Investigation phytochimique et biologique de l’espèce Astragalus armatus ssp. numidicus (Coss. et Dur.) Maire. et Synthèse catalytique de nouveaux dérivés julolidines

Abstract

In the first part of this work, our study was devoted to the phytochemical and biological investigations of the pods of Astragalus armatus ssp. numidicus (Coss. et Dur.) Maire. (Fabaceae). Separation and purification of the ethyl acetate and the n- butanol fractions led to the isolation of six compounds (four flavonoids including two triglycosyles, a saponin and a cyclitol). The structural elucidation of these compounds was determined using modern spectroscopic methods including ultraviolet spectroscopy UV, nuclear magnetic resonance spectroscopy (NMR) mono and bidimensional (1H, 13C, COSY, HSQC, HMBC and TOCSY) and with comparison with literature data. The chloroform fraction exhibited the best antibacterial activity against E. coli, S. aureus and P. aeruginosa, while the ethyl acetate fraction showed the highest antioxidant activity by the use of DPPH, ABTS, CUPRAC and metal chelate methods. Furthermore, the evaluation of the immunomodulatory activity of the n-butanol fraction with Biozzi method showed that the butanolic fraction improved the phagocytic activity by stimulating the reticuloendothelial system. In the second part, the synthesis of 12 new derivatives julolidines was carried out by hydrogen transfer process. The first transformation allowed the formation of julolidines by NC (sp2)-cyclisation of tetrahydroquinoline and propan-1,3-diols. Applying another hydrogen autotransfer process, the prepared julolidines were easily functionalized at the C2 position in green conditions with the formation of water as the only by-product. The activation of C9 was also achived. The preparation of three new iridium catalysts was performed. The structures of the synthesized compounds were mainly established by the use of NMR techniques (1H, 13C and DEPT), by high resolution mass spectrometry (HRMS) and by X-rays.