Preparation of New Sargassum fusiforme Polysaccharide Long-Chain Alkyl Group Nanomicelles and Their Antiviral Properties against ALV-J

Avian leukosis virus subgroup J (ALV-J) is an immunosuppressive virus which has caused heavy losses to the poultry breeding industry. Currently, there is no effective medicine to treat this virus. In our previous experiments, the low-molecular-weight Sargassum fusiforme polysaccharide (SFP) was proven to possess antiviral activity against ALV-J, but its function was limited to the virus adsorption stage. In order to improve the antiviral activity of the SFP, in this study, three new SFP long-chain alkyl group nanomicelles (SFP-C12M, SFP-C14M and SFP-C16M) were prepared. The nanomicelles were characterized according to their physical and chemical properties. The nanomicelles were characterized by particle size, zeta potential, polydispersity index, critical micelle concentration and morphology. The results showed the particle sizes of the three nanomicelles were all approximately 200 nm and SFP-C14M and SFP-C16M were more stable than SFP-C12M. The newly prepared nanomicelles exhibited a better anti-ALV-J activity than the SFP, with SFP-C16M exhibiting the best antiviral effects in both the virus adsorption stage and the replication stage. The results of the giant unilamellar vesicle exposure experiment demonstrated that the new virucidal effect of the nanomicelles might be caused by damage to the phospholipid membrane of ALV-J. This study provides a potential idea for ALV-J prevention and development of other antiviral drugs.     

The Use of Megamolecular Polysaccharide Sacran in Food and Biomedical Applications

Natural polymer is a frequently used polymer in various food applications and pharmaceutical formulations due to its benefits and its biocompatibility compared to synthetic polymers. One of the natural polymer groups (i.e., polysaccharide) does not only function as an additive in pharmaceutical preparations, but also as an active ingredient with pharmacological effects. In addition, several natural polymers offer potential distinct applications in gene delivery and genetic engineering. However, some of these polymers have drawbacks, such as their lack of water retention and elasticity. Sacran, one of the high-molecular-weight natural polysaccharides (megamolecular polysaccharides) derived from Aphanothece sacrum (A. sacrum), has good water retention and elasticity. Historically, sacran has been used as a dietary food. Moreover, sacran can be applied in biomedical fields as an active material, excipient, and genetic engineering material. This article discusses the characteristics, extraction, isolation procedures, and the use of sacran in food and biomedical applications.     

Polysaccharide- and β-Cyclodextrin-Based Chiral Selectors for Enantiomer Resolution: Recent Developments and Applications

Polysaccharides, oligosaccharides, and their derivatives, particularly of amylose, cellulose, chitosan, and β-cyclodextrin, are well-known chiral selectors (CSs) of chiral stationary phases (CSPs) in chromatography, because they can separate a wide range of enantiomers. Typically, such CSPs are prepared by physically coating, or chemically immobilizing the polysaccharide and β-cyclodextrin derivatives onto inert silica gel carriers as chromatographic support. Over the past few years, new chiral selectors have been introduced, and progressive methods to prepare CSPs have been exploited. Also, chiral recognition mechanisms, which play a crucial role in the investigation of chiral separations, have been better elucidated. Further insights into the broad functional performance of commercially available chiral column materials and/or the respective newly developed chiral phase materials on enantiomeric separation (ES) have been gained. This review summarizes the recent developments in CSs, CSP preparation, chiral recognition mechanisms, and enantiomeric separation methods, based on polysaccharides and β-cyclodextrins as CSs, with a focus on the years 2019–2020 of this rapidly developing field.     

