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Student Number : 0009899J - PhD thesis - School of Therapeutic Sciences - Faculty of Health Sciences / The genus Eriocephalus commonly known as ‘wild rosemary’, ‘Cape snow bush’, or ‘kapokbos’ is a member of the family Asteraceae (tribe Anthemideae). The genus is endemic to southern Africa, with the highest concentration of species in the Western and Northern Cape. The genus comprises 32 species and a total of 42 taxa, which are distributed in South Africa, Namibia, Botswana, and Lesotho. The characters used in species delimitation are purely based on morphological variation in floral and foliar parts and are highly homoplastic due to phenotypic plasticity. In many cases these features are not sufficiently distinctive, as some taxa tend to exhibit dimorphism in some character states such as the presence of opposite and alternate leaves. In some species there is extensive intergrading of the major diagnostic characters leading to uncertainty in species delimitation. Both chemical and molecular characters were used in this study in an attempt to evaluate current species delimitations in the genus, along with species-level relationships and affinities. The genus is also economically important with some of its members used as medicinals, fodder, perfumes, and cosmetics. This warrants investigation into the phytochemistry and biological activity of these species in order to determine a scientific rationale for their traditional uses. For this reason, the antimicrobial, antiinflammatory, antioxidant activities, and inhibition of acetylcholinesterase by the volatile oils and leaf extracts of the genus, which are relatively unknown for most members of the genus, were also investigated. Representatives of 22 species of the genus, eight of which were from Namibia and 14 from South Africa were collected from wild populations. In most cases multiple collections per population per species were considered. Aerial plant parts were hydrodistilled to obtain the essential oils, and phenolics were extracted from leaves using acetone. Essential oils were analysed by thin layer chromatography (TLC), gas chromatography (GC), gas chromatography coupled to mass spectroscopy (GC/MS), and phenolics were analysed using thin layer chromatography (TLC) and high performance liquid chromatography (HPLC/UV). Biological assays were carried out using the 5-lipoxygenase enzyme to evaluate antiinflammatory activity; disc diffusion and microtitre plate dilution assays were used to assess antimicrobial activities of selected fungi and bacteria; the TLC-DPPH and DPPHmicrotitre methods were used to investigate antioxidant activities and a TLC-bioautographic assay was used for testing the inhibition of the acetylcholinesterase enzyme. Total genomic DNA was extracted from silica dried leaf material. The non-coding plastid DNA regions, the psbA-trnH intergenic spacers and the internal transcribed spacer (ITS) region of nuclear ribosomal DNA were amplified, and sequenced and analysed using the parsimony algorithm. The essential oils are largely comprised of acyclic, monocyclic, and bicyclic regular and irregular mono- and sesquiterpenes of various structural groups. Two hundred compounds were noted in the essential oils with some of the common constituents being; α- and β-pinene, yomogi alcohol, ρ-cymene, 1,8-cineole, camphor, 4-terpineol, spathulenol, caryophyllene oxide, α-copaene and β-caryophyllene. Most of the species have a relatively high content of 1,8-cineole and camphor. Twenty-two chemotypes were noted and the potential for commercial development in the flavour, fragrance and pharmaceutical industries has been recorded. Among the favourable chemotypes noted includes the camphor, 1,8-cineole, bisabolol oxide B and nerolidol rich oils. However, due to the extensive variability in the essential oil profiles, standardization of oils in commercial development is crucial. The leaf extracts comprised of flavonoids with the flavones and flavanones as the major structural types present in most species. The terpene and flavonoid chemistry of the genus is highly divergent even among multiple individuals of the same species and hence not a good taxonomic marker for specific delimitation as no coherent groups was evident although some phytochemical congruence has been noted between some of the taxa. The DNA sequence data revealed lack of variability in the non-coding regions psbA-trnH and trnL-F among species of the genus. The nuclear DNA region (ITS) was variable but the number of characters separating taxa was too few for resolution of relationships between taxa. Presence of highly divergent paralogous repeats of ITS were also noted in some taxa. The combination of molecular and chemical data did not resolve the species delimitation problems due to the highly variable distribution of characters within a single species. The patterns