الدراسة الفیتوكیمیائیة و الفعالیة البیولوجیة للنوعین النباتیین Retama monosperma(L.) Boiss. (Fabaceae) Blackstonia grandiflora(Viv.) Maire. (Gantianaceae)

Abstract

In this work, we focused on phytochemical and biological study of two plant species: Retama monosperma (L.) (fabaceae) and Blackstonia grandiflora (Viv.) Maire (Gentianaceae). A phytochemical study of Blackstonia grandiflora aerial parts extracts lead to isolation of new oxygenated xanthone named 1,8-dihydroxy-2,3,4- trimethoxyxanthone, as well as to four known compounds namely methylswertianin; decussatin; halenaquinone and gentiopicroside. A detailed chemical investigation of the secondary metabolites from the extracts of fruits of Retama monosperma lead to isolation of four known compounds namely isorhamnetin; kaempferol; quercetin and genistein-8-C-glucoside. All compound structures were determined by CPG-MS, 1 D and 2-D NMR techniques. The compounds isolated from EtOAc extract of R. monosperma exhibited a great ability to inhibit the formation of fluorescent AGEs in BSA/Ribose system, whereas the aerial parts extracts from B. grandiflora showed a weak inhibitory ability against pentosidine-like AGE formation. Those extracts displayed a moderate inhibitory potency against vesperlysine-like AGE formation compared with the standard antiglycation agent aminoguanidine. The study of anti bacterial activity of aerial parts extracts of B. grandiflora carried out against two gram-negative bacteria (Escherichia coli ATCC 25922; Pseudomonas aeruginosa ATCC 27853) and two gram-positive bacteria (Staphylococcus aureus ATCC 29213; Bacillus sp.) using diffusion method. The results indicated a good inhibition of EtOAc extract of bacterial growth especially gram-negative bacteria. Furthermore, CH2Cl2 extract showed a significant inhibitory effect against gram-positive bacteria.