This study investigated the volatile flavor composition of essential oils from Ligularia fischeri and Ligularia fischeri var. spiciformis. The essential oils obtained from the plants were analyzed by gas chromatography (GC) and GC-mass spectrometry (GC-MS). 99.63% volatile flavor compounds were identified in the essential oil from the L. fischeri. The major compounds were (E)-3-hexenol (30.73%), longiverbenone (13.23%), viridiflorol (12.39%), γ-muurolene (7.32%), limonene (6.12%), and caryophyllene (β-4.24%). 99.76% volatile flavor compounds were identified in the essential oil from the L. fischeri var. spiciformis. The major compounds were ledol (42.81%), (E)-15-heptadecenoic acid (33.91%), β-bisabolol (3.23%), viridiflorol (3.08%), and cis-α-farnesene (2.60%). Although the two plants are very similar, the chemical composition of the essential oils was significantly different in quality and quantity. In the case of L. fischeri., it has high contents of monoterpene and sesquiterpene. (E)-3-hexenol, longiverbenone, α-phellandrene, and α-myrcene were regarded as the characteristic odorants of L. fischeri, but they were not identified in L. fischeri var. spiciformis. Ledo, (E)-15-heptadecenoic acid, and β-bisabolol were regarded as the characteristic odorants of L. fischeri var. spiciformis, but they were not identified in L. fischeri. The ratio of limonene, γ-muurolene and viridiflorol can be used as an indicator to distinguish between these two plants.

This study investigated the volatile flavor composition of essential oils from Chrysanthemum zawadskii var. latilobum Kitamura and Aster yomena Makino. The essential oils obtained by the hydrodistillation extraction method from the aerial parts of the plants were analyzed by gas chromatography (GC) and GC-mass spectrometry (GC-MS). One hundred (95.04%) volatile flavor compounds were identified in the essential oil from the C. zawadskii var. latilobum Kitamura. The major compounds were valencene (10.82%), δ-cadinol (9.77%), hexadecanoic acid (8.70%), 2-methyl-4-(2,6,6-trimethylcyclohex-1-enyl) but-2-en-1-ol (3.67%), and 2-(2,4-hexadiynylidene)-1,6-dioxaspiro[4,4]non-3-ene (3.57%). Ninety-eight (93.83%) volatile flavor compounds were identified in the essential oil from the Aster yomena Makino. The major compounds were and 3-eicosyne (13.61%), 9,10,12-octadecatrienoic acid (7.8%), α-caryophyllene alcohol (6.83%), 9-octadecynoic acid (6.03%), and α-caryophyllene (5.74%). Although the two plants are apparently very similar, the chemical composition of the essential oils was significantly different in quality and quantity. In the case of C. zawadskii var. latilobum Kitamura, the sesquiterpene, valencene was found to be 10.82%, but it was not identified in A. yomena Makino. δ-Cadinol appeared higher in C. zawadskii var. latilobum Kitamura than in A. yomena Makino. A clear characteristic of A. yomena Makino essential oil is that it has a high content of caryophyllene derivatives. The α-caryophyllene alcohol contained in A. yomena Makino was relatively high at 6.83%, although the compound was not identified in C. zawadskii var. latilobum Kitamura. Also α-caryophyllene was shown to be higher in A. yomena Makino than in C. zawadskii var. latilobum Kitamura.

This study investigated the chemical composition of burdock (Arctium lappa L.) leaves essential oil, and the quantitative changes of the major terpene compounds according to the specific harvesting season. The essential oils obtained by the hydrodistillation extraction (HDE) method from the aerial parts of the burdock leaves were analyzed by gas chromatography (GC) and GC-mass spectrometry (GC-MS). The essential oil composition of this plant was characterized by the higher content of phytol and 6,10,14-trimethyl-2-pentadecanone. Seventy seven (98.28%) volatile flavor compounds were identified in the essential oil from the burdock leaves harvested during the spring season of 2012, and phytol (33.47%) and 6,10,14-trimethyl-2-pentadecanone (32.47%) were the most abundant compounds. Eighty eight (99.08%) compounds were identified in the essential oil from the leaves harvested during the autumn season of 2012, and in this case, phytol (37.35%) and 6,10,14-trimethyl-2-pentadecanone (34.67%) were also the most abundant compounds. These two volatile components were confirmed as the major oil components of the burdock leaves during the time of any harvest. The ratio between the two components contained in the burdock essential oils did not differ significantly by harvesting season. But overall, the essential oil harvested during the spring season contained 65.94% of the two major components, while for the essential oil harvested during the autumn season, the total amount of these two major components was 72.02%. While the main ingredients of the essential oils were found to be unchanged from one harvest time to the next, it was found to differ in content. For the burdock leaves, the quality index of the volatile constituents according to the harvest time would be more useful for utilizing the total quantity other than the proportion between phytol and 6,10,4-trimethyl-2-pentadecone.

