The causal relationship between physical activity, sedentary behavior and brain cortical structure: a Mendelian randomization study.

Physical activity and sedentary behavior, both distinct lifestyle behaviors associated with brain health, have an unclear potential relationship with brain cortical structure. This study aimed to determine the causal link between physical activity, sedentary behavior, and brain cortical structure (cortical surface area and thickness) through Mendelian randomization analysis. The inverse-variance weighted method was primarily utilized, accompanied by sensitivity analyses, to confirm the results' robustness and accuracy. Analysis revealed nominally significant findings, indicating a potential positive influence of physical activity on cortical thickness in the bankssts (ß = 0.002 mm, P = 0.043) and the fusiform (ß = 0.002 mm, P = 0.018), and a potential negative association of sedentary behavior with cortical surface area in the caudal middle frontal (ß = -34.181 mm2, P = 0.038) and the pars opercularis (ß = -33.069 mm2, P = 0.002), alongside a nominally positive correlation with the cortical surface area of the inferior parietal (ß = 58.332 mm2, P = 0.035). Additionally, a nominally significant negative correlation was observed between sedentary behavior and cortical thickness in the paracentral (ß = -0.014 mm, P = 0.042). These findings offer insights into how lifestyle behaviors may influence brain cortical structures, advancing our understanding of their interaction with brain health.

Safety and efficacy of melatonin supplementation as an add-on treatment for infantile epileptic spasms syndrome: A randomized, placebo-controlled, double-blind trial.

This was a prospective, randomized, double-blind, single-center placebo-controlled trial to assess the efficacy and safety of melatonin as an add-on treatment for infantile epileptic spasms syndrome (IESS). Participants aged 3 months to 2 years with a primary diagnosis of IESS were recruited and assigned to two groups in a 1:1 ratio. Both treatment groups received a combination of adrenocorticotrophic hormone (ACTH) and magnesium sulfate (MgSO4 ) for 2 weeks, and the treatment group also received melatonin (3 mg) between 20:00 and 21:00 daily, 0.5-1 h before bedtime. The study's primary endpoint was the average reduction rate in spasm frequency assessed by seizure diaries. Secondary endpoints included assessment of the response rate, EEG hypsarrhythmia (Kramer score), and psychomotor development (Denver Developmental Screening Test, DDST). Sleep quality was assessed by using the Brief Infant Sleep Questionnaire (BISQ), the Infant Sleep Assessment Scale (ISAS), and actigraphy. Safety parameters were also evaluated. Statistical analyses were conducted on intention-to-treat and per-protocol populations. The trial is registered at Clinicaltrials.gov (ChiCTR2000036208). Out of 119 screened patients, 70 were randomized and 66 completed treatments. In the intention-to-treat population, there were no significant differences in the average percentage reduction of spasm frequency (median [interquartile range, IQR: Q3-Q1], 100% [46.7%] vs. 66.7% [55.3%], p = .288), the 3-day response rate (51.4% vs. 37.1%, p = .229), the 28-day response rate (42.9% vs. 28.6%, p = .212), EEG Kramer scores (2 [3.5] vs. 2 [3], p = .853), or DDST comprehensive months (5 [2.5] vs. 6 [6], p = .239) between the melatonin (n = 35) and placebo (n = 35) groups. However, caregivers reported improved sleep quality after melatonin treatment, with 85.7% reporting regular sleep compared to 42.9% with placebo (42.9%, p < .001). The melatonin group had lower ISAS scores in 4-11-month-old patients compared to the placebo (mean ± SD, 29.3 ± 4.4 vs. 35.2 ± 5.9, p < .001). Moreover, the median (IQR) value of sleep-onset latency was shortened by 6.0 (24.5) min after melatonin treatment, while that in the placebo group was extended by 3.0 (22.0) min (p = .030). The serum melatonin (6:00 h) level (pg/mL) of the children in the melatonin group after treatment was significantly higher than in the placebo group (median [IQR], 84.8 [142] vs. 17.5 [37.6], p < .001). No adverse effects related to melatonin were observed in the study, and there were no significant differences in adverse effects between the melatonin and placebo groups. Although not statistically significant, the results of this randomized clinical trial proved that melatonin supplementation, as an add-on treatment, can improve spasm control rate in the treatment of IESS. For IESS children treated with ACTH, the addition of melatonin was found to improve sleep quality, shorten sleep onset latency, and increase blood melatonin levels. Moreover, it was observed to be a safe treatment option.