of variation observed in the genus may be attributed to chemical convergence, divergence, hybridisation, differential gene expression, polymorphism and allelochemical diversification among other factors. The lack of coherence in the phylogenetic and phenetic groupings of the various taxa implies that the current species boundaries may not be a true reflection of natural taxonomic entities. The use of multiple taxa in taxonomic studies is strongly recommended due to the extensive variability noted in the chemical profiles of the taxa that is also depicted in the phylogenetic histories. It also implies that caution should be taken in bioprospecting for new natural products for commercial development, as plant chemical profiles especially from the same species can be very variable. This implies carrying out exhaustive population and genetic studies for evaluation of diversity in the study group. In the antimicrobial assay, the oils were more active against the Gram-positive bacteria (2-16 mg/ml) and yeasts (1-16 mg/ml). Bacillus cereus and Cryptococcus neofomans were the most susceptible pathogens to the oils. The extracts exhibited low activity against the test pathogens except E. aromaticus and E. pinnatus with activity of 0.2 mg/ml against Staphylococcus aureus and Bacillus cereus respectively. The susceptibility of the fungal pathogens Cryptococcus neoformans and Candida albicans and the Gram-positive bacteria Bacillus cereus to the oils and extracts is an indication of the potential for use of the members of the genus as natural antibiotics. The essential oils exhibited antiinflammatory activities with IC50 values ranging between 19.0-98.6 μg/ml. The oils did not show antioxidant activity at the starting concentration of 100 μg/ml but the acetone leaf extracts exhibited antioxidant activities with IC50 values ranging between 21.5-79.6 μg/ml. The essential oils showed inhibitory activity against acetylcholinesterase enzyme. The biological activity of the oils indicates that most of the traditional uses are influenced by the presence of the oils. The in vitro biological activity of the essential oils and extracts against the test pathogens provides a scientific basis for the use of some of the members in traditional herbal remedies and validates the use of some of the members of the genus for treatment of respiratory tract infections, gastro-intestinal disorders, mental conditions, dermal infections, and inflammation. The study records the biological activities for some of the species for the first time and their potential for use in flavourings, perfumery, cosmetics, as sources of antimicrobial drugs, permeability enhancers in pharmaceutical formulations and for use as industrial oils.

ABSTRACT This study presents a taxonomic revision of some procolophonoid parareptiles and a detailed, global analysis of procolophonid intrarelationships. The poorly known genus Candelaria, from the Middle Triassic of Brazil, is identified on the basis of new material as an owenettid, rather than a procolophonid as previously thought. Thus, Candelaria represents the youngest owenettid and the first member of this group from South America. The cranium of Candelaria is also remarkable for having temporal fenestrae, and the significance of this character within the Parareptilia is discussed. Based on a comprehensive review of specimens referred to different Procolophon species, it is proposed that only the type species, Procolophon trigoniceps, is valid. Thus, Procolophon specimens from Brazil, South Africa, and Antarctica are all referable to P. trigoniceps. Consequently, P. trigoniceps has one of the broadest known geographic ranges among Triassic tetrapod species. A comprehensive cladistic analysis of procolophonids more firmly resolves the relationships within that group. The analysis reveals that Procolophoninae and Leptopleuroninae are valid monophyletic groups, whereas Spondylolestinae is paraphyletic. The species formerly assigned to the genus ‘Thelegnathus’ from the Middle Triassic of South Africa, and those assigned to ‘Eumetabolodon’ from the Lower-Middle Triassic of China, are paraphyletic. The poorly known Spondylolestes from the Dicynodon Assemblage Zone of South Africa is considered valid and possibly represents the only Permian procolophonid in Gondwana. A new species, Kitchingnathus untabeni, is identified in the Lystrosaurus Assemblage Zone of South Africa. It is a basal member of the Procolophonidae and co-occurs with Procolophon in the Upper Katberg Formation. The new taxon is characterized by the presence of a large number of thin, bicuspid teeth. Character optimisation indicates that bicuspid teeth were acquired independently in K. untabeni, and hence originated twice during procolophonid evolution. A review of procolophonid records worldwide reveals a fossil hiatus for members of this group in the Ladinian and most of the Carnian.

