Chemical structures of water-soluble polysaccharides from Rhizoma Panacis Japonici

Valorization of cell wall polysaccharides extracted from Liubao brick tea residues: chemical, structural, and hypoglycemic properties

BACKGROUND

Tea dregs, typically generated during the production of instant tea or tea beverages, have conventionally been regarded as waste material and routinely discarded. Nevertheless, contemporary research endeavors are concentrating on discovering efficient methods for utilizing the potential of this discarded resource.

RESULTS

In this study, we employed a sequential extraction method using chemical chelating agents to extract and isolate four distinct cell wall polysaccharides, designated as CWTPS-1 through CWTPS-4, from the tea dregs of Liubao brick tea. A comprehensive investigation into their physicochemical, structural, and hypoglycemic properties was conducted. The analysis of chemical composition and physicochemical characteristics revealed that all four CWTPSs were characterized as acidic polysaccharides, albeit with varying chemical compositions and physicochemical attributes. Specifically, the xyloglucan fractions, CWTPS-3 and CWTPS-4, were found to be rich in glucose and xylose, displaying a more uniform molecular weight distribution, greater structural stability, and a more irregular surface compared to the others. Moreover, they exhibited a higher diversity of monosaccharide residues. Importantly, our research unveiled that all four CWTPSs exhibited the capacity to modulate key glucose-regulated and antioxidant enzyme activities within HepG2 cells via the IRS-1-PI3K/AKT signaling pathway, thereby ameliorating cellular insulin resistance. Furthermore, our correlation analysis highlighted significant associations between monosaccharide composition and neutral sugar content with the observed hypoglycemic activity of CWTPSs.

CONCLUSION

This study highlights the potential of utilizing tea dregs as a valuable resource, making a significant contribution to the advancement of the tea industry. Furthermore, CWTPS-4 exhibits promising prospects for further development as a functional food ingredient or additive. © 2024 Society of Chemical Industry.

Panax japonicus C.A. Meyer: a comprehensive review on botany, phytochemistry, pharmacology, pharmacokinetics and authentication

BACKGROUND

Panax japonicus C.A. Meyer (Zhujieshen) is widely used in traditional medicine as a tonic hemostatic and anti-inflammatory agent in China, Japan, and Korea. Furthermore, it is used as an important substitute for ginseng roots by minority ethnic groups in China. The purpose of this review is to summarize the latest research on Zhujieshen in recent years, aiming at providing a systematic overview of the current knowledge, and perspectives for future research and exploitation.

MAIN BODY

This review examines the research advances in botanical profile, phytochemicals, pharmacology, pharmacokinetics, and authentication of Zhujieshen. Various compounds have been reported as active components, mainly including saponins, volatile oils, and polysaccharides. Pharmacological investigations have demonstrated that Zhujieshen is an important herb with significant bioactivities, such as anti-inflammatory, hepato-protective, cardio-protective, neuro-protective, anti-tumor, anti-oxidant, anti-thrombotic and immunomodulatory activities.

CONCLUSION

Currently, research on Zhujieshen is in the preliminary stages, and further research is required to understand the active compounds present and mechanisms of action. We hope that this comprehensive review of Zhujieshen will serve as a background for future research and exploitation.

Hydrolysis and characterization of sugar recovery from bakery waste under optimized subcritical water conditions

Subcritical water hydrolysis process for sugar recovery from leftover croissants (LC) and leftover doughnuts (LD) was optimised using response surface methodology with three process parameters as dependent variables and sugar yield as the response. The process parameters: temperature (160-200 °C), time (5-15 min), and solid loading (10-50%), on the sugar yield were investigated. For the LC sample, the optimised process conditions were determined to be: 200 °C, 6.17 min, and 10% solid loading producing an 80% hydrolysis yield of 466.11 ± 0.67 mg/g. Comparatively, the LD sample optimisation parameters were: 200 °C, 5 min, and 10% solid loading producing a 76.18% hydrolysis yield of 394.34 ± 0.33 mg/g. The sugar extracts were further characterise; which through scanning electron microscopy revealed the LC had most starch granules rupture during hydrolysis, while Fourier-transform infrared spectroscopy detected the presence of monosaccharides and oligosaccharides for both LC and LD. 5-hydroxymethylfurfural (5-HMF), a sugar degradation by-product, was also detected with 39.16 ± 0.61 and 20.59 ± 0.81 mg/g for the LC and LD, respectively, at optimal conditions.

