ß-Cyclodextrin network crosslinked by novel phosphonium-based tetrakiscarboxylic acid derived from PH3 tail gas: Synthesis and application for rapid removal of organic dyes from wastewater.

Organic dyes, such as methyl orange (MO), Congo red (CR), crystal violet (CV) and methylene blue (MB), are common organic pollutants existing in wastewater. Therefore, the exploration of bio-based adsorbents for the efficient removal of organic dyes from wastewater has gained many attentions. Here, we report a PCl3-free synthetic method for the synthesis of phosphonium-containing polymers, in which the prepared tetrakis(2-carboxyethyl) phosphonium chloride-crosslinked ß-cyclodextrin (TCPC-ß-CD) polymers were applied to the removal of dyes from water. The effects of contact time, pH (1-11), and dye concentration were investigated. The selected dye molecules could be captured by the host-gest inclusion of ß-CD cavities, and the phosphonium and carboxyl groups in the polymer structure would respectively facilitate the removal of cationic dyes (MB and CV) and anionic dyes (MO and CR) via electrostatic interactions. In a mono-component system, over 99 % of MB could be removed from water within the first 10 min. Based on the Langmuir model, the calculated maximum adsorption capacities of MO, CR, MB, and CV were 180.43, 426.34, 306.57, and 470.11 mg/g (or 0.55, 0.61, 0.96 and 1.15 mmol/g), respectively. Additionally, TCPC-ß-CD was easily regenerated using 1 % HCl in ethanol, and the regenerative adsorbent still showed high removal capacities for MO, CR, and MB even after seven treatment cycles.

Comparative Investigation on the Phytochemicals and Biological Activities of Jackfruit (Artocarpus heterophyllus Lam.) pulp from Five Cultivars.

Jackfruit is one of the major tropical fruits, but information on the phytochemicals and biological benefits of its pulp is limited. In this study, the phytochemicals and biological activities including antioxidant, antitumor and anti-inflammatory activities of five jackfruit pulp cultivars (M1, M2, M3, M7 and T5) were comparatively investigated. A total of 11 compounds were identified in all cultivars of jackfruit pulp, among which 4-hydroxybenzoic acid, caffeic acid, ferulic acid and tryptophan N-glucoside were reported for the first time in jackfruit. T5 exhibited the highest total phenolic content (7.69 ± 0.73 mg GAE/g DW), antioxidant capacity (109.8, 96.7 and 207 mg VCE/g DW for DPPH, ABTS and FRAP, respectively), antitumor activity (80.31%) and anti-inflammatory activity (78.44%) among five cultivars. These results can provide a reference for growers to choose jackfruit cultivar and offer an insight into the industrial application of jackfruit pulp derived-products.

Tough complex hydrogels transformed from highly swollen polyelectrolyte hydrogels based on Cu2+ coordination with anti-bacterial properties.

The development of broad-spectrum anti-bacterial tough hydrogels without antibiotics remains a challenge in biomedical applications. In this study, we have synthesized a novel tough anti-bacterial complex hydrogel based on Cu2+ coordination. A swollen and weak poly(acrylamide-co-4-vinylbenzyl-(trihydroxymethyl-phosphonium)chloride) (P(AAm-co-VBzTHPC)) hydrogel was prepared by the radical copolymerization of AAm and VBzTHPC monomer solutions, followed by immersion in CuSO4 solution to coordinate with Cu2+ to form a strong and tough hydrogel. Fourier transform infrared (FTIR) spectra and X-ray photoelectron spectra (XPS) were used to characterize the coordination structure between phosphorus and oxygen atoms in the VBzTHPC monomer and copper ions. The water content and mechanical properties of the obtained hydrogel varied with gel composition. The prepared toughened hydrogel exhibited excellent anti-bacterial performance because of the introduction of copper ion coordination and the slow release of copper ions, with bacterial viability of 5.1% when the mole fraction of VBzTHPC was 10 mol%. Cell viability when cocultured with the toughened hydrogel was above 85% using the Cell Counting Kit-8 (CCK-8) method, indicating the good biocompatibility of the hydrogel. Compared with the control group experiment in vivo, this tough hydrogel can also promote wound healing, making it a promising candidate for wound dressing.

