A New Source of Elemol Rich Essential Oil and Existence of Multicellular Oil Glands in Leaves of theDioscoreaSpecies

Dioscoreaspecies is a very important food and drug plant. The tubers of the plant are extensively used in food and drug purposes owing to the presence of steroidal constituent’s diosgenin in the tubers. In the present study, we report for the first time that the leaves ofDioscorea compositaandDioscorea floribundagrown under the field conditions exhibited the presence of multicellular oil glands on the epidermal layers of the plants using stereomicroscopy (SM) and scanning electron microscopy (SEM). Essential oil was also isolated from the otherwise not useful herbage of the plant, and gas chromatographic-mass spectroscopy analysis revealed confirmation of the essential oil constituents. Out of the 76 compounds detected inD. floribundaand 37 fromD. compositaessential oil, major terpenoids which are detected and reported forDioscorealeaf essential oil areα-terpinene, nerolidol, citronellyl acetate, farnesol, elemol,α-farnesene, valerenyl acetate, and so forth. Elemol was detected as the major constituent of both theDioscoreaspecies occupying 41% and 22% ofD. FloribundaandD. compositaessential oils, respectively. In this paper, we report for the first timeDioscoreaas a possible novel bioresource for the essential oil besides its well-known importance for yielding diosgenin.