Photoredox-Catalyzed Selective α-Scission of PR3-OH Radicals to Access Hydroalkylation of Alkenes.

Photoinduced generation of phosphoranyl radicals offers a versatile strategy to access a variety of synthetically valuable radicals. A long-standing challenge remains in the regulation of phosphoranyl radical to undergo α-scission pathway, although the ß-scission mode has been intensively studied. We herein developed an unprecedented protocol for selective α-scission of the P(OH)R3 radical intermediate under photocatalytic conditions. This efficient P-C bond cleavage via α-scission of the P(OH)R3 radicals has been successfully utilized in the alkylation/fluoroalkylation of alkenes.

Dietary supplementation with resistant starch contributes to intestinal health.

PURPOSE OF REVIEW: Resistant starch has received much attention recently as a healthy carbohydrate component of the diet. Resistant starch is not digested in the small intestine and can thus affect the gut microbiota of the host because of its fermentability. This review summarizes the interactions along the resistant starch-gut microbiota-host axis to help understand the health effects of resistant starch. RECENT FINDINGS: Recent studies indicate that resistant starch can be a helpful dietary component for special disease states like diabetes, metabolic syndrome, chronic kidney disease, constipation, and colitis. Its health effects are associated with modulation of the gut microbiota, and with gut microbes converting resistant starch into active and bioavailable metabolites that promote intestinal health. SUMMARY: The results from human clinical trials and studies in animal models indicate that supplementation of the diet with resistant starch in different metabolic diseases help remodel gut microbiota, especially increasing short-chain fatty acid (SCFA)-producing bacteria, and produce bioactive metabolites like SCFA, bile acids, and amino acids responsible for a variety of health effects. The gut microbiota and microbial metabolites probably mediate the effects of resistant starch on intestinal health.

Identification of the CCL2 PI3K/Akt axis involved in autophagy and apoptosis after spinal cord injury.

Spinal cord injury (SCI) is a devastating neurological disease with no cure that usually results in irreversible loss of sensory and voluntary motor functions below the injury site. We conducted an in-depth bioinformatics analysis combining the gene expression omnibus spinal cord injury database and the autophagy database and found that the expression of the autophagy gene CCL2 was significantly upregulated and the PI3K/Akt/mTOR signaling pathway was activated after SCI. The results of the bioinformatics analysis were verified by constructing animal and cellular models of SCI. We then used small interfering RNA to inhibit the expression of CCL2 and PI3K to inhibit and activate the PI3K/Akt/mTOR signaling pathway; western blot, immunofluorescence, monodansylcadaverine, and cell flow techniques were used to detect the expression of key proteins involved in downstream autophagy and apoptosis. We found that when PI3K inhibitors were activated, apoptosis decreased, the levels of autophagy-positive proteins LC3-I/LC3-II and Bcl-1 increased, the levels of autophagy-negative protein P62 decreased, the levels of pro-apoptotic proteins Bax and caspase-3 decreased, the levels of the apoptosis-inhibiting protein Bcl-2 increased. In contrast, when a PI3K activator was used, autophagy was inhibited, and apoptosis was increased. This study revealed the effect of CCL2 on autophagy and apoptosis after SCI through the PI3K/Akt/mTOR signaling pathway. By blocking the expression of the autophagy-related gene CCL2, the autophagic protective response can be activated, and apoptosis can be inhibited, which may be a promising strategy for the treatment of SCI.

Tea polyphenol and epigallocatechin gallate ameliorate hyperlipidemia via regulating liver metabolism and remodeling gut microbiota.

Hyperlipidemia can directly cause metabolic diseases that seriously endanger disorder and metabolism and gut health. Tea polyphenol (TP) and epigallocatechin gallate (EGCG) was found to improve blood lipid levels and gut microbiota. This study aimed to investigate the effects of TP and EGCG on alleviating hyperlipidemia and liver fat accumulation with physiology, genomics, and metabolomics. Results showed that both TP and EGCG reduced body weight, and TP showed advantages in the decrease of serum cholesterol and triglycerides in hyperlipidemic rats induced by the high-fat diet. Moreover, EGCG may protect liver function via reducing the glycerophospholipids increased by high-fat diet intervention. TP remodeled the gut microbiota composition and enriched the abundance of beneficial bacteria (Bacteroides, Faecalibacterium, Parabacteroides, Akkermansia), and EGCG may improve gut health via promoting the acid-producing bacteria (such as Butyricimonas, Desulfovibrio). The above results provided new insights into the hypolipidemic mechanism of TP and EGCG.

Photocatalyzed Defluorinative Dichloromethylation of α-CF3 Alkenes Using CHCl3 as the Radical Source.

