| Liriope spicata(Thunb.)Lour.is belongs to the family of Liliaceae,which was used as the research material.The following researches have been carried out from the roots of L.spicata from Ankang and Hanzhong area of Shaanxi Province:(1)The dynamic cycle of accumulation of total flavonoids and saponins in the medicinal sites of L.spicata at different times;(2)Study on the biological activity of total flavonoids in L.spicata;(3)Determination of inorganic element content in L.spicata.The main findings are as follows:(1)Study on dynamic cycle of total flavonoids accumulation in L.spicataThe total flavonoids of L.spicata were extracted by alkaline extraction and acid precipitation method.Determination of total flavonoids content and dynamics of accumulation of medicinal parts in L.spicata at different stages by UV spectrophotometry.In experiments,hesperidin was used as the reference substance for total flavonoids,and the UV spectrophotometer was used to measure the absorbance at a wavelength of 283 nm.The experimental results show that with changing the growth time of L.spicata,the accumulation of total flavonoids in roots and fibrous roots of L.spicata has a certain degree of variation.During the year,the content of total flavonoids in fibrous roots was the highest in January,and the root volume in April was the highest.The highest content of total flavonoids can reach19.078 mg/g and 18.739 mg/g,respectively.The content of total flavonoids in roots and fibrous roots of L.spicata is abundant,which can be used as a basis for the development and utilization of plant resources.(2)Study on the biological activity of total flavonoids from L.spicataThe antioxidant activity of total flavonoids in L.spicata was analyzed using an in vitro antioxidant system.The research indicates showed that the total flavonoids of L.spicata had a certain antioxidant activity and certain scavenging effect on hydroxyl radicals(-OH)and DPPH.Within a certain concentration range,the total reducing power also increased by increasing the total flavonoids concentration.Gradually increasing,its effect is proportional to the concentration,but by contrast,the effect is slightly weaker than Vc.When the total flavonoid extract concentration is below 0.3 mg/mL,the total flavonoid extract concentration is positively correlated with the clearance rate.With the increase of total flavonoid concentration,the clearance rate of hydroxyl radical(-OH)increases gradually.When the concentration of flavonoids extract was 0.3 mg/mL,the total flavonoids extract had a maximum clearance rate of 43.72%,which was stronger than that of Vc at the same concentration.When the concentration of total flavonoids extract was greater than 0.3 mg/mL,the antioxidant activity of total flavonoids changed little with the concentration of flavonoids solution,and their antioxidant capacity was lower than that of Vc.When the total flavonoid concentration was 0.45 mg/mL,the DPPH scavenging rate of L.spicata sagittifolia reached a maximum of 11.4%.The total flavonoids of L.spicata in a certain concentration range,the total reducing power gradually increased with the increase of the concentration of the total flavonoids,showing a certain degree of reduction,the above experiments all use Vc as a control group.In the antibacterial experiment of L.spicata total flavonoids,methanol was used as a blank control experiment.The inhibition effect of the total flavonoids extract on the tested strains was as follows:Bacillus subtilis>Escherichia coli>Staphylococcus aureus.(3)Study on dynamic cycle of accumulation of saponins in the L.spicataIn this experiment,methanol was heated under reflux,and the filtrate was filtered.The filtrate was extracted with water-saturated n-butanol.The Ophiopogonin D and Liriopesides B were extracted from the roots and fibrous roots of L.spicata respectively.Further more a high performance liquid chromatographic(HPLC)method was established for the determination of the content of Ophiopogonin D and Liriopesides B in roots and fibrous roots,and simultaneous detection of two saponin active ingredients in L.spicata.The experimental results showed that with the change of the growth time of L.spicata,the accumulation of Ophiopogonin D in roots and fibrous roots in Ankang reached its highest level in February,being 0.487 mg/g and 1.660 mg/g,respectively.Similarily,Liriopesides B reached its highest content in roots and roots of L.spicata in Ankang city in January,which were 0.077 mg/g and0.285 mg/g,respectively.At the same time,this experiment also detected the content of Ophiopogonin D and Liriopesides B in the roots of L.spicata from Hubei Province and found that the content of Ophiopogonin D was lower than that of Ankang but the content of Liriopesides B was higher,the content was up to 0.254 mg/g,0.429 mg/g.It shows that the content of saponin in L.spicata from different places has certain differences.(4)Microwave digestion-ICP-OES method for determination of inorganic elements in the L.spicataThe samples were prepared H2O2 mixed with concentrated nitric acid system were regarded as digestion solvent and made a full spectrum scan to the samples of L.spicata by microwave digestion.The inductively coupled plasma emission spectrometry(ICP-OES)was applied to determine the inorganic elements in L.spicata.The result show that there were 12inorganic elements in L.spicata which include Ca,Sr,Mn,Fe,Zn,P,Ba,Na,K,Cu,Al,Mg.All elements have a good linear relationship in the linear range,the R~2 is between0.9994~0.9999 and the RSD is between 1.08%~4.47%,The method detection limits for all inorganic elements were with a range of 0.0507~0.5040μg/mL.The recovery rate of standard sample was from 95%to 104.5%.There were abundant inorganic elements in the L.spicata,including macronutrient elements like K,Ca,P,Na,Mg,as well as micronutrient elements such as Fe,Al,Zn,Mn,Sr,Cu,Ba.The Ni,V,Co,Li and heavy metals like Pb,Cd,Cr,Hg were not detected.The results of this study may provide a scientific basis for the further development and utilization about L.spicata. |
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