Electrospinning and electrospun polysaccharide-based nanofiber membranes: A review.

The electrospinning technology has set off a tide and given rise to the attention of a widespread range of research territories, benefiting from the enhancement of nanofibers which made a spurt of progress. Nanofibers, continuously produced via electrospinning technology, have greater specific surface area and higher porosity and play a non-substitutable key role in many fields. Combined with the degradability and compatibility of the natural structure characteristics of polysaccharides, electrospun polysaccharide nanofiber membranes gradually infiltrate into the life field to help filter air contamination particles and water pollutants, treat wounds, keep food fresh, monitor electronic equipment, etc., thus improving the life quality. Compared with the evaluation of polysaccharide-based nanofiber membranes in a specific field, this paper comprehensively summarized the existing electrospinning technology and focused on the latest research progress about the application of polysaccharide-based nanofiber in different fields, represented by starch, chitosan, and cellulose. Finally, the benefits and defects of electrospun are discussed in brief, and the prospects for broadening the application of polysaccharide nanofiber membranes are presented for the glorious expectation dedicated to the progress of the eras.

Fabrication of multi-functional biodegradable liquid mulch utilizing xyloglucan derived from tamarind waste for agricultural application.

Biodegradable liquid mulch is considered a promising alternative to plastic mulch for sustainable agriculture. This work proposed a xyloglucan-based liquid mulch with multi-function using a combination of chemical modification and blending methods. The esterification product of tamarind xyloglucan (TXG) from forestry wastes was synthesized with benzoic anhydride (BA). The effect of esterification modification was investigated, and BA-TXG was utilized as a film-forming and sand-fixation agent. The rheological properties, thermal stability, and hydrophobicity were improved following esterification. Additionally, waterborne polyurethane and urea were incorporated into the mulch to enhance its mechanical strength (23.28 MPa, 80.71 %), and homogeneity, as well as improve its nutritive properties. The xyloglucan-based liquid mulch has excellent UV protection, a high haze value (approximately 90 %), and retains water at a rate of 80.45 %. SEM and immersion experiment showed the effect of xyloglucan-based liquid mulch on sustainable sand-fixation. Moreover, the liquid mulch treatment demonstrated an impressive germination rate of 83.8 % and degradation rate of 51.59 % (60 days). The modified polysaccharide film increases stability and slows down the degradation rate. Tamarind xyloglucan-based liquid mulch exhibits powerful and diverse optical properties as well as sand fixation functions, indicating their great potential in sustainable agriculture as an alternative to plastic mulch.

Synthesis, spectroscopic analysis, DFT, docking, MD and antioxidant activity of tetrahydrocurcumin.

In recent years, numerous researchers have made local chemical modifications to the structure of curcumin while its basic structure remains unchanged, thus, producing curcumin derivatives. In this article, tetrahydrocurcumin was obtained by hydrogenation of curcumin, DFT calculation and characterization at the theoretical level of B3LYP/6 -311++G(d,p) were carried out. The observed IR and Raman spectra are in good agreement with the theoretical spectra. The FMO and ESP of tetrahydrocurcumin are predicted. The interaction in the system is shown graphically and analyzed by IGMH. Compared with curcumin, tetrahydrocurcumin lacks the unsaturated C = C bond, which makes it more stable and more bioavailable. Molecular docking with antioxidant targets elucidated the ligand-protein interaction and molecular dynamics simulation showed the antioxidant activity of tetrahydrocurcumin. The antioxidant activity of tetrahydrocurcumin was proved by DPPH• and •OH radical scavenging experiments. In essence, these derivatives exhibit enhanced physiological activity in certain aspects compared to the original curcumin. Moreover, the computational pharmacology techniques lay a theoretical groundwork for the development and modification of high-efficiency, low-toxicity drugs that interface with various targets of curcumin in the future.Communicated by Ramaswamy H. Sarma.

Efficient co-production of xylo-oligosaccharides and fermentable sugars from sugarcane bagasse by glutamic acid pretreatment.

