Constituents of essential oils from the leaves and rhizomes of Ophiopogon fruticulosus Aver., N.Tanaka & K.S. Nguyen from Vietnam

Ophiopogon fruticulosus Aver., N.Tanaka & K.S. Nguyen (local name ‘Địa Long’, meaning “Earth Dragon”) (Asparagaceae) was reported as a new Ophiopogon species in the flora of Laos and Vietnam. It is distributed in primary evergreen broad-leaved forests on limestone mountainous areas (500-1200 m above sea level) and locally abundant in Tuyen Quang province, in the North of Vietnam. From the fresh rhizomes of this plant, apleasant smelling yellow essential oilwas obtained in average of 0.99% yield (w/w) to the absolute dry mass of plant materials by steam distillation. It was soluble in alcohol and organic solvents and insoluble in water with a specific gravity of 0.875-0.975 g/mL (25 °C) and a refractive index of 1.466-1.566 (25 °C). Almost all components of the oil are terpenes including monoterpenes (hydrocarbon monoterpens, 2 compounds, 1.06% of the total oil) and sesquiterpenes (hydrocarbon and oxygenated sesquiterpenes, 23 compounds, 62.83% and 14 compounds 28.72% of the total oil, respectively). The main constituents (>10 %) of the oil were sesquiterpene compounds with the highest relative amounts including cadina - 1(10), 7(11) diene (20.61%), ishwarane (12.04%), longifolene (5.68%), α-selinene (4.13%), δ-cadinene (4.00%), and cis-calamenene (1.18%) and 1 sesquiterpene oxygenated as 1β-H-presilphiperfolane-9a-ol (9.34%). The contents of the remaining components were below 5%, most of them (35 compounds) even below 2%.