过饱和度、钙/草酸化学计量比对草酸钙晶体形成的影响及降解茯苓多糖的调控作用

为研究草酸钙(CaC₂O₄)晶体成核、生长和聚集,探讨降解茯苓多糖(PCP)的抑制作用,采用X射线衍射、FT-IR、扫描电镜、拉曼光谱、ζ电位仪和紫外分光光度计等方法对不同条件下形成的CaC₂O₄晶体进行表征。结果表明,在低过饱和度(RS≤26.6)时,主要生成一水草酸钙(COM)晶体;至RS为37.6和46.0时分别生成了11.6%和38.3%的二水草酸钙(COD)晶体,且高RS时晶体的聚集程度增加。在RS相同时,随着Ca²⁺/Ox^2-(Ox^2-=C₂O₄^2-)化学计量比(n_Ca2+/n_Ox2-)增大,晶体中COD比例增加。降解PCP的加入可增加体系中可溶性Ca²⁺浓度,减少生成的CaC₂O₄晶体质量,增加晶体表面ζ电位绝对值,这些均有利于抑制CaC_...     

Effect of the degree of deacetylation and the substitution of carboxymethyl chitosan on its aggregation behavior

The aggregation behavior of carboxymethyl chitosan (CM‐chitosan) with various degrees of deacetylation (DD) and substitution (DS) was characterized with viscometry, gel permeation chromatography (GPC), and GPC coupled with laser light scattering (GPC‐LLS). The results indicate that CM‐chitosan has a strong tendency to form aggregates in aqueous solution and the aggregation behavior depends on DD and DS values. The apparent aggregation number (N_ap), the gyration radius (R_g), and the weight fraction of the aggregates (F_a) reached maximum at a DD value of 50%, then decreased, with the DD value deviating from 50%. A higher DS value helped to form aggregates; when the DS value increased from 0.65 to above 1.0, N_ap and R_g increased sharply. The dependence of the refractive index increment (dn/dc) on the DD and DS values was related to variation of the charge density and the hydrophobic interaction along the molecular chains. The conformations of CM‐chitosan aggregates were studied by the LLS method. The aggregates showed a spherical shape, and the chain stiffness increased with introduction of the acetyl groups. The DS value had no clear influence on the chain conformation that was observed. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 296–305, 2005     

Structural Characterization of a Polygonatum cyrtonema Hua Tuber Polysaccharide and Its Contribution to Moisture Retention and Moisture-Proofing of Porous Carbohydrate Material

Porous carbohydrate materials such as tobacco shreds readily absorb moisture and become damp during processing, storage, and consumption (smoking). Traditional humectants have the ability of moisture retention but moisture-proofing is poor. Polygonatum cyrtonema Hua polysaccharide (PCP 85−1−1) was separated by fractional precipitation and was purified by anion exchange and gel permeation chromatography. The average molecular weight (Mw) of PCP 85−1−1 was 2.88 × 10³ Da. The monosaccharide composition implied that PCP 85−1−1 consisted of fucose, glucose, and fructose, and the molar ratio was 22.73:33.63:43.65. When 2% PCP 85−1−1 was added to tobacco shreds, the ability of moisture retention and moisture-proofing were significantly enhanced. The moisture retention index (MRI) and moisture-proofing index (MPI) increased from 1.95 and 1.67 to 2.11 and 2.14, respectively. Additionally, the effects of PCP 85−1−1 on the aroma and taste of tobacco shreds were evaluated by electronic tongue and gas chromatography–mass spectrometry (GC-MS). These results indicated that PCP 85−1−1 had the characteristics of preventing water absorption under high relative humidity and moisturizing under dry conditions. The problem that traditional humectants are poorly moisture-proof was solved. PCP 85−1−1 can be utilized as a natural humectant on porous carbohydrates, which provides a reference for its development and utilization.     

Studies on the Film Formation of Polysaccharide Based Furan-2-Carboxylic Acid Esters

Furan-2-carboxylic acid esters of xylan, cellulose, curdlan, dextran, and starch were synthesized and studied regarding their film formation abilities. The polysaccharide esters were utilized to prepare films of different appearance. To investigate supermolecular structures of the biopolymer derivatives, atomic force- and scanning electron microscopy were applied. The surface roughness and the macro-pore size and -distribution of the polysaccharide ester films were characterized. Starch furan-2-carboxylic acid ester (starch furoate) did not show film formation. In contrast, dextran furoates are very well suitable for the surface coating of inorganic compounds while the xylan-, cellulose-, and curdlan derivatives yield self-supporting films with different surface characteristics.     

