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Antifungal and antibacterial metabolites from a French poplar type propolis.

Boisard S, Le Ray AM, Landreau A, Kempf M, Cassisa V, Flurin C, Richomme P - Evid Based Complement Alternat Med (2015)

Bottom Line: Organic extracts showed a significant antifungal activity against C. albicans and C. glabrata (MIC80 between 16 and 31 µg/mL) but only a weak activity towards A. fumigatus (MIC80 = 250 µg/mL).DCM based extracts exhibited a selective Gram-positive antibacterial activity, especially against S. aureus (SA) and several of its methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) strains (MIC100 30-97 µg/mL).A new and active derivative of catechin was also identified whereas a synergistic antimicrobial effect was noticed during this study.

View Article: PubMed Central - PubMed

Affiliation: EA 921 SONAS/SFR 4207 QUASAV, Université d'Angers, 16 boulevard Daviers, 49045 Angers Cedex 01, France.

ABSTRACT
During this study, the in vitro antifungal and antibacterial activities of different extracts (aqueous and organic) obtained from a French propolis batch were evaluated. Antifungal activity was evaluated by broth microdilution on three pathogenic strains: Candida albicans, C. glabrata, and Aspergillus fumigatus. Antibacterial activity was assayed using agar dilution method on 36 Gram-negative and Gram-positive strains including Staphylococcus aureus. Organic extracts showed a significant antifungal activity against C. albicans and C. glabrata (MIC80 between 16 and 31 µg/mL) but only a weak activity towards A. fumigatus (MIC80 = 250 µg/mL). DCM based extracts exhibited a selective Gram-positive antibacterial activity, especially against S. aureus (SA) and several of its methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) strains (MIC100 30-97 µg/mL). A new and active derivative of catechin was also identified whereas a synergistic antimicrobial effect was noticed during this study.

No MeSH data available.


Related in: MedlinePlus

2D NMR studies of compound 40: COSY (bold lines), selected HMBC (solid arrows: 1H → 13C), and NOESY (dashed arrows) correlations.
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fig3: 2D NMR studies of compound 40: COSY (bold lines), selected HMBC (solid arrows: 1H → 13C), and NOESY (dashed arrows) correlations.

Mentions: Compound 40 was obtained as a yellow amorphous solid (0.6 μg/g of DCM extract). The molecular formula was determined as C25H22O7 by HRESIMS (found for [M+H]+ 435.1436; calculated 435.1438). The UV spectrum showed an absorption maximum at 350 nm. The IR spectrum indicated the presence of OH (3400 cm−1) as well as conjugated ketone carbonyl (1610 cm−1) groups. The 1H NMR spectrum exhibited signals due to a hydrogen-bonded OH at δH 14.49, two trans-olefinic protons (δH 8.06 and 7.63, 2 d, J = 15.7 Hz), aromatic rings (9H, δH 6.15–7.30), and one methoxyle (δH 3.92). It also showed the characteristic signals of a flavan-3-ol moiety at δH 4.68 (1H, d, J = 8.9 Hz, H2), 4.21 (1H, m, H3), 3.07 (1H, dd, J = 16.2, 5.7 Hz, H4a), and 2.53 (1H, dd, J = 16.2, 9.5 Hz, H4b). The 13C NMR and HMQC spectra confirmed the presence of 25 carbons with typical flavan-3-ol signals at δC 84.2 (C2), 66.8 (C3), and 30.6 (C4). In the 1H NMR spectrum, the signals at δH 7.11 (1H, d, J = 1.4 Hz), 6.96 (1H, dd, J = 8.4, 1.4 Hz), and 6.91 (1H, d, J = 8.4 Hz) suggested the presence of a 1′,3′,4′-trisubstituted ring B whereas a singlet at δH 6.15 (1H) indicated a pentasubstituted ring A. Two multiplets at δH 7.17 (2H) and 7.29 (3H) revealed the presence of a phenyl residue. The HMBC spectrum showed a long-range correlation between the two trans-olefinic protons [δH 7.63 (1H, d, J = 15.7, Hα) and 8.06 (1H, d, J = 15.7, Hβ)] and the ketone carbon at δC 193.2. This correlation revealed the presence of an α,β-unsaturated ketone group. The trans-olefinic proton Hβ at δH 8.06 was also correlated with the phenyl quaternary carbon at δC 136.2 (C1′′). This correlation implied the presence of a (2E)-4-phenylprop-2-en-1-one moiety. A correlation between the methoxyle protons (δH 3.92) and the carbon at δC 165.1 (C5) proved that the OCH3 was attached to C5. The NOESY spectrum showed that this methoxyle was spatially close to the proton at δH 6.15 (H6), whereas a long-range COSY indicated a correlation between H6 and one of the hydroxyl groups at δH 14.49 (OH7). Therefore a (2E)-4-phenylprop-2-en-1-one moiety was located at C8 (δC 105.9). Finally, it appeared that the aromatic ring B was substituted at C3′ and C4′ by two hydroxyl groups (NMR spectra cf. supporting information 2). 1H and 13C NMR data together with 2D NMR correlations for 40 are summarized in Table 4 and Figure 3.


