Composition and Antioxidative and Antibacterial Activities of the Essential Oil from Farfugium japonicum

The composition of volatile oils of the leaf and stem of Farfugium japonicum (L.) Kitamura were prepared by supercritical fluid extraction (SFE)-CO₂. A total 47 and 40 compounds were identified by GC/MS analysis, respectively, and only 13 compounds coexisted. The main constituent types in the leaf oil included alcohols (34.1%), hydrocarbons (24.1%), terpenoids (16.2%), benzenes (7.5%), and fatty acids (4.9%). In the stem oil, the constituent types chiefly included benzenes (18.8%), ketones (13.9%), terpenoids (17.0%), fatty acids (8.8%), phenolics (8.7%), steroids (8.6%), hydrocarbons (8.0%), and esters (5.7%). The predominant volatile compounds in the stem were 2-(1-cyclopent-1-enyl-1-methylethyl) cyclopentanone (11.7%), 1,2,3,4,5,6,7,8-octahydro- 9,10-dimethyl-anthracene (8.4%), 5-heptylresorcinol (6.5%), and α-sitosterol (5.2%). Those in the leaf mainly included (E)-3-hexen-1-ol (13.7%) and (Z)-3-hexen-1-ol (14.0%). This demonstrated a significant difference in the composition of both oils. Further study showed that stem oils demonstrated the highest DPPH (1,1-diphenyl-2-pinylhydrazyl) and ·OH free radical scavenging capacities at IC₅₀ values of 9.22 and 0.90 mg/mL, respectively. In addition, they demonstrated the strongest antibacterial capacity against the Gram-positive bacteria methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) at a minimum inhibitory concentration (MIC) of 0.16 mg/mL. This could be due to the SFE-CO₂ extraction and the high accumulation of benzenes, terpenoids, and phenolics in the stem. In particular, the monoterpenes presented in terpenoids could play a special role in these findings.

Eremophilane sesquiterpenes from Ligularia macrophylla

New eremophilane sesquiterpenes, 6beta-sarracinoyloxy-1beta,10beta-epoxy-furanoeremophilane (1), 6alpha-angeloyloxy-10betaH-furanoeremophil-1-one (2), 1alpha-hydroxy-9-deoxycacalol (3), and 1beta-hydroxy-11(R,S)-8-oxoeremophil-6,9-dien-12-al (4a+4b), together with five known sesquiterpenes (5-9) were isolated from the roots and rhizomes of Ligularia macrophylla. The structures were elucidated by spectroscopic methods including 2D NMR techniques, and the structure of 1 was confirmed by a single-crystal X-ray diffraction experiment. The compounds were also evaluated for cytotoxic activity against human lung carcinoma (A-549) and human breast adenocarcinoma (MCF-7) and were found to show only very weak cytotoxicity.