Plant polysaccharides extracted by high pressure: A review on yields, physicochemical, structure properties, and bioactivities.

Polysaccharides are biologically essential macromolecules, widely exist in plants, which are used in food, medicine, bioactives' encapsulation, targeted delivery and other fields. Suitable extraction technology can not only improve the yield, but also regulate the physicochemical, improve the functional property, and is the basis for the research and application of polysaccharide. High pressure (HP) extraction (HPE) induces the breakage of raw material cells and tissues through rapid changes in pressure, increases extraction yield, reduces extraction time, and modifies structure of polysaccharides. However, thus far, literature review on the mechanism of extraction, improved yield and modified structure of HPE polysaccharide is lacking. Therefore, the present work reviews the mechanism of HPE polysaccharide, increasing extraction yield, regulating physicochemical and functional properties, modifying structure and improving activity. This review contributes to a full understanding of the HPE or development of polysaccharide production and modification methods and promotes the application of HP technology in polysaccharide production.

Comparison in structural, physicochemical and functional properties of sweet potato stems and leaves polysaccharide conjugates from different technologies.

In order to better understand the influences of extraction techniques on the yield, characteristics, and bioactivities of polysaccharide conjugates, hot reflux extraction (HRE), ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE), complex enzymolysis extraction (CEE), ultra-high pressure extraction (UPE), ultrasonic complex enzymes extraction (UEE) were used to extract sweet potato stems leaves polysaccharide conjugates (SPSPCs), and their physicochemical characteristics, functional properties, antioxidant and hypoglycemic activities were compared. Results showed that compared with HRE conjugate (HR-SPSPC), the yield, content of uronic acid (UAC), total phenol (TPC), total flavonoid (TFC) and sulfate group (SGC), water solubility (WS), percentage of glucuronic acid (GlcA), galacuronic acid (GalA) and galactose (Gal), antioxidant and hypoglycemia activities of UEE polysaccharide conjugates (UE-SPSPC) significant increased, while its molecular weight (Mw), degree of esterification (DE), content of protein (PC) and percentage of glucose (Glc) declined, but monosaccharides and amino acid types, and glycosyl linkages were not much different. Indeed, UE-SPSPC possessed the highest antioxidant activities and hypolipidemic activities among six SPSPCs, which might be due to the high UAC, TPC, TFC, SGC, GlcA, GalA and WS, low Mw, DE and Glc of UE-SPSPC. The results reveal that UEE is an effective extraction and modification technology of polysaccharide conjugates.

Anti-gout activity and the interaction mechanisms between Sanghuangporus vaninii active components and xanthine oxidase.

Xanthine oxidase (XO) plays a critical role in the progression of gout. We showed in a previous study that Sanghuangporus vaninii (S. vaninii), a perennial, medicinal, and edible fungus traditionally used to treat various symptoms, contains XO inhibitors. In the current study, we isolated an active component of S. vaninii using high performance countercurrent chromatography and identified it as davallialactone using mass spectrometry with 97.726 % purity. A microplate reader showed that davallialactone had mixed inhibition of XO activity with a half-inhibitory concentration value of 90.07 ± 2.12 µM. In addition, the collision between davallialactone and XO led to fluorescence quenching and conformational changes in XO, which were mainly driven by hydrophobicity and hydrogen bonding. Molecular simulations further showed that davallialactone was located at the center of the molybdopterin (Mo-Pt) of XO and interacted with amino acid residues Phe798, Arg912, Met1038, Ala1078, Ala1079, Gln1194, and Gly1260, suggesting that entering the enzyme-catalyzed reaction was unfavorable for the substrate. We also observed face-to-face π-π interactions between the aryl ring of davallialactone and Phe914. Cell biology experiments indicated that davallialactone reduced the expression of the inflammatory factors, tumor necrosis factor alpha and interleukin-1 beta (P < 0.05), can effectively alleviate cellular oxidative stress. This study showed that davallialactone significantly inhibits XO and has the potential to be developed into a novel medicine to prevent hyperuricemia and treat gout.

Ultrasonic disruption effects on the extraction efficiency, characterization, and bioactivities of polysaccharides from Panax notoginseng flower.