Allantoin induces pruritus by activating MrgprD in chronic kidney disease.

Chronic kidney disease (CKD) is a disease with decreased, irreversible renal function. Pruritus is the most common skin symptom in patients with CKD, especially in end-stage renal disease. The underlying molecular and neural mechanism of CKD-associated pruritus (CKD-aP) remains obscure. Our data show that the level of allantoin increases in the serum of CKD-aP and CKD model mice. Allantoin could induce scratching behavior in mice and active DRG neurons. The calcium influx and action potential reduced significantly in DRG neurons of MrgprD KO or TRPV1 KO mice. U73122, an antagonist of phospholipase C, could also block calcium influx in DRG neurons induced by allantoin. Thus, our results concluded that allantoin plays an important role in CKD-aP, mediated by MrgprD and TrpV1, in CKD patients.

ECERIFERUM1-6A is required for the synthesis of cuticular wax alkanes and promotes drought tolerance in wheat.

Cuticular waxes cover the aerial surfaces of land plants and protect them from various environmental stresses. Alkanes are major wax components and contribute to plant drought tolerance, but the biosynthesis and regulation of alkanes remain largely unknown in wheat (Triticum aestivum L.). Here, we identified and functionally characterized a key alkane biosynthesis gene ECERIFERUM1-6A (TaCER1-6A) from wheat. The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9)-mediated knockout mutation in TaCER1-6A greatly reduced the contents of C27, C29, C31, and C33 alkanes in wheat leaves, while TaCER1-6A overexpression significantly increased the contents of these alkanes in wheat leaves, suggesting that TaCER1-6A is specifically involved in the biosynthesis of C27, C29, C31, and C33 alkanes on wheat leaf surfaces. TaCER1-6A knockout lines exhibited increased cuticle permeability and reduced drought tolerance, whereas TaCER1-6A overexpression lines displayed reduced cuticle permeability and enhanced drought tolerance. TaCER1-6A was highly expressed in flag leaf blades and seedling leaf blades and could respond to abiotic stresses and abscisic acid. TaCER1-6A was located in the endoplasmic reticulum, which is the subcellular compartment responsible for wax biosynthesis. A total of three haplotypes (HapI/II/III) of TaCER1-6A were identified in 43 wheat accessions, and HapI was the dominant haplotype (95%) in these wheat varieties. Additionally, we identified two R2R3-MYB transcription factors TaMYB96-2D and TaMYB96-5D that bound directly to the conserved motif CAACCA in promoters of the cuticular wax biosynthesis genes TaCER1-6A, TaCER1-1A, and fatty acyl-CoA reductase4. Collectively, these results suggest that TaCER1-6A is required for C27, C29, C31, and C33 alkanes biosynthesis and improves drought tolerance in wheat.

Diverse Roles of the Salicylic Acid Receptors NPR1 and NPR3/NPR4 in Plant Immunity.

The plant defense hormone salicylic acid (SA) is perceived by two classes of receptors, NPR1 and NPR3/NPR4. They function in two parallel pathways to regulate SA-induced defense gene expression. To better understand the roles of the SA receptors in plant defense, we systematically analyzed their contributions to different aspects of Arabidopsis (Arabidopsis thaliana) plant immunity using the SA-insensitive npr1-1 npr4-4D double mutant. We found that perception of SA by NPR1 and NPR4 is required for activation of N-hydroxypipecolic acid biosynthesis, which is essential for inducing systemic acquired resistance. In addition, both pattern-triggered immunity (PTI) and effector-triggered immunity (ETI) are severely compromised in the npr1-1 npr4-4D double mutant. Interestingly, the PTI and ETI attenuation in npr1-1 npr4-4D is more dramatic compared with the SA-induction deficient2-1 (sid2-1) mutant, suggesting that the perception of residual levels of SA in sid2-1 also contributes to immunity. Furthermore, NPR1 and NPR4 are involved in positive feedback amplification of SA biosynthesis and regulation of SA homeostasis through modifications including 5-hydroxylation and glycosylation. Thus, the SA receptors NPR1 and NPR4 play broad roles in plant immunity.

