ANTIPARASITIC AND INSECTICIDAL ACTIVITIES OF SESQUITERPENE LACTONES AND EUDESMANES OF FOUR ASTERACEAE SPECIES FROM AMERICA

A. SOSA; E. SALAMANCA; A. GIMENEZ; N. VERA; BARDON ALICIA DEL VALLE; S. BORKOSKY

Tokushima

Simposio; ISPSA 2015 TOKUSHIMA; 2015

Phytochemical Society of Asia

Naturalproducts continue to be an important source for the search of new therapeuticdrugs and agrochemicals. Leishmaniasis is a major threat to public health inmany countries from South America. An alternative to antiparasitic syntheticdrugs is the search of plant extracts or secondary metabolites derived fromthem. Additionally, botanical insecticides and their bioactive chemicals aregenerally pest-specific and are relatively harmless to non-target organismsincluding man. We investigated the molluscicidal, leishmanicidal andinsecticidal activities of ten lactones and seven eudesmanes withsesquiterpenoid skeleton from four species of Asteraceae: Vernonanthuranebularum, V. pinguis, Vernonia fulta, and Pluchea sagittalis. Leishmaniaamazonensis clone 1 IMHOM/BR/76/LTB-012) and L. braziliensis (RJA C192 M2904)promastigotes, the mollusk Biomphalaria peregrina, potential vector ofschistosomiasis and Spodoptera frugiperda and Ceratitis capitata, pests thatcause significant damage to crops in northwestern of Argentina, were used asexperimental models. Elephantopus-type sesquiterpene lactones (SL)from Vernonanthura nebularum were the most active against the mollusk withLE050 values of 15.8 and 31.3 pg/mL for compounds S and 10, respectively. Inantiparasitic activity assays. all SL of V. nebularum (7-10). showed a strongeffect on the promastigote forms of Leishmania atnazonensis and L.brazilienzis, with IC30 values <3.9 microg/ml for both strains. All SLtested exhibited a strong antifeedant activity against S. frugiperda underchoice conditions, compound 1 being the most active with an antifeedant index(AI) of 82.16 at 100 ppm. The ingestion of eudesmanes 15-17 by third instarlarvae reduced growth and utilization of the ingested and digested foodsignificantly. Mortality rates of larvae and pupae do not exceeded 40% in alltreatments. Finally, SL 2 and eudesmanes 11 and 14 were the most active againstC. capitata, inhibiting the oviposition rate 60%, 75% and 89%, respectively, ata dose of 30 microg/cm2.