Sequential extraction of Hericium erinaceus using green solvents

Application of Enzyme-Assisted Extraction for the Recovery of Natural Bioactive Compounds for Nutraceutical and Pharmaceutical Applications

Enzyme-assisted extraction (EAE) involves the use of hydrolytic enzymes for the degradation of the cell wall or other cell components. This supports the diffusion of the solvent into the plant or fungal material, leading to easier elution of its metabolites. This technique has been gaining increasing attention, as it is considered an eco-friendly and cost-effective improvement on classical or modern extraction methods. Its promising application in improving the recovery of different classes of bioactive metabolites (e.g., polyphenols, carotenoids, polysaccharides, proteins, components of essential oil, and terpenes) has been reported by many scientific papers. This review summarises information on the theoretical aspects of EAE (e.g., the components of the cell walls and the types of enzymes used) and the most recent discoveries in the effective involvement of enzyme-assisted extraction of natural products (plants, mushrooms, and animals) for nutraceutical and pharmaceutical applications.

A novel polysaccharide from Hericium erinaceus: Preparation, structural characteristics, thermal stabilities, and antioxidant activities in vitro

A novel polysaccharide fraction (HEP) from Hericium erinaceus was successively isolated and purified in the present study. We researched its structure and thermal stabilities, and further studied its antioxidant activities in vitro. The results showed that HEP was an acid heteropolysaccharide, with an average molecular weight of approximately 19.7 kDa by high-performance gel permeation chromatography. Ion chromatography indicated that HEP was mainly composed of fucose:galactose:glucose:mannose:gluconic acid (Fuc:Gal:Glu:Man:GlcA) in a molar ratio of 1:2.87:0.09:0.12:0.01. Additionally, Fourier-transformed infrared and NMR spectroscopy further demonstrated that HEP was a pyranose containing α-configuration, mainly consisting of α-1-4-Fuc and α-1-6-Gal as the main chain, with →3,6)-α-D-Man-(1→and→1,6)-Glc was branched, with α-D-GlcpA-(1 as T-terminal. The specific rotation of HEP was +55°; by the differential scanning calorimetry and the thermal stability measurement of thermogravimetric analysis for HEP showed that the pyrolysis process of HEP was mainly divided into two processes, and its melting point was 75.93℃. In vitro anti-oxidation experiments showed that HEP had a certain ability to scavenge DPPH, hydroxyl, superoxide anion, and ABTS radicals. It was found that HEP had a strong ability to scavenge DPPH-free radicals, and the highest scavenging rate could reach 91.72% ± 0.17%, which was basically equivalent to the scavenging ability of Vitamin C (Vc). Therefore, it was revealed that HEP might be used as a natural antioxidant component. PRACTICAL APPLICATIONS: A novel polysaccharide (HEP) had a potent activity possibly due to its monosaccharide composition, sugar residues, and physicochemical properties. This research proved the potential of HEP in anti-oxidation and provided the possibility of developing new natural anti-oxidation products.

Supercritical and ultrasound-assisted extracts from Pleurotus pulmonarius mushroom: chemical profiles, antioxidative, and enzyme-inhibitory properties

BACKGROUND

This study provides an insight into the impact of ultrasound-assisted extraction with water as solvent (UAEW) and extraction by supercritical carbon dioxide (SC-CO₂ ) with 5% EtOH on antioxidant and enzyme inhibitory activity in regard to the chemical profile of the edible and medicinal mushroom, Pleurotus pulmonarius.

RESULTS

Extraction efficiency was between 0.36% and 63.32%, depending on the extraction technique. The main compounds in the extracts were fatty acids. Supercritical CO₂ extraction with co-solvent was the most suitable method for obtaining extracts that were rich in ergosterol content, reaching a value of 40.1 mg g^-1 . The UAEW of crude mushroom powder ensured the highest yield, as well as the extracts with best antioxidative activity. The measurements of enzyme inhibitory activity revealed that all types of investigated extracts exhibited only tyrosinase and amylase inhibition at a significant level.

CONCLUSION

Based on our results, the extraction methods significantly affected the chemical profile and bioactivity of P. pulmonarius. © 2020 Society of Chemical Industry.

Pre-protective effect of polysaccharides purified from Hericium erinaceus against ethanol-induced gastric mucosal injury in rats

The β-glucan H6PC20 (Mw: 2390 kDa) and α-heteropolysaccharide HPB-3 (Mw: 15 kDa) were purified from the fruiting body of Hericium erinaceus according to the previous methods. Their gastroprotective activities and corresponding structure-activity relationship were studied in the ethanol-induced gastric ulcer model of rats. After intragastric administrated with H6PC20 and HPB-3 for 14 days, macroscopic and histological evaluation of gastric mucosa was improved significantly. The defense and repair factors (EGF, bFGF and PGE₂) were increased, meanwhile, the inflammatory cytokines (IL-1β and TNF-α) and MDA were reduced. These results indicated that H6PC20 and HPB-3 presented gastroprotective activities with the mechanism of activating repair and defense system, decreasing the inflammatory response and alleviating the oxidative injury. Furthermore, the structure-activity relationship showed that the macromolecular β-glucan was better for repair and defense system, while the low weight molecular α-heteropolysaccharide focused on the anti-inflammatory effect. The polysaccharides purified from H. erinaceus can be developed as a potential gastroprotective ingredient for applications in pharmaceutical field.

Pressurized hot water extraction of β-glucans from Cantharellus tubaeformis

Cantharellus tubaeformis was processed by pressurized hot water extraction (80-240°C) with the aim of maximizing the extraction of oligomeric fractions, β-glucans, and the in vitro antioxidant properties of the extracts. Increased severity of treatment enhanced the extraction yields above 62% at temperatures of 210ºC or higher, corresponding to the maximum β-glucan yields. The highest antioxidant capacity was obtained at 170ºC, although the highest content of phenolic compounds was obtained at the highest severity studied. This hydrothermal treatment can be considered a suitable process to obtain extracts with antioxidant properties and rich in β-glucans.