The plant kingdom contributes significantly to the natural products that are used for the treatment of a large number of ailments and disease across the globe. Included in these species is the Helichrysum genus (Asteraceae), which comprises of more then 600 species across Africa of which 244 species are found in South Africa. Helichrysum species are used in many cases for the treatment of coughs, colds, fever, infection, headaches, menstrual pain and are also very popular for wound dressing due to their potential antibacterial properties. The most common Helichrysum species used in traditional medicine and for several medicinal purposes are H. cymosum, H. odoratissimum, H. petiolare and H. nudifolium. Previously published research has shown that several of the Helichrysum species do have antimicrobial activity with the most relevant to this study being the discovery of antiviral activity of H. aureonitens against herpes simplex virus type 1 (HSV-1) as well as the reports of anti-HIV (human immunodeficiency virus) activity of several Helichrysum species. With this knowledge, a more in-depth study was initiated to identify the possible active constituents in South African Helichrysum species against HIV. Due to the need to speed up drug discovery especially against epidemic diseases like HIV, this study investigated a new tool (nuclear magnetic resonance (NMR) – based metabolomics) to speed up drug discovery form natural products especially when anti-viral constituents are investigated. odoratissimum, H. petiolare and H. nudifolium. Previously published research has shown that several of the Helichrysum species do have antimicrobial activity with the most relevant to this study being the discovery of antiviral activity of H. aureonitens against herpes simplex virus type 1 (HSV-1) as well as the reports of anti-HIV (human immunodeficiency virus) activity of several Helichrysum species. With this knowledge, a more in-depth study was initiated to identify the possible active constituents in South African Helichrysum species against HIV. Due to the need to speed up drug discovery especially against epidemic diseases like HIV, this study investigated a new tool (nuclear magnetic resonance (NMR) – based metabolomics) to speed up drug discovery form natural products especially when anti-viral constituents are investigated. In this study very promising anti-HIV results were obtained from several aqueous extracts (1:1 methanol/water) using a full virus model i.e. Helichrysum populifolium (IC50 12 μg/ml), H. appendiculatum (IC50 17 μg/ml), H. cymosum ssp. clavum (IC50 19 μg/ml), H. oxyphyllum (IC50 19 μg/ml) and H. cymosum ssp. cymosum (IC50 21 μg/ml). With the use of NMR-based metabolomics and multivariate data analysis (MVA) the specific characteristic that differentiated the active extracts from the non-active extracts was identified by making use of Orthogonal Projections to Latent Structures – Discriminant Analysis (OPLS-DA). This characteristic was then used as a “blue print” or “fingerprint” to guide the process of fractionation and purification. H. populifolium showed the highest anti-HIV activity and thus was selected as the candidate extract for further analysis. After a very quick and simple chromatographic fractionation process, seven fractions were compared against the activity profile by making use of their NMR profiles, which then visually indicated which of the fractions had the highest similarity. Fraction 6 had the most similar “fingerprint”. The compounds of this active fraction were then identified with the use of liquid chromatography – ion trap – time of flight (LC-IT-TOF) for quick identification. The analysis revealed the presence of five chlorogenic type compounds, 3,4-dicaffeoyl quinic acid (DCQA), 3,5-DCQA, 4,5-DCQA, 1,3,5- tricaffeoyl quinic acid (TCQA) and 5-malonyl-1,3,4-TCQA of which several are well known to have anti-HIV activity ranging from 0.85μM to 12μM. We were thus able to show with this study the possibility of using NMR-based metabolomics guided fractionation to guide the process of fractionation and identification from an active characteristic profile to the active constituents within the active H. populifolium extract. / Thesis (PhD)--University of Pretoria, 2013. / gm2014 / Plant Science / unrestricted

Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-05-05T14:14:07Z No. of bitstreams: 1 celsodeoliveirarezendejunior.pdf: 1703037 bytes, checksum: 06b6ddaff72097b07ba5ec7185f315b5 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-17T13:40:18Z (GMT) No. of bitstreams: 1 celsodeoliveirarezendejunior.pdf: 1703037 bytes, checksum: 06b6ddaff72097b07ba5ec7185f315b5 (MD5) / Made available in DSpace on 2017-05-17T13:40:18Z (GMT). No. of bitstreams: 1 celsodeoliveirarezendejunior.pdf: 1703037 bytes, checksum: 06b6ddaff72097b07ba5ec7185f315b5 (MD5) Previous issue date: 2010-07-30 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / Este trabalho trata da síntese de cicloexanopoliois derivados do ácido quínico, esterificados com os ácidos cafeico e gálico. Esses compostos são candidatos novos agentes antivirais, principalmente como inibidores da enzima HIV-integrase, devido à semelhança estrutural com os derivados dicafeoíl-cicloexanodiois e ácidos dicafeoíl-quínicos, potentes inibidores dessa enzima. A partir de reações de esterificação, proteção e desproteção de compostos fenólicos e cicloexanopoliois foram sintetizados 41 compostos, sendo 26 inéditos, com rendimentos que variaram de 20 a 100%. As reações de proteção e desproteção seletivas das hidroxilas foram realizadas com sucesso. Na benzilação dos compostos (1R,2S,3R,5S)-1,2-Ocicloexilideno-1,2,3,5-tetraidroxicicloexano e (1R,2S,3R,5R)-1,2-O-cicloexilideno- 1,2,3,5-tetraidroxicicloexano a metodologia por transferência de fase se mostrou mais eficiente do que a metodologia convencional. Na tentativa de clivagem seletiva dos grupos benzila dos compostos (1R,2S,3R,5S)-1,2-di-O-(3’,4’-di-O-acetil)-cafeoíl-3,5-di-O-benzil-1,2,3,5-tetraidroxicicloexano e (1R,2S,3R,5R)-1,2-di-O-(3’,4’-di-Oacetil)-cafeoíl-3,5-di-O-benzil-1,2,3,5-tetraidroxicicloexano foram utilizadas quatro metodologias diferentes obtendo-se, para cada uma, a clivagem de grupos protetores diferentes. As estruturas dos compostos obtidos foram elucidadas por espectroscopia na região do infravermelho, RMN de 1H e de 13C, além da caracterização por ponto de fusão e poder rotatório específico. Alguns compostos finais foram encaminhados para testes anti-herpes (HSV-1 e HSV-2) e para avaliação das propriedades antioxidantes e antiparasitárias e serão encaminhados para testes anti- HIV-integrase. / This work describes the synthesis of cyclohexanepoliols derived from quinic acid, esterified with caffeic and gallic acids. These compounds are candidates as new antiviral agents, particularly as inhibitors of HIV integrase, due to their structural similarity to dicaffeoyl cyclohexanediols and dicaffeoyl quinic acid derivatives, potent inhibitors of this enzyme. We synthesized 41 compounds using reactions of esterification, protection and deprotection of phenolic and cyclohexanepoliol derivatives. The reactions of protection and selective deprotection of the hydroxyl groups were performed successfully. In the benzylation of compounds (1R, 2S, 3R, 5S)-1,2-O-cyclohexylidene-1,2,3,5-tetrahydroxycyclohexane and (1R, 2S, 3R, 5R)-1,2-O-cyclohexylidene-1,2,3,5-tetrahydroxycyclohexane the methodology employing phase transfer was more efficient than the conventional method. In an attempt to cleave selectively the benzyl groups of compounds (1R, 2S, 3R, 5S)-1,2-di-O-(3',4'-di-O-acetyl)-caffeoyl-3,5-di-O-benzyl-1,2,3,5-tetrahydroxycyclohexane and (1R,2S,3R,5R)-1,2-di-O-(3',4'-di-O-acetyl)-caffeoyl-3,5-di-O-benzyl-1,2,3,5- tetrahydroxycyclo-hexane four different methodologies were used. Each procedure led to cleavage of different protecting groups. The structures of the compounds were characterized by infrared spectroscopy, 1H and 13C NMR, melting point and specific optical rotation. Final compounds were sent for testing against herpes (HSV-1 and HSV-2) and biological evaluation of their antiparasitic and antioxidant properties and will be referred for testing against HIV integrase.