Investigation of Argania spinosa L. (Skeels) polyphenols growing in arid and semi-arid conditions

Argania spinosa L. Skeels, belonging to the Argania genus of the Sapotaceae family, is a species native to Morocco and Algeria. Due to its perfect adaptation to soil and climate, this tree plays an important ecological role in a constantly threatened encroached desert region. To understand the biological role of polyphenols in making the argan tree adapts to its natural habitat, we conducted a comparative study in two of the tree development stations: Tindouf located in South-western Algeria and Stidia located in Northwest Algeria. High performance liquid chromatography (HPLC) and Gas chromatography-mass spectrometry (GC-MS) used for the analysis of flavonoids led to the identification of six flavonols (two types of myricetin, rutin, hyperoside, quercetin, kaempferol) in the leaves of Tindouf argan tree, and two molecules (myricetin and quercetin) in the leaves of Stidia argan tree. Other molecules presented are few. The determination of flavonoids by spectrophotometry revealed the richness of Tindouf argan in these compounds (20%) compared to that of Stidia argan tree (8.7%). Histolocalisation of the flavonoids, tannins and anthraquinone in the leaves and stems of the tree was done using fluorescence microscope to understand the role of these molecules in the protection of this tree in its environment. Key words: Aragania spinosa L. (Skeels), histolocalisation, polyphenols, high performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS).