DOI https://doi.org/10.36487/ACG_repo/908_41
Cite As:
Mokgalaka, NS, Combrinck, S, Lepule, SP, Regnier, TC & Weiersbye, IM 2009, 'Essential oil profiles of Lippia scaberrima Sond. from Highveld gold and uranium mines', in AB Fourie & M Tibbett (eds),
Mine Closure 2009: Proceedings of the Fourth International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 529-537,
https://doi.org/10.36487/ACG_repo/908_41
Abstract:
Lippia scaberrima Sond. is an aromatic shrub of semi-arid, summer-rainfall grassland and occurs in the
northern provinces of South Africa. The plant is a common natural coloniser of gold mine tailings and
contaminated soils, and is one of a number of similar species that has been tested for use in tailings
stabilisation. Mine rehabilitation strategies worldwide involve the use of native and locally tolerant plants.
Where such plants have commercially valuable attributes, their use to stabilise contaminated soils and
tailings also provides opportunities for local beneficiation and the development of new industries post-
mining. The production of aromatic plants is considered a particularly safe option for mine waste since they
are generally unpalatable to herbivores and the steam distillation methods used for essential oil isolation
yield products free from metal and radioactive contaminants.
In the initial part of this study the essential oil of bulk samples of L. scaberrima growing in a natural habitat
was found to exhibit strong in vitro antifungal activity against several commercially important fruit post-
harvest spoilage pathogens. Gas chromatography with flame ionisation detection (GC-FID) analysis of the
oil identified limonene, 1,8-cineole and R-carvone as the main constituents. The antifungal activity of the oil
was attributed to the presence of R-carvone. These results were confirmed by several semi-commercial and
commercial trials on mango, avocado and citrus fruit.
The potential application of L. scaberrima essential oil, rich in R-carvone, as a post-harvest fungicide of
fruit, may necessitate the large-scale production of the oil. However, essential oil profiles of Lippia spp. in
general have been shown to exhibit high intraspecific variability due to genetic differences. In this
investigation the essential oil profiles of L. scaberrima specimens from populations growing in mine-
contaminated substrata were compared to those of specimens growing in uncontaminated soils to identify a
R-carvone chemotype selected for the harsh growing conditions existing in and around mine tailings. The
findings indicate that L. scaberrima does not bioaccumulate metals present in contaminated soils, and
essential oils prepared using steam distillation were free of metals and uranium.
References:
Angus, C. (2005) The use of AFLP analysis to determine genetic differences of plant species on and off slimes dams.
Unpublished M.Sc. dissertation, Faculty of Science, University of the Witwatersrand, Johannesburg, South
Africa.
Bosabalidis, A.M. (2002) Structural features of Origanum species, In Oregano: The genera Origanum and Lippia, S.E.
Kintzios (ed), 1st edition, Taylor and Francis, London, 277 p.
Combrinck, S., Bosman, A.A., Botha, B.M., Du Plooy, W. and McCrindle, RI. (2006) Effects of post harvest drying on
the essential oil and glandular tichomes of Lippia scabberima Sond. Journal of Essential Oil Research, 18,
pp. 80–84.
Du Plooy, W., Regnier, T. and Combrinck, S. (2009) Essential oil amended coatings as alternatives to synthetic
fungicides in citrus postharvest management, Postharvest Biology and Technology, Vol. 53, pp. 117–122.
Marschner, H. (1988) Mineral Nutrition of Higher Plants, 2nd edition, Academic Press, London, 889 p.
Mengel, K. and Kirkby, E.A. (eds) (2001) Principles of plant nutrition, 5th edition, Kluwer Academic Publishers,
Dordrecht, The Netherlands, 849 p.
Pascual, M.E., Slowing, K., Carretero, E., Sanchez Mata, D. and Villar, A. (2001) Lippia: traditional uses, chemistry
and pharmacology: a review, Journal of Ethnopharmacology, Vol. 76, pp. 201–214.
Plaza, P., Torre, R., Usall, J., Larmaca, N. and Viňas, I. (2004) Evaluation of the potential of the commercial
postharvest application of essential oils to control citrus decay, Journal Horticultural Science and Biotechnology,
Vol. 79, pp. 935–940.
Regnier, T., Du Plooy, W., Combrinck, S. and Botha, B. (2008) Fungitoxicity of Lippia scaberrima essential oil and
selected terpenoid components on two mango postharvest spoilage pathogens, Postharvest Biology and
Technology, Vol. 48, pp. 254–258.
Retief, E. (2006) Lippia L. In Plants of southern Africa: an annotated checklist, G. Germishuizen, N.L. Meyer, Y.
Steenkamp, M. Keith (eds), Southern African Botanical Diversity Network Report No. 41, SABONET, Pretoria.
Tutu, H., McCarthy, T.S. and Cukrowska, E. (2008) The chemical characteristics of acid mine drainage with particular
reference to sources, distribution and remediation: The Witwatersrand Basin, South Africa as a case study,
Applied Geochemistry, Vol. 23, pp. 3666–3684.
Viljoen, A.M., Subramoney, S., Van Vuuren, S.F., Başer, K.H.C. and Demirci, B. (2005) The composition,
geographical variation and antimicrobial activity of Lippia javanica (Verbenaceae) leaf essential oils, Journal of
Ethnopharmacology, Vol. 96, pp. 271–277.
Legacy issues from abandonment to asset
Mine Closure 2009, Perth, Australia 537
Weiersbye, I.M. and Cukrowska, E.M. (2008) Elemental concentrations in wild plants and crops on the Witwatersrand
Basin gold fields: recommendations for safe land-uses, Witwatersrand University, Johannesburg, South Africa,
AngloGold Ashanti Report.
Weiersbye, I.M., Witkowski, E.T.F. and Reichardt, M.T. (2006) Floristic composition of gold and uranium tailings
dams, and adjacent polluted areas, on South Africa’s deep-level mines, Bothalia, Vol. 36, pp. 101–127.
Weiersbye, I.M., Straker, C.J. and Przybylowicz, W.J. (1999) Micro-PIXE mapping of elemental distribution in
arbuscular mycorrhizal roots of the grass, Cynodon dactylon, from gold and uranium mine tailings, Nuclear
Instrumentation and Methodology Part B, Vol. 158(1-4), pp. 335–343.
Whish, J.P.M. (1996) A flexible distillation system for the isolation of essential oils, Journal of Essential Oil Research,
Vol. 8, pp. 47–51.
Witkowski, E.T.F. and Weiersbye, I.M. (1998) Establishment of plants on gold slimes dams: characterisation of the
slimes and adjacent soils, Plant Ecology and Conservation Series No. 6, Report to Anglo American plc and
AngloGold, 111 p.
Zheljazkov, V.D. and Nielson, N.E. (1996) Studies of the effect of heavy metals (Cd, Pb, Cu, Mn, Zn, and Fe) upon the
growth, productivity and quality of lavender (Lavandula angustifolia Mill.), Journal of Essential Oil Research,
Vol. 8, pp. 259–274.