Dedjiho Codjo Camille^{1, 2}, Agbangnan Dossa Cokou Pascal^2,, Bothon Fifa Theomaine Diane^{2, 3}, Jegat Corinne¹, Majeste Jean-Charles¹

Plant exudates have been of therapeutic interest since immemorial time, but very few are scientifically known to be exploited, as is the case with exudates from Araucaria heterophylla (Ah) and Afraegle paniculata (Ap), two multi-purpose species found in Benin's flora. This first study is a scientific survey of the various properties of these two exudates with a view to exploiting their potential. After harvesting the two exudates, were submitted to physicochemical, chemical, and physical analyses. A solution test was used to identify the correct solvents and to assess the dispersibility of insoluble or low-solubility exudates. Phytochemical screening was carried out to determine the major metabolic groups present. Thermal analyses (TGA and DSC) were used to assess degradability and thermal transitions; Fourier Transform InfraRed spectroscopy was used to identify chemical functions. Results show that exudate Ap is water-soluble and both exudates are soluble in dimethylsulphoxide and disperse perfectly in polar aprotic solvents such as acetone or protic solvents such as ethanol. Exudate Ah is solid and brittle while Ap is liquid, unctuously sticky, and viscous. Infrared spectroscopy confirmed the presence of alcohol and carbonyl functions and glycosidic bonds. Phytochemical screening showed the presence of reducing sugars, mucilages, saponosides, terpenes, and sterols. Both exudates underwent thermal degradation at around 300°C, preceded by dehydration at 100°C. Ap exudate shows thermal transitions such as melting (Tm = -10°C; ∆Hm = 65.30 J. g^-1), crystallisation (Tc = -54.2°C; ∆Hc =11.35 J.g^-1). As for the Ah exudate, it exhibits a glass transition at 17±1°C. The conclusion is that exudate Ah is a totally amorphous solid and Ap is a crystalline solid or liquid as function of the temperature.

Exudate, bio-sourced, polymers, Afraegle paniculata, Araucaria heterophylla