Phytochemical study of plants used traditionally for cosmetics and medicine in the island of Mayotte.

The Indian ocean is one of the biggest source of botanical diversity in
the world, 25% of the world’s flora can be found in those islands. In addition, people
living in that area, have been using what nature has to offer to treat themselves for
centuries. In this work we focused on the Comoros archipelago and more precisely on
the island of Mayotte. The socio-economic situation of the area has been precarious
since the end of the Ylang-ylang (Cananga odorata (Lam.) Hook.f. & Thomson) industry. The aim of this thesis is to provide the inhabitants with an analysis of plant
species with the potential for the development of local cosmetic products. Through
the analysis of the traditional knowledge we were hoping to find the ideal species for
this project. First, a preliminary study was conducted leading to the identification of
more than 200 different species which could be useful. Following this first work, an
infield ethnobotanical study was conducted allowing for the identification of 69 species which were interesting. By cross referencing the previously gathered information
21 different species were identified for collection and the analysis so as to validate
their real biological activity: the lipoxygenase inhibition potential, the tyrosinase inhibition potential and the DPPH (2,2-diphenyl-1-picrylhydrazyl) reduction potential.
The most active species then underwent a selection process based on current
knowledge-to-date and availability. Following this selection, we focused on the roots
of the litchi plant (Litchi chinensis Sonn.). The last step of this work consisted of the
identification of the compound responsible for the observed activities. This was
achieved by submitting the crude extract of L. chinensis to a bio-guided fractionation
until only a single compound remained. The purified compound then went through
the following molecular identification process: UV, IR, MS, RMN and colorimetric
analysis. Finally, these process allowed us to identify a compound from the polyphenol family: cinnamtannin D2 (CAS number : 97233-47-1).