ESSENTIAL OIL OF STEMS AND LEAVES OF CHUZHOU CHRYSANTHEMUM AND APPLICATION THEREOF

Abstract

An essential oil of stems and leaves of Chuzhou chrysanthemum and its applications are provided. The essential oil is prepared by: taking and crushing fresh stems and leaves of the Chuzhou chrysanthemum by a crusher; putting the crushed stems and leaves into an extraction kettle, adding deionized water according to a ratio of 1:4 to 1:6, sealing, and connecting a cooling reflux and essential oil collection device; heating and starting counting when boiling, performing distillation extraction; then standing for cooling to room temperature, naturally layering the essential oil and water, discharging the water at a lower layer, and collecting the essential oil at an upper layer; and placing the essential oil in a brown bottle, adding anhydrous sodium sulfate to absorb water to obtain the essential oil of the stems and leaves of Chuzhou chrysanthemum.

Claims

1. An preparation method of essential oil of stems and leaves of Chuzhou chrysanthemum; wherein the preparation method of the essential oil of the stems and leaves of the Chuzhou chrysanthemum comprises the following steps: S1: taking fresh stems and leaves of the Chuzhou chrysanthemum and crushing the fresh stems and leaves of the Chuzhou chrysanthemum by a crusher; wherein conditions of the crushing comprise: 18.5 kilowatts (kW) of power and 1400 revolutions per minute (r/min) of rotational speed; S2: putting the crushed stems and leaves of the Chuzhou chrysanthemum into an extraction kettle, adding deionized water according to a ratio of the crushed stems and leaves to the deionized water of 1:5, sealing the extraction kettle, and connecting a cooling reflux and essential oil collection device to the extraction kettle; S3: heating the extraction kettle, starting timing when boiling, performing distillation extraction on the extraction kettle for 2.5 hours (h) to end distillation; S4: standing the extraction kettle for cooling to room temperature, naturally layering the essential oil and water, discharging the water at a lower layer, and collecting the essential oil at an upper layer; and S5: placing the essential oil in a brown bottle, adding anhydrous sodium sulfate to absorb water to obtain the essential oil of the stems and leaves of the Chuzhou chrysanthemum, and storing in a refrigerator at 4 C. for later use; and wherein main components of the essential oil of the stems and leaves of the Chuzhou chrysanthemum comprise: -selinene accounting for 12.43%, bornan-2-one accounting for 12.13%, camphor accounting for 11.18%, neodihydrotheasperin accounting for 9.73%, -amorphene accounting for 6.79%, and -eudesmol accounting for 6.00%.

2. (canceled)

Description

BRIEF DESCRIPTION OF DRAWINGS

[0027] FIG. 1 illustrates a total ion current (TIC) chromatogram of the essential oil of stems and leaves of Chuzhou chrysanthemum of the disclosure analyzed by gas chromatography-mass spectrometry (GC-MS).

[0028] FIG. 2 illustrates inhibitory effects of the essential oil of the stems and leaves of Chuzhou chrysanthemum on Aspergillus niger (on the 8.sup.th day, isolated from strawberry).

[0029] FIG. 3 illustrates inhibitory effects of the essential oil of the stems and leaves of Chuzhou chrysanthemum on Fusarium sulawesiensis (on the 8.sup.th day, isolated from crisp melon).

DETAILED DESCRIPTION OF EMBODIMENTS

[0030] The disclosure provides an essential oil of stems and leaves of Chuzhou chrysanthemum and its application. In order to make the purpose, technical solution and effect of the disclosure clearer and more definite, the disclosure will be further described in detail below in conjunction with the embodiments. It should be understood that the embodiments described herein are merely illustrative of the disclosure and are not intended to limit the disclosure.

Embodiment 1

[0031] Specifically, a preparation method of the essential oil of the stems and leaves of Chuzhou chrysanthemum is provided, including the following steps.

[0032] S1: fresh stems and leaves of Chuzhou chrysanthemum from Chuzhou are collected and crushed by a crusher. The crushing conditions include 18.5 kW of power and 1400 r/min of rotational speed.

[0033] S2: the crushed stems and leaves of Chuzhou chrysanthemum are put into an extraction kettle, deionized water is added according to a ratio of the crushed stems and leaves to the deionized water of 1:5, the extraction kettle is sealed with a cover, and a cooling reflux and essential oil collection device is connected.

[0034] S3: the extraction kettle is started to heat, timing is started when boiling, and distillation extraction is performed on the extraction kettle for 2.5 h to end distillation.

[0035] S4: the extraction kettle is stood for cooling to room temperature, the essential oil and water are naturally layered, the water at a lower layer is discharged, and the essential oil at an upper layer is collected.

[0036] S5: the essential oil at the upper layer is placed in a brown bottle, anhydrous sodium sulfate is added to absorb water to obtain the essential oil of the stems and leaves of Chuzhou chrysanthemum, and the essential oil is stored in a refrigerator at 4 C. for later use.

Embodiment 2

[0037] Chemical composition analysis of the essential oil of the stems and leaves of Chuzhou chrysanthemum is analyzed as follows.

1. Gas Chromatography-Mass Spectrometry (GC-MS)

[0038] The essential oil of the stems and leaves of Chuzhou chrysanthemum is diluted to 100 milligrams per liter (mg/L) with n-hexane, and 1 microliter (L) is injected into a GC-MS detector (Agilent 8890-5977B GC-MS), using an HP-5 MS ultra-inert capillary column (Agilent) with 300.25 millimeters (mm), inner diameter (i.d), 0.25 micrometers (m). The inlet temperature is set to 250 C., with helium as carrier gas at a flow rate is 1.0 milliliter per minute (mL/min).

[0039] Heating procedures are as follows: the initial temperature is 50 C. and is kept for 5 min, and the temperature is raised to 110 C. at 3 C./min; the temperature is raised to 140 C. at 2 C./min and is kept for 3 min; and the temperature is raised to 260 C. at 12 C./min and is kept for 5 min, with a total time of 55 min. The inlet temperature is 250 C., the carrier gas is high purity helium (>99.999%), the constant flow rate is 1.0 mL/min, the split ratio is 100:1, the solvent delay is 3 min, and the injection volume is 1.0 L.

[0040] Electron impact (EI) ion source, ion source temperature 230 C., quadrupole 150 C., transmission line 230 C.; electron impact energy: 70 electron volts (eV); scanning mode: full scanning, with a mass scanning range of 50-550 mass-to-charge (m/z). The n-alkane mixed standard is diluted to 5 mg/L with n-hexane, and put in an automatic injection bottle with an injection volume of 1 L (the TIC chromatogram is shown in FIG. 1).

2. Identification of Compounds

[0041] Identification of individual compounds is based on calculated retention index (RI) and comparison of their mass spectra with those of reference compounds available in National Institute of Standards and Technology (NIST) 20 database. The threshold matching ratio is set to 90. Under the same operating conditions, the RI related to the homologous series of n-alkanes (C7-C30) is calculated. The chemical composition of the essential oil of the stems and leaves of Chuzhou chrysanthemum is shown in Table 1 below.

