To provide a substituted marcfortine and paraherquamide as an excellent antiparasitic agent against endo and ecto parasites, particularly helminths and arthropods, which cause parasitic diseases in humans, animals, and plants.

The 15-alkyl-14 hydroxy compound represented by formula (III) [wherein, n1 is 1-3], the N-oxide and the pharmaceutically acceptable salt thereof, the 15-fluoroalkyl compound and the N-oxide and the pharmaceutically acceptable salt thereof are provided.