HFIP-Promoted Divergent Cycloadditions of Difluoroenoxysilanes with 2-Indolylmethanols: Synthesis of Fluoro 2H-Pyrano[3,4-b]indoles and gem-Difluoro Cyclopenta[b]indoles.

An oxa-6π-electrocyclization of difluoroenoxysilanes with diaryl 2-indolylmethanols has been developed. In addition, a rarely reported C3-nucleophilic [3+2] cycloaddition of difluoroenoxysilanes with dialkyl 2-indolylmethanols has been disclosed. This divergent cycloaddition approach affording readily available difluoroenoxysilanes as three-atom and C2 synthons provides rapid access to fluoro 2H-pyrano[3,4-b]indoles and gem-difluoro cyclopenta[b]indoles in good to excellent yields with good functional group tolerance. The metal-free and mild conditions using only HFIP as the solvent without any external acid catalyst illuminate practical and environmentally benign advantages.

Organocatalyzed Photoelectrochemistry for the Generation of Acyl and Phosphoryl Radicals through Hydrogen Atom-Transfer Process.

An organocatalyzed photoelectrochemical method for the generation of acyl and phosphoryl radicals from formamides, aldehydes, and phosphine oxides has been developed. This protocol utilizes 9,10-phenanthrenequinone (PQ) as both a molecular catalyst and a hydrogen atom-transfer (HAT) reagent, eliminating the requirement for external metal-based reagents, HAT reagents, and oxidants. The generated acyl radicals can be applied to a range of radical-mediated transformation reactions, including C-H carbamoylation of heteroarenes, intermolecular tandem radical cyclization of CF3-substituted N-arylacrylamides, as well as intramolecular cyclization reactions. The use of acyl radicals in these transformations offers an efficient and sustainable approach to accessing structurally diverse carbonyl compounds.

Synergistic synthesis of gold nanoflowers as upconversion near-infrared nanoprobe energy acceptor and recognition unit for improved hydrogen sulfide sensing.

A highly sensitive and selective upconversion near-infrared (NIR) fluorescence and colorimetric dual readout hydrogen sulfide (H2S) nanoprobe was constructed based on the excellent NIR fluorescence emission performance of upconversion nanomaterials (UCNPs), the specific recognition effect of synergistically synthesized gold nanoflowers (trypsin-stabled AuNFs (Try-AuNFs)) and the effective NIR fluorescence quenching capability. In this assay, the sensing strategy included three processes. First of all, the synthesized UCNPs can emit 803 nm NIR fluorescence when they were excited by 980 nm excitation light. Secondly, as a result of the principle of fluorescence resonance energy transfer (FRET), Try-AuNFs can effectively quench the NIR fluorescence of UCNPs at 803 nm, which can effectively improve the signal-to-background ratio of nanoprobes, thereby improving the sensitivity of the probes. Thirdly, in the presence of H2S, the Try protective layer on the surface of Try-AuNFs was specifically penetrated, which will subsequently cleave Try-AuNFs via the strong S-Au bond. As such, the NIR fluorescence of UCNPs will be restored, achieving high selectivity and sensitivity detection of H2S. Under optimized conditions, the linear response range of H2S was 0.1-300 µM, and the detection limit was 53 nM. It is worth noting that the Try on the surface of Try-AuNFs via the synergistic effect can increase the steric hindrance of the probe, and this can effectively prevent the interaction between the probe with biothiols (cysteine (Cys), homocysteine (Hcy)) and other natural amino acids (non-thiol-containing) with resultant in the high selectivity regarding the detection of H2S in human serum, which is unlikely to be achieved by AuNFs synthesized by the gold seed method (Se-AuNFs). This work not only provided a new type of UCNPs fluorescence quencher and recognition unit, but also exemplified that the use of the physical properties (steric hindrance) of protein ligands on the surface of nanoflowers can improve the specificity of the probe. This will provide new ideas for the design of other nanoprobes.

La(OTf)3-Catalyzed [3+2] Cycloaddition Reactions for the Synthesis of Benzo[d]oxazoles/Benzofurans.

The La(OTf)3-catalyzed [3+2] cycloaddition reactions for the synthesis of benzo[d]oxazoles/benzofurans via quinones and 1,2-di-tert-butyl-3-(cyanimino)diaziridine (1,3-di-tert-butyl-2-cyanoguanidine)/vinyl azides have been explored. A series of 5-hydroxybenzofuran-4-carboxylic acid derivatives and 5-hydroxybenzo[d]oxazole-4-carboxylic acid derivatives were conveniently obtained with high yields and good stereoselectivities, which could be used for further transformations to valuable compounds.