A visible-light-induced defluorinative dichloromethylation of α-CF3 alkenes was developed with cheap and readily accessible chloroform simultaneously as a dichloromethylation reagent and reaction medium, leading to the facile preparation of new polyhalogenated scaffolds. Notably, the change from CHCl3 to CDCl3 offers a straightforward pathway for accessing the deuterated analogues with excellent degrees of D incorporation. Mechanistic studies suggested the reaction underwent a radical addition of the dichloromethyl radical with alkenes, followed by sequential single-electron transfer and defluorination. This protocol features mild conditions, easy operation, facile scalability, and high efficiency, allowing convenient access to dichloronated gem-difluoroalkenes.

Photoredox-catalysed chlorination of quinoxalin-2(1H)-ones enabled by using CHCl3 as a chlorine source.

A photoredox-catalysed chlorination of quinoxalin-2(1H)-ones was developed by using CHCl3 as a chlorine source, thus affording various 3-chloroquinoxalin-2(1H)-ones in moderate to high yields. This protocol is characterized by mild reaction conditions, excellent regioselectivity, and readily available chlorination agent. Considering the operational simplicity and low cost of this chlorination approach, this developed method offers an innovative pathway for rapid incorporation of chlorine functionality into heteroarenes, and will inspire broader exploitation of new chlorination strategies.

Pyroptosis-related genes play a significant role in the prognosis of gastric cancer.

BACKGROUND: Pyroptosis is an inflammatory form of programmed cell death, which has been shown to be related to the prognosis of many tumors. However, its role in gastric cancer (GC) is not fully understood. AIM: To evaluate the expression of pyroptosis-related genes in GC and its correlation with prognosis. METHODS: We constructed prognostic multigene markers of differentially expressed genes associated with pyroptosis by least absolute contraction and selection operator Cox regression. The risk model was analyzed by Kaplan-Meier curve, two-sided log-rank test and functional enrichment analysis. RESULTS: Sixty-three pyroptosis-related genes were differentially expressed in tumor tissues and adjacent nontumor tissues. Based on these differentially expressed genes, 5 gene signature were constructed and all GC patients were classified into two risk groups. Kaplan-Meier survival curve showed that the overall survival (OS) of patients in the high-risk group was significantly lower than that of the low-risk group. Multivariate Cox regression analyses showed that the risk score was an independent risk factor for OS. Receiver operating characteristic curve analysis confirmed the predictive ability of the model. External validation indicated increased OS in the low-risk group. The immune function and immune cell scores of the high-risk group were generally higher than those of the low-risk group. CONCLUSION: Pyroptosis-related genes play a significant role in tumor immune microenvironment. This novel model, which contains 5 pyroptosis-related genes, is an independent predicting factor for OS in GC patients, and may help to evaluate the prognosis of GC.

Photoredox-Catalyzed C-H Trideuteromethylation of Quinoxalin-2(1H)-ones with CDCl3 as the "CD3" source.

Herein, readily available and inexpensive CDCl3 was first identified as a new trideuteromethylation reagent under photoredox-catalyzed conditions. Thus, a facile photocatalytic protocol for the C-H trideuteromethylation of quinoxalin-2(1H)-one was achieved. This operationally straightforward transformation displays a broad scope and provides a new route to introduce the trideuteromethyl group (CD3) with excellent levels of deuterium content.

[3 + 2] vs. [4 + 1] Annulation: revisiting mechanism studies on the phosphine-catalysed domino sequence of alkynoates and activated methylenes.

The mechanism of the phosphine-catalysed domino sequence of alkynoates and activated methylenes has been computationally studied. The computational results revealed that the [3 + 2] annulation sequence could be ruled out, due to a difficult Knoevenagel condensation of aromatic aldehydes and active methylenes. The reaction proceeds through a [4 + 1] annulation pathway, which involves a phosphine-catalysed MBH-type reaction followed by a [1,5]-proton shift and dehydration to afford vinyl phosphonium intermediates as four-carbon synthons in the annulation reaction. Then 1,3-dicarbonyls act as nucleophiles to attack vinyl phosphonium intermediates, subsequently leading to a stepwise [1,3]-proton shift and an intramolecular nucleophilic attack to close the five-member ring.

Resistant starches and gut microbiota.

