epigallocatechin gallate (EGCG) molecules with an encapsulation ratio of 12.87% (w/w), and the resulting FCMPs-EGCG complexes showed a slow release of EGCG in simulated gastrointestinal tract. Interestingly, different types of food components displayed different effects in EGCG release behavior from the FCMPs, wherein proanthocyanidin, milk and soy protein inhibited the EGCG release. In addition, the absorption of EGCG encapsulated in FCMPs in Caco-2 monolayer model was significantly improved as compared with free EGCG. This work provides a novel nano-vehicle for fabricating core-shell systems in food and drug delivery domain.

Rice bran albumin protein (RAP) is sensitive to thermal changes and tends to degrade when exposed to high-temperature processing. In this work, RAP-epigallocatechin-3-gallate (EGCG) complex (RAPE) was prepared and the thermal stability was evaluated. Fluorescence results showed that EGCG could interact with RAP with a binding number n of 0.0885:1 (EGCG:RAP, w/w) and a binding constant K of 1.02 (± 0.002) ×10

Quantitative structure-activity relationship (QSAR) has been a technique to study the relationship between chemical structures and properties, and variable selection is an important problem for finding the informative variables and building reliable models. A variable selection method based on variable stability is proposed and used for selecting the informative descriptors in the QSAR model of inhibitors. In the method, a series of models are built by leave-one-out cross validation (LOOCV), and variable stability is defined as the ratio of the absolute mean value and standard deviation of the regression coefficients in the models for a descriptor. Therefore, the descriptors with larger stabilities are more informative to the model. To further enhance the difference among the descriptors, an exponential parameter is used to modify the standard deviation. The results show that 13 descriptors are selected as informative ones from 1217 descriptors for the QSAR model of inhibitors. An effective prediction model can be constructed by them.