title: Ultrasound-Assisted Extraction May Not Be a Better Alternative Approach than Conventional Boiling for Extracting Polysaccharides from Herbal Medicines.
abstract: In clinical practice polysaccharides from herbal medicines are conventionally prepared by boiling water extraction (BWE), while ultrasound-assisted extraction (UAE) has often been used instead employed in laboratory research due to its strong extraction ability and efficiency. However, if and how the polysaccharides obtained by UAE and BWE are comparable, and hence whether the UAE-based research is instructive for the actual usage of herbal polysaccharides still requires further evaluation. To address this issue, here we chemically analyzed and compared the UAE- and BWE-obtained polysaccharides from three herbal medicines, i.e., Ginseng Radix, Astragali Radix and Dendrobii Officinalis Caulis. Then, the spike recovery of two series of standard dextran and pullulan by UAE and BWE was tested. The results showed that the polysaccharides from the herbal medicines by UAE were quantitatively and qualitatively different with those by BWE. The powerful extraction ability and polysaccharide degradation caused by ultrasound collectively contributed to these differences. It was then revealed that not only the UAE conditions but also the polysaccharide structures could affect the extraction ability and polysaccharide degradation. Given these, we highly recommended that the effects of UAE on polysaccharides from herbal medicines should be first carefully considered before employing it in relevant chemical and pharmacological analysis.
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China. 11015551@life.hkbu.edu.hk.
authors.forename: Ka-Man
authors.initials: KM
authors.lastname: Yip
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China. davidxujun@hkbu.edu.hk.
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China. 12017817@life.hkbu.edu.hk.
authors.forename: Wing-Sum
authors.initials: WS
authors.lastname: Tong
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China. 15485404@life.hkbu.edu.hk.
authors.forename: Shan-Shan
authors.initials: SS
authors.lastname: Zhou
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China. yitao@hkbu.edu.hk.
authors.forename: Tao
authors.initials: T
authors.lastname: Yi
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China. zzzhao@hkbu.edu.hk.
authors.forename: Zhong-Zhen
authors.initials: ZZ
authors.lastname: Zhao
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China. hbchen@hkbu.edu.hk.
authors.forename: Hu-Biao
authors.initials: HB
authors.lastname: Chen
mesh_terms: D027885:Astragalus propinquus; D004365:Drugs, Chinese Herbal / Q000737:chemistry; D006358:Hot Temperature; D005894:Panax / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification*; D000069453:Ultrasonic Waves
chemical_list: D004365:Drugs, Chinese Herbal; D011134:Polysaccharides; C027492:Huang Qi
keywords: degradation; extraction conditions; herbal medicines; polysaccharides; structural features; ultrasound-assisted extraction