This document discusses terpenoids, citral, and artemisin. It defines terpenoids as a large class of natural organic chemicals derived from isoprene. Citral is extracted from lemongrass oil through steam distillation and contains two isomers. It is used to produce lemon, citrus, and fruit flavors. Artemisinin is obtained from various Artemisia plants and is a powerful antimalarial drug that kills malaria parasites faster than other treatments.