Isoquinoline Alkaloids as Protein Tyrosine Phosphatase Inhibitors from a Deep-Sea-Derived Fungus Aspergillus puniceus.

Puniceusines A-N (1-14), 14 new isoquinoline alkaloids, were isolated from the extracts of a deep-sea-derived fungus, Aspergillus puniceus SCSIO z021. Their structures were elucidated by spectroscopic analyses. The absolute configuration of 9 was determined by ECD calculations, and the structures of 6 and 12 were further confirmed by a single-crystal X-ray diffraction analysis. Compounds 3-5 and 8-13 unprecedentedly contained an isoquinolinyl, a polysubstituted benzyl or a pyronyl at position C-7 of isoquinoline nucleus. Compounds 3 and 4 showed selective inhibitory activity against protein tyrosine phosphatase CD45 with IC50 values of 8.4 and 5.6 µM, respectively, 4 also had a moderate cytotoxicity towards human lung adenocarcinoma cell line H1975 with an IC50 value of 11.0 µM, and 14, which contained an active center, -C=N+, exhibited antibacterial activity. An analysis of the relationship between the structures, enzyme inhibitory activity and cytotoxicity of 1-14 revealed that the substituents at C-7 of the isoquinoline nucleus could greatly affect their bioactivity.

Pectin/Activated Carbon-Based Porous Microsphere for Pb2+ Adsorption: Characterization and Adsorption Behaviour.

The development of effective heavy metal adsorbents has always been the goal of environmentalists. Pectin/activated carbon microspheres (P/ACs) were prepared through simple gelation without chemical crosslinking and utilized for adsorption of Pb2+. Scanning electron microscopy (SEM) revealed that the addition of activated carbon increased the porosity of the microsphere. Texture profile analysis showed good mechanical strength of P/ACs compared with original pectin microspheres. Kinetic studies found that the adsorption process followed a pseudo-second-order model, and the adsorption rate was controlled by film diffusion. Adsorption isotherms were described well by a Langmuir isotherm model, and the maximum adsorption capacity was estimated to be 279.33 mg/g. The P/ACs with the highest activated carbon (P/AC2:3) maintained a removal rate over 95.5% after 10 adsorption/desorption cycles. SEM-energy-dispersive X-ray spectrum and XPS analysis suggested a potential mechanism of adsorption are ion exchange between Pb2+ and Ca2+, electronic adsorption, formation of complexes, and physical adsorption of P/ACs. All the above results indicated the P/ACs may be a good candidate for the adsorption of Pb2+.

Analysis of microbial community, physiochemical indices, and volatile compounds of Chinese te-flavor baijiu daqu produced in different seasons.

BACKGROUND: Chinese te-flavor baijiu (CTF), the most famous Chinese baijiu in Jiangxi province, China, is made from a unique daqu. Its characteristic style is closely related to the daqu used for fermentation. However, current studies on the effects of different production seasons on microbial communities, physicochemical indices, and volatile compounds in CTF daqu are very rare. RESULTS: The relationships of microbial communities, physicochemical indices, and volatile compounds in CTF daqu produced in summer (July and August) and autumn (September and October) were studied. The results of Illumina MiSeq sequencing indicated that there was greater bacterial diversity in the CTF daqu-7 (produced in July) and CTF daqu-8 (produced in August) and greater fungal diversity in the CTF daqu-9 (produced in September) and CTF daqu-10 (produced in October). The physicochemical indices of CTF daqu produced in different seasons were significantly different. It was determined that CTF daqu-9 had the highest esterification and liquefaction abilities. A total of 44 volatile compounds, including alcohols, esters, aldehydes, and ketones were identified in CTF daqu produced during different seasons. Among them, CTF daqu-9 had the greatest alcohol content. CONCLUSION: September (early autumn) is the best production period for CTF daqu. The results of the study provide a theoretical basis for the standardized and uniform production of Chinese baijiu. © 2021 Society of Chemical Industry.

