RESUMO
Objective: To study the chemical constituents of volatile oil from flower of Dendrobium candidum Wall. ex Lind1. Methods: The chemical compositions of volatile oil of the plant which were obtained by steam distillation with hexane were analyzed by GC-MS equipped with a elastic quartz capillary column-HP-5MS5% Phenyl Methyl Siloxane (30 m? 0.25 mm ?0.25 ?m). The constituents were identifi ed by their mass spectra. The relative percentage of the oil constituents was calculated from the GC peak areas. Results: Eighty-nine kinds of chemical constituents in Dendrobium candidum Wall.ex Lind1.flower were separated; of which fifty-nine compounds representing 76.51% of the oil were characterized. Relative contents that were more than 2.0% were determined as Nonanal 9.21%, Eudesma-5,11-dien-8,12-olide 5.55%, (E)-2-Decenal 4.63%, 2,3-Dehydro- 1,8-cineole 4.39%, Pentacosane 4.03%,?-Cedrol 3.69%, Isoalantolactone 3.65%, (E)-2-Heptenal 3.60%, E,E-2,4-Decadienal 2.14%,?-Phorone 2.03%.Conclusion: This paper reports, for the first time, the composition of volatile oils of Dendrobium candidum Wall.ex Lind1.flower by GC/MS.