Copper-Catalyzed Oxidative [1+2+1+2] Cascade Cyclization of N,N-Dimethyl Enaminones with Benzylamines: A Facile Access to Functionalized 1,4-Dihydropyridines.

Using benzylamines as the C4 source of 1,4-dihydropyridines (1,4-DHPs), a Cu-catalyzed oxidative [1+2+1+2] cascade cyclization for the synthesis of 1,4-DHPs was firstly developed. A broad range of easily available N,N-dimethyl enaminones and benzylamines are employed smoothly to provide a diverse range of 1,4-DHPs with high efficiency. This method is performed by a one-pot cascade C(sp3 )-H bond functionalization/C(sp3 )-N cleavage/cyclization strategy to form simultaneously two C(sp3 )-C(sp2 ) bonds, two C(sp2 )-N bonds, and a 1,4-DHP ring.

A potential immunotherapy target for breast cancer: parenchymal and immune-stromal expression of the NLRP3 inflammasome pathway.

BACKGROUND: The NOD-, LRR- and pyrin domain­containing 3 (NLRP3) inflammasome is a critical component of the innate immune system. It has been known to play an important role in the carcinogenesis and prognosis of breast cancer patients. While the clinical evidence of the relationship between NLRP3 inflammasome activation and long-term survival is still limited, the possible roles of parenchymal or immune-stromal cells of breast cancer tissues in contributing to such carcinogenesis and progression still need to be clarified. This study is an analysis of patients receiving breast cancer surgery in a previous clinical trial. METHODS: Immunohistochemistry (IHC) was used to detect the expression levels of NLRP3 inflammasome pathway-related proteins, including NLRP3, caspase-1, apoptosis-associated speck-like protein (ASC), IL-1ß, and IL-18, in parenchymal and immune-stromal cells of breast cancer tissues compared to those of adjacent normal tissues, respectively. The relationship between NLRP3 inflammasome expression and clinicopathological characteristics, as well as 5-year survivals were analyzed using the Chi-square test, Kaplan-Meier survival curves, and Cox regression analysis. RESULTS: In the parenchymal cells, ASC and IL-18 protein levels were significantly up-regulated in breast cancer tissues compared with adjacent normal tissues (P<0.05). In the immune-stromal cells, all the five NLRP3 inflammasome pathway-related proteins were significantly elevated in breast cancer tissues compared with adjacent normal tissues (P < 0.05). Carcinoma cell embolus was found to significantly correlate with high NLRP3 expression in parenchymal cells of the tumor (x2=4.592, P=0.032), while the expression of caspase-1 was negatively correlated with tumor progression. Histological grades were found to have a positive correlation with IL-18 expression in immune-stromal cells of the tumor (x2=14.808, P=0.001). Kaplan-Meier survival analysis revealed that high IL-18 expression in the immune-stromal cells and the positive carcinoma cell embolus were both associated with poor survival (P < 0.05). The multivariable Cox proportional hazards regression model implied that the high IL-18 expression and positive carcinoma cell embolus were both independent risk factors for unfavorable prognosis. CONCLUSIONS: The activation of NLRP3 inflammasome pathways in immune-stromal and tumor parenchymal cells in the innate immune system was not isotropic and the main functions are somewhat different in breast cancer patients. Caspase-1 in parenchymal cells of the tumor was negatively correlated with tumor progression, and upregulation of IL-18 in immune-stromal cells of breast cancer tissues is a promising prognostic biomarker and a potential immunotherapy target. TRIAL REGISTRATION: This clinical trial has been registered at the Chictr.org.cn registry system on 21/08/2018 (ChiCTR1800017910).

