Chemical composition of essential oil from Hydrangea macrophylla flower

Abstract

Hydrangea is a genus of the plant family Saxifragaceae, with approximately 73 species in Asia, North America, and Central and South America, of which 46 species and 10 varieties are distributed in China, especially in the southwest and southeast. Most of them are evergreen or deciduous sub-shrubs, shrubs, and small trees; the minority are woody lianas or lianoid shrubs [1]. The blossoms of Hydrangea macrophylla (Thunb.) Ser. are mainly used for ornamental purposes [2,3]. This plant is also a traditional Chinese herb and has been used for the treatment of malaria, heart hot fright, and dysphoria [4]. The pharmacological studies show that it has an antimalarial [5–7], antiallergic [8], antifungal [9], antidiabetic [10, 11], anticoccidial, antihypercholesterolemic, and antioxidative activities [12]. This is the first report on the compositions of essential oil from this plant. The flower of H. macrophylla was collected in August 2011 from the campus of Southwest Forestry University, Kunming City, Yunnan Province, China. The species was identified by Prof. Fan Du (College of Forestry, Southwest Forestry University, Kunming City, Yunnan Province, China). A voucher specimen (No. 110804) is deposited in the Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountains of China, Southwest Forestry University, Kunming City, Yunnan Province, China. The sample was kept from direct light and air-dried at room temperature. Hydrodistillation was carried out under atmosphere pressure for 6 h to extract the essential oils. The distillate was extracted with ether and then frozen at –18 C to remove water. The essential oil of H. macrophylla flower gave a yield of approximate 0.2% (w/w). In Table 1, data of essential oils from H. macrophylla are given. A total of 30 compounds was detected, amounting to 91.6% of total oils. Organic acid as the dominant class of compounds constituted 55.2% of the total oil, including hexadecanoic acid (35.8%) as the main components. Alkanes (23.6%) were the next major component. Monoterpenes (6.2%) were the third main component. The analysis was carried out using an Agilent GC-6890N with flexible fused silica capillary column (30 m 0.25 mm, 0.25 m film thickness), coupled to a mass selective detector (MSD5973N, ionization voltage 70 eV). Helium was the carrier gas. Oven temperature was from 80 C to 290 C at a rate of 4 C/min, and held for 30 min. The components were identified by comparison of their mass spectra with those of the NIST02 mass spectra library.