TABLE-US-00001 TABLE 1 Analysis of chemical components of the essential oil of the stems and leaves of Chuzhou chrysanthemum Retention Relative Number time Compound name CAS RI content 1 8.62 (1S,4R)-()-Camphene 5794-04-7 943 0.10 2 12.31 Eucalyptol 470-82-6 1035 1.70 3 12.39 (E)-3,7-dimethylocta-1,3,6-triene 3779-61-1 1036 0.26 4 12.84 Ocimenec 13877-91-3 1047 0.10 5 13.26 -terpinene 99-85-4 1056 0.24 6 15.41 cis-4-thujanol 546-79-2 1105 0.15 7 16.38 (1S,4R)-1-methyl-4-prop-1-en- 7212-40-0 1126 0.12 2-ylcyclohex-2-en-1-ol 8 16.46 -Camphor 4501-58-0 1128 0.06 9 17.15 (E)-Carveol 547-61-5 1143 0.34 10 17.51 Bornan-2-one (also referred to 464-49-3 1150 12.13 as D-camphor) 11 18.22 Pinocarvone 30460-92-5 1166 0.24 12 18.43 Camphor 76-22-2 1171 11.18 13 18.59 2,2,4-Trimethyl-3- 80514-13-2 1174 0.11 cyclopentene-1-ethanol 14 18.86 Terpineol-4 562-74-3 1180 0.67 15 19.34 Isocarveol 35907-10-9 1190 0.08 16 19.51 Terpineol 98-55-5 1194 0.28 17 19.74 ()-Myrtenol 19894-97-4 1199 0.34 18 20.12 Bornyl acetate 124-76-5 1207 0.08 19 20.8 ()-Carvacrol 1197-06-4 1222 0.09 20 23.82 L-Born-2-yl acetate 5655-61-8 1289 1.27 21 28.71 ()--elemene 515-13-9 1388 0.49 22 30.02 Caryophyllene 87-44-5 1414 1.61 23 31.34 Sesquisabinene 58319-04-3 1439 0.18 24 31.76 -caryophyllene 6753-98-6 1447 0.16 25 32.18 -(Z)-Farnesene 28973-97-9 1455 1.01 26 32.87 Amorphadiene 211237-38-6 1468 0.49 27 33.30 -Amorphene 6980-46-7 1476 6.79 28 33.60 -Selinene 17066-67-0 1482 12.43 29 33.78 2,4-Diisopropenyl-1- 61142-58-3 1485 0.23 methylcyclohexane 30 34.08 -Cedrene 469-61-4 1491 1.61 31 34.47 -Guaiene 1000159-39-3 1498 0.19 32 34.84 Bornyl valerate 7549-41-9 1505 0.64 33 35.15 Pseudopterosin-1-ol 1000140-22-9 1511 0.21 34 35.36 Bornyl isovalerate 76-50-6 1514 0.18 35 35.58 B-Sesquiphellandrene 20307-83-9 1518 2.61 36 36.28 ()-Italicene ether 104188-25-2 1531 0.10 37 36.81 (E)-Sesquisabinene hydrate 145512-84-1 1540 0.12 38 37.26 -(Z)-Curcumene-12-ol 698365-10-5 1548 0.26 39 37.71 Camphor (E)-2-methyl-2- 101223-92-1 1557 1.01 butenoic acid 40 37.91 Nerolidol 7212-44-4 1560 0.61 41 38.37 Germacrene D-4-ol 198991-79-6 1568 0.42 42 38.51 (+)-Spathulenol 6750-60-3 1571 0.44 43 38.65 1-(4-Methylphenyl)-2-methyl- 83173-76-6 1273 0.27 3-buten-1-ol 44 38.87 Trans-7-epi-sesquisabinene 1000374-17-7 1577 2.30 hydrate 45 39.13 Isoeudesmol 88395-46-4 1582 0.08 46 39.26 Globulol 489-41-8 1584 0.38 47 39.97 Thujopsal 470-41-7 1597 0.29 48 40.56 Cedr-13-ol 18319-35-2 1613 1.12 49 40.81 Shogaol 58334-55-7 1620 0.43 50 41.00 Bisoprolol-1-oxide 1000156-11-0 1626 0.17 51 41.23 Trans-longifolinol 1000159-36-5 1633 1.08 52 41.59 Caryophyll-4(12),8(13)-diene- 19431-80-2 1643 0.76 5-ol 53 41.77 (+)-Ledene 21747-46-6 1649 0.53 54 41.84 Scutellarin 66873-38-9 1651 0.50 55 42.11 -Eudesmol 473-15-4 1659 6.00 56 42.31 Neodihydrotheasperin 5945-72-2 1665 9.73 57 42.42 Trans-torreya alcohol 39599-18-3 1668 0.51 58 42.58 -Caryophyllene alcohol 77171-55-2 1673 0.70 59 42.76 Epiglobulol 88728-58-9 1678 1.07 60 42.97 Octahydro-tetramethyl- 34413-94-0 1685 0.56 cyclopropa-azulene-ketone 61 43.06 Levomecol 23089-26-1 1687 0.72 62 43.21 -Bisabolol 515-69-5 1692 2.22 63 43.35 Allo-aromadendrene oxide-(1) 1000156-12-8 1696 0.14 64 43.47 Parthenolide 20554-84-1 1700 0.13 65 43.55 14-Hydroxycaryophyllene 50277-33-3 1704 0.14 66 43.74 Ledene oxide 1000159-36-7 1715 0.90 67 43.84 Bicyclo[11.3.0]hexadecane- 1000196-24-4 1720 0.21 2,14-dione 68 43.95 Matricin 529-05-5 1727 0.29 69 44.06 Isododecane epoxide 1000159-36-6 1733 3.89 70 44.21 -Cyperone 473-08-5 1741 0.57 71 44.41 Calamenene epoxide 1000151-46-0 1753 0.21 72 44.47 Cedrone 108645-54-1 1756 0.18 73 44.71 Allo-aromadendrene oxide-(2) 1000156-12-7 1769 0.72 74 44.89 Achilleolide 38022-97-8 1780 0.09 75 45.05 Humuleneol-II 19888-00-7 1789 0.30 76 45.29 Eudesmene oxide-(1) 1000151-98-4 1803 0.07 77 45.40 Isolongifolol 1139-17-9 1812 0.11 78 45.86 (+/)-Phytone 502-69-2 1847 0.08 79 45.91 Oxacyclotetradeca-4,11-diyne 6568-32-7 1851 0.06 80 46.34 1,4,9-Tridecenylbenzene 13393-63-0 1884 0.41 81 46.46 Linolenic acid 463-40-1 1894 0.05 82 47.13 Geranyl--terpinene 1000374-18-8 1956 0.10 83 47.23 Palmitic acid 57-10-3 1965 0.09 84 47.90 Falcarinol 21852-80-2 2033 0.18 85 48.55 Methyl linoleate 301-00-8 2104 0.05 86 48.64 Phytol 150-86-7 2114 0.28