In the production of xylo-oligosaccharides (XOS) by organic acid pretreatment, it is often difficult to isolate organic acids from XOS. Here, an acidic amino acid, glutamic acid (GA), was used to pretreat sugarcane bagasse (SCB) to prepare XOS and fermentable sugars. The effects of GA concentration, hydrolysis temperature, and pretreatment time on the yield and polymerization distribution of XOS were investigated. After hydrolysis by 0.2 M GA at 140 °C for 30 min, the maximum yield of X2-5 was 53.3%, and the concentrations of xylose and furfural were 1.8 g/L and 0.1 g/L, respectively. Meanwhile, GA increased the pore size and porosity of SCB as well as the number of functional groups of amino acid residues, which improved the enzymatic efficiency and the maximum yield of glucose was 95.3%. Thus, GA pretreatment provides a more economical, environmentally friendly and sustainable method for the co-production of XOS and glucose from SCB.

Synthesis and anti-proliferative activity of dehydroabietinol derivatives bearing a triazole moiety.

In search of more efficacious antitumor agents, a series of novel dehydroabietinol derivatives containing a triazole moiety was synthesized, and evaluated for cytotoxicity against four human cancer cell lines. Many exhibited superior cytotoxic profiles compared to the parent molecule, dehydroabietic acid. In particular, compounds 5g, 5i and 5j exhibited promising cytotoxicity with IC50 values ranging from 4.84 to 9.62 µM against all the test cell lines. Cell clone formation and migration tests of compound 5g showed that it not only effectively inhibited the formation of MGC-803 cell colonies but also inhibited the MGC-803 cell migration and invasion. Additionally, the preliminary pharmacological mechanism indicated compound 5g induced apoptosis, arrested the mitotic process at the G0/G1 phase of the cell cycle, reduced the mitochondrial membrane potential, and increased the intracellular ROS and Ca2+ levels.

Synthesis, Antifungal Activity, 3D-QSAR and Controlled Release on Hydrotalcite Study of Longifolene-Derived Diphenyl Ether Carboxylic Acid Compounds.

Twenty-two novel longifolene-derived diphenyl ether-carboxylic acid compounds 7a-7v were synthesized from renewable biomass resources longifolene, and their structures were confirmed by FT-IR, 1H NMR, 13C NMR, and HRMS. The preliminary evaluation of in vitro antifungal activity displayed that compound 7b presented inhibition rates of 85.9%, 82.7%, 82.7%, and 81.4% against Alternaria solani, Cercospora arachidicola, Rhizoctonia solani, and Physalospora piricola, respectively, and compound 7l possessed inhibition rates of 80.7%, 80.4%, and 80.3% against R. solani, C. arachidicola, P. piricola, respectively, exhibiting excellent and broad-spectrum antifungal activities. Besides, compounds 7f and 7a showed significant antifungal activities with inhibition rates of 81.2% and 80.7% against A.solani, respectively. Meanwhile, a reasonable and effective 3D-QSAR mode (r2 = 0.996, q2 = 0.572) has been established by the CoMFA method. Furthermore, the drug-loading complexes 7b/MgAl-LDH were prepared and characterized. Their pH-responsive controlled-release behavior was investigated as well. As a result, complex 7b/MgAl-LDH-2 exhibited excellent controlled-releasing performance in the water/ethanol (10:1, v:v) and under a pH of 5.7.

Fabrication and evaluation of dodecyl imide maleopimaric acid glycidyl methacrylate ester modified silica with multiple retention mechanisms for reversed phase liquid chromatography.

