Chemical composition and biological activities of essential Oil from leaf and bark of Nyctanthesarbor-tristis L. from Nepal

The essential oil from the leaves and barks of Nyctanthes arbor-tristis, collected from Biratnagar, Nepal, was hydrodistilled and analyzed by GC-MS. A total of 26 compounds were identified in the leaf oil, accounting for 100% of the oil while a total of 20 compounds were identified in the bark oil accounting for only 89.4% of the oil. Both the leaf and bark oil had similar quantities of hexadecanoic acid (26.4% and 34.3%, respectively) and octadecanoic acid (3.9 and 6.2%, respectively). However, the leaf oil also consisted of linalool (11.0%), (E)-phytol (13.6%) and (3Z)-hexenyl benzoate (11.0%), which were absent in the bark oil. Besides fatty acids, the bark oil exhibited significantly different composition with mostly β-eudesmol and other eudesmol isomers (27.5%). The oil was screened for antimicrobial activity and showed marginal activity against Bacillus cereus and Aspergillus niger (MIC = 625 μg mL). N. arbor-tristis leaf oil was inactive in the brine shrimp lethality test (LC50 > 100μg/mL).