Composition and bioactivities of the leaf essential oils of Cinnamomum subavenium Miq. from Taiwan Chen-Lung Ho 1,2 Eugene I-Chen Wang 2 Yu-Chang Su 1* 1 Department of Forestry, National Chung Hsing University 2 Division of Wood Cellulose, Taiwan Forestry Research Institute * Corresponding Author

 Initially we used hydrodistillation and headspace-GC methods to isolate leaf oils and headspace volatiles, and GC/FID and GC/MS to compare the leaf oil compositions from 2 different collection sites. Fushan Botanical Garden (FSB) Fushan Botanical Garden (FSB) Lienhuachih Research Center (LHC) Lienhuachih Research Center (LHC)  With regard to the oil yields, we used the multiple headspace extraction (MHE) of the headspace-GC (HS- GC) method to conduct the comparative analysis.  The second part of the study involved bioactivity analysis, including antioxidant and antimicrobial activities, for multi-purpose utilization of the leaf essential oil of C. subavenium.

Plant Materials Fushan Botanical Garden (FSB) Fushan Botanical Garden (FSB) Lienhuachih Research Center (LHC) Lienhuachih Research Center (LHC)  In August 2005 Both plantations were 22 years old Both plantations were 22 years old Leaves of the species were collected for subsequent extraction and analysis. Leaves of the species were collected for subsequent extraction and analysis.

Results  Leaf oil yields Hydrodistillation Hydrodistillation MHE MHE Hydrodistillation and the HS-GC methods gave comparable leaf essential oil yields.

Results Hydrodistillation V.S. HS-GC Hydrodistillation V.S. HS-GC FSB- HD  44 compounds were identified  Main components being methyl eugenol (75.9%), linalool (7.3%), eugenol (6.6%) methyl chavicol (2.6%), caryophyllene oxide (1.1%).  26 compounds were identified  Main components beingmethyl eugenol (78.7%), linalool (7.7%), eugenol (6.3%), methyl chavicol (3.0%), caryophyllene oxide (1.0%)  Main components being methyl eugenol (78.7%), linalool (7.7%), eugenol (6.3%), methyl chavicol (3.0%), caryophyllene oxide (1.0%) methyl eugenol linalool eugenol methyl chavicol caryophyllene oxide FSB-HS-GC

Results Hydrodistillation V.S. HS-GC Hydrodistillation V.S. HS-GC LHC-HD LHC-HS-GC  88 compounds were identified  Main components being p- cymene (21.6%), 1,8-cineole (16.5%), linalool (11.9%), α- pinene (6.3%), caryophyllene oxide (6.2%)  65 compounds were identified  Main components beingp- cymene (21.7%), 1,8-cineole (20.5%), linalool (13.7%), α- pinene (6.5%), caryophyllene oxide (6.6%)  Main components being p- cymene (21.7%), 1,8-cineole (20.5%), linalool (13.7%), α- pinene (6.5%), caryophyllene oxide (6.6%) p-cymene 1,8-cineole linalool α-pinene caryophyllene oxide

Results 1 Consituents K.I. a) Concentration (%) Identification d) FSBLHC HD b) HS c) HDHS α-pinene MS, KI, ST camphene β-pinene979 t f) t MS, KI, ST β-myrcene979tt p-cymene 1025tt MS, KI, ST limonene β-phellandrene cineole linalool terpinen-4-ol1177t cryptone α-terpineol t methyl chavicol MS, KI, ST cumin aldehyde MS, KI, ST thymol eugenol methyl eugenol MS, KI, ST caryophyllene oxide MS, KI, ST Yield (%)  HS-GC yielded main components similar to those of the hydrodistillation results.

 Leaf oil yields Hydrodistillation and the HS-GC methods gave comparable leaf essential oil yields. Hydrodistillation and the HS-GC methods gave comparable leaf essential oil yields.  Main components FSB FSB methyl eugenol, linalool, eugenol methyl eugenol, linalool, eugenolLHC p-cymene, 1,8-cineole, linalool p-cymene, 1,8-cineole, linalool

Results 2  DPPH photometric assay  Both leaf essential oils had excellent antioxidant activities  FSB essential oil having the best free radical scavenging capacity, and an IC 50 value of merely μg/mL

Results 3  FSB leaf oil 10 μl/disc Ampicillin 1000 ppm Penicillin 1000 ppm X and Y axis represent inhibition zone in diameter (mm)  LHC leaf oil  Disk-diffusion method Both leaf essential oils had excellent antimicrobial activity as well. The FSB sample had the best suppression activity.

Conclusion  Both leaf oils had the best bioactivities. We determined that the main sources of bioactivity were phenolic compounds, such as eugenol, thymol, and carvacrol.