[Research progress in macrophage migration inhibitory factor (MIF) in tumor immune response].

Macrophage migration inhibitor factor (MIF), as a pro-inflammatory and oncogenic cytokine, is highly expressed in a variety of malignant tumors and recruits tumor cells or immune cells into the tumor microenvironment. MIF affects the development of tumor by altering the tumor microenvironment. In the process of tumor, MIF not only plays an anti-inflammatory role, but also promotes tumorigenesis by immune escape and immune tolerance.This is closely related to immune cells that play a role in the tumor immune response, mainly including natural killer (NK) cells, macrophages, dendritic cells, B cells, T cells and myeloid-derived suppressor cells. The article summarizes the role of MIF in tumor immune and the relationship between MIF and the development of malignant tumors, in order to provide new ideas and possible therapy for tumor treatment.

A combined transcriptomics and proteomics approach to reveal the mechanism of AEE relieving hyperlipidemia in ApoE-/- mice.

Hyperlipidemia caused by abnormal lipid metabolism has reached epidemic proportions. This phenomenon is also common in companion animals. Previous studies showed that AEE significantly improves abnormal blood lipids in hyperlipidemia rats and mice, but its mechanism is still not clear enough. In this study, the mechanism and potential key pathways of AEE on improving hyperlipidemia in mice were investigated through the transcriptome and proteome study of ApoE-/- mice liver and the verification study on high-fat HepG2 cells. The results showed that AEE significantly decreased the serum TC and LDL-C levels of hyperlipidemia ApoE-/- mice, and significantly increased the enzyme activity of CYP7A1. After AEE intervention, the results of mice liver transcriptome and proteome showed that differential genes and proteins were enriched in lipid metabolism-related pathways. The results of RT-qPCR showed that AEE significantly regulated the expression of genes related to lipid metabolism in mice liver tissue. AEE significantly upregulated the protein expression of CYP7A1 in hyperlipidemia ApoE-/- mice liver tissue. The results in vitro showed that AEE significantly decreased the levels of TC and TG, and improved lipid deposition in high-fat HepG2 cells. AEE significantly increased the expression of CYP7A1 protein in high-fat HepG2 cells. AEE regulates the expression of genes related to lipid metabolism in high-fat HepG2 cells, mainly by FXR-SHP-CYP7A1 and FGF19-TFEB-CYP7A1 pathways. To sum up, AEE can significantly improve the hyperlipidemia status of ApoE-/- mice and the lipid deposition of high-fat HepG2 cells, and its main pathway is probably the bile acid metabolism-related pathway centered on CYP7A1.

[Advance of research on Hereditary spastic paraplegia type 4].

Spastic paraplegia type 4 (SPG4) is the most common type of autosomally inherited spastic paraplegia. Its main clinical features include typical simple hereditary spastic paraplegia, with neurological impairments limited to lower limb spasticity, hypertonic bladder dysfunction, and mild weakening of lower limb vibration sensation, without accompanying features such as nerve atrophy, ataxia, cognitive impairment, seizures, and muscle tone disorders. SPAST is the main pathogenic gene underlying SPG4, and various pathogenic SPAST variants have been discovered. This disease has featured a high degree of clinical heterogeneity, and the same pathogenic variant can have different age of onset and severity among different patients and even within the same family. There is a lack of systematic research on the correlation between the genotype and phenotype of SPG4, and the pathogenic mechanism has remained controversial. This article has provided a review for the clinical characteristics, pathogenic gene characteristics, correlation between the genotype and phenotype, and pathogenic mechanism of this disease, with an aim to provide reference for its clinical diagnosis and treatment.

Computational simulations on the taste mechanism of steviol glycosides based on their interactions with receptor proteins.

Steviol glycoside (SG) is a potential natural sugar substitute. The taste of various SG structures differ significantly, while their mechanism has not been thoroughly investigated. To investigate the taste mechanism, molecular docking simulations of SGs with sweet taste receptor TAS1R2 and bitter taste receptor TAS2R4 were conducted. The result suggested that four flexible coils (regions) in TAS1R2 constructed a geometry open pocket in space responsible for the binding of sweeteners. Amino acids that form hydrogen bonds with sweeteners are located in different receptor regions. In bitterness simulation, fewer hydrogen bonds were formed with the increased size of SG molecules. Particularly, there was no interaction between RM and TAS2R4 due to its size, which explains the non-bitterness of RM. Molecular dynamics simulations further indicated that the number of hydrogen bonds between SGs and TAS1R2 was maintained during a simulation time of 50 ns, while sucrose was gradually released from the binding site, leading to the break of interaction. Conclusively, the high sweetness intensity of SG can be attributed to its durative concurrent interaction with the receptor's binding site, and such behavior was determined by the structure feature of SG.