As green, less toxic, and abundant ligands with rich functional groups, natural products are widely used in synthesis of chromatographic stationary phases. In this work, dodecyl imide maleopimaric acid glycidyl methacrylate ester (C12-MPAGN) was prepared from maleopimaric acid through the imidization and ring-opening based esterification reaction. By using "thiol-ene" click chemistry, it was chemically bonded to the silica and (3-mercaptopropyl) trimethoxysilane (γ-MPS) was used as the coupling agent to obtain dodecyl imide maleopimaric acid glycidyl methacrylate ester bonded silica stationary phase (Sil-C12-MPAGN). Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopies (SEM), and elemental analysis (EA) were utilized to verify that the Sil-C12-MPAGN stationary phase was successfully prepared with C12-MPAGN immobilized on the silica surface. In order to evaluate the chromatographic performance and retention mechanisms of the Sil-C12-MPAGN column and compared with C18 column, a variety of compounds were used, including stander mixture of Tanaka, alkylbenzenes, polycyclic aromatic hydrocarbons (PAHs), phenols and flavonoids. Based on these multiple interactions, including hydrophobic, hydrogen-bonding, and π-π interactions, high selectivity and superior separation performance were demonstrated by the Sil-C12-MPAGN column for probe molecules what had previously been mentioned. In addition, the quantitative determination of paclitaxel content in Yew bark extract was conducted with this column, which was found that the concentration was 83.67 mg/L, respectively. In short, the present study proposes a new strategy for introducing rosin to liquid chromatography with high selectivity and separation performance.

Separation of Panax notoginseng saponins on modified rosin ester-bonded silica stationary phase and its mechanism.

A column prepared using a unique three-membered phenanthrene skeleton of rosin has complementary selectivity to a C18 column for some separation tasks. In this study, propylene pimaric acid (16-hydroxyethyl acrylate-34-n-butyl) ester (BRB) and propylene pimaric acid (16-hydroxyethyl acrylate-34-dodecyl) ester (BRLA) were used as functional ligands to prepare two novel stationary phases, namely BRB@SiO2 and BRLA@SiO2, through a "thiol-ene" click chemistry reaction. The characterization results of Fourier transform infrared spectroscopy, thermogravimetric analysis, nitrogen adsorption-desorption measurements, and contact angle tests showed that the BRB@SiO2 and BRLA@SiO2 stationary phases were successfully prepared. In addition, the performance of the columns was evaluated using the Tanaka test and hydrophobic subtraction model, which showed that the stationary phases exhibited typical reversed-phase chromatography performance and good hydrophobicity, hydrophobic selectivity, and steric selectivity. The changes in the retention of Panax notoginseng saponins on a column under different chromatographic conditions (acetonitrile content, flow rate, and column temperature) were investigated. The separation effect of BRB@SiO2 and BRLA@SiO2 columns on P. notoginseng saponins was better than that of the C18 column and the BRLA@SiO2 column could replace the C18 column for the detection of P. notoginseng saponins.

Changes in structure and physicochemical properties of Sophora japonica f. pendula galactomannan in late growth stage.

Galactomannan (GM) has been widely applied in food and other fields due to its appealing physicochemical properties. In this work, considering the changes in structural and physicochemical properties of Sophora japonica f. pendula (SJ-GM) with very high mannose to galactose (M/G) ratio in the late deposition stage, extensive exploration is conducted. The core of structural change is the change of M/G ratio (4.94-5.68), which is caused by the loss of galactose side residues modulated by α-d-galactosidase during seed maturation. Afterwards, the more compact conformation, the higher molecular weight, the increased hydrophobicity, and the greater solution viscosity of SJ-GM can be caused. Notably, the gel strength of SJ-GM with the highest M/G surpasses other GMs, including fenugreek gum (M/G = 1.20), guar gum (M/G = 1.80), Gleditsia microphylla gum (M/G = 2.77), and LBG (M/G = 4.00). Finally, SJ-GM is proven to be an attractive alternative to other GMs.

Enzymatically mediated Gleditsia sinensis galactomannan based hydrogel inspired by wound healing process.

The self-healing property based on metal-ligand physical coordination is particularly interesting in bio-hydrogel science due to its allowance for multiple local healing events to process. As the most abundant renewable green resource in nature, Gleditsia sinensis galactomannan has great potential as a starting material for functional materials. In this study, the biocompatible Gleditsia sinensis galactomannan and cellulose were firstly chemically modified and then taken as the main constituent for constructing the metal-ligand coordination through an enzyme-regulated strategy. The hydrogel could quickly gelatinize in the surrounding environment, corresponding to the violent exothermic phenomenon, and exhibit extraordinary self-healing behavior. The molecular dynamics simulation of the hydrogel confirmed the more stable coordinated configuration from Fe(III)-chelates than Fe(II)-chelates. The morphology, mechanical property, antibacterial, and cytotoxicity of the prepared hydrogel were also studied. Our results indicated that galactomannan hydrogel based on the metal-ligand networks could balance the kinetic stability and intrinsic healability through the enzyme-induced route, which provide a new perspective in the field of biomaterial applications.