Preparation of pectin/poly(m-phenylenediamine) microsphere and its application for Pb2+ removal.

Novel pectin/poly(m-phenylenediamine) (P/PmPDA) microspheres with different content of PmPDA were prepared by assembling PmPDA on the surface of pectin microsphere. The successful preparation was confirmed by the results of Fourier Transform Infrared spectra (FTIR), scanning electron microscopy (SEM) and elemental analysis. Compared with pectin microsphere, the Pb2+ adsorption performance of P/PmPDA microspheres was significantly improved. The results of batch adsorption experiments were in good agreement with the Langmuir isotherm model for Pb2+ adsorption, indicating the adsorption was monolayer. The maximum adsorption capacity of Pb2+ was found to be 390.9 mg/g. The kinetic adsorption process was well described by the pseudo-second-order model and chemical adsorption dominated the adsorption process. The potential mechanisms of Pb2+ adsorption were speculated as ion exchange and chelation, which were supported by X-ray photoelectron spectroscopy (XPS). The P/PmPDA microspheres showed good recyclability after five adsorption/desorption cycles. All these results indicated the potential of P/PmPDA microspheres for removing Pb2+.

Phosphonium Modification Leads to Ultrapermeable Antibacterial Polyamide Composite Membranes with Unreduced Thickness.

Water transport rate in network membranes is inversely correlated to thickness, thus superior permeance is achievable with ultrathin membranes prepared by complicated methods circumventing nanofilm weakness and defects. Conferring ultrahigh permeance to easily prepared thicker membranes remains challenging. Here, a tetrakis(hydroxymethyl) phosphonium chloride (THPC) monomer is discovered that enables straightforward modification of polyamide composite membranes. Water permeance of the modified membrane is ≈6 times improved, give rising to permeability (permeance × thickness) one magnitude higher than state-of-the-art polymer nanofiltration membranes. Meanwhile, the membrane exhibits good rejection (RNa2SO4 = 98%) and antibacterial properties under crossflow conditions. THPC modification not only improves membrane hydrophilicity, but also creates additional angstrom-scale channels in polyamide membranes for unimpeded transport of water. This unique mechanism provides a paradigm shift in facile preparation of ultrapermeable membranes with unreduced thickness for clean water and desalination.

Pb2+ adsorption by ethylenediamine-modified pectins and their adsorption mechanisms.

Ethylenediamine-modified pectins (EPs) with different degrees of amidation (DA) were prepared and characterized by Fourier Transform Infrared spectra (FTIR), elemental analysis, X-ray photoelectron spectroscopy (XPS). The prepared EPs were then used to remove Pb2+ from the aqueous solution. It was found that EPs with the highest DA (EP48) exhibited great removal efficiency of Pb2+ (≥94 %) at low concentrations of 40-80 mg/L. The zeta potential analysis showed that EP48 had the fastest increase in zeta potential when Pb2+ was continuously added and was the first to be electroneutralized. Particle size analysis further confirmed that EP48 was the first precipitated and formed a larger EP48-Pb2+ complex. The FTIR and XPS analyses indicated that Pb2+ was adsorbed via the ion exchange of carboxylic groups and chelation with acylamino and amino groups. These results suggested that the EP48 might be a promising adsorbent for the removal of low concentrations of Pb2+ in contaminated water.

A new pre-gelatinized starch preparing by gelatinization and spray drying of rice starch with hydrocolloids.