A novel truncated variant in SPAST results in spastin accumulation and defects in microtubule dynamics.

OBJECTIVE: Haploinsufficiency is widely accepted as the pathogenic mechanism of hereditary spastic paraplegias type 4 (SPG4). However, there are some cases that cannot be explained by reduced function of the spastin protein encoded by SPAST. The aim of this study was to identify the causative variant of SPG4 in a large Chinese family and explore its pathological mechanism. MATERIALS AND METHODS: A five-generation family with 49 members including nine affected (4 males and 5 females) and 40 unaffected individuals in Mongolian nationality was recruited. Whole exome sequencing was employed to investigate the genetic etiology. Western blotting and immunofluorescence were used to analyze the effects of the mutant proteins in vitro. RESULTS: A novel frameshift variant NM_014946.4: c.483_484delinsC (p.Val162Leufs*2) was identified in SPAST from a pedigree with SPG4. The variant segregated with the disease in the family and thus determined as the disease-causing variant. The c.483_484delinsC variant produced two truncated mutants (mutant M1 and M87 isoforms). They accumulated to a higher level and presented increased stability than their wild-type counterparts and may lost the microtubule severing activity. CONCLUSION: SPAST mutations leading to premature stop codons do not always act through haploinsufficiency. The potential toxicity to the corticospinal tract caused by the intracellular accumulation of truncated spastin should be considered as the pathological mechanism of SPG4.

Single-Molecule Detection of α-Synuclein Oligomers in Parkinson's Disease Patients Using Nanopores.

α-Synuclein (α-Syn) is an intrinsically disordered protein whose aggregation in the brain has been significantly implicated in Parkinson's disease (PD). Beyond the brain, oligomers of α-Synuclein are also found in cerebrospinal fluid (CSF) and blood, where the analysis of these aggregates may provide diagnostic routes and enable a better understanding of disease mechanisms. However, detecting α-Syn in CSF and blood is challenging due to its heterogeneous protein size and shape, and low abundance in clinical samples. Nanopore technology offers a promising route for the detection of single proteins in solution; however, the method often lacks the necessary selectivity in complex biofluids, where multiple background biomolecules are present. We address these limitations by developing a strategy that combines nanopore-based sensing with molecular carriers that can specifically capture α-Syn oligomers with sizes of less than 20 nm. We demonstrate that α-Synuclein oligomers can be detected directly in clinical samples, with minimal sample processing, by their ion current characteristics and successfully utilize this technology to differentiate cohorts of PD patients from healthy controls. The measurements indicate that detecting α-Syn oligomers present in CSF may potentially provide valuable insights into the progression and monitoring of Parkinson's disease.

AEE alleviates ox-LDL-induced lipid accumulation and inflammation in macrophages.

Atherosclerosis is a chronic immune inflammatory disease. Aspirin eugenol ester (AEE) is a novel safe and non-toxic compound with many pharmacological effects such as anti-inflammatory, anti-hyperlipidemic and anti-thrombotic action. In order to investigate the effect of AEE on the inhibition of aortic lipid plaque formation and macrophage-derived foam cell formation induced by oxidized low density lipoprotein (ox-LDL), in vivo atherosclerosis model by feeding ApoE-/- mice with a high-fat diet and foam cells formation in vitro model by ox-LDL-induced RAW264.7 macrophages were established. It was found that AEE decreased the levels of TC and LDL-C in serum, and the plaque formation area and lipid accumulation in the aortic intima of ApoE-/- mice. In vitro studies showed that AEE could prevent the uptake of ox-LDL and reduce the contents of TC and FC in cells. AEE enhanced the cholesterol efflux by increasing the expression of ABCA1, ABCG1 and PPARγ, which effectively alleviated excess cholesterol accumulated in the cells. Meanwhile, AEE also reduced the secretion and expression of inflammatory factors in the cells. In addition, AEE could reverse the action of PPARγ inhibitor T0070907 and/or ox-LDL. Therefore, AEE may become an effective candidate drug for the prevention of atherosclerosis.

The digestive behavior of pectin in human gastrointestinal tract: a review on fermentation characteristics and degradation mechanism.