Synthesis of Fluorine-Containing Multisubstituted Oxa-Spiro[4,5]cyclohexadienones via a Fluorinated Alcohol-Catalyzed One-Pot Sequential Cascade Strategy.

In recent years, the application of fluorinated alcohols as solvents, cosolvents, or additives has become important in modern organic synthesis. However, their potential as efficient catalysts in organic synthesis has not been well-explored. In this article, we report on the development of a one-pot sequential cascade reaction of p-quinone methides with difluoroenoxysilanes using hexafluoroisopropanol as catalyst. This reaction allows for the preparation of fluorinated multisubstituted oxa-spiro[4,5]cyclohexadienones. By using 50 mol % 1,1,1,3,3,3-Hexafluoroisopropanol (HFIP), the reaction proceeds smoothly to yield 1,6-conjugated products, which are then subjected to oxidative dearomatization/hemiacetalization using PhI(OAc)2. The overall process affords moderate to high yields and excellent diastereoselectivities.

Hyper-production of porcine contagious pleuropneumonia subunit vaccine proteins in Escherichia coli by developing a bicistronic T7 expression system.

The ApxII toxin and the outer membrane lipoprotein (Oml) of Actinobacillus pleuropneumoniae are important vaccine antigens against porcine contagious pleuropneumonia (PCP), a prevalent infectious disease affecting the swine industry worldwide. Previous studies have reported the recombinant expression of ApxII and Oml in Escherichia coli; however, their yields were not satisfactory. Here, we aimed to enhance the production of ApxII and Oml by constructing a bicistronic expression system based on the widely used T7 promoter. To create efficient T7 bicistronic expression cassettes, 16 different fore-cistron sequences were introduced downstream of the T7 promoter. The expression of three vaccine antigens Oml1, Oml7, and ApxII in the four strongest bicistronic vectors were enhanced compared to the monocistronic control. Further optimization of the fermentation conditions in micro-well plates (MWP) led to improved production. Finally, the production yields reached unprecedented levels of 2.43 g L-1 of Oml1, 2.59 g L-1 of Oml7, and 1.21 g L-1 of ApxII, in a 5 L bioreactor. These three antigens also demonstrated well-protective immunity against A. pleuropneumoniae infection. In conclusion, this study establishes an efficient bicistronic T7 expression system that can be used to express recombinant proteins in E. coli and achieves the hyper-production of PCP vaccine proteins.

Highly Diastereoselective [3 + 2] Cycloaddition of Aziridines with Difluorinated Silyl Enol Ethers: Divergent Synthesis of 4,4-Difluoropyrrolidines and 4-Fluoropyrroles.

A highly diastereoselective [3 + 2] cycloaddition of aziridines with difluorinated silyl enol ethers has been developed. This approach provides a facile methodology for highly functionalized gem-difluorinated pyrrolidines in good to excellent yields with good functional group tolerance. A one-pot, two-step approach for synthesis of structurally interesting fluorinated pyrroles has also been developed through a cycloaddition/aromatization/desulfonation sequence. Moreover, readily available substrates, mild reaction conditions, and easy scale-up synthesis show practical advantages.

Four uncommon cycloamphilectane-type diterpenoids with antibacterial activity from the South China Sea soft coral Sinularia brassica.

The chemical investigation on the soft coral Sinularia brassica collected off Xuwen Country, Guangdong Province, China, has resulted in the isolation and characterization of three uncommon cycloamphilectane-type diterpenoids, namely sinucycloamtin A-C (1-3), along with two known analogues (5 and 6). In addition, compounds 2 and 3 were hydrolyzed and their hydrolytic derivative sinucycloamtin D (4) was obtained. The structures of these previously undescribed compounds were established on the basis of extensive spectroscopic analysis, X-ray diffraction analysis, chemical conversion, as well as the comparison with the literature reported data. Compounds 1-3 represented the first examples of benzene-containing cycloamphilectane-type diterpenoids isolated from soft coral of genus Sinularia. In the in vitro bioassays, all the isolated and derived diterpenoids exhibited significant antibacterial activities against the fish pathogenic bacteria Phoyobacterium damselae FP2244 and Streptococcus parauberis SPOF3K with MIC90 values ranging from 3.7 to 9.1 µM.

