Chemical constituents of the essential oils of Tephrosia purpurea and Ipomoea carnea and their repellent activity against Odoiporus longicollis

The chemical constituents of the essential oils (EOs) obtained from stem and root of Tephrosia purpurea (L.) Pers. and Ipomoea carnea Jacq. were investigated by gas chromatography mass spectrometry (GC MS). The total contents of lipid and oil were higher in the stem than in the root of T. purpurea and I. carnea. The essential oils extracted from the stem and root of T. put-put-ea and I. carnea contained 9 and 8 compounds, respectively. Hexadecanoic acid was found to be the principal constituent of stem (69.61 %) and root (46.97 %) of T. purpurea and of the stem (70.61 %) and root (88.89 %) of I. carnea. The findings of the present study suggest that the EOs of T. purpurea and I. carnea could be a source of hexadecanoic acid that could be used for industrial purposes. The essential oils of T. purpurea and I. carnea showed stronger repellent activity for males (-0.73 and -0.70 for T. purpurea and I. carnea stem EO, respectively) than for females (-0.63 and -0.59 for T. purpurea and I. carnea stern EO, respectively) of the banana pseudostem weevil Odoiporus longicollis. The results indicated that the active compounds of essential oils from stems of T. put-put-ea and I. carnea could be explored as natural repellents for the control of Odoiporus longicollis. Keywords: Tephrosia purpurea; Ipomoea carnea; essential oils; hexadecanoic acid; repellent activity.