Search

A simplified and green strategy was provided for the synthesis of cellulose acetate. Cellulose acetate (CA) was isolated from the directly acetylated eucalyptus powder after hydrothermal treatment to selectively remove hemicellulose without delignification. The conversion rate of cellulose (90.75%) and the yield of the acetylated product (61.34%) were greatly improved by hydrothermal treatment, while the re-condensation of lignin during hydrothermal treatment made no adverse difference. The characterization results verified that the acetylated product was cellulose acetate with uniform molecular weight, good thermal stability and semi-crystalline structure. Moreover, CA was used to reinforce polylactic acid (PLA) films prepared by solvent casting. The PLA-CA composite with 5 wt% CA showed an increase of 80.63% in tensile strength and 59.51% in Young's modulus, and their density decreased from 1.2427 g/cm3 to 1.0028 g/cm3. The lightweight and excellent mechanical properties promote the application potential of biodegradable composites to replace petroleum-based plastics.

Lignin/tannin/ZnONP composite coatings were designed for paper-based green packaging. Multiple functions, such as high strength, moisture resistance, low air permeance, heat endurance, UV aging resistance, and antibacterial/mold properties, were successfully integrated into one biobased coating. Prepolymerization improved the physical properties of coatings at high lignin contents. The best ingredient ratio was: 40% lignin, 15% tannin, and 10% ZnONPs (based on tannin weight), and the as-prepared biocoating was labeled LTZn-10. After coated with LTZn-10, the tensile strength and bursting strength of the packaging were efficiently enhanced by more than 3 times and were dramatically increased by 51.6 and 5.6 times at the wet state, respectively, which reveals that the packaging has favorable moisture resistance and it can be used in high humidity environments. Scanning electron microscopy (SEM) proved that most of the pores on the paper were blocked by the coatings, which helped to decrease the air permeance by 10.3 times. Meanwhile, ZnONPs were evenly spread on the coatings, which endowed the packaging with excellent antibacterial/mold performance. No colony or mycelium was found in the test against Gram-negative/positive bacteria and eight common molds. Besides, antibacterial activity is only available while the bacteria come in contact with the coating and no active substances were released into the culture medium, which is a good property that can keep the cargo from contamination of antibacterial agents. In addition, the coated paper presented an improved Tg and thermal degradation temperature, indicating that the coated package has favorable thermostability and can maintain its outstanding physical properties in a wider temperature range. Lignin and tannin promoted the UV stability and service life of the coated paper, as a rare physical decrease was observed after UV aging for 72 h. The function-integrated biobased coating with favorable sustainability is a good candidate to be widely used in paper-based green packaging fields.

A Co(II)-catalyzed cycloaddition reaction of alkynyl ketones and 2-acetylpyridines using 2,2'-bipyridine as the ligand has been developed. These reactions have been realized through Co-catalyzed reductive coupling of two molecules of 2-acetylpyridine followed by regioselective insertion of the alkynone. It is the first example of regioselective cyclotrimerization of one molecule of alkyne and two molecules of monoketone to polysubstituted benzene derivatives in good to excellent yields. A mechanism involving the formation of a cobaltacyclopentane via homocoupling of 2-acetylpyridines is proposed, and it is supported by the DFT calculations.

A lignin-based PU coating was prepared for paper-based green packaging. Two representative diisocyanate were used to prepare the coatings. Due to the rigid aromatic, the physical properties of the TDI system reached the maximum below the lignin content of 40%. The HDI that contains flexible aliphatic chains alleviated the brittleness of coating, and it showed physical advantages when the lignin content was more than 50%. Owing to the high lignin content, the coating presented enhanced thermal stability. After coated with the lignin-based PU coatings, the dry tensile strength of coated paper was improved by 126%. Amazingly, the wet strength was increased from 0.31 to 12.6 MPa with an improvement nearly 40 times. Based on the coordination of lignin, Ag+ was introduced into the PU matrix, which imparted the coating with excellent antibacterial ability. The colony forming units of E. coli and S. aureus were both less than 1. However, no inhibition halo was observed, which indicated that the Ag was firmly anchored on the coating and the antibacterial ability is only available when the bacterial contact the coating surface. The lignin-based PU coating with favorable sustainability and properties shows great potential in paper-based green packaging fields.