Rice starch with hydrocolloids (pectin, xanthan gum, sodium alginate or ι-carrageenan) was gelatinized and subsequently spray dried to prepare pre-gelatinized rice starch (PRS) with hydrocolloids (PRS-H). The PRS-H displayed concave granular shape with amorphous structure, indicating rice starch in PRS-H was completely gelatinized. Cold paste viscosity of PRS-H was enhanced in comparison with that of PRS. Especially, xanthan and ι-carrageenan increased cold paste viscosity of PRS-H more than pectin and alginate did. Cold paste viscosity of physically mixed PRS and hydrocolloids (PRS+H), and flow behavior of hydrocolloids themselves as well as gelatinized starch-hydrocolloids without spray drying (GRS-H) indicated interactions existed between starch and hydrocolloids during the preparation. Swelling power, water solubility index, and dynamic viscoelastic properties of PRS-H were also adjusted by different hydrocolloids. These results showed that premixing hydrocolloids with starch before gelatinization in method of spray drying would be a suitable methodology for manufacture PRS with altered properties.

Solubility Difference between Pectic Fractions from Creeping Fig Seeds.

Crude water-extracted pectin (WEP) isolated from creeping fig seeds were mainly fractionated into WEP-0.3 and WEP-0.4 fractions. Fractions were confirmed to be nonstarch, nonreducing sugars, nonpolyphenols and protein-unbounded acidic polysaccharides. Interestingly, a significant difference in solubility was found between WEP-0.3 (higher solubility than WEP) and WEP-0.4 (remarkably insoluble), which was consistent with the amorphous and porous sponge-like structure of WEP-0.3 as well as the crystalline and dense rod-like state of WEP-0.4. However, the result of the FT-IR spectra was contradicted by the solubility of WEP-0.4, which possessed the lowest degree of methoxylation and ought to possess the highest solubility. Through mineral analysis, a considerably high content of Ca2+ was found in WEP-0.4, suggesting that the low solubility of WEP-0.4 was probably attributable to the formation of microgels during dialysis. Therefore, metal divalent cations in the dialysate were suggested to be depleted for the dialysis of low methoxyl pectin.

Catgut implantation at acupoints increases the expression of glutamate aspartate transporter and glial glutamate transporter-1 in the brain of rats with spasticity after stroke.

Catgut implantation at acupoints has been shown to alleviate spasticity after stroke in rats. However, the underlying mechanisms are poorly understood. In this study, we used the rat middle cerebral artery occlusion model of stroke. Three days after surgery, absorbable surgical catgut sutures were implanted at Dazhui (GV14), Jizhong (GV6), Houhui, Guanyuan (CV4) and Zhongwan (CV12). The Zea Longa score was used to assess neurological function. The Modified Ashworth Scale was used to evaluate muscle tension. The 2,3,5-triphenyl-tetrazolium chloride assay was used to measure infarct volume. Immunohistochemical staining was performed for glutamate aspartate transporter (GLAST) and glial glutamate transporter-1 (GLT-1) expression. Western blot assay was used to analyze the expression of GLAST and GLT-1. Reverse transcription and polymerase chain reaction were carried out to assess the expression of GLAST and GLT-1 mRNAs. After catgut implantation at the acupoints, neurological function was substantially improved, muscle tension was decreased, and infarct volume was reduced in rats with spasticity after stroke. Furthermore, the expression of GLAST and GLT-1 mRNAs was increased on the injured (left) side. Our findings demonstrate that catgut implantation at acupoints alleviates spasticity after stroke, likely by increasing the expression of GLAST and GLT-1.

Dynamic high-pressure microfluidization assisting octenyl succinic anhydride modification of rice starch.

Octenyl succinic anhydride (OSA) modified starch is widely used in food industries. In this study, rice starch (RS) was pretreated by dynamic high-pressure microfluidization (DHPM) and subsequently modified by OSA. The influence of DHPM on OSA modification of rice starch was investigated. Results showed that DHPM pretreatment enhanced the degree of substitution by changing the morphology and crystallinity of rice starch. Compared with the rice starch modified by OSA without DHPM pretreatment (OSA-RS), the DHPM-pretreated OSA starch (DHPM-OSA-RS) presented higher peak viscosity and lower pasting temperature. DHPM-OSA-RS also exhibited better emulsifying activity and emulsion stability. This study suggested that DHPM will provide an opportunity to change the physicochemical properties of starch, with the resulting starch being more suitable for chemical modification.

