... structure of compound 7. Journal of Physical Science, Vol. 21(2), 99–107, 2010 99 Selective Oxygenation and Plant-Growth Regulatory Activity of Sesquiterpene Lactones Sabir Hussain* and ... Lett., 39(31), 5655–5658. Oxygenation and Plant-Growth Regulatory Activity 102 showed IR bands (CHCl3) at 3500, 1760, 1669, 1455, 920, and 862 cm–1 and 1H NMR signals (CDCl3, ... mp, IR and NMR of the authentic samples. Compound 9 showed IR bands at 1780 cm–1 due to the presence of δ-lactone, bands at 3540 cm–1 due to the hydroxyl group and bands at 1755 and 1640...