Pathogenic germline variants in BRCA1 and TP53 increase lung cancer risk in Chinese.

BACKGROUD: Multiple studies have identified pathogenic germline variants in cancer susceptibility genes (CSGs) in Chinese lung cancer patients; however, accurate assessment of these variants' contributions to cancer predisposition is always hampered by the absence of data on the prevalence of these variants in the general population. It is necessary to conduct a large-scale case-control study to identify CSGs that significantly increase the risk of lung cancer. MATERIALS AND METHODS: We performed targeted sequencing of a CSGs panel in 1117 lung cancer patients and 16,327 controls from the general Chinese population. RESULTS: In comparison to controls, lung cancer patients had a considerably higher prevalence of pathogenic and likely pathogenic (P/LP) variations. Among lung cancer patients, 72% of P/LP variants carriers did not have a family cancer history, who would be ignored if germline testing was only provided for patients meeting family history-based criteria. Furthermore, compared to individuals with late-onset lung cancer, patients with early-onset lung cancer had a considerably higher prevalence of P/LP variations. With odds ratios (ORs) ranging from 4-fold (BRCA1: OR, 4.193; 95%CI, 1.382-10.768) to 29-fold (TP53: OR, 29.281; 95%CI, 1.523-1705.506), P/LP variants in the BRCA1 and TP53 genes were discovered to be strongly related to increased lung cancer risk. Additionally, with ORs ranging from 7.322-fold to infinity, we discovered 23 variations previously categorized as non-P/LP variants were highly enriched in lung cancer patients. CONCLUSION: Our findings indicated that P/LP variants in BRCA1 and TP53 conferred increased risk of lung cancer in Chinese.

High-throughput process development from gene cloning to protein production.

In the post-genomic era, the demand for faster and more efficient protein production has increased, both in public laboratories and industry. In addition, with the expansion of protein sequences in databases, the range of possible enzymes of interest for a given application is also increasing. Faced with peer competition, budgetary, and time constraints, companies and laboratories must find ways to develop a robust manufacturing process for recombinant protein production. In this review, we explore high-throughput technologies for recombinant protein expression and present a holistic high-throughput process development strategy that spans from genes to proteins. We discuss the challenges that come with this task, the limitations of previous studies, and future research directions.

Synthesis of Fluoro 3(2H)-Furanones via a TFA-Catalyzed Dehydrofluorinative Cyclization of 2,2-Difluoro-3-hydroxy-1,4-diketones.

A TFA-catalyzed dehydrofluorinative cyclization of 2,2-difluoro-3-hydroxy-1,4-diketones has been developed in the presence of amines under mild conditions in which the difluorinated substrates are readily prepared according to our reported literature. This protocol provides a rapid construction of fluoro 3(2H)-furanones in good to excellent yields with good functional group tolerance. Easy scale-up synthesis also shows a practical advantage.

Lobosteroids A-F: Six New Highly Oxidized Steroids from the Chinese Soft Coral Lobophytum sp.

To explore the steroidal constituents of the soft coral Lobophytum sp. at the coast of Xuwen County, Guangdong Province, China, a chemical investigation of the above-mentioned soft coral was carried out. After repeated column chromatography over silica gel, Sephadex LH-20, and reversed-phase HPLC, six new steroids, namely lobosteroids A-F (1-6), along with four known compounds 7-10, were obtained. Their structures were determined by extensive spectroscopic analysis and comparison with the spectral data reported in the literature. Among them, the absolute configuration of 1 was determined by X-ray diffraction analysis using Cu Kα radiation. These steroids were characterized by either the presence of an α,ß-α',ß'-unsaturated carbonyl, or an α,ß-unsaturated carbonyl moiety in ring A, or the existence of a 5α,8α-epidioxy system in ring B, as well as diverse oxidation of side chains. The antibacterial bioassays showed that all isolated steroids exhibited significant inhibitory activities against the fish pathogenic bacteria Streptococcus parauberis FP KSP28, Phoyobacterium damselae FP2244, and Streptococcus parauberis SPOF3K, with IC90 values ranging from 0.1 to 11.0 µM. Meanwhile, compounds 2 and 6-10 displayed potent inhibitory effects against the vancomycin-resistant Enterococcus faecium bacterium G7 with IC90 values ranging from 4.4 to 18.3 µM. Therefore, ten highly oxidized steroids with strong antibacterial activities were isolated from the Chinese soft coral Lobophytum sp., which could be developed as new chemotypes of antibacterial drug leads.

Multicomponent Dearomative Difluoroalkylation of Isoquinolines with Difluorinated Silyl Enol Ethers: Divergent Synthesis of gem-Difluorinated Heterocycles.

A multicomponent dearomative difluoroalkylation of isoquinolines has been developed with difluorinated silyl enol ethers serving as poor nucleophiles without an additional transition-metal or organic catalyst. The sequential oxidative rearomatization under different alkaline conditions provides a controllable formal C-H difluoroalkylation and difluoromethylation method for isoquinolines without peroxide or metal oxidant. A series of isoquinolines including a pharmaceutical, phenanthridine, quinolines, and difluorinated silyl enol ethers were suitable substrates to construct gem-difluorinated heterocycles. The inexpensive starting materials, mild reaction conditions, and simple operation also show practical and environmentally benign advantages.

Leaderless Bicistronic Design for Precise and Reliable Control of Gene Expression in Corynebacterium Glutamicum.

In synthetic biology, the precise control of gene expression is challenging due to the limited orthogonality of expression elements. Here, to address this issue and improve the reusability of genetic elements, we developed a bicistronic expression cassette in Corynebacterium glutamicum based on a leaderless promoter lacking a 5'UTR. The created leaderless bicistronic design (BCD) significantly improved the orthogonality of expression elements across different genes of interest. We also explored the importance of the fore-cistron and SD motif in maintaining the strength of leaderless BCDs. Additionally, we established a library containing 55,901 fore-cistrons and demonstrated that the regulatory range of gene expression in leaderless BCDs can be broader by modifying the fore-cistron sequence. This study provides a novel synthetic biology tool based on leaderless BCD for fine-tuning gene expression in C. glutamicum using fore-cistrons. Moreover, the strategy developed here can also be applied to improve the performance of other leaderless promoters in other bacteria.

Palladium-Catalyzed C-H Allylation/Annulation Reaction of Amides and Allylic Alcohols: Regioselective Construction of Vinyl-Substituted 3,4-Dihydroisoquinolones.

A palladium-catalyzed highly regioselective C-H allylation/annulation reaction of N-sulfonyl amides with secondary or tertiary allylic alcohols has been developed to construct 3,4-dihydroisoquinolones bearing a synthetically valuable vinyl substituent. This cascade cyclization approach of allylic alcohols involving C-H allylation has not been reported previously. The commercially available allylic alcohol substrates, the only by-product of water, and the used terminal oxidant of O2 provide environmentally benign advantages.

Genome-Wide Identification and Expression Analysis of the NAC Gene Family in Kandelia obovata, a Typical Mangrove Plant.

The NAC (NAM, ATAF1/2, and CUC2) gene family, one of the largest transcription factor families in plants, acts as positive or negative regulators in plant response and adaption to various environmental stresses, including cold stress. Multiple reports on the functional characterization of NAC genes in Arabidopsis thaliana and other plants are available. However, the function of the NAC genes in the typical woody mangrove (Kandelia obovata) remains poorly understood. Here, a comprehensive analysis of NAC genes in K. obovata was performed with a pluri-disciplinary approach including bioinformatic and molecular analyses. We retrieved a contracted NAC family with 68 genes from the K. obovata genome, which were unevenly distributed in the chromosomes and classified into ten classes. These KoNAC genes were differentially and preferentially expressed in different organs, among which, twelve up-regulated and one down-regulated KoNAC genes were identified. Several stress-related cis-regulatory elements, such as LTR (low-temperature response), STRE (stress response element), ABRE (abscisic acid response element), and WUN (wound-responsive element), were identified in the promoter regions of these 13 KoNAC genes. The expression patterns of five selected KoNAC genes (KoNAC6, KoNAC15, KoNAC20, KoNAC38, and KoNAC51) were confirmed by qRT-PCR under cold treatment. These results strongly implied the putative important roles of KoNAC genes in response to chilling and other stresses. Collectively, our findings provide valuable information for further investigations on the function of KoNAC genes.

Characterization of the complete chloroplast genome of Handroanthus chrysanthus (Bignoniaceae).