Pluronics modified liposomes for curcumin encapsulation: Sustained release, stability and bioaccessibility.

The present work evaluated the feasibility of different pluronics (F127, F87 and P85) utilized as modifiers to improve the stability and bioaccessibility of curcumin liposomes (cur-Lps). Pluronics modified curcumin liposomes (cur-pluronic-Lps) were prepared by thin film evaporation combined with dynamic high pressure microfluidization. The particle size and polydispersity index of cur-pluronic-Lps was significantly lower than cur-Lps. Fourier transform infrared spectroscopy analysis revealed that curcumin was loaded in liposomes successfully and X-ray diffraction suggested that curcumin in the liposomes was in an amorphous state. In vitro release studies demonstrated that 73.4%, 63.9%, 66.7% and 58.9% curcumin released from cur-Lps, cur-F127-Lps, cur-F87-Lps and cur-P85-Lps, respectively. Compared with cur-Lps, cur-pluronic-Lps showed a slower release rate and lower cumulative release percentage for curcumin. Non-Fickian transport was the main release mechanism for cur-Lps, cur-F127-Lps and cur-F87-Lps, and typically the first-order model fitted cur-P85-Lps release. Stability studies (exposure to solutions of different pH and heat treatment) indicated that pluronics modification could enhance their pH stability and thermal stability. In vitro simulated gastrointestinal tract studies suggested that pluronics modification could significantly improve the absorption of cur-Lps. Bioaccessibility of curcumin liposomes increased in the following order: cur-Lps < cur-F87-Lps < cur-P85-Lps < cur-F127-Lps. These results may guide the potential application of pluronics modified liposomes as carriers of curcumin in nutraceutical and functional foods.

Molecular and Functional Properties of Protein Fractions and Isolate from Cashew Nut (Anacardium occidentale L.).

Some molecular and functional properties of albumin (83.6% protein), globulin (95.5% protein), glutelin (81.3% protein) as well as protein isolate (80.7% protein) from cashew nut were investigated. These proteins were subjected to molecular (circular dichroism, gel electrophoresis, scanning electron microscopy) and functional (solubility, emulsification, foaming, water/oil holding capacity) tests. Cashew nut proteins represent an abundant nutrient with well-balanced amino acid composition and could meet the requirements recommended by FAO/WHO. SDS-PAGE pattern indicated cashew nut proteins were mainly composed of a polypeptide with molecular weight (MW) of 53 kDa, which presented two bands with MW of 32 and 21 kDa under reducing conditions. The far-UV CD spectra indicated that cashew proteins were rich in ß-sheets. The surface hydrophobicity of the protein isolate was higher than that of the protein fractions. In pH 7.0, the solubility of protein fractions was above 70%, which was higher than protein isolate at any pH. Glutelin had the highest water/oil holding capacity and foaming properties. Protein isolate displayed better emulsifying properties than protein fractions. In summary, cashew nut kernel proteins have potential as valuable nutrition sources and could be used effectively in the food industry.

Dynamic High-Pressure Microfluidization-Treated Pectin under Different Ethanol Concentrations.

We previously reported that dynamic high-pressure microfluidization (DHPM) can degrade pectin in aqueous solution. In this study, we further investigated the effect of DHPM on pectin in water-ethanol systems. In the absence of DHPM treatment, it was found that pectin exhibited increased average particle size and unchanged average molecular weight, but a decline in reducing-sugar-ends content with the increase of ethanol concentrations (0⁻10% v/v). These results indicated that the addition of ethanol induced aggregation of pectin. During DHPM treatment, pectin underwent disaggregation and degradation under all measured ethanol concentrations. Disaggregation was enhanced but degradation was weakened with the increase of ethanol concentration. FT-IR and UV spectra indicated that demethylation but no ß-elimination occurred in the water-ethanol system during DHPM. Finally, the mechanism of DHPM-induced disaggregation and degradation of pectin under a water-ethanol system was updated. This work may help us to find a suitable condition for reducing the degradation of pectin during the process of homogenization.

