South African Journal of Botany 2002, 68: 41–46 Copyright © NISC Pty Ltd Printed in South Africa — All rights reserved SOUTH AFRICAN JOURNAL OF BOTANY ISSN 0254–6299 Variation in antibacterial activity of Schotia species LJ McGaw, AK Jäger and J van Staden* Research Centre for Plant Growth and Development, School of Botany and Zoology, University of Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa * Corresponding author, e-mail:
[email protected] Received 29 March 2001, accepted in revised form 7 June 2001 The roots and bark of Schotia brachypetala are used in ture, or as an extract residue at -15°C, had little effect on South African traditional medicine as a remedy for the antibacterial activity. In general, the ethanolic dysentery and diarrhoea. The paucity of pharmacologi- extracts were more active than the aqueous extracts. cal and chemical data on this plant prompted an inves- The chemical profiles on TLC chromatograms were tigation into its antibacterial activity. The differences in compared and found to be very similar in the case of activity of ethanol and water extracts with respect to ethanol extracts prepared in different months of the plant part, season and geographical position were year, and from different trees. The extracts of the three analysed. No extreme fluctuations in activity were species and of the leaves stored under various condi- noted. Two other Schotia species, S. afra and S. capita- tions also showed similar TLC fingerprints, however, ta, were included in the study, and both displayed good various plant parts of S. brachypetala showed distinctly in vitro antibacterial activity.