Pectin is widely spread in nature and it develops an extremely complex structure in terms of monosaccharide composition, glycosidic linkage types, and non-glycosidic substituents. As a non-digestible polysaccharide, pectin exhibits resistance to human digestive enzymes, however, it is easily utilized by gut microbiota in the large intestine. Currently, pectin has been exploited as a novel functional component with numerous physiological benefits, and it shows a promising prospect in promoting human health. In this review, we introduce the regulatory effects of pectin on intestinal inflammation and metabolic syndromes. Subsequently, the digestive behavior of pectin in the upper gastrointestinal tract is summarized, and then it will be focused on pectin's fermentation characteristics in the large intestine. The fermentation selectivity of pectin by gut bacteria and the effects of pectin structure on intestinal microecology were discussed to highlight the interaction between pectin and bacterial community. Meanwhile, we also offer information on how gut bacteria orchestrate enzymes to degrade pectin. All of these findings provide insights into pectin digestion and advance the application of pectin in human health.

Amino-terminated SiO2-Al2O3 composite aerogels from fly ash for improved removal of Cu2+ and Pb2+ ions in wastewater: one-pot synthesis, excellent adsorption capacity and mechanism.

In this study, by using a sol-gel grafting-atmospheric drying method, amino-terminated SiO2-Al2O3 composite aerogels, namely 3-aminopropyltriethoxysilane (APTES) or 3-(2-amino-ethoxy) propylmethyldimethoxysilane (AEAPMDS) modified SiO2-Al2O3 aerogels (AMSAAs), were synthesized from the fly ash and characterized by field-emission scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy etc.. And the AMSAAs were verified as excellent adsorbents for removing heavy metal ions (Cu2+ and Pb2+ ions) from wastewater. The effects of modification conditions and testing parameters including pH value, adsorbent dose, initial ions concentration, adsorption time and temperature were systematically investigated. Results demonstrated that 0.2 mol/L APTES modified aerogels (0.2APTES-SAAs) possessed the best adsorption properties. Under the optimal pH value of 4.0-6.0 and the adsorbent dose of 0.4-0.6 g/L, the equilibrium adsorption capacities of Cu2+ and Pb2+ ions were as high as 195 mg/g and 500 mg/g within 20-30 min, respectively. The adsorption processes were agreed fairly well with Freundlich isotherm adsorption model and the pseudo-second-order kinetic model, which indicated that the adsorption processes were heterogeneous multilayer adsorption and controlled by the chemical reaction between AMSAAs and heavy metal ions. The obtained adsorption thermodynamic parameters (ΔH°, ΔS° and ΔG°) revealed that the adsorption processes were exothermic and spontaneous with decreased randomness at the solid-liquid interface. The excellent recyclability of as-prepared AMSAAs proved as economically promising adsorbents for practical applications.

Injectable decellularized dental pulp matrix-functionalized hydrogel microspheres for endodontic regeneration.

The sufficient imitation of tissue structures and components represents an effective and promising approach for tissue engineering and regenerative medicine applications. Dental pulp disease is one of the most common oral diseases, although functional pulp regeneration remains challenging. Herein, we propose a strategy that employs hydrogel microspheres incorporated with decellularized dental pulp matrix-derived bioactive factors to simulate a pulp-specific three-dimensional (3D) microenvironment. The dental pulp microenvironment-specific microspheres constructed by this regenerative strategy exhibited favorable plasticity, biocompatibility, and biological performances. Human dental pulp stem cells (hDPSCs) cultured on the constructed microspheres exhibited enhanced pulp-formation ability in vitro. Furthermore, the hDPSCs-microcarriers achieved the regeneration of pulp-like tissue and new dentin in a semi-orthotopic model in vivo. Mechanistically, the decellularized pulp matrix-derived bioactive factors mediated the multi-directional differentiation of hDPSCs to regenerate the pulp tissue by eliciting the secretion of crucial bioactive cues. Our findings demonstrated that a 3D dental pulp-specific microenvironment facilitated by hydrogel microspheres and dental pulp-specific bioactive factors regenerated the pulp-dentin complex and could be served as a promising treatment option for dental pulp disease. STATEMENT OF SIGNIFICANCE: Injectable bioscaffolds are increasingly used for regenerative endodontic treatment. Despite their success related to their ability to load stem cells, bioactive factors, and injectability, conventional bulk bioscaffolds have drawbacks such as ischemic necrosis in the central region. Various studies have shown that ischemic necrosis in the central region can be corrected by injectable hydrogel microspheres. Unfortunately, pristine microspheres or microspheres without dental pulp-specific bioactive factor would oftentimes fail to regulate stem cells fates in dental pulp multi-directional differentiation. Our present study reported the biofabrication of dental pulp-derived decellularized matrix functionalized gelatin microspheres, which contained dental pulp-specific bioactive factors and have the potential application in endodontic regeneration.