Relating physicochemical properties of alginate-HMP complexes to their performance as drug delivery systems.

This study aims to analyze the effect of physicochemical properties of alginate-high methoxyl pectin (HMP) complexes on their performance as drug delivery systems. Rheology, textural properties and swelling behavior of alginate-HMP complexes were determined. HMP alone showed weak gelling ability. As ratio of alginate increased, gel capability, hardness and adhesiveness of gels increased, but swelling rate decreased. Bovine serum albumin (BSA) was used as a model drug and entrapped in the alginate-HMP beads. Morphology of beads was correlated with adhesiveness. Drug loading content and encapsulation efficiency were related to electrostatic interactions between BSA and alginate-HMP complexes. Drug release profiles were correlated with both texture and swelling properties of alginate-HMP complexes and morphology of beads in simulated gastric fluids, while release in simulated intestinal fluids was affected by drug loading content. This study gives enlightenment that pre-selection of encapsulation materials may be achieved prior to encapsulation based on physicochemical properties of materials.

Pathway and rate-limiting step of glyphosate degradation by Aspergillus oryzae A-F02.

Aspergillus oryzae A-F02, a glyphosate-degrading fungus, was isolated from an aeration tank in a pesticide factory. The pathway and rate-limiting step of glyphosate (GP) degradation were investigated through metabolite analysis. GP, aminomethylphosphonic acid (AMPA), and methylamine were detected in the fermentation liquid of A. oryzae A-F02, whereas sarcosine and glycine were not. The pathway of GP degradation in A. oryzae A-F02 was revealed: GP was first degraded into AMPA, which was then degraded into methylamine. Finally, methylamine was further degraded into other products. Investigating the effects of the exogenous addition of substrates and metabolites showed that the degradation of GP to AMPA is the rate-limiting step of GP degradation by A. oryzae A-F02. In addition, the accumulation of AMPA and methylamine did not cause feedback inhibition in GP degradation. Results showed that degrading GP to AMPA was a crucial step in the degradation of GP, which determines the degradation rate of GP by A. oryzae A-F02.

Phytochemical profiles and antioxidant activity of brown rice varieties.

The phytochemical content and antioxidant activity of eight varieties of brown rice (BR) are reported. The total phenolic contents of BR ranged from 72.45 to 120.13mg of gallic acid equiv./100g. The phenolics from bound fraction contributed 40.6-50.2% of the total phenolic content. The total flavonoid contents of BR ranged from 75.90 to 112.03mg catechin equiv./100g. The flavonoids from the bound fraction contributed 26.9-48.2% of total flavonoids. Trans-ferulic acid was the predominant phenolic acid in BR. Total trans-ferulic acid content ranged from 161.42 to 374.81µg/100g. The percentage of trans-ferulic acid in bound fraction ranged from 96.4% to 99.2%. Only α- and γ-tocopherols and -tocotrienols were detected in BR with α-tocopherol and γ-tocotrienol being the predominant. The total peroxyl radical scavenging capacity (PSC) of BR ranged from 18.29 to 40.33mg vitamin C equiv./100g. The bound fraction contributed 67.2-77.2% of total PSC.

Issues deserve attention in encapsulating probiotics: Critical review of existing literature.

Probiotic bacteria are being increasingly added to food for developing products with health-promoting properties. However, the efficacy of probiotics in commercial products is often questioned due to the loss of their viability during shelf storage and in human gastrointestinal tracts. Encapsulation of probiotics has been expected to provide protection to probiotics, but not many commercial products contain encapsulated and viable probiotic cells owing to various reasons. To promote the development and application of encapsulation technologies, this paper has critically reviewed previous publications with a focus on the areas where studies have fallen short, including insufficient consideration of structural effects of encapsulating material, general defects in encapsulating methods and issues in evaluation methodologies and risk assessments for application. Corresponding key issues that require further studies are highlighted. Some emerging trends in the field, such as current treads in encapsulating material and recently advanced encapsulation techniques, have also been discussed.