Optimization and Physicochemical Characterization of Polysaccharide Purified from Sonneratia caseolaris Mangrove Leaves: a Potential Antioxidant and Antibiofilm Agent

The Box-Behnken design was applied to determine the optimal parameters of the extraction condition by using the response surface methodology (RSM) from the leaves of Sonneratia caseolaris L. The result indicates the best-optimized conditions used for the extraction of polysaccharides at 84.02 °C temperature, 3.12 h time, and 27.31 mL/g for the water-to-material ratio. The maximum experimental yield of 8.81 ± 0.09% was obtained which is in agreement with the predicted value of 8.79%. Thereafter, low molecular weight polysaccharide (SCLP) was separated after sequentially being purified through column chromatography with a relative molecular weight of 3.74 kDa. The physicochemical properties were evaluated by characterization techniques such as FT-IR spectra, NMR spectrum, and SEM analysis. RP-HPLC analysis confirmed that SCLP was a heteropolysaccharide, majorly comprising rhamnose (28.25%), and xylose (27.17%) residues, followed by mannose (18.90%), and galactose (17.17%), respectively. Thermal analysis (TGA-DSC) results showed that SCLP is a highly thermostable polymer with a degradation temperature of 361.63 °C. X-ray diffraction patterns and tertiary structure analyses indicate that SCLP had a semi-crystalline polymer having a triple-helical configuration. Moreover, SCLP displayed potential antibiofilm ability for all the tested pathogens while stronger activity against Klebsiella pneumoniae and Pseudomonas aeruginosa. In addition, SCLP has potential in vitro antioxidant activity on DPPH, ABTS radical, superoxide, and Fe2+ chelating. These findings indicate that the polysaccharide has potentially been used in functional food, cosmetics, and pharmacological industries.

Carboxymethylation of Desmodium styracifolium Polysaccharide and Its Repair Effect on Damaged HK-2 Cells

Objective

Desmodium styracifolium is the best traditional medicine for treating kidney calculi in China. This study is aimed at increasing the carboxyl (-COOH) content of D. styracifolium polysaccharide (DSP0) and further increasing its antistone activity.

Methods

DSP0 was carboxymethylated with chloroacetic acid at varying degrees. Then, oxalate-damaged HK-2 cells were repaired with modified polysaccharide, and the changes in biochemical indices before and after repair were detected.

Results

Three modified polysaccharides with 7.45% (CDSP1), 12.2% (CDSP2), and 17.7% (CDSP3) -COOH are obtained. Compared with DSP0 (-COOH content = 1.17%), CDSPs have stronger antioxidant activity in vitro and can improve the vitality of damaged HK-2 cells. CDSPs repair the cell morphology and cytoskeleton, increase the cell healing ability, reduce reactive oxygen species and nitric oxide levels, increase mitochondrial membrane potential, limit autophagy level to a low level, reduce the eversion of phosphatidylserine in the cell membrane, weaken the inhibition of oxalate on DNA synthesis, restore cell cycle to normal state, promote cell proliferation, and reduce apoptosis/necrosis.

Conclusion

The carboxymethylation modification of DSP0 can improve its antioxidant activity and enhance its ability to repair damaged HK-2 cells. Among them, CDSP2 with medium -COOH content has the highest activity of repairing cells, whereas CDSP3 with the highest -COOH content has the highest antioxidant activity. This difference may be related to the active environment of polysaccharide and conformation of the polysaccharide and cell signal pathway. This result suggests that Desmodium styracifolium polysaccharide with increased -COOH content may have improved potential treatment and prevention of kidney calculi.

Isolation, purification, structure and antioxidant activity of polysaccharide from pinecones of Pinus koraiensis

The polysaccharides (PKP-E) extracted from the pinecones of Pinus koraiensis were studied, which was fractionated using DEAE-52 cellulose and Sephadex G-100. Four novel polysaccharide fractions were obtained, which were PKP-E-1-1, -1-2, -2-1, and -2-2, respectively. The structural features were characterized using HPGPC, monosaccharide composition analysis, Congo red test, periodate oxidation, Smith degradation, FTIR and NMR spectroscopy. The results showed the 4 purified fractions were non-triple helical structured heteropolysaccharides and composed of l-rhamnose, l-arabinose, d-mannose, d-glucose, and d-galactose. The fractions were mainly linked by 1→6 or 1→ glycosidic bonds and the backbone of 4 fractions was probably composed of→2, 6)-β-d-Man-(1→ and α-d-GalpA-(1→), which resembles pectin. Moreover, the antioxidant activities of the polysaccharides were measured by scavenging radical capacity tests. The PKP-E-2-1 was the most stable and active fraction, and the respective IC₅₀ for the hydroxyl and ABTS^·+ radicals were 3.0 and 23.6 mg/mL.

