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Surface functionalization by covalent immobilization of an innovative carvacrol derivative to avoid fungal biofilm formation.

Gharbi A, Legigan T, Humblot V, Papot S, Berjeaud JM - AMB Express (2015)

Bottom Line: On the contrary, when a phenyl group replaced the terpenic moiety, the yeast culturability increased by about 30%, highlighting the specific activity of carvacrol grafted on the surfaces.Confocal microscopy analyses showed that the mode of action of the functionalized surfaces with the ester or the ether of carvacrol was, in both cases, fungicidal and not anti-adhesive.Finally, this study shows that covalently immobilization of terpenic compounds can be used to design promising antimicrobial surfaces.

View Article: PubMed Central - PubMed

Affiliation: Ecologie & Biologie des Interactions - UMR CNRS 7267, Microbiologie de l'eau, Université de Poitiers, 1 Rue Georges Bonnet, TSA 51106, 86073 Poitiers Cedex 9, France.

ABSTRACT
Carvacrol, an aromatic terpenic compound, known to be antimicrobial was grafted onto gold surfaces via two strategies based on newly-synthesized cross-linkers involving either an ester bond which can be cleaved by microbial esterases, or a covalent ether link. Surface functionalizations were characterized at each step by reflection absorption infrared spectroscopy (RAIRS). The two functionalized gold samples both led to a loss of culturability of the yeast Candida albicans, higher than 65%, indicating that the activity of the freshly-designed surfaces was probably due to still covalently immobilized carvacrol. On the contrary, when a phenyl group replaced the terpenic moiety, the yeast culturability increased by about 30%, highlighting the specific activity of carvacrol grafted on the surfaces. Confocal microscopy analyses showed that the mode of action of the functionalized surfaces with the ester or the ether of carvacrol was, in both cases, fungicidal and not anti-adhesive. Finally, this study shows that covalently immobilization of terpenic compounds can be used to design promising antimicrobial surfaces.

No MeSH data available.


PM-RAIRS spectra of the two consecutive steps leading to the immobilization Phe-NH2. Spectrum (a) represents the control Au–MUA and spectrum (b) is associated to the covalent binding of the CAR derivative.
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Fig8: PM-RAIRS spectra of the two consecutive steps leading to the immobilization Phe-NH2. Spectrum (a) represents the control Au–MUA and spectrum (b) is associated to the covalent binding of the CAR derivative.

Mentions: On spectrum b, on Figure 8, corresponding to the Phe-NH2 molecule, the amid I and II bands (νC = O and δNH, respectively) are found at 1646 and 1553 cm−1 showing the covalent bound formed between the activated COOH group and the NH2 group of the designed molecule. Moreover, the vibrations associated to the triazole cycle are observed, namely the νC = C at 1604 cm−1 and the weak bands νN = C-N at 1518 cm−1 (with a “shoulder” at 1533 cm−1). Finally the characteristic νC-O-C symmetric and antisymmetric vibrations of the backbone of the molecules are found on one hand at 1105 and 1048 cm−1 and at 1262 and 1220 cm−1 on the other hand. PM-RAIRS measurements confirmed the grafting of Phe-NH2 molecule.Figure 8


Surface functionalization by covalent immobilization of an innovative carvacrol derivative to avoid fungal biofilm formation.

Gharbi A, Legigan T, Humblot V, Papot S, Berjeaud JM - AMB Express (2015)

PM-RAIRS spectra of the two consecutive steps leading to the immobilization Phe-NH2. Spectrum (a) represents the control Au–MUA and spectrum (b) is associated to the covalent binding of the CAR derivative.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4384722&req=5

Fig8: PM-RAIRS spectra of the two consecutive steps leading to the immobilization Phe-NH2. Spectrum (a) represents the control Au–MUA and spectrum (b) is associated to the covalent binding of the CAR derivative.
Mentions: On spectrum b, on Figure 8, corresponding to the Phe-NH2 molecule, the amid I and II bands (νC = O and δNH, respectively) are found at 1646 and 1553 cm−1 showing the covalent bound formed between the activated COOH group and the NH2 group of the designed molecule. Moreover, the vibrations associated to the triazole cycle are observed, namely the νC = C at 1604 cm−1 and the weak bands νN = C-N at 1518 cm−1 (with a “shoulder” at 1533 cm−1). Finally the characteristic νC-O-C symmetric and antisymmetric vibrations of the backbone of the molecules are found on one hand at 1105 and 1048 cm−1 and at 1262 and 1220 cm−1 on the other hand. PM-RAIRS measurements confirmed the grafting of Phe-NH2 molecule.Figure 8

Bottom Line: On the contrary, when a phenyl group replaced the terpenic moiety, the yeast culturability increased by about 30%, highlighting the specific activity of carvacrol grafted on the surfaces.Confocal microscopy analyses showed that the mode of action of the functionalized surfaces with the ester or the ether of carvacrol was, in both cases, fungicidal and not anti-adhesive.Finally, this study shows that covalently immobilization of terpenic compounds can be used to design promising antimicrobial surfaces.

View Article: PubMed Central - PubMed

Affiliation: Ecologie & Biologie des Interactions - UMR CNRS 7267, Microbiologie de l'eau, Université de Poitiers, 1 Rue Georges Bonnet, TSA 51106, 86073 Poitiers Cedex 9, France.

ABSTRACT
Carvacrol, an aromatic terpenic compound, known to be antimicrobial was grafted onto gold surfaces via two strategies based on newly-synthesized cross-linkers involving either an ester bond which can be cleaved by microbial esterases, or a covalent ether link. Surface functionalizations were characterized at each step by reflection absorption infrared spectroscopy (RAIRS). The two functionalized gold samples both led to a loss of culturability of the yeast Candida albicans, higher than 65%, indicating that the activity of the freshly-designed surfaces was probably due to still covalently immobilized carvacrol. On the contrary, when a phenyl group replaced the terpenic moiety, the yeast culturability increased by about 30%, highlighting the specific activity of carvacrol grafted on the surfaces. Confocal microscopy analyses showed that the mode of action of the functionalized surfaces with the ester or the ether of carvacrol was, in both cases, fungicidal and not anti-adhesive. Finally, this study shows that covalently immobilization of terpenic compounds can be used to design promising antimicrobial surfaces.

No MeSH data available.