| Magnolia wufengensis L.Y.Ma et L.R.Wang is a new flower species of the magnolia genus.As an ornamental flower,most of the petals are discarded after the flowering period,causing a waste of resources.Therefore,it is of great significance to speed up the research of magnolia.At present,there are few studies on magnolia wufengensis L.Y.Ma et L.R.Wang at home and abroad,mostly focusing on physiological characteristics and genetic breeding,but lacking regarding reports on flavonoids activities.Flavonoids are secondary metabolites of plants that widely exist in nature,with a variety of physiologically active functions,such as antioxidant,hypoglycemic,anti-inflammatory,and antibacterial,etc.In view of the above situation,this subject systematically studied the extraction process,separation and purification,physiological activity and structure of flavonoids from magnolia wufengensis L.Y.Ma et L.R.Wang compared with magnolia denudata.The aim was to obtain flavonoids with higher purity and stronger activity,turning waste from agriculture and forestry into treasure,and providing technical support for the comprehensive utilization of magnolia wufengensis L.Y.Ma et L.R.Wang.The main research conclusions were as follows:(1)The optimal conditions for ultrasonic-assisted extraction were as follows: ultrasonic temperature 69℃,ultrasonic time 40 min,ethanol concentration 56%,liquid-to-solid ratio 60 m L/g.Under these conditions,the extraction rate of flavonoids in magnolia wufengensis L.Y.Ma et L.R.Wang was 13.91%,which was 2.7 times than that of magnolia denudata.(2)The crude flavonoids were purified by using AB-8 macroporous resin.With magnolia denudate as the reference,the static-dynamic adsorption and desorption conditions were studied to determine the best purification conditions: the concentration of sample flavonoids was 0.81 mg/m L,p H value was 2.0,the flow rate was 1.5 BV/h.The impurities were washed with 8 BV deionized water at a flow rate of 4.5 BV/h,and then flavonoids were eluted with 80% ethanol as eluent at a rate of 4.5 BV/h.Under these conditions,the purity of flavonoids from magnolia wufengensis L.Y.Ma et L.R.Wang increased from 25.67% to 73.80%,and the purity of flavonoids from magnolia denudata increased from 10.18% to 51.35%.The results showed that AB-8 microporous resin had good purification effect on above flavonoids.(3)Compared with the crude flavonoids,the purified flavonoids had better antioxidant activity.When the concentration was 0.12 mg/m L,the scavenging rates of flavonoids of magnolia wufengensis L.Y.Ma et L.R.Wang to free radicals including DPPH and ABTS were 92.46% and 81.86%,respectively,and the total reducing capacity also increased with the increase of purity.The 1.2 mg/m L purified flavonoids from magnolia wufengensis L.Y.Ma et L.R.Wang had an inhibition rate of 82.64% for α-glucosidase,which was the closest to the inhibition rate of acarbose(89.70%).The inhibition of the 1.2 mg/m L purified flavonoids from magnolia wufengensis L.Y.Ma et L.R.Wang on AGEs were 45.52%(BSA-Glu)and 65.74%(BSA-MGO),respectively,and the inhibition rate of acetylcholinesterase was 57.22%,which were significantly stronger than purified flavonoids from magnolia denudata.It demonstrated that magnolia wufengensis L.Y.Ma et L.R.Wang had more significant activities in hypoglycemic and inhibitory of acetylcholinesterase.(4)HPLC-MS was applied to analyze and preliminarily identify the components of flavonoids from magnolia wufengensis L.Y.Ma et L.R.Wang and Magnolia denudate.This study showed that quercetin-3-glucoside and rutin were found in both kinds of magnolias,but a variety of anthocyanin flavonoids,such as peonidin,delphinidin,cyanidin,petunidin,were only detected in magnolia wufengensis L.Y.Ma et L.R.Wang.Based on the physiological activity research section,it was speculated that the contents and components of anthocyanins had to do with the hypoglycemic activity and acetylcholinesterase inhibitory activity. |
PDF Full Text Request