Resistant starches (RS), which are considered as one of the dietary fibers, could exert widely beneficial impacts, reduce fat accumulation, show significant effects on regulating blood glucose metabolism and insulin levels, and have protective effects on the gut. Five types of RS have different responses to chronic disease by modulating gut microbiota. Short-chain fatty acids are the linkage between gut microbiota and RS, and RS could improve the metabolism of gut microbiota as well as increase the abundance of beneficial microbes in the gut. The composition of gut microbiota is associated with RS properties, which is reflected by the changes of butyrate-producing bacteria primarily influenced by consumption of RS with various fine structures and types of crystallinities. RS with different fine structures and properties is consumed to varying degrees by gut microbiota, which can be applied to produce functional foods for gut health in future.

Polysaccharides from fermented Momordica charantia L. with Lactobacillus plantarum NCU116 ameliorate metabolic disorders and gut microbiota change in obese rats.

Obesity is a chronic disease characterized by overweight resulting from fat accumulation, along with disturbance of metabolism and gut microbiota. Fermentation, as a green processing method, is beneficial for improving the nutrition capacity of food components. Polysaccharides are considered as one of the important components in food and are also potential supplements for anti-obesity treatment. This study aimed to investigate the anti-obesity effects of polysaccharides from fermented and non-fermented Momordica charantia L. with Lactobacillus plantarum NCU116 (FP and NFP) on obese rats by serum metabolomics and gut microbiota analysis. Metabolomics results revealed that abnormal lipid metabolism was formed due to obesity. The supplement of FP and NFP improved the glycerophospholipids, glycosphingolipids, and amino acid metabolism of the obese rats, which alleviated the hypercholesterolemia and overweight in rats. Furthermore, the disorder of gut microbiota was ameliorated by FP and NFP. FP promoted the growth of beneficial bacteria, such as phylum Firmicutes, Actinobacteria, and genera Anaerostipes, Coprococcus, Lactobacillus, and Bifidobacterium. FP also reduced several harmful bacteria belonging to the phylum Proteobacteria and genera Helicobacter. The positive correlation of the weight loss and lowering of serum lipids with the increased beneficial bacteria further elucidated that the anti-obesity effect of FP in obese rats is associated with the regulation of gut microbiota and serum metabolites. The results of this study could provide information for developing probiotic products in the future that may have beneficial effects on the prevention or treatment of obesity.

The complete plastid genome of cherry plants Prunus discoidea (Rosaceae) and its phylogenetic implication.

Prunus discoidea is an endemic cherry species with ornamental value, spread in eastern China (Anhui, Jiangxi, Zhejiang provinces). Little information is available regarding its genomic, with limited phylogenetic relationship study performed on P. discoidea until now. The plastid genome was 158,024 bp in length consisting of four regions: large single-copy region (85,953 bp), small single-copy region (19,113 bp), and a pair of inverted repeat regions (26,469 bp each). The plastid genome contained a total of 129 genes, including 84 coding genes, 8 rRNA genes, and 37 tRNA genes. Phylogenetic analysis for 20 reported genomes within the Prunus sensu lato showed three main clades of Prunus s.l. with strong supports.

[Effectiveness on the education and food safety programs among senior primary students in 2 counties from west China-a cluster randomized trial].

OBJECTIVE: To evaluate the effectiveness of nutrition and food safety educational programs on primary students from grade 4 to 6 in impoverished areas of Western China, under a school-based cluster-randomized trial. METHODS: Twelve primary schools were selected from 2 impoverished counties in West China and assigned to intervention or control groups, randomly, with 6 schools in each group. Self-rating knowledge, attitude and practice questionnaires were used at both baseline and final stages. Textbooks and supportive materials were designed according to the characteristics of baseline data. All students in the intervention group were treated with targeted nutrition and food safety lectures of 0.5 hour per week for 2 semesters. Generalized linear mixed effects model was applied to fit the random effects on individual and clusters as well as to fit the fixed effect of the programs. RESULTS: Three hundred seventy-eight students from grade 4 to 6 were randomly selected at the baseline study and the differences of scores on knowledge, attitude and practice between the 2 groups were statistically insignificant (P > 0.05). No cluster was lost during the trial. In the final investigation, 478 students were randomly selected at the individual level. Scores on knowledge, attitude and practice among students in the intervention group were significantly higher, when comparing to the control group (P < 0.01). At the cluster level, more schools in the intervention group showed significant changes on knowledge and practice, yet the change in attitude was less obvious. Data from the mixed-effects model demonstrated that the program served as an influential factor on scores related to knowledge after the intervention(P = 0.015)but did not affect the scores on related attitude or practice (P > 0.05). CONCLUSION: Lectures seemed to have improved the cognition of nutrition and food safety among primary students from grade 4 to 6. However, long-term observation and larger sample size were needed to evaluate the changes on attitude and practice among the students.

