Larvicidal activity and docking study of Ramalina complanata and Cladonia verticillaris extracts and secondary metabolites against Aedes aegypti

da Silva A.S., Aguiar J.C.R.O.F., Nascimento J.S. , Costa E.C.S., dos Santos F.H.G., de Araújo H.D.A., da Silva N.H., Pereira E.C., Martins M.C., Falcão E.P.S., Scotti L., Scotti M.T. & Navarro D.M.A.F.
Industrial Crops and Products
195: 116425 [8 p.]
Highlights ● Ramalina complanata and Cladonia verticillaris extracts showed larvicidal activity. ● Fumarprotocetraric acid was a better larvicidal as Divaricatic acid. ● The TRP286 residue may have contributed to the very good activity of FUM. The Aedes aegypti mosquito is the main vector of the arboviruses that cause Zika, Yellow Fever, Dengue, and Chikungunya, incapacitating diseases that may even be fatal. There are still no vaccines for any of these viruses. Therefore, the only way to contain outbreaks is to control the vector that transmits them. In the present study, we investigated the larvicidal activity of lichen extracts (Ramalina complanata (Sw.) Ach., 1810 and Cladonia verticillaris (Raddi) Fr.), isolating components that were used against larvae of the mosquito A. aegypti. The ether extract from R. complanata exhibited an LC50 = 5.9 µ−1, while a compound isolated from this species, divaricatic acid, had an LC50 = 27.1 µ−1. The acetone extract of C. verticilaris exhibited an LC50 = 17.4 µ−1 and the isolated compound fumarprotocetraric acid (FUM) had an LC50 = 13.6 µ−1. These results demonstrate that extracts and isolated compounds from the two lichen species have strong larvicidal activities. FUM is the most active compound in our investigation. The molecular docking studies of divaricatic acid and FUM demonstrated that they bind to the active site of AaAChE1 in an energetically favorable manner. The TRP286 residue may have contributed to the more pronounced activity of fumarprotocetraric acid compared to divaricatic acid. Other aspects related to the more pronounced activity of fumarprotocetraric acid are its molecular weight and higher solubility. Our results provide evidence of the importance of studying lichen secondary metabolites as natural sources of insecticides and investigating possible interactions with AaAChE1. Keywords: Ramalina complanata; Cladonia verticillaris; Divaricatic acid; Fumarprotocetraric acid; Larvicidal; Docking.
Sunday, 19 March 2023 16:59