The role of Rho GTPases' substrates Rac and Cdc42 in osteoclastogenesis and relevant natural medicinal products study

Recently, Rho GTPases substrates include Rac (Rac1 and Rac2) and Cdc42 that have been reported to exert multiple cellular functions in osteoclasts, the most prominent of which includes regulating the dynamic actin cytoskeleton rearrangements. In addition, natural products and their molecular frameworks have a long tradition as valuable starting points for medicinal chemistry and drug discovery. Although currently, there are reports about the natural product, which could play a therapeutic role in bone loss diseases (osteoporosis and osteolysis) through the regulation of Rac1/2 and Cdc42 during osteoclasts cytoskeletal structuring. There have been several excellent studies for exploring the therapeutic potentials of various natural products for their role in inhibiting cancer cells migration and function via regulating the Rac1/2 and Cdc42. Herein in this review, we try to focus on recent advancement studies for extensively understanding the role of Rho GTPases substrates Rac1, Rac2 and Cdc42 in osteoclastogenesis, as well as therapeutic potentials of natural medicinal products for their properties on the regulation of Rac1, and/or Rac2 and Cdc42, which is in order to inspire drug discovery in regulating osteoclastogenesis.

Evaluation of the effect of soluble polysaccharides of palm kernel cake as a potential prebiotic on the growth of probiotics

This paper deliberates the extraction, characterization and examination of potential application of soluble polysaccharides of palm kernel cake (PKC) as a prebiotic. The PKC was defatted and crude polysaccharide was obtained through water, citric acid or NaOH extraction. The physiochemical properties of the extracted polysaccharides viz. total carbohydrates, protein content, solubility rate, monosaccharides composition, structural information and thermal properties were also determined. The extracted soluble polysaccharides were further subjected to a digestibility test using artificial human gastric juice. Finally, their prebiotic potential on two probiotics, namely Lactobacillus plantarum ATCC 8014 and Lb. rhamnosus ATCC 53103 were evaluated in vitro. It was observed that PKC contained ash (5.2%), moisture (7.4%), carbohydrates (65.8%), protein (16.5%) and fat (5.1%). There were significant differences (P < 0.05) between the values of NaOH-extracted crude polysaccharides (8.73%) and that of water (3.03%) and citric acid (3.07%)-extracted polysaccharides. The extracted polysaccharides composed of mannose, galactose, glucose, arabinose, xylose and rhamanose, with highest percentage of mannose (62.49%) and galactose (25.42%) in SP_CA. Total carbohydrate content in SCP_W, SCP_CA and SCP_N are 57.11%, 56.94% and 50.95%, respectively. The polysaccharides from PKC in this study were found to be highly soluble (> 95%). Protein content in SCP_W, SCP_CA and SCP_N are 0.72, 0.40 and 0.58, respectively, and the peaks which indicated the presence of protein were observed at approximately 1640 cm^-1 (amide I). FTIR spectroscopy revealed that the polysaccharides extracts were linked to β and α-glycosidic bonds and thermal analysis using differential scanning calorimeter (DSC) showed the main degradation temperature of SP is about 121 to 125 °C. The SP were found to be highly resistance (> 96%) to hydrolysis when subjected to artificial human gastric juice. The prebiotics potentials of the polysaccharides on probiotics in vitro demonstrated an increase in proliferation of Lb. plantarum ATCC 8014 and Lb. rhamnosus ATCC 53103 with decrease in the pH of the medium and producing organic acids.All the above findings strongly indicated that polysaccharides extracted from PKC, an industrial waste, have a potential to be exploited as novel prebiotics.

Characterization of a novel alkali-soluble heteropolysaccharide from tetraploid Gynostemma pentaphyllum Makino and its potential anti-inflammatory and antioxidant properties

A novel polysaccharide (GPP-S), with a molecular mass of 1.2 × 10(6) Da, was isolated from the tetraploid Gynostemma pentaphyllum Makino by alkali extraction followed by purifications using DEAE and Sephacryl S-400 column chromatographies. The monosaccharide composition of GPP-S was determined as rhamnose, arabinose, glucose, and galactose with a molar ratio of 1.00:3.72:19.49:7.82. The structural analysis suggested that the backbone of GPP-S is (1→4)-linked-glucose and (1→6)-linked-galactose with a (1→4,6)-linked-glucose branch every six monosaccharide residues. The terminals were 1-)-α-arabinose, glucuronic acid, and other monosaccharides. GPP-S exhibited scavenging capacities against hydroxyl, peroxyl, and DPPH(•) radicals in vitro. GPP-S also had inhibitory activities on IL-1β, IL-6, and COX-2 gene expressions in RAW 264.7 mouse macrophage cells. These results suggested that GPP-S could be developed as a bioactive ingredient for functional foods and dietary supplements.