Background Although previous studies have found that maternal fish intake is associated with fetal growth, the role of freshwater fish intake remains unknown. Objective Our aim was to examine the relationships of freshwater fish and n-3 polyunsaturated fatty acids (PUFAs) intake with the risk of small for gestational age (SGA) in Chinese pregnant women. Design This was a prospective analysis of data from the Tongji Birth cohort in Wuhan, China, from 2018 to 2021. Participants/settings This study included 1,701 pregnant women who had completed a food frequency questionnaire dietary assessment during mid-pregnancy. Main outcome measures Intake of fish was assessed by a semi-quantitative food frequency questionnaire. Total intake of n-3 PUFAs was the sum of data collected from both dietary and supplemental sources of n-3 PUFAs. Birth information was extracted from medical records. Statistical analyses Multivariate logistic regression models were applied to estimate odds ratios and 95% CIs. Results The median (interquartile range) intake of freshwater fish and total n-3 PUFAs was 12.1 (4.3 to 26.4) g/d and 68.2 (24.5 to 370.0) mg/d, respectively. Moderate intake of freshwater fish was associated with reduced risk of SGA. Compared with the lowest quintile (0–3.2 g/d), the multivariable-adjusted odds ratio for women in the fourth quintile of freshwater fish intake (17.9 to 30.0 g/d) was 0.50 (95% CI 0.25 to 0.96). We found a nonlinear association between freshwater fish intake and SGA risk (Pnonlinearity = .027). However, maternal n-3 PUFAs intake was not significantly associated with SGA risk, either from total intake or from dietary sources alone. Conclusions Moderate freshwater fish intake during pregnancy is associated with lower risk of SGA in a Chinese population. This finding provides supportive evidence for freshwater fish intake during pregnancy, particularly for the inland areas of developing countries.

Background. Asthma is a complex inflammatory disorder that plagues a large number of people. Schisandrin B is an active ingredient of the traditional Chinese herbal medicine Schisandra with various proven physiological activities such as anti-inflammatory and antioxidant activities. In this study, we explored the anti-inflammatory and antioxidant effects and provided the mechanistic insights into the activity of schisandrin B in a mouse model of ovalbumin- (OVA-) induced allergic asthma. Methods. Male BALB/c mice were sensitized and challenged with OVA to induce asthma and treated with various doses (15 mg/kg, 30 mg/kg, and 60 mg/kg) of SCH to alleviate the features of allergic asthma, airway hyperresponsiveness, inflammatory response, OVA-specific immunoglobulin (Ig)E level, and pathological injury. Results. Schisandrin B significantly attenuated the airway hyperresponsiveness induced by OVA. Moreover, schisandrin B administration suppressed inflammatory responses, reduced the level of IgE, and attenuated pathological injury. Mechanistically, schisandrin B treatment promoted the activation of nuclear erythroid 2-related factor 2 (Nrf2), but suppressed the stimulation of the NF-κB pathway caused by OVA. Conclusion. Taken together, our study suggests that schisandrin B attenuates the features of asthmatic lungs by inhibiting the NF-κB pathway and activating the Nrf2 signaling pathway.

A novel Fe-catalyzed protocol for the controllable synthesis of pyrido[2,3-b]indol-4-ones or indolo[3,2-b]quinolines has been developed by using indole-2-carboxylic derivatives as starting materials. Indole-2-carboxenamines were transformed into pyrido[2,3-b]indol-4-ones through intramolecular N–H/C–H coupling, in which a carbonyl 1,2-migration was involved. Whereas, when indole-2-carboxarylamines were employed, indolo[3,2-b]quinolones were produced through direct N–H/C–H coupling. The desired products were obtained under mild reaction conditions in moderate to good yields with wide substrate scope. The natural product quindolinone was conveniently prepared by this reaction.

A cobalt-catalyzed C H activation/cyclization of N-carbamoyl indole/benzamides with maleimides assisted by pyridinylmethylamine under mild reaction conditions is described. The synthetic strategy was developed to access imidazo[1,5-a]indole-/isoindolone-incorporated spirosuccinimides with a broad substrate scope and high regiospecificity.

