Evaluation of selected South African ethnomedicinal plants as mosquito repellents against the Anopheles arabiensis mosquito in a rodent model

<p>Abstract</p> <p>Background</p> <p>This study was initiated to establish whether any South African ethnomedicinal plants (indigenous or exotic), that have been reported to be used traditionally to repel or kill mosquitoes, exhibit effective mosquito repellent properties.</p> <p>Methods</p> <p>Extracts of a selection of South African taxa were tested for repellency properties in an applicable mosquito feeding-probing assay using unfed female <it>Anopheles arabiensis</it>.</p> <p>Results</p> <p>Although a water extract of the roots of <it>Chenopodium opulifolium </it>was found to be 97% as effective as DEET after 2 mins, time lag studies revealed a substantial reduction in efficacy (to 30%) within two hours.</p> <p>Conclusions</p> <p>None of the plant extracts investigated exhibited residual repellencies >60% after three hours.</p

Incorporation of Gas Chromatography–Mass Spectrometry into the Undergraduate Organic Chemistry Laboratory Curriculum

Gas chromatography–mass spectrometry (GC–MS) is a powerful analytical tool for detection, identification, and quantification of many volatile organic compounds. However, many colleges and universities have not fully incorporated this technique into undergraduate teaching laboratories despite its wide application and ease of use in organic chemistry. In this article, a set of experiments are provided to educators for the purposeful integration of the GC–MS technique into undergraduate organic chemistry laboratories. The laboratories provide students experimental opportunities to use GC–MS as the main analytical tool for (a) identification and quantification of major and minor product(s) formed in three common organic synthesis reactions and (b) extraction, separation, and identification of multiple natural products found in fruits and vegetables