Whole-Genome Survey Analyses Provide a New Perspective for the Evolutionary Biology of Shimofuri Goby, Tridentiger bifasciatus.

The shimofuri goby (Tridentiger bifasciatus) is a small and highly adaptable goby, distributed along the coasts of China, the Sea of Japan, and the west coastal and estuarine areas of the Northwest Pacific. Next-generation sequencing was used to generate genome-wide survey data to provide essential characterization of the shimofuri goby genome and for the further mining of genomic information. The genome size of the shimofuri goby was estimated to be approximately 887.60 Mb through K-mer analysis, with a heterozygosity ratio and repeat sequence ratio of 0.47% and 32.60%, respectively. The assembled genome was used to identify microsatellite motifs (Simple Sequence Repeats, SSRs), extract single-copy homologous genes and assemble the mitochondrial genome. A total of 288,730 SSRs were identified. The most frequent SSRs were dinucleotide repeats (with a frequency of 61.15%), followed by trinucleotide (29.87%), tetranucleotide (6.19%), pentanucleotide (1.13%), and hexanucleotide repeats (1.66%). The results of the phylogenetic analysis based on single-copy homologous genes showed that the shimofuri goby and Rhinogobius similis can be clustered into one branch. The shimofuri goby was originally thought to be the same as the chameleon goby (Tridentiger trigonocephalus) due to their close morphological resemblance. However, a complete mitochondrial genome was assembled and the results of the phylogenetic analysis support the inclusion of the shimofuri goby as a separate species. PSMC analysis indicated that the shimofuri goby experienced a bottleneck event during the Pleistocene Glacial Epoch, in which its population size decreased massively, and then it began to recover gradually after the Last Glacial Maximum. This study provides a reference for the further assembly of the complete genome map of the shimofuri goby, and is a valuable genomic resource for the study of its evolutionary biology.

[Analysis of pathogenic gene variant in two children with Treacher-Collins syndrome].

OBJECTIVE: To explore the clinical and genetic characteristics of two children with a clinical diagnosis of Treacher Collins syndrome (TCS). METHODS: Whole-exome sequencing was used to screen potential variants in the two children. Confirmation of suspected variants was performed through Sanger sequencing, multiplex ligation dependent probe amplification and real-time PCR in probands and their parents. RESULTS: A heterozygous deletion variant, c.4357_4360delGAAA, was detected in case one, while was de novo and verified by Sanger sequencing. The variant was classified as pathogenic (PVS1 +PM2+PM6) according to ACMG guideline. The heterozygous deletion of exon 1-7 was seen in the same gene in case 2, which MLPA verified as heterozygous deletion of exon 1-6. This deletion was inherited from the father with a normal phenotype, and the father's TCOF1 gene was suspected to be chimeric heterozygous deletion of exon 1-6 verified by MLPA. CONCLUSION: The identified variants in the TCOF1 gene probably underlie the two cases of TCS. There was no apparent correlation between genotype and phenotype. In addition, it shows a high interfamilial variability ranging from normal to full presentation of TCS. Genetic detection provided clinical diagnosis and genetic counselling for TCS patients.

Fisetin-induced cell death in human ovarian cancer cell lines via zbp1-mediated necroptosis.

BACKGROUND: Among reproductive cancers, ovarian cancer leads to the highest female mortality rate. Fisetin, a natural flavonoid, exerts pharmacological effects, inhibiting cancer growth with various origins. Although multiple mechanisms are involved in regulating cell death, it is still unclear whether and how fisetin exhibits anticancer effects on ovarian cancer. The present study aimed to evaluate cell apoptotic and necroptotic processes occurring in ovarian carcinoma (OC) cell lines induced by fisetin. METHODS: Cell growth was evaluated by MTT assay in OC cell lines treated with or without fisetin. Annexin V/propidium iodide staining followed by flow cytometry was used to characterize fisetin-induced cell death. The apoptotic process was suppressed by z-VAD intervention, and cell necroptosis was assessed by introducing ZBP1-knockdown OC cell lines coupled with fisetin intervention. The expression of necroptosis-related mediators and the migration capability of the respective cells were evaluated by Western blotting and in vitro cell invasion assay. RESULT: Fisetin successfully reduced cell growth in both OC cell lines in a dose-dependent manner. Both apoptosis and necroptosis were induced by fisetin. Suppression of the cell apoptotic process failed to enhance the proliferation of fisetin-treated cells. The induced cell death and robust expression of the necroptotic markers RIP3 and MLKL were alleviated by knocking down the expression of the ZBP1 protein in both OC cell lines. CONCLUSION: The present study provided in vitro evidence supporting the involvement of both apoptosis and necroptosis in fisetin-induced OC cell death, while ZBP1 regulates the necroptotic process via the RIP3/MLKL pathway.

