This article describes a part of the results obtained from the cooperation between the University of Lyon1 (France) and the University of Antananarivo (Madagascar). It shows (among others) that useful research can be carried out in developing countries of the tropics if their social, technical, and economic conditions are taken into account. The concepts and methods associated with so-called “green chemistry” are particularly appropriated for this purpose. To illustrate this approach, two examples are shown. The first deals with industrial ecology and concerns waste transformation from the production of cashew nut into an amphiphilic product, oxyacetic derivatives. This product was obtained with a high yield and in a single step reaction. It exhibited an important surfactant property similar to those of the main fossil-based ones but with a much lower ecological impact. The second talks about chemical ecology as an alternative to insecticides and used to control dangerous mosquito populations. New substituted chromones were synthesized and showed biological activities toward Aedes albopictus mosquito species. Strong repellent properties were recorded for some alkoxylated products if others had a significant attractant effect (Kairomone) depending on their stereochemistry and the length of the alkyl chain.

Dengue and Zika viruses are identified as the most medically important arthropod-borne viral pathogens. Over the past 20 years, the global dengue incidence has dramatically increased with epidemics of severe dengue where the case fatality rate can reach up to 20% in untreated patients. The association between Zika virus infection and severe congenital anomalies was first reported in 2015. Today no specific antiviral therapies are available for dengue and Zika virus infections, accentuating the need of adapted antiviral strategies based on medicinal plant drug discovery. Plants are a potential source of antiviral phytocompounds which act primarily by blocking virus entry in the host-cell. In the present study, we evaluated whether crude extracts from Stenocline ericoides DC. and Stenocline inuloides DC., two endemic plants from Madagascar, may have antiviral effects against dengue and Zika viruses. We showed that S. ericoides has virucidal action whereas S. inuloides inhibits the early steps of virus infection with a non-cytotoxic effect in human cells. The administration of S. ericoides and S. inuloides extracts in zebrafish had no effect on the behavior of animals at the active doses against dengue and Zika viruses, suggesting the absence of adverse effects at these doses. LC-HRMS2 and molecular networking analyses revealed the richness of these two plants in polyphenols and flavonoid with the presence of clusters of phytocompounds specific to each Stenocline species. Consequently, S. ericoides and S. inuloides represent potential sources for natural and safe antiviral phytocompounds against flaviviruses of medical concern.