Recovery, concentration and purification of phenolic compounds by adsorption: A review

Antioxidants: Characterization, natural sources, extraction and analysis

The original pyrogallol (1,2,3-trihydroxybenzene) method, which was developed specifically for superoxide dismutase, is now widely used for measuring superoxide-scavenging of other antioxidants. However, the strong pH effect has been ignored. In this study, the influencing factors have been systematically investigated for the first time, and a number of experiments have proved that the pH is of major importance. As major antioxidants contain carboxylic acid, ester, or lactone groups, pH 8.2 should be modified to physiological pH 7.4. The improved procedure is as follows. A pyrogallol solution (in 1 M HCl) is thoroughly mixed with pH 7.4 Tris-HCl buffer; A(325 nm) is measured every 30 s for 5 min at 37 °C. As the ΔA(325 nm, control) value reflects the initial concentration of substrate (•)O(2)(-), it should be well controlled to guarantee the accuracy of the method. The improved pyrogallol method is a reliable and cheap superoxide-scavenging assay suitable for all types of antioxidants.

Improved Pyrogallol Autoxidation Method: A Reliable and Cheap Superoxide-Scavenging Assay Suitable for All Antioxidants

Exotic Fruits as Therapeutic Complements for Diabetes, Obesity and Metabolic Syndrome.

MALDI-TOF MS suggested that the high molecular weight proanthocyanidin (condensed tannin) from persimmon (Diospyros kaki L.) pulp comprised a heteropolyflavanol series with flavan-3-O-galloylated extenders, flavan-3-ol and flavonol terminal units, and A-type interflavan linkages. Thiolysis-HPLC-ESI-MS with DAD, electrochemical, and ESI-MS detection confirmed a previously unreported terminal unit, the flavonol myricetin, in addition to the typical flavan-3-ols catechin and epigallocatechin gallate. The extender units were epicatechin, epigallocatechin, (epi)gallocatechin-3-O-gallate, and (epi)catechin-3-O-gallate. The crude tannin had a high prodelphinidin content (65%) and a high degree of 3-O-galloylation (72%). The material was fractionated on Toyopearl TSK-HW-50-F to yield fractions distinguished by degree of polymerization (DP). Thiolysis suggested that the persimmon tannin was composed of polymers ranging from 7 to 20 kDa (DP 19-47), but sizes estimated by GPC were 50-70% smaller. The crude material was chemically degraded with acid to yield products that were amenable to NMR and ESI-MS analysis, which were used to establish for the first time that persimmon tannin has a mixture of B-type and A-type linkages.

High Molecular Weight Persimmon (Diospyros kaki L.) Proanthocyanidin: A Highly Galloylated, A-Linked Tannin with an Unusual Flavonol Terminal Unit, Myricetin

Structural features and antioxidant activity of tannin from persimmon pulp

Abstract Oudemansiella raphanipes (OR) is a commercial mushroom which possesses high nutritional value and excellent and unique flavors. In this study, various agricultural wastes were utilized as substitute materials in the low‐cost and high‐yield production of mycelia biomass and polysaccharides by liquid fermentation. The sawdust, wheat bran, apple pomace, sugarcane, and corn particles were employed to cultivate OR, using the potato dextrose broth as control. Additionally, a preliminary characterization and in vitro antioxidant activities of partial purified OR polysaccharides were investigated. The substrate of sugarcane was suitable for mycelia growth of OR, with high yield of mycelia biomass and polysaccharides content. In vitro antioxidant activity assays demonstrated that OR polysaccharides could effectively scavenge 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) and 1,1‐diphenyl‐2‐picrylhydrazyl radicals. OR polysaccharides had configuration as revealed by Fourier transform infrared, and was mainly composed of fucose (Fuc), rhamnose (Rha), arabinose (Ara), galactose (Gal), glucose (Glc), xylose (Xyl), mannose (Man), ribose (Rib), and galacturonic acid (Gal‐UA), with mass percentages of 3.29%, 0.64%, 1.09%, 16.03%, 72.69%, 0.56%, 3.18%, 0.93%, and 1.59%, respectively. This study may offer support for decreasing the cost of OR polysaccharides production and dealing with these agricultural wastes.

Evaluation of different agricultural wastes for the production of polysaccharides from Oudemansiella raphanipes and its antioxidant properties

The invention relates to a preparation method of active components of plant antiophidica. The preparation method takes persimmon as raw material, and comprises the processes of preliminary treatment, extracting, separation of active components, etc., fetching fresh persimmon pulp and pulping evenly, or taking the persimmon pulp as raw material, wherein the persimmon pulp is dried in vacuum at low temperature and then crushed to 20-80 meshes; ultrasonically circulating and extracting for 30-60 min by extraction agent or heating, reflowing and extracting for 40-60 min at 90-100 DEG C, filtering, the filter liquor is recovered to ethanol or methanol solvent, obtaining concentrated solution 1; diluting the concentrated solution 1 by water, filling macroporous resin, reserving the sample for 0.5-1h after sampling, firstly using distilled water to elute, and then, using methanol to elute, collecting eluent A, recovering solvent, obtaining concentrated solution 2; diluting the concentrated solution 2 by water, hyper-filtrating and separating by polysulphone hollow fiber ultrafiltration membrane group with the intercepted molecular weight of 6000-10000u, the active components of antiophidica are obtained by concentrating and drying the intercepted liquor. The experiment in the body of the animals shows that the active components of antiophidica have the effect of detoxification.

Method for preparing plant effective component for detoxifying snake poison

Oudemansiella raphanipes is a commercially popular edible medicinal mushroom. The polysaccharides from O. raphanipes are the natural therapy for various metabolic diseases. Therefore, we have developed the optimal extraction conditions for extraction of polysaccharides from the mycelia of O. raphanipes and investigated their antioxidant activities. The optimal conditions of extracting polysaccharides from the mycelia of O. raphanipes were 85°C for 3.5 h, and the material-to-liquid ratio of 1:31. Under these conditions, the polysaccharides recovery was 91.89 mg/g, which was close to the predicted value (92.49 mg/g). In vitro antioxidant activity assays exhibited that the polysaccharides from the mycelia of O. raphanipes could effectively scavenge the 1,1-diphenyl-2-picrylhydrazyl, 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid), and hydroxyl radicals, and it also exhibited the reducing power against K3Fe (CN)6. These results suggested that the polysaccharides from the mycelia of O. raphanipes could be used as the source of natural antioxidants.

Mei-hong Chen

Papers

Structural features and antioxidant activity of tannin from persimmon pulp

Evaluation of different agricultural wastes for the production of polysaccharides from Oudemansiella raphanipes and its antioxidant properties

Method for preparing plant effective component for detoxifying snake poison

Extraction and Antioxidant Activities of Polysaccharides Produced by Submerged Mycelia Culture of Oudemansiella raphanipes