Orientador: Irani Quagio Grassiotto / Banca: Daniela Calcanhotto / Banca: Marco Aurélio Azevedo / Resumo: O gênero Moenkhausia é um dos mais especiosos em Characidae, com cerca de 65 espécies válidas, amplamente distribuídas nas bacias hidrográficas da América do Sul. Atualmente, este gênero é reconhecido como não monofilético e incertae sedis em Characidae. Os estudos taxonômicos e sistemáticos para o gênero são poucos e foram realizados com base em características morfológicas externa e interna e osteológicas. Sabe-se que as características reprodutivas podem conter sinais filogenéticos. Com o objetivo de contribuir para o entendimento das relações de parentesco do gênero Moenkhausia e outros tetragonopteríneos (sensu Géry, 1977), estudou-se o tipo de espermiogênese e os caracteres ultraestruturais dos espermatozóides de 21 espécies, sendo 17 pertencentes ao gênero Moenkhausia, e 1 espécie de Astyanax, Hasemania, Hemigrammus e Thayeria. Os dados obtidos das espécies de Moenkhausia foram comparados entre si e com a espécie-tipo, Moenkhausia xinguensis, na tentativa de se encontrar caracteres compartilhados que evidenciem uma maior relação destes. Além disso, os dados de M. xinguensis foram comparados com as espécies Hasemania nana, Hemigrammus bleheri, Thayeria boehlkei (este estudo), e Hemigrammus erythrozonus, Hyphessobrycon herbertaxelrodi, Tetratonopterus argenteus (dados da literatura) possivelmente relacionadas, de acordo com a literatura, com o intuito de identificar possíveis características compartilhadas entre os táxons estudados. Os espermatozóides das 21 espécies analisadas apresentam espermiogênese incompleta do tipo I. O processo de espermiogênese destas espécies apresenta variações com relação à rotação nuclear que permitem agrupar três grupos distintos dentro do gênero Moenkhausia: E1, o núcleo sofre uma rotação em relação ao eixo flagelar entre 70º e 80º e compreende as espécies M. chrysargyrea, M. collettii, M. comma... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The genus Moenkhausia is composed by 65 species and widely distributed in hydrographic basins of South America. Currenty, this genus cannot be recognized as a monophyletic unit. Taxonomic and phylogenetic studies that included the genus Moenkhausia are few and were realized based on morphological and osteological characters. Besides the traditional data, reproductive characters show potentially useful in the cladistics analysis. In attempt to contribute to knowledge of relationships of the genus Moenkhausia with others species of Tetragonopterinae (sensu Géry, 1977), the spermiogenesis and sperm ultrastructure from 17 species of Moenkhausia, 1 species of Astyanax, Hasemania, Hemigrammus, Thayeria (this study), and Hemigrammus erythrozonus, Hyphessobrycon herbertaxelrodi, Tetratonopterus argenteus (literature) were studied with the intention of diagnostic characters shared among them. Specimens were obtained from aquarious shop and mainly from zoological collections and were prepared and analyzed under Transmission Electron Microscopy. All species analyzed present spermiogenesis I with a variation on nuclear rotation. Based on nuclear rotation ranging the Moenkhausia species were grouped in three distinct patterns: E1, in which the nuclear rotation in relation to the flagellar axis is about 70º to 80º. This pattern is shared M. chrysargyrea, M. collettii, M. comma, M. cotinho, M. diktyota, M. doceana, M. cf. georgiae, M. latissima and M. sanctafilomenae. In the second pattern, herein termed E2, nuclear rotation is inferior to 50º. This pattern is subdivided in two subtypes E2-A and E2-B. In the subtype E2-A, as occurs in M. phaeonota and M. pyrophthalma, just after the accomplishment of the nuclear rotation, the nucleus slightly turns back and becomes strongly eccentric in relation to the flagellum. In subtype E2-B share by M. costae, M. grandisquamis, M. megalops, M. nigromarginata... (Complete abstract click electronic access below) / Mestre

Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Graduation date: 2000

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 94-103).