Microwave‐Assisted Degradation of Polysaccharide from Polygonatum sibiricum and Antioxidant Activity

Abstract

Four polysaccharide fractions (P‐1: 71.40%, P‐2: 1.95%, P‐3: 1.14%, P‐4: 1.64%) were isolated from crude Polygonatum sibiricum polysaccharide (PSP), processed by water extraction, ethanol precipitation, and further separated with diethylaminoethyl cellulose‐52 anion‐exchange chromatography. Their molecular weights and monosaccharide compositions were characterized by high performance gel chromatography with evaporative light scattering detector and ultraviolet–visible detector. The antioxidant activity of four polysaccharides fractions were assessed by the electron transfer menchanism (DPPH, ferric reducing power, and ABST assays) and chelation of transition metals (Fe2+ and Cu2+ chelation ability). The highest content fraction P‐1 exhibited the lowest antioxidant activity, and the ranking of antioxidant capacity was P‐4 > P‐3 > P‐2 > PSP > P‐1. After processed by microwave‐assisted degradation, the molecular weight of P‐1 was decreased from 2.99 × 105 to 2.33 × 103 Da, while the antioxidant activity of degraded P‐1 was about eightfold higher than natural P‐1. These results indicated that the proposed microwave‐assisted degradation approach was an efficacious methodology to improve their bioactivity by lower the molecular weight of polysaccharides. Practical Application This study provided an environmentally friendly, convenient and efficient microwave‐assisted degradation technology to process the neutral polysaccharides from Polygonatum sibiricum. The results could be used for the development and utilization of various plant polysaccharides as a kind of food supplement in our daily life.

Optimization of Microwave-Assisted Extraction of Polysaccharides from Ulva pertusa and Evaluation of Their Antioxidant Activity

“…However, the structure of the target compound is degraded at high values of microwave power [19]. The degradation of polysaccharides by temperature was reported in different materials such as the roots of valerian [19], Polygonatum sibiricum [32], and Eucommia ulmoides Oliver leaves [33]. As the water-to-raw-materials ratio continued to increase, the yield tended to decrease.…”

Physicochemical Property and Pharmacological Activity of Exopolysaccharide From Endophytic Bacterium Bacillus Sp. B3 Isolated From Polygonatum Sibiricum

“…Overall, the antioxidant activity of EPS-B3 is relatively poor in its natural neutral form [3] . The chemically modi ed or degraded polysaccharides exhibited stronger biological activities [3,27] , so further work could be performed to improve the antioxidant activity of EPS-B3.…”

“…2, the EPS-B3 was composed of galactose, glucose, mannose with a molecular ratio of 15:3:1, respectively, which suggested that monosaccharide composition of EPS-B3 was relatively simple. It was interesting that the monosaccharide composition of EPS-B3 was totally different from that of PSP, which consists of ve different monosaccharides [3,27] .…”

“…and characterized, such as saponins, cyrtonema, lectins, polyphenolics, and polysaccharides [2,3] . An increasing number of evidences indicated that polysaccharides derived from TCM have potent bioactivities, such as immune enhancing property, antitumor activity and antiviral activity [4][5][6] .…”

“…Polygonatumsibiricum is a common traditional Chinese medicine with various functions widely used in some Asian countries [3] to help facilitate secretion of uid and quench thirst, treat dryness and cough, and so on [7,8] . The polysaccharide is one of the main bioactive components from P. sibiricum exhibiting remarkable pharmacological applications and biological activities [2,9,10] , such as antioxidant [3] , anti-tumor [11,12] , anti-atherosclerosis activity and immunity enhancement effect [10,13] .…”