Aminoguanidine-Catalyzed Reductive Cyclization of o-Phenylenediamines with CO2 in the Presence of Triethoxysilane.

An inexpensive and efficient aminoguanidine-catalyzed reductive cyclization of o-phenylenediamines with CO2 in the presence of triethoxysilane is described. Various functionalized benzimidazoles, benzoxazole, and benzothiazole were synthesized in high yields. Mechanistic studies indicate that formic acid as a cocatalyst promotes the cyclization reaction.

Synthesis of 4-Alkylated 1,4-Dihydropyridines: Fe(II)-Mediated Oxidative Cascade Cyclization Reaction of Cyclic Ethers with Enaminones.

Syntheses of highly functionalized 4-alkylated 1,4-dihydropyridines (1,4-DHPs) from cyclic ethers and enaminones via iron(II)-mediated oxidative free radical cascade C(sp3)-H bond functionalization/C(sp3)-O bond cleavage/cyclization reaction have been first developed. This novel synthetic strategy offers an alternative method for the construction of 1,4-DHPs by using esters as the C4 sources, as well as expands the application of ethers in heterocycle synthesis.

Fe-mediated oxidative cascade [1 + 2 + 3]-cyclization/esterification reaction: synthesis of 4-alkylated 1,4-dihydropyridines.

An Fe-mediated four-component reaction of enaminones, anhydrides and tetrahydrofuran through a cascade [1 + 2 + 3]-cyclization/esterification process is presented. This protocol provides a new and effective method to construct 4-alkylated 1,4-dihydropyridines with an ester fragment. Cyclic ether is employed as the C4 source of 1,4-dihydropyridines for the first time.

ent-Pimarane Diterpenes from the Aerial Parts of Siegesbeckia pubescens.

Five new ent-pimarane diterpenes (1-5) and five known analogs (6-10) were isolated from the aerial parts of Siegesbeckia pubescens. Their structures, including absolute configurations, were determined by comprehensive spectroscopic methods especially 1D and 2D NMR and quantum chemical electronic circular dichroism calculations. All the isolated compounds were evaluated for their cytotoxicity against human BT549, A549 and H157 cancer cell lines. Among them, compounds 1 and 2 showed mild cytotoxicity against lung cancer cell lines H157 with IC50 values of 16.35±2.59 and 18.86±4.83 µM, respectively.

Grading for suction loss in small incision lenticule extraction.

INTRODUCTION: To observe the characteristics of suction loss in small-incision lenticule extraction (SMILE) and analyze the factors affecting the stability of the suction ring, classify and grade suction loss, and determine the principles for its prevention and control. METHODS: This study enrolled patients who underwent SMILE between June 2014 and June 2017. The relationship between the stability of the suction ring and suction loss was ascertained using surgical records and video recordings. The suction loss was classified and graded according to its characteristics and relationship with eye or head movement. The effect of target intervention on suction loss was observed. RESULTS: Suction loss can be divided into sudden and progressive types. According to the severity, the latter was divided into three grades (grade 1A or 1B, 2 and 3). Of the 1200 eyes (608 patients), two (0.17%) had sudden suction loss, and 132 (11%) had progressive suction loss. The superior part, inferior part, and other parts accounted for 63.4%, 19.3%, and 17.3% of progressive suction loss, respectively. The proportion of grades 1A, 1B, 2, and 3 suction loss was 53%, 34%, 12%, and 1%, respectively. The location of the threatened suction loss was opposite to the direction of the patient's head movement. After the intraoperative intervention, grades 1 and 2 did not develop into "actual" suction loss. CONCLUSIONS: Progressive suction loss was the most frequently observed suction loss during SMILE procedure. Grading suction loss can elucidate its underlying mechanism, which can guide targeted intervention measures to effectively control and reduce suction loss-induced damage, and further improve the safety and efficacy of SMILE.

