No abstract available. / Thesis (M.Sc.)-University of Natal, Durban, 2001.

Ledebouria ovatifolia (Bak.) lessop, Clivia caulescens R.A.Dyer and Haemanthus pauculifolius Snijman & Van Wyk were the three species investigated in this work. Ledebouria ovatifolia belongs to the family Hyacinthaceae (Liliaceae sensu lato) and, to date, the chemical composition of this species has not been investigated. Members of this family are widely distributed, but are particularly well represented in Southern Africa. The Ledebouria genus was formerly classified as part of the Scilla genus from which a large number of naturally occurring oxygen heterocycles known as homoisoflavonoids have been isolated. In this work the bulbs of L. ovatifolia were investigated and two compounds were isolated. These were the homoisoflavonoid, 5,7-dihydroxy-3-(4'-hydroxybenzyl)-4-chromanone and the chalcone, 6',2'-dimethoxy-4,4'dihydroxychalcone, both of which are known naturally occurring compounds. Clivia caulescens and Haemanthus pauculifolius are both members of the Amaryllidaceae family. The plants of the Amaryllidaceae family form a large group of over sixty genera, which are concentrated mainly in Southern Africa. Plants from this family have been extensively used in traditional medicines and many have pharmacological properties. The compounds responsible for most of these effects are a group of isoquinoline alkaloids, which are found almost exclusively in plants belonging to this family. The alkaloids isolated from plants belonging to this group are known to cause poisoning in low doses and can cause excessive salivation and diarrhoea. Higher doses of the active compounds can cause CNS depression and large enough doses can prove fatal. Although many of these alkaloids are harmful to man, some of the unique Amaryllidaceae alkaloids exhibit anti-tumour and anti-viral activities, and are thus potentially beneficial to man. The Clivia genus is endemic to South Africa and the most common species, C. miniata, is used by traditional healers to facilitate childbirth and as a snake bite remedy. In this chemical investigation both the bulbs and the leaves of C. caulescens were investigated. The ethanol extract of the bulbs yielded four alkaloids, hippeastrine, haemanthamine, lycorine and ll-(S)-hydroxyvittatine. The investigation of the leaf extract also yielded lycorine and hippeastrine as well as an additional alkaloid sternbergine. Haemanthus pauculifilius is a recently described member of the Haemanthus genus, which consists of 27 taxa that are restricted to Southern Africa and Namibia. In this chemical investigation the ethanol extract of the bulbs and leaves yielded the common triterpenoid sitosterol as well as two novel 5,11-methanomorphanthridine type alkaloids, montanine hydrochloride and manthidine. / Thesis (M.Sc.)-University of Natal, Durban, 1999.

This work is an account of investigations into the chemistry of one of the members of the Amaryllidacae family, Ammocharis coranica, and one of the members of the Fabaceae family, Sophora velutina. Chapter one is an account of the extractives from the bulbs of Ammocharis coranica. In all, twelve compounds, eight alkaloids and four cycloartane compounds have been isolated of which one alkaloid and one cycloartane compound have not been described previously. Plants belonging to the Amaryllidacae family have been used by traditional healers, especially in Africa, to treat a range of illnesses and diseases. The alkaloids isolated from these plants have been shown to exhibit responses to muscle stimulant, antiviral, antifungal, antiyeast, antimalarial, cytotoxic and antitumoural activities. Ammocharis coranica is used by the Zulu tribe in South Africa to treat any illness believed to be caused by witchcraft. Alkaloids from the three most common types among the isoquinoline group were found in this species. These are lycorine, 1-O-acetyllycorine, hippadine, acetylcaranine, and the novel 1-O- acetyl-9-norpluviine from the lycorine type, 6-α-hydroxypowelline from the crinine type and hamayne and crinamine from the haemanthamine type. Cycloartane compounds have not been reported previously from the Amaryllidaceae family. All four cycloartane compounds had a common side chain, containing an olefinic methylene group at position 24, but differed in their substituents at positions 3 and 4. These compounds were found to be 24-methylenecycloartan-3β-ol, cycloeucalenol, cycloeucalenone and the novel compound 4-methylenepollinastanone. Chapter two is an account of the extractives from the seeds of Sophora velutina. The seeds of other Sophora species have been used in traditional ceremonies by the Indians of the Southwest United States and adjacent Mexico because of their hallucinogenic activity. The seeds of Sophora velutina subsp. zimbabweensis found in Zimbabwe are suspected to have historically been used by the natives for their hallucinogenic properties. These plants have been known to contain several quinolizidine alkaloids, flavonoids and isoflavonoids. One alkaloid, N-methylcytisine and two isoflavones, pseudobaptigenin and calycosin, as well as the common phytosterol, β-sitosterol were isolated from the seeds of this species. N-methylcytisine is a common quinolizidine alkaloid, isolated previously from several Sophora species and pseudobaptigenin and calycosin are well known isoflavones, isolated previously from several species in the Fabaceae. / Thesis (M.Sc.)-University of Natal, Durban, 1999.

