Antimicrobial and antioxidant properties of phenolic acids alkyl esters

Abstract

Merkl R., Hrádková I., Filip V., Šmidrkal J. (2010): Antimicrobial and antioxidant properties of phenolic acids alkyl esters. Czech J. Food Sci., 28: 275-279.Some phenolic acids alkyl esters (methyl, ethyl, propyl, butyl and hexyl) and determine their antioxidant and antimicrobial activities were prepared. The antimicrobial activity against the tested microorganisms escherichia coli DMF 7503, Bacillus cereus DMF 2001, listeria monocytogenes DMF 5776, Fusarium culmorum DMF 0103, and Saccharomyces cerevisiae DMF 1017 was investigated and expressed by minimum inhibitory concentration (MIC) in the range of 1.2-20mM. The inhibitory activity of phenolic acids butyl esters was found to be higher than that of methyl esters (MIC below 1.25mM). The antioxidant activity of the selected phenolic acids alkyl esters was investigated by Rancimat method. The esters of 3,4-dihydroxyphenolic acids (protocatechuic and caffeic acids) exhibited higher antioxidant activities in comparison with the respective phenolic acids. The highest antioxidant activity was found in the case of caffeic alkyl esters.

Fine-tuning of the hydrophobicity of caffeic acid: studies on the antimicrobial activity against Staphylococcus aureus and Escherichia coli

“…The MIC was defined as the lowest concentration of tested compound at which no bacterial growth was detected. 20,37 After MIC determination, a volume of 10 µL of each concentration tested for MIC assessment was plated out on MHA. Plates were incubated at 30 ⁰C for 24 h and growth was visually inspected.…”

“…13,14 Bacterial susceptibility to phytochemicals, especially phenolic compounds, have been studied by several authors and, in general, they present a promising antimicrobial profile. 8,9,[15][16][17][18][19][20][21][22] Polyphenols are the most important and abundant group of phytochemicals and can be found in diverse dietary products like vegetables, fruits, chocolates and beverages (as common non-flavonoid naturally occurring phenolics which contain two distinguishing constitutive carbon frameworks: the hydroxycinnamic (C 6 C 3 ) and hydroxybenzoic (C 6 C 1 ) structure. Only a minor fraction of phenolic acids exists in the free form.…”

Filamentous fungi from Plantago lanceolata L. leaves: Contribution to the pattern and stability of bioactive metabolites

“…Thus, it is likely, that fungal infestation can influence the antioxidant capacity of herbal materials. CA, being present in high concentration, can also alter the antimicrobial activity and microbiological pattern of the plant material in a real-world situation, as it was shown to have antimicrobial properties (Merkl et al, 2010). CA, VA, PCA, HT and HBA were all shown to have activity against bacteria (Escherichia coli, Bacillus cereus) and fungi (Fusarium culmorum) in the 1.25-10 mmol/l range (Merkl et al, 2010).…”

“…Therefore, the phenolic acid mixture was considered the agent responsible for the protection of acteoside in the current experiment. As the produced phenolic compounds are considered powerful antioxidants (Merkl et al, 2010), a mechanism involving prevention of oxidation was suspected behind the inhibition of degradation.…”

Influence of Organic Farming on the Potato Transcriptome

“…As reported in a review by Brandt et al [29], the plants managed by organic practices have necessarily to cope more frequently with pathogens, and accordingly accumulate more defence-related compounds than conventionally produced tubers. Among these defence compounds, phenylpropanoids are extensively studied because of their association with health-promoting effects, mainly related to their antioxidant activity [30]. Accordingly, in 2008, when pathogen attacks occurred with a low severity, phenylpropanoid metabolism was scarcely modulated (Figure 2).…”