Handroanthus chrysanthus is a deciduous broadleaved species with ecological and medicinal value. Here, the complete chloroplast genome of H. chrysanthus is characterized to investigate its phylogenetic position in Bignoniaceae. The chloroplast genome is 159,437 bp in size with GC content of 38.1%, including a large single copy region of 85,659 bp, a small single copy region of 12,824 bp and a pair of inverted repeats of 30,477 bp. It encodes 132 genes, including 87 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Based on current available chloroplast genome sequences, the phylogenetic analysis indicated that H. chrysanthus is closely related to Tabebuia nodosa.

Effect of Bodybuilding and Fitness Exercise on Physical Fitness Based on Deep Learning.

With the rapid development of society and economy, people's living standards are improving day by day, and increasingly attention is paid to physical health, which has set off a fitness upsurge. The purpose of this paper was to analyze the impact of bodybuilding exercise on physical fitness based on deep learning. It provides a reference for fitness enthusiasts to choose scientific and targeted exercise methods, and provides a theoretical basis for the promotion of bodybuilding and fitness. This paper first gives a general introduction to deep learning and adds image segmentation technology to design experiments for bodybuilding and fitness. The experiment was divided into groups A and B, and control group C. In this paper, recurrent neural network and gated recurrent neural network are introduced to compare and analyze the data, and the stability of data processing with different activation functions is compared. The data results show that under the scientific and reasonable arrangement of exercise conditions, bodybuilding and fitness exercises have a corresponding positive effect on the body shape and posture of the subjects. It is more practical to choose a combination of aerobic and anaerobic exercise. In this paper, based on the deep learning algorithm, compared with the recurrent neural network, the gated recurrent neural network is more suitable for processing sequence problems. In the experimental analysis part, this paper compares and analyzes the experimental results of the data under different activation functions, sigmoid function, and tanh function. It is found that the tanh activation function and the gated recurrent neural network are more stable for data processing. The highest AUC value of the traditional recurrent neural network differs by 0.78 from the highest AUC value of the gated recurrent neural network. The data analysis results are in line with the actual situation.

Hypersecretion of OmlA antigen in Corynebacterium glutamicum through high-throughput based development process.

Outer membrane lipoprotein A (OmlA) is a vaccine antigen against porcine contagious pleuropneumonia (PCP), a disease severely affecting the swine industry. Here, we aimed to systematically potentiate the secretory production of OmlA in Corynebacterium glutamicum (C. glutamicum), a widely used microorganism in the food industry, by establishing a holistic development process based on our high-throughput culture platform. The expression patterns, expression element combinations, medium composition, and induction conditions were comprehensively screened or optimized in microwell plates (MWPs), followed by fermentation parameter optimization in a 4 × 1 L parallel fermentation system (CUBER4). An unprecedented yield of 1.01 g/L OmlA was ultimately achieved in a 5-L bioreactor following the scaling-up strategy of fixed oxygen mass transfer coefficient (kLa), and the produced OmlA antigen showed well-protective immunity against Actinobacillus pleuropneumoniae challenge. This result provides a rapid and reliable pipeline to achieve the hyper-production of OmlA, and possibly other recombinant vaccines, in C. glutamicum. KEY POINTS: • Established a holistic development process and applied it to potentiate the secretion of OmlA. • The secretion of OmlA reached an unprecedented yield of 1.01 g/L. • The recombinant OmlA antigen induced efficient protective immunity.

Introducing panda bean (Vigna umbellata (Thunb.) Ohwi et Ohashi) protein isolate as an alternative source of legume protein: Physicochemical, functional and nutritional characteristics.

Panda bean protein isolate (PDPI), a legume-protein with Chinese characteristics, was investigated as an alternative potential food protein source. The physicochemical characteristics, functional properties and amino-acid composition of PDPI were determined and compared with soybean (SPI) and pea protein isolate (PPI). Results showed that PDPI was rich in phaseolin (mainly 7S vicilin), and its molecular weight was lower than that of SPI and PPI which were rich in legumin and vicilin. In comparison to SPI and PPI, PDPI showed the lowest solubility, surface-charge and surface-tension at pH 3.0, 7.0 and 9.0, but it exhibited comparable or even superior functionalities, especially in emulsifying and foaming abilities, gelling behaviour, rheological and textural properties. Moreover, the amino-acid composition and protein efficiency ratio of PDPI were excellent. The knowledge gained in the study is expected to provide reliable scientific science data for the potential application of PDPI in the food industry.