Volatile Constituents of Semnostachya menglaensis Tsui

摘要

Semnostachya menglaensis Tsui(Acanthaceae)is a rare plant indigenous to Mengla in the tropical rainforest of the Xishuangbanna prefecture in the south of Yunnan province,People's Republic of China.When the leaves are crushed,a characteristic smell of basmati rice or pandan leaves develops.Their hexane extract,prepared from a specimen growing in a greenhouse of the botanical garden of the Kunming Institute of Botany,contains 1-(3,4,5,6-tetrahydro-2-pyridyl)-1-propanone(41.2%)and 1-(1,4,5,6-tetrahydro-2-pyridyl)-1-propanone(37.5%)which constitute the main part of the volatile compounds.Minor components are 1-(3,4,5,6-tetrahydro-2-pyridyl)-1-ethanone(4.9%),1-(1,4,5,6-tetrahydro-2-pyridyl)-1-ethanone(4.8%),1-(2-piperidyl)-1-propanone(5.2%),1-octen-3-ol(3.2%),1-octen-3-one(1.9%),and 3-octanol and 1-(2-pyridyl)-1-propanone in trace amounts.