Regnier, TC, Kouekam, CR, Leonard, CM, Mokgalaka, NS & Weiersbye, IM 2009, 'Chemical analysis and potential use of the tree Combretum erythrophyllum grown on gold and uranium mine tailings seepage', in AB Fourie & M Tibbett (eds), Mine Closure 2009: Proceedings of the Fourth International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 539-547, https://doi.org/10.36487/ACG_repo/908_42 (https://papers.acg.uwa.edu.au/p/908_42_Regnier/) Abstract: Combretum erythrophyllum is a southern African riparian tree, which is widely used in traditional medicine to combat microbial infections. More than seven flavonoids with antimicrobial properties, including apigenin, genkwanin, rhamnocitrin and kaempferol, have been previously isolated from methanolic extracts of leaf material. The species occurs naturally in the Witwatersrand Basin gold fields, and is included in experimental trials of acid and salt-tolerant trees for seepage control purposes around gold mine tailings at AngloGold Ashanti Ltd (the Mine Woodlands Project). In this study, C. erythrophyllum, harvested from the mine woodland trials, was investigated as a source of secondary metabolites for the control of food-borne pathogens. The phenolic profiles of methanolic leaf extracts from trees growing on acid mine drainage and non-impacted surrounding soils were compared to those from a natural population, using high performance liquid chromatography. The concentrations of apigenin, genkwanin and kaempferol are currently being determined in dry leaf material. These extracts were evaluated for their ability to inhibit the growth of Listeria monocytogenes and Candida albicans biofilm formation. No significant differences between the phenolic profiles of samples from different substrata or regions could be discerned. Selected extracts of both mine and natural populations were able to significantly inhibit biofilm formation in the case of C. albicans. The activity against L. monocytogenes was substantially lower. Micrographs obtained using confocal laser scanning microscopy confirmed the inhibitory effects. These results demonstrate the potential of C. erythrophyllum as a good candidate for application in food safety. Such commercial attributes can add value to C. erythrophyllum and other species used for mine rehabilitation, and provide a basis for the development of secondary industries based on renewable natural resources alongside mine closure.