[0042] As can be seen from Table 1, 86 components are detected in the essential oil of the stems and leaves of Chuzhou chrysanthemum. The contents of -selinene (12.43%), bornan-2-one (12.13%), camphor (11.18%), neodihydrotheasperin (9.73%), -amorphaene (6.79%) and B-eudesmol (6.00%) are more than 5%, which accounted for 58.26% of the total content of the essential oil, which are the main components of the essential oil of the stems and leaves of Chuzhou chrysanthemum.

Embodiment 3

Antimicrobial Activity Assay

1. Bacterial Inhibition Assay

[0043] Cultured Escherichia coli and Staphylococcus aureus are diluted into 10.sup.6 colony forming units per milliliter (CFU/mL) bacterial solution respectively, and evenly spread on a potato dextrose agar (PDA) plate. After standing for 10 min, the filter paper with a diameter of 6 mm made by a punch is spread on the PDA plate, and 6 pieces are evenly placed in each plate. 10 L of essential oil of stems and leaves of Chuzhou chrysanthemum with a concentration of 5 mg/mL is added with a pipette, and the culture dish is placed in a 37 C. incubator for culture. In the same way, the bacterial inhibition assay of the essential oil of the stems and leaves of Chuzhou chrysanthemum is carried out at the concentrations of 10, 20, 50,and 100 mg/mL. After 16 to 18 h of incubation, a diameter of a bacteriostatic ring (including the piece) is measured with a vernier caliper and recorded. When measuring the bacteriostatic ring, the bacteriostatic ring with uniform and completely sterile growth should be selected, and its diameter should be measured with an outer edge of the bacteriostatic ring as the boundary. Six parallel experiments are performed for each concentration, and the mean and standard deviation are calculated. Ethyl acetate is used as blank control, and streptomycin sulfate and ampicillin are used as positive controls.

TABLE-US-00002 TABLE 2 Inhibitory effects of the essential oil of stems and leaves of Chuzhou chrysanthemum on Escherichia coli and Staphylococcus aureus Escherichia coli Staphylococcus aureus Bacteriostatic Bacteriostatic Concentration ring diameter Inhibitory rate ring diameter Inhibitory rate (mg/mL) (mm) (%) (mm) (%) Ethyl acetate (control) 7.73 0.33E 7.73 0.33G 5 8.65 0.36E 10.51 3.69F.sup. 8.48 0.31G 8.72 3.37G 10 10.82 0.66D 28.37 4.19E.sup. 11.44 0.84F.sup. 32.11 5.11F.sup. 20 15.2 1.35C 48.83 4.36D 12.92 0.63E.sup. 40.03 2.87E.sup. 50 17.77 1.41B 56.26 3.63B 15.15 0.66D 48.89 2.21D 100 19.70 0.54A 60.73 1.09A 20.75 1.13A 62.64 2.08A Streptomycin 15.98 0.43C .sup.51.61 1.3CD 18.10 0.48B 57.27 1.13B sulfate 500 ppm Ampicillin 17.12 0.63B .sup.54.79 1.66BC 16.58 1.17C 53.2 3.03C 50 ppm