Biochar application with reduced chemical fertilizers improves soil pore structure and rice productivity.

Biochar is an efficient amendment to improve soil quality and crop productivity, but the potential of biochar as a substitute for chemical fertilizers is still unknown. Here we conducted a 6-year field experiment to investigate how partial substitution of biochar to NPK fertilizers affect soil quality and rice yield in the northeast of China. The experiment included three treatments: Control (B0: NPK fertilizers only: 240 kg N ha-1, 52 kg P ha-1, and 100 kg K ha-1); Low-input biochar (B1.5: 95% N, 89% P, 75% K + 1.5 t biochar ha-1 year-1); and High-input biochar (B3.0: 90% N, 78% P, 50% K + 3.0 t biochar ha-1 year-1). The amounts of NPK application in the biochar treatments were determined according to an equivalent method. We evaluated the soil pore structure characteristics via a CT technology, and investigated soil nutrients, plant biomass, root growth, and grain yields. The results showed that, after the 6-year application, the soil pore structure and rice productivity of B1.5 were significantly improved in compared to those of B0 and B3.0. B1.5 had similar soil available NPK contents, but 6.6% higher rice yield as compared to B0, because of increased root length density (33.2%) and aboveground biomass (10.2%). B1.5 also increased soil macroporosity (>100 µm) (141.4%), fraction dimension (8.4%), and pore connectivity (16.6%) in compared with those of B0. However, B3.0 showed the lowest rice yield due to lower soil available N content (19.2%), macroporosity (28.5%), fraction dimension (5.5%), and pore connectivity (85.3%) than B0. This study demonstrated that a moderate NPK fertilizer replacement by biochar could be an effective practice that improves soil quality, increases rice growth and yield, and reduces the input of chemical fertilizers for rice production.

Ribosomal L1 domain-containing protein 1 coordinates with HDM2 to negatively regulate p53 in human colorectal Cancer cells.

BACKGROUND: Ribosomal L1 domain-containing protein 1 (RSL1D1) is a nucleolar protein that is essential in cell proliferation. In the current opinion, RSL1D1 translocates to the nucleoplasm under nucleolar stress and inhibits the E3 ligase activity of HDM2 via direct interaction, thereby leading to stabilization of p53. METHODS: Gene knockdown was achieved in HCT116p53+/+, HCT116p53-/-, and HCT-8 human colorectal cancer (CRC) cells by siRNA transfection. A lentiviral expression system was used to establish cell strains overexpressing genes of interest. The mRNA and protein levels in cells were evaluated by qRT-PCR and western blot analyses. Cell proliferation, cell cycle, and cell apoptosis were determined by MTT, PI staining, and Annexin V-FITC/PI double staining assays, respectively. The level of ubiquitinated p53 protein was assessed by IP. The protein-RNA interaction was investigated by RIP. The subcellular localization of proteins of interest was determined by IFA. Protein-protein interaction was investigated by GST-pulldown, BiFC, and co-IP assays. The therapeutic efficacy of RSL1D1 silencing on tumor growth was evaluated in HCT116 tumor-bearing nude mice. RESULTS: RSL1D1 distributed throughout the nucleus in human CRC cells. Silencing of RSL1D1 gene induced cell cycle arrest at G1/S and cell apoptosis in a p53-dependent manner. RSL1D1 directly interacted with and recruited p53 to HDM2 to form a ternary RSL1D1/HDM2/p53 protein complex and thereby enhanced p53 ubiquitination and degradation, leading to a decrease in the protein level of p53. Destruction of the ternary complex increased the level of p53 protein. RSL1D1 also indirectly decreased the protein level of p53 by stabilizing HDM2 mRNA. Consequently, the negative regulation of p53 by RSL1D1 facilitated cell proliferation and survival and downregulation of RSL1D1 remarkably inhibited the growth of HCT116p53+/+ tumors in a nude mouse model. CONCLUSION: We report, for the first time, that RSL1D1 is a novel negative regulator of p53 in human CRC cells and more importantly, a potential molecular target for anticancer drug development.

