16:00 - 18:00
Room: Poster Area - Poster Shed
Poster Presentation
Ellagitannins in antimycobacterial extracts of Combretum hartmannianum, a savannah woodland tree
Enass Salih 1, 2, Markku Kanninen 2, Riitta Julkunen-Tiitto 3, Marketta Sipi 2, Olavi Luukkanen 2, Heikki Vuorela 1, Pia Fyhrquist 1
1 Division of Pharmaceutical Biosciences, Faculty of Pharmacy, P.O. Box 56, FIN-00014, University of Helsinki, Finland, Helsinki
2 Department of Forest Sciences, Viikki Tropical Resources Institute (VITRI), Faculty of Agriculture and Forestry, P.O. Box 27, FIN-00014, University of Helsinki, Finland, Helsinki
3 Natural Product Research Laboratory, Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland, Joensuu

Combretum hartmannianum Schweinf. (Combretaceae) is native to East Africa, growing naturally in woodland areas in Eritrea, Ethiopia, South Sudan and Sudan [1]. Various parts of this plant, including roots and stem are used traditionally in Africa against bacterial infections and their symptoms such as cough [2].

We have assessed the antimycobacterial activity of extracts of C. hartmannium against the TB model bacterium Mycobacterium smegmatis ATCC 14468 . The most promising growth inhibitory activity was observed for root extracts, such as a methanol soxhlet extract (IZ 31.5mm, MIC 312.5 µg/ml) and an ethyl acetate extract (MIC 1250 µg/ml). Cold methanol extracts of the stem bark and wood gave a MIC of 5000 µg/ml. Hexane and dichloromethane extracts of the stem wood and stem bark were devoid of activity. HPLC-DAD and UHPLC/QTOF-MS analysis of the ethyl acetate extract of the root resulted in the characterization of fifteen ellagitannins, among them punicalagin, castalagin, corilagin, tellimagrandin, terflavin B and S-flavogallonic acid, none of which have been identified before in C. hartmannianum. Six of the identified ellagitannins are unknown and NMR is needed to elucidate their molecular structures. Previously, flavogallonic acid dilactone and terchebulin have been identified in C. hartmannianum stem bark [3]. Our results indicate that roots of C. hartmannianum contain a high diversity and concentration of ellagitannins which could be potential agents against tuberculosis.

Acknowledgements: Viikki Tropical Resources Institute (VITRI), Department of Forest Sciences, University of Helsinki and Division of Pharmaceutical Biosciences, University of Helsinki are acknowledged for technical assistance. Ekhaga Foundation, Sweden, is gratefully acknowledged for project funding.

References:

  1. World Conservation Monitoring Centre. 1998. http://dx.doi.org/10.2305/IUCN.UK.1998.RLTS.T36464A9997265.en .
  2. Neuwinger HD . African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany; 2000: 589 pp.
  3. Mohieldin, M.A.E. et al. BMC Compl & Altern Med 2017; 17 (224): 2-11.

Reference:
Poster Session-PO-104:
Session:
Poster Presentation-1
Presenter/s:
Enass Salih
Presentation type:
Poster presentation
Room:
Poster Area - Poster Shed
Date:
Monday, 27th August, 2018
Time:
16:00 - 18:00
Session times:
16:00 - 18:00