BdFAR4, a root-specific fatty acyl-coenzyme A reductase, is involved in fatty alcohol synthesis of root suberin polyester in Brachypodium distachyon.

Suberin is a complex hydrophobic polymer of aliphatic and phenolic compounds which controls the movement of gases, water, and solutes and protects plants from environmental stresses and pathogenic infection. The synthesis and regulatory pathways of suberin remain unknown in Brachypodium distachyon. Here we describe the identification of a B. distachyon gene, BdFAR4, encoding a fatty acyl-coenzyme A reductase (FAR) by a reverse genetic approach, and investigate the molecular relevance of BdFAR4 in the root suberin synthesis of B. distachyon. BdFAR4 is specifically expressed throughout root development. Heterologous expression of BdFAR4 in yeast (Saccharomyces cerevisiae) afforded the production of C20:0 and C22:0 fatty alcohols. The loss-of-function knockout of BdFAR4 by CRISPR/Cas9-mediated gene editing significantly reduced the content of C20:0 and C22:0 fatty alcohols associated with root suberin. In contrast, overexpression of BdFAR4 in B. distachyon and tomato (Solanum lycopersicum) resulted in the accumulation of root suberin-associated C20:0 and C22:0 fatty alcohols, suggesting that BdFAR4 preferentially accepts C20:0 and C22:0 fatty acyl-CoAs as substrates. The BdFAR4 protein was localized to the endoplasmic reticulum in Arabidopsis thaliana protoplasts and Nicotiana benthamiana leaf epidermal cells. BdFAR4 transcript levels can be increased by abiotic stresses and abscisic acid treatment. Furthermore, yeast one-hybrid, dual-luciferase activity, and electrophoretic mobility shift assays indicated that the R2R3-MYB transcription factor BdMYB41 directly binds to the promoter of BdFAR4. Taken together, these results imply that BdFAR4 is essential for the production of root suberin-associated fatty alcohols, especially under stress conditions, and that its activity is transcriptionally regulated by the BdMYB41 transcription factor.

Exploring the Effect of Pd on the Oxygen Reduction Performance of Pt by In Situ Raman Spectroscopy.

Directly monitoring the oxygen reduction reaction (ORR) process in situ is very important to deeply understand the reaction mechanism and is a critical guideline for the design of high-efficiency catalysts, but there is still lack of definite in situ evidence to clarify the effect between adsorbed intermediates and the strain/electronic effect for enhanced ORR performance. Herein, in situ surface-enhanced Raman spectroscopy (SERS) was employed to detect the intermediates during the ORR process on the Au@Pd@Pt core/shell heterogeneous nanoparticles (NPs). Direct spectroscopic evidence of the *OOH intermediate was obtained, and an obvious red shift of the *OOH frequency was identified with the controllable shell thickness of Pd. Detailed experimental characterizations and density functional theory (DFT) calculations demonstrated that such improved ORR activity after inducing Pd into Au@Pt NPs can be attributed to the optimized adsorbate-substrate interaction due to the strain and electronic effect, leading to a higher Pt-O binding energy and a lower O-O binding energy, which was conducive to O-O dissociation and promoted the subsequent reaction. Notably, this work illustrates a relationship between the performance and strain/electronic effect via the intermediate detected by SERS and paves the way for the construction of ORR electrocatalysts with high performance.

Tangeretin protects mice from diet-induced metabolic inflammation via activating adipose lactate accumulation and macrophage M2 polarization.

