SARChI National Research Chair in Indigenous Plant Use, Department of Botany and Plant Biotechnology, University of Johannesburg, P.O. Box 524, Johannesburg 2006, South Africa
Prof. Dr. Ben-Erik Van Wyk
SARChI National Research Chair in Indigenous Plant Use, Department of Botany and Plant Biotechnology, University of Johannesburg, P.O. Box 524, Johannesburg 2006, South Africa
Resolving the phylogenetic relationships of the deep nodes of papilionoid legumes (Papilionoideae) is essential to understanding the evolutionary history and diversification of this economically and ecologically important legume subfamily. The early-branching papilionoids include mostly Neotropical trees traditionally circumscribed in the tribes Sophoreae and Swartzieae. They are more highly diverse in floral morphology than other groups of Papilionoideae. For many years, phylogenetic analyses of the Papilionoideae could not clearly resolve the relationships of the early-branching lineages due to limited sampling. In the eight years since the publication of Legumes of the World, we have seen an extraordinary wealth of new molecular data for the study of Papilionoideae phylogeny, enabling increasingly greater resolution and many surprises. This study draws on recent molecular phylogenetic studies and a new comprehensive Bayesian phylogenetic analysis of 668 plastid matK sequences. The present matK phylogeny resolves the deep-branching relationships of the papilionoids with increased support for many clades, and suggests that taxonomic realignments of some genera and of numerous tribes are necessary. The potentially earliest-branching papilionoids fall within an ADA clade, which includes the recircumscribed monophyletic tribes Angylocalyceae, Dipterygeae, and Amburanae. The genera Aldina and Amphimas represent two of the nine main but as yet unresolved lineages comprising the large 50-kb inversion clade. The quinolizidine-alkaloid-accumulating Genistoid s.l. clade is expanded to include Dermatophyllum and a strongly supported and newly circumscribed tribe Ormosieae. Sophoreae and Swartzieae are dramatically reorganized so as to comprise monophyletic groups within the Core Genistoid clade and outside the 50-kb inversion clade, respectively. Acosmium is excluded from the Genistoids s.l. and strongly resolved within the newly circumscribed tribe Dalbergieae. By providing a better resolved phylogeny of the earliest-branching papilionoids, this study, in combination with other recent evidence, will lead to a more stable phylogenetic classification of the Papilionoideae
Southern Africa is an important focal point of botanical and cultural diversity but only a few plant species have hitherto become fully commercialised as medicinal products. In recent years there has been an upsurge in research and development activity, resulting in several new products and new crops. In this review, more than 90 of the best-known and most promising indigenous South African plants are listed and subjectively evaluated in the context of their potential for commercialisation as medicinal products for a variety of applications. The history of product development relating to the following species is briefly discussed and the plants and some of their products are illustrated: Agathosma betulina (buchu), Aloe ferox (bitter aloe), Artemisia afra (African wormwood), Aspalathus linearis (rooibos tea), Bulbine frutescens (burn jelly plant); Cyclopia genistoides (honeybush tea), Harpagophytum procumbens (devil's claw), Hoodia gordonii (hoodia, ghaap), Hypoxis hemerocallidea (“African potato”), Lippia javanica (fever tea), Mesembryanthemum tortuosum (=Sceletium tortuosum) (kanna, kougoed), Pelargonium sidoides (“Umckaloabo”), Siphonochilus aethiopicus (African ginger), Sutherlandia frutescens (=Lessertia frutescens) (cancer bush), Warburgia salutaris (pepperbark tree) and Xysmalobium undulatum (“Uzara”). The main factors that are apparently responsible for failure or success will be highlighted, especially the importance of marketing strategy, proof of concept and barriers to market entry
The genus Aloe (Asphodelaceae), with nearly 420 species confined mainly to Africa, has over the years proved to be one of the most important sources of biologically active compounds. Over 130 compounds belonging to different classes including anthrones, chromones, pyrones, coumarins, alkaloids, glycoproteins, naphthalenes and flavonoids have so far been reported from the genus. Although many of the reports on Aloe are dominated by A. vera and A. ferox, there have also been a number of fruitful phytochemical studies on many other members of the genus. In this review an attempt is made to present all compounds isolated to date from Aloe. The biogenesis and chemotaxonomic significance of these compounds are also discussed.