Design, Synthesis, and Molecular Docking Study of Novel 3-Cyanopyridine Derivatives for the Anti-Cancer Drug Target Survivin Protein.

Survivin is an important member of the antiapoptotic protein family and controls the cell's life cycle. Overexpression of survivin in tumor cells leads to inhibition of apoptosis, thus contributing to cancer cell proliferation. The largest binding pocket in the survivin dimer was located in the BIR domain. The key to the efficacy of 3-cyanopyridines was their surface interaction with the survivin amino acid Ile74. METHODS: Through the optimization of the 3-cyanopyridine, 29 new compounds with a 3- Cyanopyridine structure were designed, synthesized, and characterized by NMR, IR, and mass spectrometry. The antitumor activity of the compounds in vitro was detected by the MTT method. RESULTS: In vitro anti-tumor experiments showed that some compounds exhibited good anti-cancer effects. The IC50 values of the compound 2-amino-6-(2,4-difluorophenyl)-4-(4-hydroxyphenyl) nicotinonitrile (10n) against human liver cancer (Huh7), human glioma (U251), and human melanoma (A375) cells were 5.9, 6.0 and 7.2 µM, respectively. The IC50 values of the compound 6-(2,4-difluorophenyl)- 4-(4-hydroxyphenyl)-2-oxo-1,2-dihydropyridine-3-carbonitrile (9o) against Huh7, U251 and A375 cells were 2.4, 17.5 and 7.2 µM, respectively, which were better than those of 10- hydroxycamptothecin and 5-fluorouracil. Analysis of the results of molecular dynamics simulation established that the BIR domain is the optimal binding site on the survivin protein, and the fingerprints of the eight most active compounds and the molecular docking to the survivin protein are analyzed. CONCLUSION: 3-Cyanopyridine is an excellent backbone for antitumor lead compounds, 10n and 9o, as derivatives of 3-Cyanopyridine are excellent survivin protein-targeting inhibitors worthy of further study. The key factor in inhibiting survivin protein through the action of amino acid Ile74.

Facile Access to Gleditsia microphylla Galactomannan Hydrogel with Rapid Self-Repair Capacity and Multicyclic Water-Retaining Performance of Sandy Soil.

Sandy soil has poor water-holding performance, making it difficult for plants to survive, which worsens the deterioration of the ecological environment. Therefore, borax cross-linked Gleditsia microphylla galactomannan hydrogel (GMGH) was prepared, and its practicability as a water-retaining agent was analyzed. GMGH exhibited fast self-healing performance (150 s, ≈100%) and a high swelling index (88.70 g/g in pH 9). The feasibility of improving the water absorption and retention properties of sandy soil was explored by mixing different proportions (0.1, 0.3, 0.5 wt % sandy soil) of GMGH and sandy soil. The results showed that sandy soil had a more porous structure after adding 0.5 wt % GMGH, and its water absorption index increased from 15.68 to 38.12%. In an artificial climate box, the water-holding time of the sandy soil was extended from 3 to 23.5 days, and the cycles of water absorption and retention were more than 10 times. Therefore, GMGH has broad application prospects as a potential water-retaining agent for desertification control.

Production of xylooligosaccharides from Camellia oleifera Abel fruit shell using a shell-based solid acid catalyst.

This study aimed to produce xylooligosaccharides (XOS) from Camellia oleifera Abel fruit shell (CFS) using a shell-based solid acid derived from CFS (CFS-BSA). CFS-BSA preparation was optimized by incomplete carbonization at 450 °C for 1 h, followed by sulfonation at 130 °C for 8 h to yield a -SO3H functional group concentration of 1.04 mmol/g. When CFS-BSA was used to hydrolyze CFS with a 1:5 ratio of CFS-BSA to CFS at 170 °C for 20 min, a maximum XOS yield (X2-X5) of 51.41 % was achieved, which was notably higher than when using subcritical H2O solely. CFS-BSA can be recycled and reused at least six times by sieving without a substantial loss in its catalytic activity. CFS-BSA can also be used to produce XOS from other lignocellulosic materials such as corncob (41.04 %), sugarcane bagasse (45.03 %), corn stalk (45.89 %), birchwood (46.05 %), and poplar (40.10 %).