Objective Obesity is now a worldwide disease and is mainly attributable to increased body fat deposition. In a growing number of epidemiological studies, lutein has been revealed to have different degrees of anti-obesity properties, but the potential underlying mechanisms that have been reported are limited. Therefore, we aimed to clarify the protective effects of lutein against excessive lipid accumulation, and we explored the role of SIRT1 and SIRT1-mediated pathways both in abdominal adipose tissue and mature 3T3-L1 cells during lutein administration. Methods In our design, male Sprague–Dawley rats were fed either control or high-fat diets with or without 25 mg/kg·bw/day lutein for 5 weeks. Additionally, differentiated 3T3-L1 cells were incubated with 40 μM lutein or 10 μM Ex527 for 24 h. Results Lutein supplementation decreased the body weight, abdominal fat index ratio, frequency and mean area of larger adipocytes in HE staining induced by the high-fat diet and then activated the expression of SIRT1 and thus upregulated FoxO1, ATGL, and HSL expression and downregulated SREBP-1, FAS, and ACC expression both in abdominal adipose tissue and differentiated 3T3-L1 cells. However, coincubation with Ex527 and lutein suppressed the activation of SIRT1 and reversed the expression of FoxO1, ATGL, HSL, SREBP-1, FAS, and ACC in comparison to those in the Lut group. Conclusions Overall, we suggest that the effects of lutein on attenuating excessive lipid accumulation are dependent on the SIRT1-mediated pathway in vivo and in vitro, which indicates that lutein administration may be a potential strategy for preventing excessive lipid accumulation and obesity.

Isoindigo (iI)-containing donor (D)–acceptor (A)-type polymers have rarely been used as electrochromic materials although their applications in the field of organic photoelectric devices have achieved significant progress in only a few years. Three conjugated polymers, namely, P1–P3, were synthesized via the random copolymerization of three units, including thiophene and 3,3-bis-decyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine (ProDOT-decyl2) as the D units, and alkyl-substituted isoindigo as the A unit, and the reactions were conducted by the Stille polymerization method. The results showed that the feed ratio of the D units to the A unit had a substantial effect on the electrochemical properties, optical band gap, color presentation, and electrochromic parameters (changes in transmittance, response time, coloration efficiency and persistence of optical contrasts for a long period) of the conjugated polymers. Polymers were easily obtained with the feed ratios (thiophene:iI:ProDOT) of 2:1:1, 4:1:3, and 5:1:4 for P1, P2 and P3, respectively. P1 exhibits a cyan color in the neutral state and a transmissive grey color in the oxidized state. Both P2 and P3 display a change from black to transmissive on conversion from the neutral to the oxidized state. An increase in the ProDOT content was helpful for enabling the extension of the absorption peak of the polymers across the entire spectrum and also improving the switching property of the polymers. In general, the introduction of iI as the A unit for the construction of D–A-type polymers provides the field of electrochromic devices with verifiable performance and deserves further investigation to obtain more promising electrochromic materials.

Rapeseed peptides were prepared by means of the combined methods of the laboratory bacteria enzyme synergy and the solid-state fermentation of rapeseed meal. The rapeseed peptides were separated and purified with the tumor cell in vitro anti-proliferative activity as an index. Moreover, a kind of rapeseed peptide component RSP-4-3-3 (rapeseed anti-tumor peptide RSP-4-3-3) with high activity was selected. Furthermore, by using reversed-phase high performance liquid chromatography (RP-HPLC) coupled with electrospray ionization mass spectrometry (ESI-MS/MS), the analysis result of its possible amino acid sequence showed that it was Trp-Thr-Pro (408.2 Da). Inverted microscope observation technology and western blot experiments were applied to explore the antitumor impact of the rapeseed peptide RSP-4-3-3 on tumor cells. The results showed that the rapeseed antitumor peptide RSP-4-3-3 could significantly change the morphological features of the HepG2 cells in vitro and cause apoptosis, thus inhibiting the proliferation of the HepG2 cells.