Infiltration by adipose tissue macrophages (ATMs) and subsequent metabolic inflammation are the key causes of obesity-induced insulin resistance and metabolic disorders. In this study, we analyzed the potential protective effect of tangeretin, a key flavonoid found extensively in citrus peels, against diet-induced metabolic inflammation. Daily gavages of tangeretin at 20 mg/kg protected the mice from high fat diet (HFD) feeding-induced insulin resistance, ATMs activation, and M1 macrophage polarization. Interestingly, in vitro assays using bone marrow-derived macrophages (BMDMs) showed that tangeretin had only a minimal effect on macrophage polarization. Assays of central carbon metabolism (CCM) in adipose tissue showed that tangeretin treatment rerouted the carbon metabolism and caused lactate accumulation in the microenvironment. Co-culture assays further suggested that tangeretin enhanced M2 polarization of BMDMs when adipocytes were present, whereas blocking the lactate uptake in macrophages reversed the effect of tangeretin on polarization. Taken together, these findings indicated that tangeretin provided indirect protection from diet-induced ATMs activation by reprogramming glucose metabolism and promoting lactate accumulation that subsequently promoted macrophage M2 polarization and reduced inflammation.

Acyl-CoA desaturase ADS4.2 is involved in the formation of characteristic wax alkenes in young Arabidopsis leaves.

Monounsaturated alkenes are present in the cuticular waxes of diverse plants and are thought to play important roles in their interactions with abiotic and biotic factors. Arabidopsis (Arabidopsis thaliana) leaf wax has been reported to contain alkenes; however, their biosynthesis has not been investigated to date. Here, we found that these alkenes have mainly ω-7 and ω-9 double bonds in characteristically long hydrocarbon chains ranging from C33 to C37. A screening of desaturase-deficient mutants showed that a single desaturase belonging to the acyl-CoA desaturase (ADS) family, previously reported as ADS4.2, was responsible for introducing double bonds en route to the wax alkenes. ADS4.2 was highly expressed in young leaves, especially in trichomes, where the alkenes are known to accumulate. The enzyme showed strong activity on acyl substrates longer than C32 and ω-7 product regio-specificity when expressed in yeast (Saccharomyces cerevisiae). Its endoplasmic reticulum localization further confirmed that ADS4.2 has access to very-long-chain fatty acyl-CoA substrates. The upstream biosynthesis pathways providing substrates to ADS4.2 and the downstream reactions forming the alkene products in Arabidopsis were further clarified by alkene analysis of mutants deficient in other wax biosynthesis genes. Overall, our results show that Arabidopsis produces wax alkenes through a unique elongation-desaturation pathway, which requires the participation of ADS4.2.

Insights into the mechanism underlying remediation of Cr(VI) contaminated aquifer using nanoscale zero-valent iron@reduced graphene oxide.

Currently, there is an urgent need to develop functional nanomaterials for highly effective environmental remediation. However, the long-term effect of remedial materials upon their injection into contaminated aquifer has frequently been overlooked. Here, the remediation of Cr(VI) contaminated aquifer by reduced graphene oxide (rGO) supported nanoscale zero-valent iron (nZVI@rGO) was investigated from a long-term perspective. The performances of nZVI@rGO samples with different rGO loadings in the removal of aqueous Cr(VI) were evaluated in batch experiments. The electron transfer properties different nZVI@rGO samples were investigated by measuring their corrosive potentials using the steady-state Tafel polarization curves. The results show that the electron transfer efficiency between Cr(VI) and nZVI@rGO is enhanced owing to the large reactive conjugated structure of rGO. Besides, the surface passivation of nZVI is effectively retarded due to the uniform accommodation of Cr(III) precipitates on rGO. The structure and composition of nZVI@rGO before and after Cr(VI) removal were analyzed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The characterization results revealed that most Cr(VI) ions (∼90%) will be reduced to Cr(III) precipitates on nZVI@rGO as the passivation product. Accordingly, Cr(VI) ions tend to react more readily at less blocked regions on the surface of rGO, and a layer-by-layer passivation model on nZVI@rGO surface is proposed. Our results provide new insights into the mechanism underlying the long-term remediation of Cr(VI) contaminated aquifer using nZVI@rGO, which helps design new materials and approaches for practical in-situ remediation engineering.

Nicotine Inhibits the Cytotoxicity and Genotoxicity of NNK Mediated by CYP2A13 in BEAS-2B Cells.

