1. Department of Life Sciences, Universidad Politécnica Salesiana, Av. Isabel La Católica 23-52, Quito, Ecuador
2. Department of Organic Chemistry, University of Pavia, Viale Taramelli 10, 27100 Pavia, Italy
3. Department of Territorial Ecology and Environment, University of Pavia, Via S. Epifanio 14, 27100 Pavia, Italy