First Report on the Chemical Composition, Antioxidant Capacity, and Preliminary Toxicity to Artemia salina L. of Croton campinarensis Secco, A. Rosario & PE Berry (Euphorbiaceae) Essential Oil, and In Silico Study

Croton campinarensis Secco, A. Rosario & PE Berry is an aromatic species recently discovered in the Amazon region. This study first reports the chemical profile, antioxidant capacity, and preliminary toxicity to A. salina Leach of the essential oil (EO) of this species. The phytochemical profile of the essential oil was analyzed by gas chromatography (GC/MS) and (GC-FID). The antioxidant capacity of the EO was measured by its inhibition of ABTS(center dot+) and DPPH center dot radicals. Molecular modeling was used to evaluate the mode of interaction of the major compounds with acetylcholinesterase (AChE). The results indicate that the EO yield was 0.24%, and germacrene D (26.95%), bicyclogermacrene (17.08%), (E)-caryophyllene (17.06%), and delta-elemene (7.59%) were the major compounds of the EO sample. The EO showed a TEAC of 0.55 +/- 0.04 mM center dot L-1 for the reduction of the ABTS(center dot+) radical and 1.88 +/- 0.08 mM center dot L-1 for the reduction of the DPPH center dot radical. Regarding preliminary toxicity, the EO was classified as toxic in the bioassay with A. salina (LC50 = 20.84 +/- 4.84 mu g center dot mL(-1)). Through molecular docking, it was found that the majority of the EO components were able to interact with the binding pocket of AChE, a molecular target related to toxicity evaluated in A. salina models; the main interactions were van der Waals and pi-alkyl interactions.