This thesis describes a phytochemical investigation of four medicinal plants, namely, Agave attenuata (Agavaceae), Balanites maughamii (Balanitaceae), Astrotrichilia parvifolia (Meliaceae) and Combretum fragrans (Combretaceae). Investigations of A. attenuata and B. maughamii were undertaken as biological studies have shown that these plants possess anti-bilharzial properties. Schistosomiasis is an important public health issue in South Africa and attempts to deal with infected rural communities have forced scientists to focus their attention on snail control using plant molluscicides. A. attenuata yielded two glycosides, timosaponin A III (compound I) and 5?-pregn-16-en-20one- 3?-O-tetrasaccharide (compound II), while a coumarin, scopoletin (compound III) and a sterol, stigmasterol (compound IV) were isolated from B. maughamii A dammarane, shoreic acid (compound V) was isolated from A. parvifolia, this formed part of an ongoing investigation into the Meliaceae of Madagascar. Plants of the family Combretaceae are widespread in Africa and are used by traditional healers for a wide range of illnesses. The leaves and bark are used abundantly, however, the winged fruits are never eaten as they are highly toxic to animals and humans. The leaf surface is covered with epidermal scale-like trichomes through which acidic triterpenoid mixtures are secreted. Six lupane-type triterpenoids were isolated from C. jragrans, namely, lupeol (compound VI), lupenone (compound VII), lupeol 3?- docosanoate (compound VIII), lupeol 3?-eicosanoate (compound IX) hennadiol (compound X) and 30hydroxylupenone (compound XI). All the above compounds were isolated by column chromatography and the structures were elucidated by means of NMR spectroscopy, mass spectrometry and infra red spectroscopy. / Thesis (M.Sc.)-University of Natal, Durban, 2000.

Momordica foetida Schum. & Sond. (Cucurbitaceae), locally known as iNtshungu, is widely used by the Zulu people of Natal-KwaZulu for the treatment of a variety of ailments. The dried leaves leaves and stems of this plant was subjected to soxhlet extraction by refluxing with hexane, chloroform and methanol successively. Thin layer chromatography of the chloroform extract of the leaves revealed a multiplicity of compounds. The chloroform extract was further partitioned with sodium hydroxide resulting in an organic and aqueous phase. The organic phase, containing extract A, afforded two compounds, viz. compounds 1 and 2. The basic aqueous fraction was neutralised and re-extracted with chloroform to give extract B, affording five compounds, viz. compounds 3,4,5,6 and 7. Structural elucidation was accomplished by techniques such as IH and 13C NMR spectroscopy, HETCOR, COSY, FTIR and High Resolution Mass Spectrometry. Compounds 1 and 2 were identified as cucurbitane triterpenoids known as momordicines which had been previously discovered in the related species of this plant, Momordica charantia L. The remaining five compounds were identified as novel compounds, although natural derivatives of compounds 6 and 7 had been isolated previously from Momordica charantia L. Compounds 3-7 were each isolated as an epimeric mixture but it was possible to select the resonances corresponding to the major epimer. These five epimers were respectively identified as 5, 19-epoxy-19(R)-hydroxy-25-methoxy-5β- cucurbita-6,23-diene-3β-ol [102], 5,19-epoxy-19(R),25-dihydroxy-5β-cucurbita- 6,23-diene-3β-ol [103], 5,19-epoxy-19(R)-methoxy-25-hydroxy-5β-cucrbita- 6,23-diene-3β-ol [104], 5,19-epoxy-25-methoxy-5β-cucurbita-6,23diene- 3β-ol [105] and 5,19-epoxy-19(R),25-dimethoxy-5β-cucurbita-6,23diene- 3β-ol [106]. Appropriate reactions were performed, where possible, on the compounds isolated in order to confirm their identity. / Thesis (M.Sc.)-University of Natal, Durban, 1994.

