Resourceful Utilization Of Invasive Plant Eupatorium Adenophorum

Eupatorium adenophorum is a perennial herb of the family Asteraceae and a native to Mexico of South America.It has been one of the main invasive weed of China and caused very serious economic and environmental problems.Many methods have been developed to control it,including chemical,biological,and mechanical control.However,no significant progress has been made.Utilization of the weed provides more benefits besides control processes,it can improve its economic value.In this study,Phytochemical evaluation was performed to analyze the components in E.adenophorum.The bioactive components were purificated and the main toxins were removed.Safety evaluation of the purified products was performed.It will provide scientific evidence for possible utilization of the weed.The main results are as follows:The isomers of mono-caffeoylquinic acid in E.adenophorum were purified and identified.Three mono-caffeoylquinic acids,including 3-O-caffeoylquinic acid,5-O-caffeoylquinic acid,and 4-O-caffeoylquinic acid were obtained by preparative HPLC.3-O-caffeoylquinic acid and 4-O-caffeoylquinic were purified and identified in E.adenophorum for the first time.In vitro hepatotoxicity of different solvent extracts from E.adenophorum were studied.It is deduced that sesquiterpenes are the main hepatic toxins in E.adenophorum based on the comparison of composition analysis of the different solvent extracts.Three sesquiterpenes were purified and identified as 9-oxo-10,11-dehydroageraphorone,10H?-9-oxo-ageraphorone,and 10H?-9-oxo-ageraphorone.The three components were confirmed to be hepatotoxic components.The operational conditions of extraction of mono-caffeoylquinic acids from E.adenophorum were studied.The yield of mono-caffeoylquinic acids obtained through stirring extraction was higher than ultrasound-assisted extraction under the optimized conditions.A second-order kinetic model was successfully developed for describing the mechanism of stirring extraction under different temperatures.The optimized conditions were 60%ethanol,solid to liquid ratio 1/30,and the temperature was set as 80? for the stirring extraction.The extraction yields were 6.46,19.73,and 3.32 mg/g for 3-O-caffeoylquinic acid,5-O-caffeoylquinic acid,and 4-O-caffeoylquinic acid,respectively.In a laboratory preparative-scale extraction with solid-liquid ratio 1:10 for two times,the recovery of 5-O-caffeoylquinic acid was 96.86%.Different methods for separation of chlorogenic acid from E.adenophorum extracts were compared among macroporous resin column chromatography,ultrafiltration,and liquid-liquid extraction.Macroporous resin column chromatography gave the highest purity.The adsorption properties of nine macroporous resins were measured.NKA-? resin showed much better adsorption/desorption properties.The adsorption of chlorogenic acid on NKA-? resin was well fitted to Langmuir isotherm model and pseudo-second-order kinetic model.In a laboratory preparative-scale experiment under the optimized separation conditions,the content of chlorogenic acid in the product was 22.17%,with a recovery yield of 82.41%.The process was effective and stable.The chlorogenic acid product separated by macroporous resin was further purified to obtain a product with a high purity.The methods of polyamide resin column chromatography and liquid-liquid extraction-crystallization were compared.The adsorption properties of chlorogenic acid on polyamide resin were studied and the laboratory preparative-scale experiment were performed under the optimized separation conditions.The content of chlorogenic acid in the product was 86.53%,obtaining a recovery yield of 84.77%.After concentration and crystallization,the purity of chlorogenic acid was 96.82%.The purity of chlorogenic acid product after crystallization was 96.03%,and the method was easier to operate.Safe evaluation of three chlorogenic acid products with different purities of 6.11%,22.17%,and 96.03%was performed.Phytochemical analysis showed that the main toxins of sesquiterpenes were almost completely removed in sample preparation procedure.All the products exhibited no cytotoxic effects at a dose of 400 ?g/mL in a cell viability assay in vitro.When administered in vivo at a single dose up to 15 g/kg bw,all three products caused no signs or symptoms of toxicity in mice.These results demonstrated that the three chlorogenic acid products were rather safe.In vitro antioxidant activity and mouse splenic lymphocyte proliferation tests were carried out on three chlorogenic acid products with different purities.In vitro antioxidant activity increased with the increase of contents of chlorogenic acid.All of the three products at a high concentration echanced the proliferation of mouse splenic lymphocyte proliferation in vitro.Among them,the crude extract worked the best.It suggested that the other components may play synergistic effects.After composting the raw material and extracted residue for a full utilization of E.adenophorum,all the indexes met the standards of maturity.The major allelochemical,9-oxo-10,11-dehydroageraphorone,was not detected after composting.Seed germination experiments suggested that the products after composting did not have any toxicity to plants.