Antifungal and antibacterial metabolites from a French poplar type propolis.

Boisard S, Le Ray AM, Landreau A, Kempf M, Cassisa V, Flurin C, Richomme P - Evid Based Complement Alternat Med (2015)

2D NMR studies of compound 40: COSY (bold lines), selected HMBC (solid arrows: 1H → 13C), and NOESY (dashed arrows) correlations.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4385655&req=5

fig3: 2D NMR studies of compound 40: COSY (bold lines), selected HMBC (solid arrows: 1H → 13C), and NOESY (dashed arrows) correlations.
Mentions: Compound 40 was obtained as a yellow amorphous solid (0.6 μg/g of DCM extract). The molecular formula was determined as C25H22O7 by HRESIMS (found for [M+H]+ 435.1436; calculated 435.1438). The UV spectrum showed an absorption maximum at 350 nm. The IR spectrum indicated the presence of OH (3400 cm−1) as well as conjugated ketone carbonyl (1610 cm−1) groups. The 1H NMR spectrum exhibited signals due to a hydrogen-bonded OH at δH 14.49, two trans-olefinic protons (δH 8.06 and 7.63, 2 d, J = 15.7 Hz), aromatic rings (9H, δH 6.15–7.30), and one methoxyle (δH 3.92). It also showed the characteristic signals of a flavan-3-ol moiety at δH 4.68 (1H, d, J = 8.9 Hz, H2), 4.21 (1H, m, H3), 3.07 (1H, dd, J = 16.2, 5.7 Hz, H4a), and 2.53 (1H, dd, J = 16.2, 9.5 Hz, H4b). The 13C NMR and HMQC spectra confirmed the presence of 25 carbons with typical flavan-3-ol signals at δC 84.2 (C2), 66.8 (C3), and 30.6 (C4). In the 1H NMR spectrum, the signals at δH 7.11 (1H, d, J = 1.4 Hz), 6.96 (1H, dd, J = 8.4, 1.4 Hz), and 6.91 (1H, d, J = 8.4 Hz) suggested the presence of a 1′,3′,4′-trisubstituted ring B whereas a singlet at δH 6.15 (1H) indicated a pentasubstituted ring A. Two multiplets at δH 7.17 (2H) and 7.29 (3H) revealed the presence of a phenyl residue. The HMBC spectrum showed a long-range correlation between the two trans-olefinic protons [δH 7.63 (1H, d, J = 15.7, Hα) and 8.06 (1H, d, J = 15.7, Hβ)] and the ketone carbon at δC 193.2. This correlation revealed the presence of an α,β-unsaturated ketone group. The trans-olefinic proton Hβ at δH 8.06 was also correlated with the phenyl quaternary carbon at δC 136.2 (C1′′). This correlation implied the presence of a (2E)-4-phenylprop-2-en-1-one moiety. A correlation between the methoxyle protons (δH 3.92) and the carbon at δC 165.1 (C5) proved that the OCH3 was attached to C5. The NOESY spectrum showed that this methoxyle was spatially close to the proton at δH 6.15 (H6), whereas a long-range COSY indicated a correlation between H6 and one of the hydroxyl groups at δH 14.49 (OH7). Therefore a (2E)-4-phenylprop-2-en-1-one moiety was located at C8 (δC 105.9). Finally, it appeared that the aromatic ring B was substituted at C3′ and C4′ by two hydroxyl groups (NMR spectra cf. supporting information 2). 1H and 13C NMR data together with 2D NMR correlations for 40 are summarized in Table 4 and Figure 3.

Bottom Line: Organic extracts showed a significant antifungal activity against C. albicans and C. glabrata (MIC80 between 16 and 31 µg/mL) but only a weak activity towards A. fumigatus (MIC80 = 250 µg/mL).DCM based extracts exhibited a selective Gram-positive antibacterial activity, especially against S. aureus (SA) and several of its methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) strains (MIC100 30-97 µg/mL).A new and active derivative of catechin was also identified whereas a synergistic antimicrobial effect was noticed during this study.

View Article: PubMed Central - PubMed

Affiliation: EA 921 SONAS/SFR 4207 QUASAV, Université d'Angers, 16 boulevard Daviers, 49045 Angers Cedex 01, France.

ABSTRACT
During this study, the in vitro antifungal and antibacterial activities of different extracts (aqueous and organic) obtained from a French propolis batch were evaluated. Antifungal activity was evaluated by broth microdilution on three pathogenic strains: Candida albicans, C. glabrata, and Aspergillus fumigatus. Antibacterial activity was assayed using agar dilution method on 36 Gram-negative and Gram-positive strains including Staphylococcus aureus. Organic extracts showed a significant antifungal activity against C. albicans and C. glabrata (MIC80 between 16 and 31 µg/mL) but only a weak activity towards A. fumigatus (MIC80 = 250 µg/mL). DCM based extracts exhibited a selective Gram-positive antibacterial activity, especially against S. aureus (SA) and several of its methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) strains (MIC100 30-97 µg/mL). A new and active derivative of catechin was also identified whereas a synergistic antimicrobial effect was noticed during this study.

No MeSH data available.


Related in: MedlinePlus