The potential growth-regulating compound 4-chloroglutaranilic acid (CGA) was tested in whole-plant bioassay systems which utilized sunflower seedlings (Helianthus annuus, L.). Test systems included the growth of plants in soil , solid inert (Vermiculite) substrate, and hydroponic (Seed-Pak) pouches.

Aims. The objectives of this study were (i) to isolate and characterize by conventional column chromatography, structurally diverse triterpenes from G. lucidum to serve as chemical markers; (ii) to develop a high performance liquid chromatography (HPLC) method for the quality control and/or standardization of Lingzhi-containing products; (iii) to utilize and optimize operating conditions for the newer extraction technology: supercritical fluid extraction (SFE), in order to maximize yields of bioactive triterpenes, and to reduce time and costs. / Background. The dried fruiting body of Ganoderma lucidum, commonly known as Lingzhi, has been used extensively as a traditional Chinese medicine (TCM) for many centuries not only in China, but also in other countries such as Japan and Korea. In recent years, Lingzhi has also become a popular health supplement in many Western countries. The chemical composition of Lingzhi is complex, but it has been well documented that the lipophilic triterpenoid class of compounds possess a range of biological effects that include antitumor, immunomodulatory, cardiovascular, respiratory and antihepatotoxic activity. A major drawback in TCM research has been the lack of authentic chemical standards, and efficient methods for the extraction and analysis of bioactive fractions and/or single components. Conventional extraction methods for G. lucidum are time-consuming and laborious, and often result in low yields of useful chemical constituents. / Conclusion. This study enabled the development of a method for the simultaneous analysis of structurally diverse triterpenes with remarkably different chromatographic profiles. The isolated triterpenes, as chemical markers, and the HPLC method can readily be used for quality control and/or standardization purposes in evaluating Lingzhi-containing products. Optimization of operating conditions for SFE facilitated the rapid and selective extraction of acidic triterpenes from raw G. lucidum in significantly higher yields. / Methods. Raw material of G. lucidum was extracted with 80% ethanol; subjected to repeated column chromatography to purify triterpenes; and characterized by NMR (1H and 13C) and mass spectroscopy. Isolated lipophilic triterpenes were qualitatively and quantitatively analyzed by reversed-phase HPLC using an ODS column (150 x 4.6 mm) and PDA detection at 256 nm. The assay was validated over appropriate concentration ranges and benzophenone was used as an internal standard. Supercritical fluid extraction of G. lucidum was carried out using a commercial supercritical fluid extractor system Thar, SFE-1000M. Briefly, the raw powder of G. lucidum was soaked in ethanol containing 10% aqueous ammonia for 30 minutes prior to extraction. Extractions were performed at temperatures of 40, 50 and 60°C; and pressures of 200, 250, 300 and 350 bar; 5% ethanol was used as the co-solvent; and the flow rate of CO 2 was set at 20 g/min. / Results. Eight compounds were isolated and identified from G. lucidum: four triterpenes; namely, lucidenic acid N, ganoderic acid B, ganodermanontriol, and ganodermadiol; two steroids; ergosterol-7, 22-dien-3beta-ol and ergosterol peroxide; and two fatty acids, oleic acid and tetracosanoic acid. The four triterpenes were utilized as chemical markers, and the developed HPLC method was able to simultaneously analyze the structurally diverse components with good resolution. The total analysis run time was 110 min, and retention times (tR) were 14.88, 18.96, 63.88 and 90.73 min respectively, and the eluting system was a mixture of three solvents, methanol (A), acetonitrile (B) and 2% acetic acid solution (C): 0-22 min, 5% A, 25% B and 70% C; 22-85 min, gradient elution, the ratio changed gradually to 5% A, 80% B and 15% C; 85-110 min, gradient elution, the ratio changed gradually to 5% A, 85% B and 10% C. The validated HPLC method and the isolated chemical markers were effectively applied to determine the triterpenoid contents in a variety of commercial Lingzhi products. Supercritical fluid extraction conditions of: pressure 300 bar and temperature 50°C, gave the highest yields of triterpene-containing extracts. HPLC analysis of the SFE extracts showed predominantly acidic triterpenes such as lucidenic acid N and ganoderic acid B. / Hong Xin. / "December 2006." / Advisers: Ho Yee Ping; Albert H. L. Chow. / Source: Dissertation Abstracts International, Volume: 68-09, Section: B, page: 5968. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 149-175). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