This study investigated the chemical composition of headspace gas from white-flowered lotus (Nelumbo nucifera Gaertner). Volatile flavor compositions of headspace from white-flowered lotus (floral leaf, stamen, flower stalk, stem) were investigated through the solid-phase microextraction method using polydimethylsiloxane-divinylbenzene fiber. The headspace was directly transferred to a gas chromatography-mass spectrometry. Sixty-three volatile flavor constituents were detected in the headspace of lotus floral leaves, and undecanoic acid (7.81%) was the most abundant component. Fifty-three volatile flavor constituents were detected in the headspace of lotus stamina, and isobutylidene phthalide (7.94%) was the most abundant component. Forty-four volatile flavor constituents were detected in the headspace of lotus flower stalks, and 3-butyl dihydrophthalide (11.23%) was the most abundant component. Fifty-nine volatile flavor constituents were detected in the headspace of lotus stems, and ligustilide (16.15%) was the most abundant component. The content of phthalides was higher in the headspace of flower stalks and stems, while alcohols and acids were the predominant compounds in lotus floral leaves.

This study investigated the chemical composition of Petasites japonicus (S. et Z.) Maxim essential oil. During the period 2011~2013, P. japonicus (S. et Z.) Maxim plant was investigated for composition of the essential oil. Chemical composition and characteristic compounds of the essential oils from the aerial parts of the plant according to the crop year studied. The essential oils consisted of sesquiterpene compounds, which were the most abundant components. Samples collected in 2011 were found to be richer in oxygenated sesquiterpenes, while samples collected in 2012 and 2013 were richer in diterpene alcohols and sesquiterpene hydrocarbons, respectively. Ninety-two compounds were identified in the P. japonicus (S. et Z.) Maxim essential oil of 2011, and caryophyllene oxide (20.49%), β-caryophyllene (10.28%), β-bisabolene (6.80%), and alloaromadendrene (6.50%) were the major compounds. Seventy-four compounds were identified in the plant essential oil of 2012, and phytol (17.22%), α-farnesene (15.31%), α-caryophyllene (9.93%), and β-caryophyllene (6.12%) were the major compounds. Ninety-two compounds were identified in the plant essential oil of 2013, and α-farnesene (22.42%), α- caryophyllene (21.49%), pentadecane (15.35%), and germacrene (5.70%) were the major compounds. The content of most of the chemical constituents varied significantly with different harvesting time. The content of α-caryophyllene and caryophyllene oxide was increased significantly from 2011 to 2013. The content of α-caryophyllene and isocaryophyllene was decreased significantly from 2011 to 2013.

This study investigated the chemical composition of Cirsium japonicum var. ussurience Kitamura essential oil and the quantitative changes of major volatile flavor compounds according to the harvesting season. The essential oils obtained by the method of hydrodistillation extraction from aerial parts of C. japonicum var. ussurience Kitamura were analyzed by GC and GC-MS. Sixty-four volatile flavor compounds were identified in the essential oil from C. japonicum var. ussurience Kitamura harvested in May 2012; hexadecanoic acid (49.31%) was the most abundant compound, followed by 6,10,14- trimethyl-2-pentadecanone (13.72%), phytol (13.40%) and 9-hexadecenoic acid (4.16%). Eighty-three compounds were identified in the essential oil from the plant harvested in October 2012; phytol (40.56%), hexadecanoic acid (17.69%), 6,10,14- trimethyl-2-pentadecanone (13.71%), and caryophyllene oxide (4.15%) were the most abundant compounds. Types and levels of volatile compounds from different harvesting seasons varied. The essential oil composition of C. japonicum var. ussurience Kitamura harvested in the spring and autumn was characterized by higher contents of aliphatic fatty acid, diterpene and sesquiterpene, respectively.