Ganoderma lucidum polysaccharides (GLPs), the main efficacy components of G. lucidum body, have remarkable efficacy in improving immunity, anti-tumor and liver protection and so on. In order to reveal the effect of gradient ethanol precipitation process on the structural characteristics and biological activity of GLPs, the crude GLPs were extracted from G. lucidum body using anhydrous ethanol to removal impurities such as pigments and hot water extraction process. GLPs were classified by gradient ethanol (40%, 50%, 60%, 70%, 80% and 90%) precipitation, and 6 GLPs, including GLP40, GLP50, GLP60, GLP70, GLP80 and GLP90, were obtained. The structural features of GLPs such as composition, functional group characteristics, molecular weight distribution, and biological activities such as in vitro antioxidant activity and the growth effect of Lactobacillus rhamnosus LGG were characterized by GC-MS, near infrared GC-MS, NIR spectroscopy, gel chromatography and other modern instruments. The results showed that the 6 GLPs contained rhamnose, xylose, arabinose, mannose, glucose and galactose, with glucose, mannose and xylose predominating, GLP40 mainly consisted of mannose and xylose, GLP50, GLP60, GLP70, GLP80 and GLP90 mainly consisted of glucose and mannose, and the highest percentage of glucose was found in GLP80 and GLP90. The typical functional groups of the 6 GLPs fractions at 892.9 cm-1, 1048-1084 cm-1, etc. were intact and did not differ significantly from each other, and all of them were β-type glucan conformations. The molecular weight of the 6 GLPs was different, and the heavy average molecular weight, number average molecular weight and peak molecular weight showed positive correlations. 97-14 925, 99-49 410, 98-32 030, 3614-19 589, 3614-10 795, 4385-11 084 g/mol, with preferential precipitation of high molecular weight GLPs at low ethanol concentrations. 6 GLPs had stronger DPPH radical scavenging ability, hydroxyl radical scavenging ability, and total antioxidant capacity, and GLP90 had stronger antioxidant activity than the other fractions. The 6 GLPs helped to promote the growth of L. rhamnosus LGG. The above findings would provide data support for the study of GLPs extraction process and product development.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |