Comparison between essential oil compositions of Zanthoxylum armatum DC. fruits grown at different altitudes and populations in Nepal

The fruits of Zanthoxylum armatum DC. were collected from different altitudes (1000-2000 m) and populations (wild and cultivated) from Salyan district, Nepal. The essential oil was extracted by Clevenger apparatus and the components were analyzed through GC-MS. The yield of essential oil obtained from hydro-distillation of fruits ranged from 2.72 to 7.6%. The maximum yield was 7.6% from wild fruits at 1600-1800 m altitude and the minimum was 2.72% from cultivated fruits at 1000-1200 m altitude. This was the highest recorded essential oil yield from Z. armatum fruits. A total of 13 volatile compounds were identified from the essential oil by GC-MS analysis. The major components were linalool, cinnamate (E)methyl, limonene, myrcene, sabinene and terpinen-4-ol, which were present in higher proportion in all the samples. Other components were identified in a very low proportion. The main component linalool occurred in the highest proportion (74.12%) from wild populations at 1600-1800 m altitude and the lowest (44.73%) was from cultivated populations at 1000-1200 m altitude. The highest proportion of linalool was also reported for the first time in this study from Z. armatum fruits. Among the six major components of the essential oil, terpinen-4-ol was present in the lowest proportion. Results of the present study indicated that the altitude and habitat types could affect the essential oil composition in Zanthoxylum armatum fruits.