[Status on knowledge, attitudes, behavior regarding nutrition and food safety among 4-6 grade students from Chinas' two poverty-stricken counties].

OBJECTIVE: To investigating knowledge, attitudes, current behavior among primary school students on nutrition and food safety in two State-level poverty-stricken counties, and to explore the best educational model on nutrition and food safety. METHODS: 478 pupils at 4-6 grades were selected, using the method of stratified cluster sampling and questionnaire. RESULTS: The average score on knowledge was 18.66 ± 3.75, with the qualified rate as 61.09% (the highest was 60.6%). The average score in the section of attitude was 5.82±1.50. More than 97% of the students agreed that it was necessary to receive knowledge on nutrition and food safety. The average score of behavior was 8.52±2.56. CONCLUSION: Rate of awareness on knowledge of nutrition and food safety had greatly improved among the students under study. Their habit tended to be more regular. However, we also noticed the gap between knowledge and behavior on this issue.

Observation of anisotropy in thermal conductivity of individual single-crystalline bismuth nanowires.

The thermal conductivity of individual single-crystalline Bi nanowires grown by the on-film formation of nanowires (ON-OFF) has been investigated. We observed that the thermal conductivity of single-crystalline Bi nanowires is highly anisotropic. Thermal conductivity of nanowires (diameter ∼100 nm) in the off-axis [102] and [110] directions exhibits a difference of ∼7.0 W/m·K. The thermal conductivity in both growth directions is diameter-dependent, which indicates that thermal transport through the individual Bi nanowires is limited by boundary scattering of both electrons and phonons. This huge anisotropy in thermal conductivities of Bi nanowires suggests the importance of direction-dependent characterization of charge, thermal transport, and thermoelectric properties of Bi nanowires.

Diarylheptanoids from the Rhizomes of Curcuma kwangsiensis.

Twelve new diarylheptanoids and six known compounds were isolated from rhizomes of Curcuma kwangsiensis. Structures of the new compounds were elucidated by spectroscopic and chemical methods as (3S)- and (3R)-1,7-bis(4-hydroxyphenyl)-(6E)-6-hepten-3-ol (1a and 1b), (3S)- and (3R)-1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)-(6E)-6-hepten-3-ol (2a and 2b), (3S)- and (3R)-1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)heptan-3-ol (3a and 3b), (3R)-1-(3,4-dihydroxyphenyl)-7-phenyl-(6E)-6-hepten-3-ol (4b), (3S)- and (3R)-3-acetoxy-1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)-(6E)-6-heptene (5a and 5b), (3S)- and (3R)-3-acetoxy-1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)heptanes (6a and 6b), and (E)-1,7-bis(4-hydroxyphenyl)-6-hepten-3-one (7). The absolute configurations were determined using the modified Mosher's method. Separation of the enantiomeric mixtures (1a and 1b, 2a and 2b, 3a and 3b, 4a and 4b, 5a and 5b, 6a and 6b) was achieved on a chiral column using acetonitrile-water mixtures as eluents. The S enantiomers exhibited negative specific optical rotations in MeOH, and the R enantiomers were positive. Inhibitory effects of the compounds on nitric oxide production in lipopolysaccaride-activated macrophages were evaluated.

[Round window area temporal bone section versus CT].

OBJECTIVE: To locate round window area and its related structure on auris transection and CT for anatomical evidence of image diagnosis and clinical operation. METHODS: Fifteen normal head specimen fixed with 10% dehyde were scanned by high-resolution computed tomography on canthomeatal line. CT image (depth 1.00 mm, thick 1.00 mm) was obtained. Temporal bone-centered tissues were taken, decalcified, desiccated and socked with collodion, then embedded and made into sequential transactions (thick 1.00 mm). Lower surface of section was observed by both naked eyes and microscope, then scanned and photographed. Versus CT image, auditory ossicle, osseous semicircular canals, vestibule, round window, niche, cochlea, pyramidal eminence, internal acoustic meatus and cochlear aqueduct were identified respectively. RESULTS: There were 18-22 layers of temporal transection on CT image. Round window and round window niche always appeared on the 10th layer (R) and the 11th layer (L). The mean of the depth of anterior wall was 0.92 mm (R) and 0.90 mm (L), and depth 1.89 mm (R) and 2.04 mm (L). The average distance from niche to jugular fossa wall was 2.10 mm (R) and 2.39 mm (L). No significant difference among of thickness, depth and distance from niche to jugular fossa wall. CONCLUSIONS: Temporal bone transection specimen had a clear picture of anatomical position between round window area and its related structure. Versus CT, the result contributed to image diagnosis and operation on auris diseases.