Antibacterial activities of the methanol extracts, fractions and compounds from Fagara tessmannii.
BACKGROUND
Fagara tessmannii is a shrub of the African rainforests used to treat bacterial infections, cancers, swellings and inflammation. In the present study, the methanol extract from the leaves (FTL), bark (FTB), and roots (FTR) of this plant as well as fractions (FTR1-5) and compounds isolated from FTR namely β-sitosterol-3-O-β-d-glucopyranoside (1), nitidine chloride (2) and buesgenine (3), were tested for their antimicrobial activities against a panel of Gram-negative bacteria including multidrug resistant (MDR) phenotypes.


METHODS
The broth microdilution method was used to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the above samples; Column chromatography was used for the fractionation and purification of the roots extract whilst the chemical structures of compounds were determined using spectroscopic techniques.


RESULTS
Results of the MIC determinations indicated that the crude extracts from the roots as well as fraction FTRa4 were active on all the 26 tested bacterial strains. MIC values below 100µg/mL were obtained with roots, leaves and bark extract respectively against 30.8%, 15.4% and 11.5% tested bacteria. The lowest MIC value below of 8µg/mL was obtained with extract from the roots against Escherichia coli MC100 strain. The lowest MIC value of 4µg/mL was also obtained with compound 3 against E. coli AG102 and Klebsiella pneumoniae ATCC11296 CONCLUSIONS: The present study demonstrates that F. tessmannii is a potential source of antimicrobial drugs to fight against MDR bacteria. Benzophenanthrine alkaloids 2 and 3 are the main antibacterial consituents of the roots of the plant.
Department of Biochemistry, Faculty of Science, University of Dschang, Cameroon.
Simplice B
SB
Tankeo
Laboratory of Natural Products Chemistry, Department of Chemistry, Faculty of Science, University of Dschang, Cameroon.
Francois
F
Damen
Laboratory of Natural Products Chemistry, Department of Chemistry, Faculty of Science, University of Dschang, Cameroon.
Maurice D
MD
Awouafack
Laboratory of Natural Products Chemistry, Department of Chemistry, Faculty of Science, University of Dschang, Cameroon.
James
J
Mpetga
Laboratory of Natural Products Chemistry, Department of Chemistry, Faculty of Science, University of Dschang, Cameroon.
Pierre
P
Tane
Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.
Jacobus N
JN
Eloff
Department of Biochemistry, Faculty of Science, University of Dschang, Cameroon. Electronic address: kuetevictor@yahoo.fr.
Victor
V
Kuete
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D053119:Benzophenanthridines / Q000302:isolation & purification / Q000494:pharmacology; D005960:Glucosides / Q000302:isolation & purification / Q000494:pharmacology; D000432:Methanol / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D010617:Phenanthridines / Q000302:isolation & purification / Q000494:pharmacology; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D012855:Sitosterols / Q000302:isolation & purification / Q000494:pharmacology; D032106:Zanthoxylum / Q000737:chemistry*
C507786:6-(2'-ethoxy-2'-(2'',4'',5''-trimethoxyphenyl)) ethyl-7,8-dimethoxy-5-methyl-2,3-methylenedioxy-5,6-dihydrobenzo(c)phenanthridine; D000900:Anti-Bacterial Agents; D053119:Benzophenanthridines; D005960:Glucosides; D010617:Phenanthridines; D010936:Plant Extracts; D012855:Sitosterols; C472604:sitosterol-3-O-glucopyranoside; C013615:nitidine; D000432:Methanol
Antibacterial; Benzophenanthrine; Buesgenine; Chloramphenicol; Dimethyl sulfoxide; Fagara tessmannii; Nitidine; Nitidine chloride; Rutaceae; p-Iodonitrotetrazolium chloride; β-sitosterol-3-O-β-D-glucopyranoside