An effective high-speed countercurrent chromatography method was successfully established by using ionic liquids as the modifier of the two-phase solvent system. Adding a small amount of ionic liquids significantly shortens the separation time and improves the separation efficiency. The conditions of ionic-liquid-modified high-speed countercurrent chromatography including solvent systems, types and content of added ionic liquids, and ionic liquids post-treatment were investigated. The established method was successfully applied to separate alkaloids from lotus leaves using a two-phase solvent system composed of petroleum ether/ethyl acetate/methanol/water/[C4mim][BF4] (1:5:1:5:0.15, v/v). Four alkaloids pronuciferine (1.7 mg), N-nornuciferine (4.3 mg), nuciferine (3.1 mg), and roemerine (2.1 mg) were obtained with the purities of 90.53, 92.25, 99.86 and 98.63%, respectively from 100 mg crude extract of lotus leaves. The results indicated that ionic-liquid-modified high-speed countercurrent chromatography method was suitable for alkaloid separation from lotus leaves and would be a promising method for the separation of alkaloids from other natural products. This article is protected by copyright. All rights reserved

Summary Based on previously determined preparation conditions of rapeseed peptides by mixed solid-state fermentation, the optimisation of the fermentation conditions of rapeseed meal to obtain rapeseed peptides using the cooperation of mixed bacteria and a neutral protease was studied. The appropriate parameters of synergistic fermentation using mixed bacteria and a neutral protease were as follows: initial fermentation pH of 6.5, fermentation temperature of 35 °C, fermentation time of 2 day and the added amount of neutral protease of 200 U g−1 weight of dry rapeseed meal. Furthermore, Tricine-SDS-PAGE analysis of the rapeseed peptide extracts was performed, and the amino acid composition of the rapeseed meal before and after fermentation was evaluated. Then, the analysis of cytotoxicity and antiproliferative activity of the extracts on human HepG2 liver cancer cells, human MCF-7 breast cancer cells and human HeLa cervical cancer cells indicated that the extracts had an antiproliferative effect on the cancer cells.

Consumption of whole grains has been associated with reduced risk of developing major chronic diseases. These health benefits have been attributed in part to their unique phytochemicals. Little is known about the complete profiles of phytochemicals and antioxidant activities of different adlay varieties. The objectives of this study were to determine the phytochemicals profiles of the three adlay varieties, including both free and bound of total phenolics and total flavonoids, and to determine the total antioxidant activity of adlay. The free, bound, and total phenolic contents of adlay samples ranged from 31.23 to 45.19 mg of gallic acid equiv/100 g of sample, from 28.07 to 30.86 mg of gallic acid equiv/100 g of sample, and from 59.30 to 76.04 mg of gallic acid equiv/100 g of sample, respectively. On average, the bound phenolics contributed 45.3% of total phenolic content of the adlay varieties analyzed. The free, bound, and total flavonoid contents of adlay samples ranged from 6.21 to 18.24 mg of catechin equiv/100 g, from 18.68 to 35.27 mg of catechin equiv/100 g, and from 24.88 to 52.86 mg of catechin equiv/100 g, respectively. The average values of bound flavonoids contributed 71.1% of total flavonoids of the adlay varieties analyzed. The percentage contribution of flavonoid content to phenolic content of free, bound, and total ranged from 11.6 to 35.2%, from 50.5 to 66.8%, and from 24.6 to 50.5%. The free, bound, and total oxygen radical absorbance capacity (ORAC) values of adlay samples ranged from 231.9 to 316.6 mg of Trolox equiv/100 g, from 209.0 to 351.4 mg of Trolox equiv/100 g, and from 440.9 to 668.0 mg of Trolox equiv/100 g, respectively. The average ORAC values of bound phytochemicals contributed 48.1% of total antioxidant activity of the adlay varieties analyzed. The content of total polyphenol and the antioxidant capacity are obviously different among different species. Liaoning 5 adlay and Longyi 1 adlay are significantly better than Guizhou heigu adlay. The adlay extracts have obvious proliferate inhibition on human liver cancer cells, and substantially in the experimental concentration range, the adlay sample itself has no cytotoxicity. Knowing the phytochemical profiles and antioxidant activity of adlay gives insights to its potential application to promote health.