Studies on the Antimicrobial Activity of Olive Phenolic Compounds

Abstract

Summary. Treatment of green olives for 2 min with dilute hot alkali before brining increased the release of sugars, B complex vitamins, amino acids and phenolic compounds, and enhanced the establishment of lactic acid bacteria in the brine. Two components of the ethyl acetate extract of green olives, which showed an antibacterial activity, were isolated and identified as the glycoside oleuropein and its phenolic aglycone. The inhibition of Lactobacillus plantarum by the ethyl acetate extract or by oleuropein was augmented by reducing the concentration of organic nitrogenous compounds, increasing the NaCl concentration in the assay medium and decreasing the inoculum size. Besides its activity towards various bacteria, oleuropein inhibited the growth of Geotrichum candidum Link, Rhizopus sp. and Rhizoctonia solani Kühn. On the basis of these findings, an explanation for some problems in the lactic fermentation of green olives is suggested.

Localization of the noncovalent binding site between amyloid-β-peptide and oleuropein using electrospray ionization FT-ICR mass spectrometry

“…In addition, noncovalent complexes of OE with the [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] fragment, derived from the chymotryptic activity of the enzyme, was also detected.…”

“…When OE was added into already digested A␤ samples with trypsin ( Similarly, ESI-MS analysis of the A␤-OE Glu-C digest yielded signals corresponding to the expected A␤ fragments [4 -11], [12][13][14][15][16][17][18][19][20][21][22], and [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] following cleavage at the carboxy-terminus of glutamic acid (E) residues (Table 2), and the noncovalent complexes between OE and the [4 -11] and [12][13][14][15][16][17][18][19][20][21][22] A␤ Glu-C fragments ( Figure 3). Interactions between OE and the partially cleaved peptide fragments [4 -40] and (Table 4) When OE was added into already digested A␤ samples with Glu-C (Table 4), ESI signals corresponded to ...…”

“…Interactions between OE and the partially cleaved peptide fragments [4 -40] and (Table 4) When OE was added into already digested A␤ samples with Glu-C (Table 4), ESI signals corresponded to the noncovalent interactions of OE with the [4 -11] A␤ fragment, the partially cleaved peptide fragments [ [1][2][3][4][5][6][7][8][9][10][11] and (Table 4), and the [(4 -11)ϩ (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)] added A␤ fragments. Processing of the aforementioned mapping data derived from the two different digestion protocols utilized in this study revealed the important regions and residues for the noncovalent interaction between A␤ and OE.…”

“…One interaction of this kind has been established between the Olea europaea derived bioactive compound, oleuropein (OE), and A␤ by means of electrospray ionization mass spectrometry (ESI-MS) [6]. This interaction could prove potent in inhibiting its aggregation.OE is a polyphenol extracted from the fruits and leaves of Olea europaea L. and possesses a wide range of pharmacological properties, such as antioxidant [7][8][9], anti-inflammatory [10, 11], antiatherogenic [12-14], antibacterial [15][16][17], and anticancer [18,19]. Moreover, OE and its metabolites have been shown to be potent against contemporary diseases, such as HIV [20,21] and osteoporosis [22,23].…”

“…OE is a polyphenol extracted from the fruits and leaves of Olea europaea L. and possesses a wide range of pharmacological properties, such as antioxidant [7][8][9], anti-inflammatory [10,11], antiatherogenic [12][13][14], antibacterial [15][16][17], and anticancer [18,19]. Moreover, OE and its metabolites have been shown to be potent against contemporary diseases, such as HIV [20,21] and osteoporosis [22,23].…”