| Magnolia grandiflora is a large evergreen broad-leaved tree with beautiful shape,large and beautiful flowers,thick and glossy leaves.It is widely planted in China and rich in resources.But at present,it is mainly used in landscaping as an ornamental tree species.In the process of cultivation,a lot of pruning will be carried out,and the pruned branches and leaves will be discarded,which undoubtedly causes a huge waste.In this paper,the leaves and branches of Magnolia grandiflora were extracted with ethanol,acetone and water,and the components of Magnolia grandiflora extract were analyzed by infrared spectroscopy,gas chromatography-mass spectrometry and high-resolution liquid chromatography.The antibacterial activity,cytotoxicity and antioxidant activity of the extract were investigated.Thermogravimetric analysis and nano catalytic pyrolysis were used to analyze the thermogravimetric changes and pyrolysis components of Magnolia grandiflora extraction residue.All of these is to provide scientific basis and technical support for functional component analysis and resource utilization of Magnolia grandiflora.The main results are as follows:(1)Infrared spectrum analysis of solid powder and extract from leaves and branches of Magnolia grandiflora.The types of substances in leaves,branches and extracts of Magnolia grandiflorawere similar,including alcohols,acids,alkanes,olefins,amines and other substances.(2)Analysis of volatile components of Magnolia grandiflora extract.There were many kinds of volatile components,such as alcohols,esters,olefins,alkanes,amides and so on.The content of each substance in different solvent extracts was different,among which the content of ethanol extract from leaves was higher than 10%were esters,alcohols and olefins.In the acetone extract of leaves,the contents of olefins and ketones were both higher than 10%.The content of water extract from leaves was higher than 10%were amides,alkanes,sugars and phenols,and the content of ethanol extract from branches was higher than 10%were sugars,esters,amides and alkenes.The content of amides,alkenes,ketones and sugars were more than 10%in the acetone extract,while the content of amides and alkanes were more than 10%in the water extract.The volatile components of Magnolia grandiflora extract have a wide range of functional applications,which can be used in chemical,pharmaceutical,energy,food,spices and cosmetics industries,but the relative content of volatile components applied in chemical and pharmaceutical fields is relatively high.(3)Analysis of nonvolatile components of Magnolia grandiflora extract.These were abundant non-volatile components in theMagnolia grandiflora extracts,including alcohols,esters,glycosides,terpenoids,flavonoids,alkaloids,phenols and other active components.The contents of alcohols in the six extracts of Magnolia grandiflorawere as follows:ethanol and acetone extract of leaves>ethanol and acetone extract of branches>water extract of leaves and branches.The contents of esters in the six extracts were relatively high,and there was no significant difference.The content of glycosides,terpenoids and flavonoids in leaf extract were higher than those in branch extract,while the content of alkaloids was higher in the branch extract,and the content of alkaloids in the water extract of branch was the highest.Magnolia grandiflora has high medicinal value.(4)Antibacterial activity analysis of Magnolia grandiflora extract.The ethanol and acetone extracts of leaves and branches had significant inhibitory effect on Staphylococcus aureus,and the inhibitory effect was as follows:acetone extract of leaves>ethanol extract of leaves>ethanol and acetone extract of branches.The water extract had no inhibitory effect on Staphylococcus aureus.The results showed that the three solvent extracts of leaves and the ethanol and acetone extracts of branches had different degrees of inhibition on Bacillus subtilis,and the order was ethanol extract of leaves>acetone extract of leaves>water extract of leaves>ethanol and acetone extract of branches.The ethanol and acetone extracts of Magnolia grandiflora leaves had inhibitory effect on Bacillus cereus,while the water extracts of leaves and the three solvent extracts of branches had no significant inhibitory effect on Bacillus cereus.The results showed that the ethanol and acetone extracts of Magnolia grandiflora leaves had different degrees of inhibition on the three kinds of bacteria,and the minimum inhibitory concentration data further showed that the higher the concentration of sample,the better the antibacterial effect.By comparing the antibacterial effect of different parts and different solvent extracts,it was found that the effective parts of leaves and organic solvent extracts had better antibacterial effect.(5)Cytotoxicity analysis of Magnolia grandiflora extract.The results showed that the three solvent extracts of leaves and branches had stronger inhibitory effect on Hela cervical cancer cells,SGC-7901 human gastric cancer cells and K562 leukemia cells,but weaker inhibitory effect on MCF7 human breast cancer cells.Only the acetone extract of leaves,water extract of leaves and acetone extract of branches had stronger inhibitory effect on Hepg2 hepatoma cells.Among them,the ethanol extract of branches had the strongest inhibitory effect on Hela cervical cancer cells and MCF7 human breast cancer cells,the water extract of branches had the strongest inhibitory effect on SGC-7901 human gastric cancer cells,the water extract of leaves had the strongest inhibitory effect on Hepg2 hepatoma cells,with a lethal rate of 90%,and the strongest inhibitory effect on K562 leukemia cells,with a lethal rate of 80%,The anticancer effect of water extract and ethanol extract was better.(6)Antioxidant activity of Magnolia grandiflora extract.Different solvent extracts of Magnolia grandiflora had different degrees of scavenging ability to DPPH free radical and ABTS free radical,and the antioxidant ability was enhanced with the increase of concentration.The ethanol extract of Magnolia grandiflora branch had the strongest scavenging ability to these two kinds of free radicals,and the antioxidant effect was the best.The antioxidant effect of organic solvent extract was higher than that of water extract.(7)Thermogravimetric analysis of extraction residue of Magnolia grandiflora.The thermogravimetric changes of leaf and branch extraction residues can be divided into four stages.At 85.1℃ of the first stage(50℃-125℃),the weight loss rate of leaf extraction residue reaches the maximum value in this stage.At this time,the sample had a violent reaction.In the second stage(125℃-190℃),there was basically no reaction.In the third stage(190℃-600℃),the weight loss rate was the maximum,In the fourth stage(600℃-800℃),the weight loss rate of the sample was stable.At 85.2℃ of the first stage(50℃-135℃),the weight loss rate of branch extract residue reached the maximum at this stage.At this time,the sample had a violent reaction.In the second stage(135℃-195℃),the weight loss rate of branch extract residue did not occur a violent reaction.In the third stage(195℃600℃),the weight loss rate was the maximum.In this stage,a violent reaction occurred and reached the maximum at 290.2℃,In the fourth stage(600℃-800℃),the sample did not react and gradually stabilized.The results showed that the weight loss stage of leaves and branches of Magnolia grandiflora and the temperature at which the weight loss rate reached the maximum were similar.(8)Analysis of pyrolysis components of Magnolia grandiflora extraction residue.There were many kinds of pyrolysis components in leaves and branches,including olefins,aromatics,alcohols,phenols,acids,alkanes,ketones and so on.The content of alcohols was the highest in the leaf extraction residue without catalyst and with nano Ag and Fe2O3,followed by olefins.The content of aromatic hydrocarbon was the highest,followed by olefin.After adding nano-Fe2O3 catalyst,the content of olefins was the highest,followed by alcohols.The content of olefins was the highest in the residue without catalyst,followed by alcohols.The content of phenols was the highest in the residue with nano Ag catalyst,followed by olefins.The content of olefins was the highest in the residue with nano Fe2O3 catalyst and two kinds of composite catalyst,followed by phenols.The pyrolysis components of extraction residue are widely used in chemical industry,medicine,perfume and other fields,but most of them are mainly used in chemical industry. |
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