Planta Med 2015; 81 - PW_03
DOI: 10.1055/s-0035-1565627

Ellagitannins, ellagic acid derivatives, stilbenes and flavonoids in antibacterial stem bark and leaf extracts of African medicinal plants Combretum psidioides and Combretum fragrans

P Fyhrquist 1, E Salih 1, I Laakso 1, H Vuorela 1, R Julkunen-Tiitto 2
  • 1Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
  • 2Natural Product Research Laboratory, Department of Biology, University of Eastern Finland, Joensuu, Finland

Combretum psidioides and C. fragrans are used as decoctions for diarrhea and wounds in African traditional medicine [1]. In Nigeria, C. fragrans is used for the treatment of Blackleg disease in cattle among Fulani pastoralists. There exists no research on antibacterial compounds of these species but some phytochemical investigations have been performed on C. psidioides; fourteen phenanthrenes and stilbenes are known from the heart wood and pentacyclic triterpenoids have been characterized from the roots [2].

We have found that methanol and butanol extracts of the stem bark of C. psidioides gave good growth inhibitory effects against Mycobacterium smegmatis, S. aureus and P. aeruginosa. Our UHPLC-MS-QTOF results show that the stem bark of C. psidioides contains corilagin and punicalagin along with other ellagitannins as well as ellagic acid rhamnoside. These compounds have not previously been identified in C. psidioides. In addition, combretastatin B-2 along with its dihydrostilbene derivative were for the first time identified in the stem bark of C. psidioides.

A leaf extract of C. fragrans showed promising antibacterial effects, especially against Micrococcus luteus and S. aureus. Our preliminary HPLC-DAD results indicate that this extract contains luteolin and related flavonoids and three unknown ellagitannins. Mass spectrometric data is needed to confirm the identity of the compounds.

Acknowledgements: This study has been supported by Finnish Medical Association and Swedish Cultural Foundation in Finland. The first author is grateful for this support. This abstract is dedicated to the memory of Professor Raimo Hiltunen (1944 – 2014) who has greatly contributed to this work through his mentorship.


[1] Haerdi F. Die Eingeborenen-Hielpflanzen des Ulanga-Distriktes Tanganjikas (Ostafrika). Acta Tropi 1964; Suppl. 8: 1 – 278

[2] Kilonda A et al. Acetylation products of pentacyclic triterpene glucosides from Combretum psidioides. Arkivoc 2003; (iv): 3 – 21