A Comparison Study on Polysaccharides Extracted from Atractylodes chinensis (DC.) Koidz. Using Different Methods: Structural Characterization and Anti-SGC-7901 Effect of Combination with Apatinib

For hundreds of years, Atractylodes chinensis (DC.) Koidz. (AK) has been widely used as a treatment for spleen and stomach diseases in China. The AK polysaccharides (AKPs) have been thought to be the important bioactive components. In this stud, the impacts of different extraction methods were analyzed. The differences between AKPs extracted by hot water extraction (HWE), AKPs extracted by ultrasonic extraction (UAE), and AKPs extracted by enzyme extraction (EAE) were compared in terms of yield, total carbohydrate content, molecular weight distribution, monosaccharide composition, and synergistic activity of the AKPs with apatinib were determined. The results indicated that the yield of the polysaccharide obtained from HWE was higher than that of UAE and EAE. However, activity assays indicated that UAE-AKPs and HWE-AKPs enhanced apoptosis of human gastric cancer cells (SGC-7901) treated with apatinib and UAE-AKPs showed the strongest synergistic activities. This is also in agreement with the fact that UAE-AKPs have a smaller molecular weight, β-configuration, and higher galactose content. These findings suggested that UAE is an efficient and environmentally friendly method for producing new polysaccharides from Atractylodes chinensis (DC.) Koidz. for the development of natural synergist and for the treatment of gastric cancer.     

Comparative Characterization and Immunomodulatory Activities of Polysaccharides Extracted from the Radix of Platycodon grandiflorum with Different Extraction Methods

Platycodon grandiflorum is an edible and medicinal plant, and polysaccharides are one of its important components. To further improve the utilization rate of P. grandiflorum, we investigated the effects of four different extraction methods, including hot water, ultrasonic-assisted, acid-assisted, and alkali-assisted extractions, on the polysaccharides, which were named PG-H, PG-U, PG-C, and PG-A. The findings indicated that the extraction method had a significant impact on the yield, characteristics, and immunoregulatory activity. We observed that the yields decreased in the following order: PG-H, PG-U, PG-C, and PG-A. Galacturonic acid, glucose, galactose, and arabinose were the most prevalent monosaccharides in the four PGs. However, their proportions varied. In addition, the difference between the content of glucose and galacturonic acid was more significant. PG-U had the highest glucose content, whereas PG-C had the lowest. Galacturonic acid content was highest in PG-A, while the lowest in PG-U. The molecular weight decreased in the order of PG-U, PG-H, PG-C, and PG-A; the particle size was in the order of PG-U, PG-A, PG-H, and PG-C. Moreover, the extraction method had a great impact on immunoregulatory activity. The ability to stimulate the immune function of macrophages was as follows: PG-A > PG-C > PG-U > PG-H. The results indicated that PGs, with lower molecular weights and higher GalA content, exhibited better immune-stimulating activity. And more important the AAE method was a good way to extract polysaccharides from Platycodon grandiflorum for use as a functional product and immunological adjuvant.     

Acid Hydrolysis of Pectin and Mucilage from Cactus (Opuntia ficus) for Identification and Quantification of Monosaccharides

Pectin and mucilage are polysaccharides from the cactus Opuntia ficus-indica, which are also known as hydrocolloids, with useful properties in industries such as food, pharmaceuticals, and construction, among others. In the present work, cactus hydrocolloids were hydrolyzed characterized using two techniques: first, thin-layer chromatography, to identify the monosaccharides present in the sample, followed by the phenol–sulfuric acid method to determine the monosaccharide content. The hydrolyzing method allowed us to reduce the processing time to 180 min and, considering the identification and quantification procedures, the proposed methodology is much simpler and more cost-effective compared to other methods, such as high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR), and mass spectrometry. The analysis of the results revealed that the maximum concentration of monosaccharides was obtained after hydrolyzing for 90 min. Under such conditions, with pectin being the main component contained in the cactus hydrocolloids analyzed here, galacturonic acid was found in the largest quantities.