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Abstract
The essential oil of Citrus grandis Osbeck (Rutaceae) is used as the major ingredients of flavors. The fruits of Citrus grandis Osbeck are usually consumed, and the leaves are used as food flavoring by the tribe of Hakka in Taiwan. The other parts of Citrus grandis Osbeck are also used as herbal galenical in traditionalChinese medicine.
The leaves of white pummelo of Citrus grandis Osbeck were gathered in Miaoli, Taiwan. The essential oil was obtained from the leaves of Citrus grandis Osbeck by steam distillation and solvent extraction before treated with base to remove the acidic compounds. The components of the essential oil were separated by column chromatography and identified with gas chromatography-flame ionization detector (GC-FID), gas chromatography-mass spectrometer detector (GC-MSD), Fourier Transform infrared spectroscopy (FTIR), and nuclear magnetic resonance spectroscopy (NMR). Twenty six components were identified as o-cymene, limonene, 3-thujene, ocimene, δ-elemene, copaene, β-elemene, α-santalene, β-cubebene, β-caryophyllene, aromadendrene, τ-muurolene, β-selinene, α-muurolene, γ-cadinene, calamenene, 2,6-dimethyl-5-hepten-1-ol, isopulegol, β-citronellal, β-citronellol, menthoglycol, spathulenol, caryophyllene oxide, isophytol, hexahydrofarnesylacetone, and phytol.
Comparison of the identified constituents of white pummelo to red pummelo was also performed by comparing the hydrogenated and the oxygenated portions of the leave extract. In the hydrogenated fraction, γ-elemene and β-caryophyllene were two major constituents in the leaves of red pummelo, while β-caryophyllene was the only major constituent in white pummelo. Leaves from both plants contain limonene, copaene, β-elemene, aromadendrene, α-muurolene, γ-cadinen in the hydrogenated fraction. In the oxygenated fraction, phytol was the major constituent in the leaves of red pummelo, while caryophyllene oxide and β-citronellol were the major constituents in the white pummelo.
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