Structure analysis of polysaccharides purified from Cyclocarya paliurus with DEAE-Cellulose and its antioxidant activity in RAW264.7 cells

CPP was isolated from Cyclocarya paliurus (C. paliurus) and CPP-D was purified from CPP with a further step by DEAE-Cellulose. In this study, the structure and antioxidant activities of these two polysaccharides were investigated. The molecular weight of CPP was determined as 1.15 × 10⁵ Da and the monosaccharides of it were Rha, Ara, Xyl, Man, Glc, Gal in a molar ratio of 0.021:0.237:0.020:0.036:0.454:0.231, while the molecular weight of CPP-D was 9.1 × 10³ Da and the monosaccharides of it were Man, Glc, Gal in a molar ratio of 0.235:0.677:0.088. CPP-D consisted of three structural residues →4)-β-D-Glc-(1→, →2,6)-β-D-Man-(1→ and →4)-β-D-Gal. These structures were characterized by SEM, FT-IR, GC-MS, HPGPC, and NMR. The antioxidant assay in RAW264.7 cell showed that both CPP and CPP-D promoted cell viability and antioxidant activity, which decreased the content of MDA and increased the activity of SOD, T-AOC, CAT (P < .05). As a result, CPP-D isolated by DEAE-Cellulose didn't reduce the antioxidant activity of C. paliurus polysaccharide and could enhance the cell viability.

Antineurodegenerative Labdane Diterpenoid Glycosides from the Twigs of Pinus koraiensis

Eleven new labdane-type diterpenoid glycosides, koraiensides A-K (1-11), together with two known analogues were isolated from the twigs of Pinus koraiensis. Their structures were elucidated via NMR, HRMS, and ECD data, DP4+ statistical analysis, and hydrolysis. The metabolites were tested for induction of nerve growth factor in C6 glioma cells to evaluate their potential neuroprotective activity. The compounds were measured for production of nitric oxide levels in lipopolysaccharide (LPS)-activated murine microglia BV2 cells to assess their antineuroinflammatory activity. Compounds 10 and 13 showed NGF secretion inducing effects from C6 glioma cells (162.3 ± 13.9% and 162.7 ± 6.9%, respectively). Compound 6 showed an IC₅₀ value of 24.1 μM, implying significant inhibition of NO production.

The Preparation and Structure Analysis Methods of Natural Polysaccharides of Plants and Fungi: A Review of Recent Development

Polysaccharides are ubiquitous biomolecules found in nature that contain various biological and pharmacological activities that are employed in functional foods and therapeutic agents. Natural polysaccharides are obtained mainly by extraction and purification, which may serve as reliable procedures to enhance the quality and the yield of polysaccharide products. Moreover, structural analysis of polysaccharides proves to be promising and crucial for elucidating structure–activity relationships. Therefore, this report summarizes the recent developments and applications in extraction, separation, purification, and structural analysis of polysaccharides of plants and fungi.

Deciphering the anti-Parkinson’s activity of sulphated polysaccharides from Chlamydomonas reinhardtii on the α-Synuclein mutants A30P, A53T, E46K, E57K and E35K

Parkinsonism-linked mutations in alanine and glutamic acid residues of the pre-synaptic protein α-Synuclein (α-Syn) affect specific tertiary interactions essential for stability of the native state and make it prone to more aggregation. Many of the currently available drugs used for the treatment of Parkinson’s disease (PD) are not very effective and are associated with multiple side effects. Recently, marine algae have been reported to have sulphated polysaccharides which offers multiple pharmaceutical properties. With this background, we have isolated sulphated polysaccharides from Chlamydomonas reinhardtii (Cr-SPs) and investigated their effects on inhibition of fibrillation/aggregation of α-Syn mutants through a combination of spectroscopic and microscopic techniques. The kinetics of α-Syn fibrillation establishes that Cr-SPs are very effective in inhibiting fibrillation of α-Syn mutants. The morphological changes associated with the fibrillation/aggregation process have been monitored by transmission electron microscopy. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis gel image suggests that Cr-SPs increase the amount of soluble protein after completion of the fibrillation/aggregation process. The circular dichroism results showed that Cr-SPs efficiently delay the conversion of native protein into β-sheet-rich structures. Thus, the current work has considerable therapeutic implications towards deciphering the potential of Cr-SPs to act against PD and other protein aggregation-related disorders.

A novel polysaccharide from Rhizoma panacis japonica exerts anti-inflammatory effects via STAT3 signal pathway

PJ-1 modulates the function of macrophages via the STAT3 signal pathway.