Ultrasonic disruption extraction (UDE) and heat reflux extraction (HRE) were used to extract polysaccharides (PNFPs) from Panax notoginseng flower, and the yield, physicochemical characteristics, structural characteristics, functional properties and biological activities were evaluated and compared. Results indicated that UDE changed the above properties of PNFPs. Compared with HRE (H-PNFPs), the yields, uronic acid contents, total phenolic content, total flavonoid content, water-solubility, water holding capacity, and oil holding capacity of the polysaccharides (U-PNFPs) extracted by UDE increased by 48.63%, 47.36%, 39.98%, 7.41%, 2.26%, 15.56%, and 1.34%, respectively. In comparison, the molecular weight and protein content decreased by 43.53% and 16.46%. Results demonstrate that UDE could effectively improve the physicochemical and functional properties, and bioactivities. These findings are helpful for better understanding the relationship between the physicochemical properties and bioactivities of U-PNFPs, especially U-PNFP-2 exhibited the most significant antioxidant activity, which can prevent oxidative stress, applications in food and pharmaceutical industries.

Effects of multi-frequency ultrasonic on the physicochemical properties and bioactivities of polysaccharides from different parts of ginseng.

The effect of multi-frequency ultrasonic extraction (MUE) on the yields, physicochemical properties, antioxidant and α-glucosidase inhibitory activities of polysaccharides (GPs) from different parts of ginseng were compared. Results demonstrated that yields of polysaccharides from different parts were found to vary significantly differences, in the order of roots (M-GRPs) > flowers (M-GFPs) > leaves (M-GLPs). Compared with heat reflux extraction, MUE not only increased the yield of GPs by up to 9.14%-210.87%, with higher uronic acid content (UAC: increased by 4.99%-53.48%), total phenolics content (TPC: increased by 7.60% to 42.61%), total flavonoids content (TFC: increased by 2.52%-5.45%), and lower molecular weight (Mw: reduced by 6.51%- 33.08%) and protein content (PC: reduced by 5.15%-8.95%), but also improved their functional properties and bioactivities. All six purified polysaccharides extracted by MUE were acidic pyran polysaccharide with different monosaccharide composition, possessed remarkable antioxidant and α-glucosidase inhibitory activities. Especially, M-GFP-1 exhibited the highest bioactivities, illustrated that the activities were highly correlated with UAC and TPC, Mw, and triple helical structure. These results indicate that MUE was an efficient technique for improving yields, physicochemical and functional properties and enhancing biological activities of polysaccharide.

Antibacterial and NF-κB Inhibitory Lumazine Peptides, Aspochalasin, γ-Butyrolactone Derivatives, and Cyclic Peptides from a Hawaiian Aspergillus flavipes.

Five new lumazine peptides (1-5), a new aspochalasin derivative (6), and a new γ-butyrolactone derivative (7), together with seven known compounds (8-14), were isolated from a Hawaiian fungal strain, Aspergillus flavipes FS888. Compound 1 is an uncommon natural product containing an isocyano group. The structures of the new compounds 1-7 were elucidated by NMR spectroscopy, HRESIMS, chemical derivatization, and ECD analysis. Compounds 12-14 showed significant antibacterial activity against S. aureus when in combination with disulfiram. Additionally, compounds 9 and 13 showed NF-κB inhibitory activity with IC50 values of 3.1 ± 1.0 and 10.3 ± 2.0 µM, respectively.

Isolation of four high-purity dammarane saponins from extract of Panax notoginseng by centrifugal partition chromatography coupled with evaporative light scattering detection in one operation.

INTRODUCTION: Centrifugal partition chromatography (CPC), as a continuous liquid-liquid partition chromatography with no solid support matrix, combined with evaporative light scattering detection (ELSD) was employed for systematic separation and purification of weak-chromophoric saponins from a highly valued and important traditional Chinese herbal medicine, Panax notoginseng. OBJECTIVE: To separate and isolate high-purity saponins from extract of Panax notoginseng using CPC-ELSD with a simple and low toxicity solvent system. METHODOLOGY: Samples were preparaed by extracting the root material with acetone, treated with n-butanol and then freeze-dried. CPC-ELSD was applied in the separation and detection of notoginsenoside and ginsenosides from extract of Panax notoginseng using a solvent system composed of ethyl acetate-n-butanol-water (1:1:2, v/v/v). The saponins were analysed and identified by their retention time with high-performance liquid chromatography (HPLC) coupled with ELSD, as well as electrospray ionisation tandem mass spectrometry (ESI-MS(n) ) in the negative and positive ion modes with the authentic standards. RESULTS: A total of 9.6 mg of notoginsenoside R1, 67.8 mg of ginsenoside Rg1, 2.3 mg of Re and 286.5 mg of Rb1 were purified from 487.2 mg of n-butanol extract of P. notoginseng. The purities of obtained saponins in a single run were assessed to be over 98% by HPLC-ELSD. CONCLUSION: CPC-ELSD was proved to be a very fast and efficient tool for separation of high-purity dammarane saponins.