Extraction of some Antimicrobial Peptides from Rubiaceae Flowers and Studying their Activity Against some Pathogenic Bacteria

Abstract

This research was performed to isolate and purify the Plant Antimicrobial peptides (Cyclotides type) from Rubiaceae family (Gardenia florida and Coffea arabica), and study their antimicrobial activity against some multidrug pathogenic bacteria (Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, E.coli: 0157: H7), and compare it with theantibiotics effect. The results of isolating and purifying these Cyclotides showed that it could be obtained from the studied plants. The RP-HPLC technique results showed that there were (9) absorption peaks in cyclotide crud extract isolated from Gardenia florida flowers, (8) absorption peaks from Coffea arabica. These absorbing peaks of cyclotides varied in retention time, height and area percentages. The results of the antimicrobial activity of the isolated cyclotides against studied pathogenic bacteria showed that all these peptides were effective with different ratios, and there was no resistance against them. Cyclotides isolated from Coffea arabica flowers were the best. Both types of gram-positive bacteria were the most effected, especially against cyclotides isolated from Coffea arabica, with (33) mm and (31)mm, inhibition zone for E. faecalis and S. aureus respectively.