N-doped pinecone-based carbon with a hierarchical porous pie-like structure: a long-cycle-life anode material for potassium-ion batteries.

Pinecone-based biomass carbon (PC) is a potential anode material for potassium-ion batteries because it is abundant, cheap, renewable, and easy to obtain. However, because of inferior kinetics and the effects of volume expansion due to the large radius of the K+ ion, it does not meet commercial performance requirements. In this study, nitrogen-doped PC (NPC) was prepared by carbonization in molten ZnCl2 with urea as a nitrogen source. A strategy based on synergistic effects between N doping and ZnCl2 molten salt was used to produce a hierarchically porous pie-like NPC with abundant defects and active sites and an enlarged interlayer distance-properties that enhance K+ adsorption, promote K+ intercalation/diffusion, and reduce the effects of volume expansion. This NPC exhibited a high reversible capacity (283 mA h g-1 at 50 mA g-1) and superior rate performance and cyclic stability (110 mA h g-1 after 1000 cycles at 5 A g-1), demonstrating its potential for use in potassium-ion batteries.

Study on the structure and physicochemical properties of fenugreek galactomannan modified via octenyl succinic anhydride.

To improve the mechanical strength of borax-crosslinked fenugreek galactomannan hydrogels and broaden the application field of galactomannan-based hydrogels, fenugreek galactomannan (FG) was esterified via octenyl succinic anhydride (OSA), and the parameters affecting the esterification reaction were systematically studied. The optimum process for OSA-modified FG (OFG) was as follows: FG concentration 1.5 wt%, n (OSA): n (FG) = 2, n (4-dimethylamino-pyridine, DMAP): n (FG) = 4, and reaction time 12 h. Under this condition, the degree of substitution (DS) was 0.31, and the product yield was 115.05 %. Characterization of FT-IR, H1 NMR, and HPLC confirmed that the OSA group was successfully introduced into the FG skeleton. The mechanical strength of borax crosslinked OFG hydrogel (OFGH) is 18 times higher than that of FG hydrogel. OFGH shows excellent self-healing, injectable properties and electrical conductivity. This will further expand the application of borax crosslinked galactomannan-based hydrogels in the fields of sensors, drug delivery, and wound dressing.

A novel approach for authentication of shellac resin in the shellac-based edible coatings: Contain shellac or not in the fruit wax preservative coating.

As an edible coating substrate, the detection of shellac resin has always been an intractable problem. In this paper, an authentication method of shellac resin in shellac-based edible coatings was established. Results showed that the authentication of shellac resin could be skillfully transformed as the identification of 13 targeted metabolites which were monomer compounds of shellac resin. The 13 targeted metabolites were further divided into 6 differential metabolites and 7 common metabolites with the metabonomic method and difference analysis of targeted metabolite contents. Then, four commercial soi-disant shellac-based coating solutions were selected to verify the feasibility of this method, and 7 common metabolites were detected in only one commercial sample, highly consistent with the results of shellac resin. All the above results indicated that the targeted metabolomics approach established in this study could provide a scientific basis for the qualitative authentication of shellac resin in the preservation coating.

Removing Calcium Ions from Remelt Syrup with Rosin-Based Macroporous Cationic Resin.