Recovery of steviol glycosides from industrial stevia by-product via crystallization and reversed-phase chromatography.

Mother liquor sugar (MLS), as the by-product of stevia production, contained ~65% steviol glycosides (SGs). Recovery of the SGs from MLS was achieved by crystallization coupled with reversed-phase chromatography. Crystallization was done by dissolving MLS in methanol solution and SGs were crystallized due to the polarity difference from the medium. Composition of SGs crystals differed with various temperature, time, solid-to-liquid ratio and water content. SGs were 42.25% recovered with high purity of 96.89% under optimal conditions (solid-to-liquid ratio = 1:5 (w/v), T = 25 °C, t = 24 h) in absolute methanol. The liquid phase after crystallization was subsequently subjected to reversed-phase chromatography, whereby the impurities were firstly eluted with 35% (v/v) ethanol solution and the purified SGs were then desorbed by absolute ethanol, finally recovering 95.20% of SGs in the purity of 98.08%. The total SGs recovery of the whole procedure was 97.23%. The two-step purification was easy-to-operate and feasible to scale-up for industrial application.

Purification, isolation, and structure characterization of water soluble and insoluble polysaccharides from Maitake fruiting body.

The crude polysaccharides (GFP) were isolated from the Maitake fruiting body (Grifola frondosa) and purified by DEAE Cellulose-52 ionic-exchange chromatography and Sephadex G-25 gel filtration chromatography in that order. Five main fractions, GFP-1 to GFP-5 were obtained through the isolation and purification steps. Free sugars were isolated by G-25 gel filtration chromatography and identified glucose and (α,α)-trehalose by nuclear magnetic resonance (NMR). GC-MS and methylation analysis that linkages were mainly ß-1,3 and ß-1,6, ß-1,4 and ß-1,2 bonds in WIP. Seven main oligomer products were detected and their structures characterized by mass spectrum. Experimental results shown the similarity in structure between water soluble polysaccharides (WSP) and water insoluble polysaccharides (WIP), thus WSP can be the product of cell wall by breakdown.

Extraction of sunflower head pectin with superfine grinding pretreatment.

Effect of superfine grinding on pectin extraction was investigated. Sunflower heads were grinded into microparticles of ~50 µm, thus pectin chains were fully exposed due to cell wall breakdown. A good pectin yield of 14.5 ± 0.36% (w/w) was subsequently achieved at mild conditions (pH 5.0, 25 °C, 2 h) associated with 0.8% (w/v) sodium citrate (SC). However, the molecule weight of pectin was greatly reduced (Mw = 7.87 ± 0.21 kDa) due to the action of endo-pectinases. With heating (pH 5.0, 85 °C for 20 min, 25 °C for 1.5 h) the endo-pectinases were effectively inhibited, thus Mw was increased to 338.07 ± 12.37 kDa. With superfine grinding, pectin extracted with different conditions presented various properties. Pectin extracted at pH 2.5 had higher esterification degree (DE, ~40%) and gelled at 3% (w/v) concentration. In contrast, pectin extracted under mild condition with low DE (21%) cannot gel at the same concentration. Conclusively, superfine grinding has potential application in pectin extraction.

Purification of the mother liquor sugar from industrial stevia production through one-step adsorption by non-polar macroporous resin.

Steviol glycosides (SGs)-enriched mother liquor sugar (MLS) used to be considered as a by-product of industrial stevia production. This work developed an efficient purification strategy to remove impurities from MLS. A non-polar macroporous adsorption resin (MAR) NDR-1 was selected as the adsorbent and ethanol solution was used as the mobile phase. The adsorption ratio of SGs and impurities was highly affected by ethanol concentration (v/v) due to the polarity difference and competition. In particular, in 25% (v/v) ethanol solution, SGs were mostly adsorbed on NDR-1 while impurities were completely dissolved in ethanol solution. After static adsorption in 25% ethanol solution and desorption in pure ethanol, the impurity content of MLS was decreased from 34.15% to 12.88%, with a high adsorption ratio of 92.24%. At the same condition, dynamic adsorption presented a better purification result with low impurity content of 4.78% and high SGs recovery rate of 89.88%.