Compounds
isolated from botanical sources represent innovative
and promising alternatives to conventional insecticides. Carlina oxide
is a compound isolated fromCarlina acaulisL. (Asteraceae)
essential oil (EO) with great potential as bioinsecticide, being effective
on various arthropod vectors and agricultural pests, with moderate
toxicity on non-target species. Since the production from the wild
source is limited, there is the need of exploring new synthetic routes
for obtaining this compound and analogues with improved bioactivity
and lower toxicity. Herein, the chemical synthesis of carlina oxide
analogues was developed. Their insecticidal activity was assessed
on the vectorsMusca domesticaL. andCulex
quinquefasciatusSay, and their cytotoxicity was evaluated
on a human keratinocyte cell line (HaCaT). The compounds’ activity
was compared with that of the natural counterparts EO and carlina
oxide. In housefly tests, the analogues were comparably effective
to purified carlina oxide. InCx. quinquefasciatusassays, themeta-chloro analogue provided a significantly
higher efficacy (LC50of 0.71 μg mL–1) than the EO and carlina oxide (LC501.21 and 1.31 μg
mL–1, respectively) and a better safety profile
than carlina oxide on keratinocytes. Overall, this study can open
the way to an agrochemical production of carlina oxide analogues employable
as nature-inspired insecticides.