Effect of glucans from Caripia montagnei mushroom on TNBS-induced colitis

In this study, we evaluated the effect of different doses of polysaccharides extracted from Caripia montagnei mushroom at different intervals of treatment on colonic injury in the model of colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS). The FT-IR analysis and NMR showed that the polysaccharides from this species of mushroom are composed of α- and β-glucans. The colonic damage was evaluated by macroscopic, histological, biochemical and immunologic analyses. The results showed the reduction of colonic lesions in all groups treated with the glucans. Such glucans significantly reduced the levels of IL-6 (50 and 75 mg/kg, p < 0.05), a major inflammatory cytokine. Biochemical analyses showed that the glucans from C. montagnei acted on reducing levels of alkaline phosphatase (75 mg/kg, p < 0.01) and myeloperoxidase (p < 0.001), a result confirmed by the reduction of cellular infiltration observed microscopically. The increase of catalase activity possibly indicates a protective effect of these glucans on colonic tissue, confirming their anti-inflammatory potential.

Characterization of a novel polysaccharide from tetraploid Gynostemma pentaphyllum makino

A novel heteropolysaccharide (GPP-TL) was isolated from tetraploid Gynostemma pentaphyllum (Makino) leaf by hot water extraction and anion-exchange and gel permeation chromatography approaches. GPP-TL had a molecular weight of 9.3 × 10(3) Da and was primarily composed of glucose, galactose, and arabinose, with a molar ratio of 43:5:1, respectively. The chemical structure of GPP-TL was characterized using chemical and instrumental analyses. The results indicated the presence of (1→4)-α-d-glucopyranosyl, (1→4)-β-d-galactopyranosyl, (1→4,6)-linked-α-d-glucopyranosyl, and terminal 1→)-α-d-glucopyranosyl moieties in a molar ratio of 5.7:1:1.5:1, respectively. The results indicated that GPP-TL had glucose and galactose residues in the main chain with (1→6)-linked branches at glucose residues. In addition, GPP-TL exhibited scavenging capacities against hydroxyl, peroxyl, and DPPH radicals in vitro and had a stronger bile acid-binding ability than psyllium on a same-weight basis.

Isolation and characterization of hemicelluloses extracted by hydrothermal pretreatment

The dewaxed sample from Triploid of Populus tomentosa Carr. was extracted by using organic alkaline solvent (Dimethylformamide, DMF) via hydrothermal pretreatment. Neutral sugar compositions and molecular weight analysis demonstrated that the hemicellulosic fractions with a higher Uro/Xyl ratio, namely the more branched hemicelluloses, had higher molecular weights. Interestingly, these results were different from the previous report, in which the ratio of Uro/Xyl in the water-soluble hemicellulosic fraction was more than that of the alkali-soluble hemicellulosic fraction. Spectroscopy (FTIR, (1)H NMR, (13)C NMR, and HSQC) analysis indicated that the hemicellulosic fractions were mainly composed of (1→4)-linked α-D-glucan from starch and (1→4)-linked β-D-xylan attached with minor amounts of branched sugars from hemicelluloses. In addition, thermal analysis implied that linear hemicelluloses showed more thermal stability than the branched ones during pyrolysis.

Prebiotic activity of polysaccharides extracted from Gigantochloa levis (Buluh beting) shoots

Bamboo shoot crude polysaccharides (BSCP) extracted from the shoots of Gigantochloa levis gave about 3.27 ± 0.18% on dry basis and a very minute percentage of protein (0.02 ± 0.01%). The molecular weight of BSCP estimated by gel chromatography was found to be around 7.49 × 10³ Da, while the molecular weights of purified fractions (F1 to F5) were around 1550.96, 1471.63, 1685.78, 1691.61 and 1551.67 Da, respectively. The FTIR spectrum of BSCP revealed the possibility that the extract contains β-glucan, which can be considered a valuable compound for the medical and food industries. These relate to the resistance of BSCP towards artificial human gastric juice which is more than 99%. Prebiotic activity tested using BSCP as a carbon source showed significant increase in the growth of B. animalis ATCC 1053, B. longum BB 536 and L. acidophilus ATCC 4356 as compared to the use of FOS. Survivality of S. choleraesuis JCM 6977 was found to be slower in both BSCP and FOS. Study conducted reflects a good sign for the BSCP to be exploited as a promising prebiotic.