[0044] It can be seen from Table 2 that the diameters of the bacteriostatic ring of the essential oil of the stems and leaves of Chuzhou chrysanthemum against Escherichia coli and Staphylococcus aureus increase with the increase of the concentration of the essential oil, indicating that the inhibitory effect of the essential oil of the stems and leaves of Chuzhou chrysanthemum against the two bacteria increases with the increase of the concentration of the essential oil, showing a good dose-response relationship. When the concentration of the essential oil of the stems and leaves of Chuzhou chrysanthemum is 5 mg/mL, both Escherichia coli and Staphylococcus aureus show low sensitivity, with inhibition rates of 10.51% and 8.72% respectively. When the concentration of the essential oil of the stems and leaves of Chuzhou chrysanthemum is 20 mg/mL, Escherichia coli and Staphylococcus aureus show moderate sensitivity, with inhibition rates of 48.83% and 40.03% respectively. When the concentration of the essential oil of the stems and leaves of Chuzhou chrysanthemum is 50mg/mL, Escherichia coli and Staphylococcus aureus show high sensitivity, with inhibition rates of 56.26% and 48.89% respectively. When the concentration of the essential oil of the stems and leaves of Chuzhou chrysanthemum is 100 mg/mL, the diameter of the bacteriostatic ring of Staphylococcus aureus is 20.75 mm, greater than 20 mm, and the inhibition effect is extremely sensitive, with an inhibition rate of 62.64%.

2. Fungal Inhibition Assay

[0045] The antimicrobial activity of the essential oil of stems and leaves of Chuzhou chrysanthemum against Fusarium sulawesiensis and Aspergillus niger is determined by growth rate method. When the PDA culture media are cooled to about 50 C., the essential oils of stems and leaves of Chuzhou chrysanthemum are added respectively, immediately shaken, poured into five 90 mm Petri dishes to prepare plates with different concentrations of essential oils of 5 g/mL, 10 g/mL, 20 g/mL, 50 g/mL and 100 g/mL, respectively. Using a sterilized punch with an inner diameter of 3 mm, the mycelial block is punched on the cultured flat plate media of Fusarium sulawesiensis and Aspergillus niger, the mycelial block is stuck upside down on the flat plate media with tweezers, cultured in an incubator at 25 C. for 8 days, and the colony diameter is measured by a cross method.

TABLE-US-00003 TABLE 3 Inhibitory effects of the essential oil of stems and leaves of Chuzhou chrysanthemum on Fusarium sulawesiensis and Aspergillus niger Fusarium sulawesiensis Aspergillus niger Concentration Colony diameter Inhibitory rate Colony diameter Inhibitory rate (g/mL) (mm) (%) (mm) (%) Blank control 61.39 2.20A 31.53 0.90A 5 50.37 1.36B 17.95 2.21E 29.55 0.44B .sup.6.27 1.39E 10 48.02 0.62C 21.78 1.01D 26.29 0.79C 16.61 2.51D 20 31.70 1.26D 48.37 2.06C 24.65 0.93D 21.80 2.95C 50 19.41 2.26E.sup. 68.39 3.68B 20.61 1.78E 34.61 5.64B 100 6.76 0.75F 88.98 1.23A 10.96 1.44F.sup. 65.25 4.58A

[0046] It can be seen from Table 3 that the colony diameters of Fusarium sulawesiensis and Aspergillus niger decrease with the increase of the concentration of the essential oil of the stems and leaves of Chuzhou chrysanthemum, indicating a good dose-response relationship in the inhibitory effect of the essential oil on the two fungi. Moreover, the inhibitory effect of the essential oil of the stems and leaves of Chuzhou chrysanthemum on Fusarium sulawesiensis is significantly stronger than that on Aspergillus niger. When the concentration of the essential oil of the stems and leaves of Chuzhou chrysanthemum is 20 g/mL, the inhibition rate of Fusarium sulawesiensis is 48.37%, while that of Aspergillus niger is only 21.80%. When the concentration of the essential oil of the stems and leaves of Chuzhou chrysanthemum is 50 g/mL, the inhibition rate of Fusarium sulawesiensis is 68.39%, while that of Aspergillus niger is 34.61%. When the concentration of the essential oil of the stems and leaves of Chuzhou chrysanthemum is 100 g/mL, the inhibition rate of Fusarium sulawesiensis is 88.98%, while that of Aspergillus niger is 65.25%.