Mineral ions (mainly calcium ions) from sugarcane juice can be trapped inside the heating tubes of evaporators and vacuum boiling pans, and calcium ions are precipitated. Consequently, sugar productivity and yield are negatively affected. Calcium ions can be removed from sugarcane juice using adsorption. This paper described the experimental condition for the batch adsorption performance of rosin-based macroporous cationic resins (RMCRs) for calcium ions. The kinetics of adsorption was defined by the pseudo-first-order model, and the isotherms of calcium ions followed the Freundlich isotherm model. The maximal monolayer adsorption capacity of calcium ions was 37.05 mg·g-1 at a resin dosage of 4 g·L-1, pH of 7.0, temperature of 75 °C, and contact time of 10 h. It appeared that the adsorption was spontaneous and endothermic based on the thermodynamic parameters. The removal rate of calcium ions in remelt syrup by RMCRs was 90.71%. Calcium ions were effectively removed from loaded RMCRs by 0.1 mol·L-1 of HCl, and the RMCRs could be recycled. The dynamic saturated adsorption capacity of RMCRs for calcium ions in remelt syrup was 37.90 mg·g-1. These results suggest that RMCRs are inexpensive and efficient adsorbents and have potential applications for removing calcium ions in remelt syrup.

[Preparation and chromatographic performance of cardanol-bonded silica stationary phase].

As green, less toxic, widely available, and site-rich functional ligands, natural products are widely used for the development of chromatographic stationary phases. In this work, a novel stationary phase, cardanol-bonded on silica (CBS) was prepared using γ-glycidoxypropyltrimethoxysilane (KH-560) as the coupling reagent and cardanol as the functional ligand. The synthesized stationary phase was characterized by Fourier transform-infrared spectra (FT-IR), thermogravimetric analysis (TGA), elemental analysis (EA), and N2 adsorption-desorption analysis. The results revealed that cardanol was successfully immobilized on the surface of spherical silica by the ring-opening reaction of the epoxy groups in phenolic hydroxyl. The retention mechanism and chromatographic performance of the CBS column were further evaluated and compared with those of a commercial C18 column using different classes of analytes, e. g., Tanaka standard test mixtures, alkylbenzenes, polycyclic aromatic hydrocarbons (PAHs), phenols, and aromatic positional isomers. The retention of alkylbenzenes under different chromatographic conditions revealed that the CBS column was a typical reversed-phase liquid chromatographic column, similar to the commercial C18 column. From the results of the Tanaka test, it was concluded that CBS could provide various interactions for different solutes e. g., hydrogen bonding and π-π interactions, along with hydrophobic interactions. The synergistic effects resulting from the aromatic rings, the hydroxyl and alkyl linkers in the new stationary phase improved the separation selectivity via multiple retention mechanisms. Based on these interactions, different solute probes such as hydrophobic alkylbenzenes, PAHs, and phenols were successfully separated in the reversed-phase liquid chromatography (RPLC) mode. For example, the aromatic positional isomers o-terthenyl, m-terphenyl, and triphenylene were used to investigate the chromatographic performance of the CBS column. These PHAs were baseline separated with good peak shapes. The resolution of m-terphenyl and triphenylene was as high as 6.81, while the two isomers could not be separated on the C18 column under the same chromatographic conditions. The repeatability and column stability of the CBS column was evaluated, and excellent repeatability and column stability were observed. The relative standard deviations (RSDs) of the retention time, peak area, and peak height for alkylbenzenes with 10 replicate injections were 0.052%-0.079%, 0.104%-0.847%, and 0.081%-0.272%, respectively. Traditional Chinese medicines have contributed notably to the Chinese civilization and human health. However, the complicated chemical compositions, unclear medicinal action mechanisms, and low purification efficiency for the traditional Chinese medicines have limited further development. Therefore it is necessary to establish an efficient, simple and feasible method for the separation and purification of herbal medicines. HPLC has been widely used in traditional Chinese medicines for the separation and detection of various components. In order to explore the CBS column for analysis of the traditional Chinese medicines, the ethanol extracts of fruits of Evodiae fructus and Camptotheca acuminata were used to test the separation performance of this column. The resolution of camptothecin from the preceding and following impurity peaks was 4.23 and 2.71. The resolution between evodiamine and rutaecarpin was 5.43, while the resolution from the adjacencies of impurity peaks was 2.20 and 1.69, respectively. The above mentioned results indicated that the CBS column shows good separation performance for the main active ingredients in the ethanolic extracts of these drugs, this validating its great potential for the analysis of real samples. Overall, the present study not only provides a new approach for the preparation of chromatographic stationary phases but also opens a new possibility for the separation and purification of camptothecin and evodiamine in real samples. This is an extension of the application of cardanol to chromatographic separation materials.

