Effects of ultrasonic treatment on the physicochemical properties and DPPH radical scavenging activity of polysaccharides from mushroom Inonotus obliquus.
An ultrasonic technique was employed to extract polysaccharides from Inonotus obliquus (UPS). The effects of ultrasonic conditions on the recovery and 1, 1-diphenyl -2-picrylhydrazyl (DPPH) radical scavenging activity of UPS were evaluated. The physicochemical properties of UPS were analyzed by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and UV-visible spectrophotometry. Molecular weights of UPS were determined by gel permeation chromatography (GPC). The optimal ultrasonic conditions to obtain the highest recovery of polysaccharides were 80 min, 75 degrees C, and 100 w. While the optimal ultrasonic conditions to obtain the strongest DPPH scavenging activity of polysaccharide were 80 min, 95 degrees C, and 160 w. The differences were found by DSC, SEM, GPC analysis and no apparent differences were found from the UV-vis spectra of the polysaccharides after the ultrasonic treatment, which indicated that ultrasonic treatment might cause the physicochemical changes in UPS conformation and degradation of UPS chain but not the main groups. Ultrasonic technique was an effective method to extract bioactive polysaccharides from I. obliquus (UPS).


CONCLUSIONS
Polysaccharides from Inonotus obliquus exhibited many biological activities including antitumor, antioxidant, hypoglycemic, immune-stimulating effects, and so on. Ultrasonic treatment is now an usual proceeding technique for the extraction of some bioactive constituents. But there was no information about the effects of ultrasonic treatment on the physicochemical properties and DPPH radical scavenging activity of polysaccharides from I. obliquus until now. Ultrasonic technique was an effective method to extract bioactive polysaccharides from I. obliquus (UPS) according to this study.
Fu
Lingling
L
Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin Univ., Tianjin, 300072, PR China.
Chen
Haixia
H
Dong
Peng
P
Zhang
Xin
X
Zhang
Min
M
D000363:Agaricales / Q000737:chemistry*; D001713:Biphenyl Compounds / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D055598:Chemical Phenomena; D002850:Chromatography, Gel; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000302:isolation & purification; D006358:Hot Temperature; D008519:Medicine, Traditional; D008855:Microscopy, Electron, Scanning; D008970:Molecular Weight; D010851:Picrates / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification / Q000648:ultrastructure; D013010:Sonication; D013053:Spectrophotometry; D013997:Time Factors; D014465:Ultrasonics
D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010851:Picrates; D011134:Polysaccharides; C004931:1,1-diphenyl-2-picrylhydrazyl