Embodiment 4

Determination of Antioxidation Activity

1. Determination of Hydroxyl Free Radical (OH) Scavenging Ability

[0047] 1 mL of essential oil solutions with different concentrations (0.625 mg/mL, 1.25 mg/mL, 2.5 mg/mL, 5 mg/mL, 10 mg/mL, 20 mg/mL) and 1 mL of 6 millimoles per liter (mmol/L) of FeSO.sub.4 solution are put into each test tube and mixed, and 1 mL of 6 mmol/L H.sub.2O.sub.2 is added after mixing well. After mixing well in the dark and standing for 10 min, 1 mL of 6 mmol/L salicylic acid solution is added, and reacted in water bath at 37 C. for 30 min. After taking it out, the absorbance is measured at 510 nanometers (nm), with ascorbic acid (V.sub.C) as positive control, and the parallel measurement is repeated for 3 times. Formula: R (%)=[(A.sub.0-A.sub.i)/A.sub.0]100. For the above formula, R represents the scavenging ability, and A.sub.0 represents the absorbance of the mixed solution of experimental reagent solution and 1 mL absolute ethanol; A.sub.i represents the absorbance of the mixed solution of experimental reagent solution and 1 mL sample solution.

2. Determination of DPPH Free Radical Scavenging Ability

[0048] 1 mL of essential oil solutions with different concentrations (0.625 mg/mL, 1.25 mg/mL, 2.5 mg/mL, 5 mg/mL, 10 mg/mL, 20 mg/mL) and 2 mL of DPPH solution are put into each test tube and mixed, and reacted in the dark for 30 min, the absorbance is measured at 517 nm, with ethanol as the blank control and V.sub.C as positive control, and the parallel measurement is repeated for 3 times. Formula: R (%)=[(A.sub.0-A.sub.i)/A.sub.0]100. From the analysis of the above formula, it can be known that: R represents the scavenging ability, and A.sub.0 represents the absorbance of the mixed solution of experimental reagent solution and 1 mL absolute ethanol; A.sub.i represents the absorbance of the mixed solution of experimental reagent solution and 1 mL sample solution.

3. Determination of ABTS Free Radical Scavenging Ability

[0049] 1 mL of essential oil solutions with different concentrations (0.625 mg/mL, 1.25 mg/mL, 2.5 mg/mL, 5 mg/mL, 10 mg/mL, 20 mg/mL) and 2 mL of ABTS solution are put into each test tube and mixed, and reacted in the dark for 30 min, the absorbance is measured at 734 nm, with ethanol as the blank control and V.sub.C as positive control, and the parallel measurement is repeated for 3 times. Formula: R (%)=[(A.sub.0-A.sub.i)/A.sub.0]100. From the analysis of the above formula, it can be known that: R represents the scavenging ability, and A.sub.0 represents the absorbance of the mixed solution of experimental reagent solution and 1 mL absolute ethanol; A.sub.i represents the absorbance of the mixed solution of experimental reagent solution and 1 mL sample solution.

TABLE-US-00004 TABLE 4 Antioxidation activity of the essential oil of the stems and leaves of Chuzhou chrysanthemum Scavenging Scavenging Scavenging ability of ability of ability of hydroxyl DPPH ABTS Concentration free free free (mg/mL) radical radical radical 0.625 18.74 1.89F.sup. 19.99 1.66F.sup. 18.14 1.32F.sup. 1.25 27.22 1.15E 24.10 1.33E 36.21 1.91E 2.5 34.66 1.08D 28.37 1.13D 44.90 1.86D 5 38.57 1.28C 33.88 1.15C 71.94 1.65C 10 46.39 1.45B 38.67 1.39B 87.54 1.44B 20 55.11 1.60A 44.64 1.85A 94.05 0.72A

[0050] When the concentration of the essential oil of the stems and leaves of Chuzhou chrysanthemum in the disclosure is in the range of 0.625-20 mg/mL, the scavenging rates of hydroxyl free radical, DPPH free radical and ABTS free radical increase with the increase of the concentration of the essential oil, showing a good dose-response relationship. When the concentration of the essential oil of the stems and leaves of Chuzhou chrysanthemum is 20 mg/mL, the scavenging rates of three free radicals reach the maximum, which are 55.11%, 44.64%, and 84.05%, respectively. The scavenging effect of the essential oil of the stems and leaves of Chuzhou chrysanthemum on the ABTS free radical is the strongest, followed by the scavenging effect on the hydroxyl free radical.