[Preparation of modified rosin bonded silica high performance liquid chromatographic stationary phase and separation of Panax notoginseng saponins].

The sanqi is the dried root of Panax notoginseng (Burk.) F. H. Chen. The main components responsible for the drug actions of sanqi are notoginsenoside R1, ginsenoside Rg1, ginsenoside Re, ginsenoside Rb1, and ginsenoside Rd, which account for about 80% of the saponin content in sanqi. It is widely used in the treatment of anemia, coronary heart disease, hypertension, stroke sequelae, and other diseases. However, sanqi has many chemical components with complex and similar structures, which are difficult to separate. In this study, alkylated silica gel bonded with hydrogenated rosin hydroxyethyl acrylate (HRHA) was prepared via mercapto-ene click chemistry. A new type of modified rosin-bonded silica stationary phase (SiO2@HRHA) for high performance liquid chromatography was prepared for the separation of five saponins (R1, Rg1, Re, Rb1, and Rd). It was characterized by thermogravimetric analysis, Fourier-transform infrared spectroscopy, specific surface area and microporous physical adsorption and elemental analysis. The results showed that SiO2@HRHA had a regular spherical shape with porous surfaces, along with a specific surface area of 308.55 m2/g and an average pore diameter of 6.78 nm. Performance evaluation of the column revealed that the SiO2@HRHA column showed typical reversed-phase chromatographic behavior with better flowability and reproducibility. Results of the Tanaka test showed that SiO2@HRHA column had good stereoselectivity and hydrogen bond capacity. Compared to other stationary phases, e. g. silica modified with acrylopimaric acid (16-hydroxyethyl-34-hydroxyethyl acrylate) ester (AAE) and dihydroterpineol (DTP), which were prepared in our laboratory at the same time, the SiO2@HRHA column demonstrated better resolution (Rs) for the separation of the five saponins under optimal chromatographic conditions. The Rs values for R1, Rg1, Re, Rb1, and Rd were 3.33, 3.54, 20.17 and 9.72, respectively on the SiO2@HRHA column. Rs between Rg1 and Re was also better than that obtained on a C18 column. Panax notoginseng saponins were separated on the SiO2@HRHA column using acetonitrile and water as the mobile phases at the flow rate of 1.0 mL/min at 25 ℃. The optimal UV detection wavelength was 203 nm. It was found that the five saponins could be separated better using the SiO2@HRHA column than the SiO2@AAE and SiO2@DTP columns. Because the ternary phenanthrene skeleton of the rosin group in SiO2@HRHA had structural similarity and good stereoselectivity to the polycyclic compounds (Panax notoginseng saponins). In addition, according to the hydrophobicity evaluation, the SiO2@HRHA column showed the best hydrophobicity among the three columns, which may be conducive to the separation of the five saponins. Thus, this study can provide a new avenue for the separation and purification of Panax notoginseng saponins from actual samples.

Coproduction xylo-oligosaccharides with low degree of polymerization and glucose from sugarcane bagasse by non-isothermal subcritical carbon dioxide assisted seawater autohydrolysis.

High pretreatment temperature is necessary to obtain xylo-oligosaccharides (XOS) with low degree of polymerization (DP). However, traditional isothermal pretreatment for XOS production may increase the generation of xylose and furfural with the reaction time extending (10-100 min). In this study, non-isothermal subcritical CO2-assisted seawater autohydrolysis (NSCSA) firstly used seawater and CO2 for the coproduction of XOS with low DP and glucose. 51.44% XOS was obtained at 205 °C/5 MPa, and low-DP (2-4) XOS accounted for 79.13% of the total XOS. Furthermore, the specific surface area and total pore volume of the pretreated sugarcane bagasse (SCB) were 1.96 m2/g and 0.011 cm3/g, respectively, increased by 148% and 83% than that of nature SCB. Compared with subcritical CO2 pretreatment, NSCSA is an efficient method for the coproduction of XOS with low DP and glucose through inorganic salts in seawater and H2CO3 formed from CO2.