Content area
Full text
INTRODUCTION
Nature is a source of chemical diversity that should not be underestimated. Along the history, humans have exploited the different biological activities of many terrestrial and marine organisms, most of the times in an intuitive way. Antitumor, anti-inflammatory, anti-diabetic, anti-bacteria, anti-fungal, and many other activities have been investigated for natural-producing compounds during the last years (Verpoorte, 2000; Dewick, 2002; Prashar et al., 2012). Nowadays, an emerging but every time more priority interest is focused on the role of natural compounds in crop development and protection. We should not look down at the strong selection that nature has done for centuries on this plethora of compounds. Exploring the chemistry of molecules already selected by nature to play a role in ecological defense appears as an essential starting point to look for new pest control products.
During the last decades, large amounts of synthetic pesticides have been used mainly in intensive agriculture for crop protection in a non controlled-way. The abuse of synthetic herbicides in the field has led to the emergence of weeds agrochemical-resistant (Brazier et al., 2002; Powles and Yu, 2010) with strong economic losses, potential health risks and environmental contamination (Pesce et al., 2011; Magnusson et al., 2013). Pesticides (fungicides, insecticides and bactericides) have been broadly searched among natural compounds, but also herbicides, bioherbicides, and new more ecologically friendly herbicides have being assayed during the last years (Duke et al., 2000; Copping and Duke, 2007; Dayan et al., 2009). The aim of these investigations is to look for compounds with new mechanisms of action different from those used by synthetic agrochemicals, in order to obtain effective compounds with low environmental impact.
When searching for new compounds with a desirable biological activity, such as herbicidal activity, it is useful to select candidates that show a broad spectrum of demonstrated biological activities. Chalcones and chalcone derivatives have a huge number of different biological activities, which are highly appreciated in many areas. In fact, chalcones are bioactive against virtually all eukaryotes and some prokaryotes, and their molecular targets are numerous (Zhou and Xing, 2015).
During the last decades, numerous investigations were carried out on the pharmacological activities of naturally occurring and synthetic chalcones, i.e. the anti-inflammatory, the antioxidant, the antiinfective (such as antileishmanial and antimalarial, and...