Planta Med 2007; 73 - P_126
DOI: 10.1055/s-2007-986907

Antimicrobial activity of D:A-friedo-nor-oleanane triterpenoids

MR López 1, IA Jiménez 2, IL Bazzocchi 2, L Moujir 1
  • 1Departamento de Microbiología y Biología Celular, Facultad de Farmacia. Avda Astrofísico F
  • coSánchez s/n. Universidad de La Laguna, 38206, La Laguna, Tenerife, Canary Islands, Spain
  • 2Instituto Universitario de Bio-Orgánica „Antonio González“. Universidad de La Laguna, 38206, La Laguna, Tenerife, Canary Islands, Spain

The study of the antimicrobial activity (MIC and MBC) of two natural triterpenophenols: 6-deoxoblepharodol (1), 8-epi-6-deoxoblepharodol (2) and two derivatives: 2,3-diacetoxy-6-deoxoblepharodol (3) and 2,3-diacetoxy-8-epi-6-deoxoblepharodol (4) obtained after acetylation, were determined. The natural products showed antimicrobial activity against Gram positive bacteria. The relation structure-activity demonstrates that the presence of the hydroxyl groups in C2 and C3 is necessary for antimicrobial activity.

We studied the mode of action of 1 and 2 against Bacillus subtilis. The time-kill curves for both compounds verified that inclusion of either compound in the log phase was bactericidal (> or=3 log10 CFU/ml reduction). However, when 2 was added in the lag phase it reduced the initial inoculum by 2-log10 in the nine hours of treatment (bacteriostatic activity), while 1 showed bactericidal activity.

The activity of 1 was bactericidal at different bacterial concentrations (107, 106, 105, and 104 UFC/ml), where 2 showed bacteriostatic activity for all inoculum densities except for 107 UFC/ml, in which it was inactive.

R1

R2

R3

R4

1

OH

OH

–-

–-

2

–-

–-

OH

OH

3

AcO

AcO

–-

–-

4

–-

–-

AcO

AcO

Acknowledgements: This study was supported by Spanish Grants CTQ2006–13376-BQU