Both tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and nicotine can be metabolized by cytochrome P450 2A13 (CYP2A13). Previous studies have shown that nicotine has a potential inhibitory effect on the toxicity of NNK. However, due to the lack of CYP2A13 activity in conventional lung cell lines, there had been no systematic in vitro investigation for the key target organ, the lung. Here, BEAS-2B cells stably expressing CYP2A13 (B-2A13 cells) were constructed to investigate the effects of nicotine on the cytotoxicity and genotoxicity of NNK. The results showed more sensitivity for NNK-induced cytotoxicity in B-2A13 cells than in BEAS-2B and B-vector cells. NNK significantly induced DNA damage, cell cycle arrest, and chromosomal damage in B-2A13 cells, but had no significant effect on BEAS-2B cells and the vector control cells. The combination of different concentration gradient of nicotine without cytotoxic effects and a single concentration of NNK reduced or even counteracted the cytotoxicity and multi-dimensional genotoxicity in a dose-dependent manner. In conclusion, CYP2A13 caused the cytotoxicity and genotoxicity of NNK in BEAS-2B cells, and the addition of nicotine could inhibit the toxicity of NNK.

Characterization of an alkylresorcinol synthase that forms phenolics accumulating in the cuticular wax on various organs of rye (Secale cereale).

Alkylresorcinols are bioactive compounds produced in diverse plant species, with chemical structures combining an aliphatic hydrocarbon chain and an aromatic ring with characteristic hydroxyl substituents. Here, we aimed to isolate and characterize the enzyme that forms the alkylresorcinols accumulating in the cuticular wax on the surface of all above-ground organs of rye. Based on sequence homology with other type-III polyketide synthases, a candidate alkylresorcinol synthase was cloned. Yeast heterologous expression showed that the enzyme, ScARS, is highly specific for the formation of the aromatic resorcinol ring structure, through aldol condensation analogous to stilbene synthases. The enzyme accepts long-chain and very-long-chain acyl-CoA starter substrates, preferring saturated over unsaturated chains. It typically carries out three rounds of condensation with malonyl-CoA prior to cyclization, with only very minor activity for a fourth round of malonyl-CoA condensation and cyclization to 5-(2'-oxo)-alkylresorcinols or 5-(2'-hydroxy)-alkylresorcinols. Like other enzymes involved in cuticle formation, ScARS is localized to the endoplasmic reticulum. ScARS expression patterns were found correlated with alkylresorcinol accumulation during leaf development and across different rye organs. Overall, our results thus suggest that ScARS synthesizes the cuticular alkylresorcinols found on diverse rye organ surfaces.

Extraction, structural characterization, and antioxidant and immunomodulatory activities of a polysaccharide from Notarchus leachii freeri eggs.

The crude polysaccharides (NLCEP) were extracted from Notarchus leachii freeri eggs strings by the saltextractionmethod. The extraction conditions were optimized using the single-factorexperimentmethod and response surface method (RSM). The results showed that the maximum extraction yield of NLCEP was obtained under the following conditions: NaCl solution concentration of 2.96 %, raw material to liquid ratio of 1: 40 g/mL, extraction time of 2 h and extraction temperature of 69 °C. A new novel pure polysaccharide fraction named as NLCEPs-1 was fractionated from NLCEP by using DEAE-Cellulose 52 and Sephadex G-100. Its structure and immunomodulatory and antioxidant activities were analyzed. The results exhibited that the molecular weight of NLCEPs-1 was 31.4 kDa and it was composed of rhamnose, glucose, galactose, xylose and arabinose in the molar percentage of 11.128: 63.770: 5.439: 6.585: 13.077. The backbone of NLCEPs-1 was mainly consisted of â†’ )4-α-d-Glcp (1→, →6)-α-d-Glcp (1→, →1)-ß-d-Galp and ß-d-Galp-(1→. NLCEPs-1 exhibited the strong antioxidant activity in scavenging ability of various free radicals and immunomodulatory activity by the enhancement of the pinocytic capacity, nitric oxide (NO) and cytokines.