A number of recent research studies have been done on different species of the plants of the genus Phyllanthus. The plants are widely distributed in most tropical and subtropical countries and have long been used for the treatment of liver diseases in China and India. / Hepatitis B virus (HBV) is a major pathogen of human viral hepatitis. It has been estimated that 350 million people are chronic carriers of HBV throughout the world. Increasing evidence indicates that persistent viral infection of the liver is associated with cirrhosis and hepatocellular carcinoma. Hepatitis B virus belongs to a family of DNA viruses called hepadnaviruses. The current treatments of HBV infection with interferon or lamivudine have several disadvantages, and there appears to be much room for improvement in terms of medical treatment. / My project research focuses on two poorly characterized Indian Phyllanthus species called Phyllanthus nanus ("PN") and Phyllanthus niruri ("PI"). In my studies, random amplified polymorphic DNA ("RAPD") technique and high performance liquid chromatography ("HPLC") fingerprinting were used to authenticate different species of Phyllanthus. Both aqueous and ethanolic extracts of PN and PI were prepared to study their cytotoxicity in hepatoma cell lines. The effect of these extracts on hepatitis B virus was also examined in the HBV-genome integrated cell lines - PLC/PRF/5 (Alexander) and HepG2 2.2.15. Microparticle enzyme immunoassay ("MEIA") and enzyme-linked immunosorbent assay were used to measure the amount of hepatitis B surface antigen ("HBsAg") and hepatitis B e antigen ("HBeAg") secretion from the cell lines. RT-PCR was used to detect the change in HBsAg mRNA's expression level in the drug-treated cell lines. Real-time PCR was also employed to examine the effect of drug treatment on the level of HBV DNA replication and the amount of virions secreted into the medium. The experimental results showed that both the aqueous and ethanolic extracts of PN and PI exerted suppressive effect on HBsAg secretion and HBsAg mRNA level. The PN and PI ethanolic extracts also showed mild suppression of viral replication in vitro. The ethanolic extract of PN seemed to be more potent in suppressing HBV than the other extracts tested. (Abstract shortened by UMI.) / Lam Wai Yip. / "June 2005." / Advisers: Mary Waye; Vincent Ooi. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3594. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 217-234). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.

Ganoderma lucidum and Cordyceps sinensis are medicinal fungi commonly used in Chinese medicine. The allied species of G. lucidum, G. sinense and G. tsugae as well as the allied species of C. sinensis, C. militaris are also commercially available as health supplements. The present study aimed at evaluating and comparing the biological activities of the different parts of fruiting bodies of Ganoderma species (whole fruiting body, pileus, stipe, spores and spore oil) and Cordyceps species (whole fruiting body, stroma and larva/pupa). / The extracts of C. sinensis and C. mililaris could stimulate secretion in human airway epithelial cell Calu-3, implying the potentials of these extracts to modulate the mucociliary clearance. The potencies of the stimulatory effects of the stroma of fruiting bodies showed stronger effects than the larva/pupa. All parts of C. sinensis and the stroma of C. mililaris could modulate the proliferation of human peripheral blood mononuclear cells and the different potencies of immunomodulatory effects were also observed. / The results demonstrated that the hot water extracts of G. lucidum, G. sinense and G. tsugae possessed antiproliferative effects on human breast cancer cell lines MCF-7 and MDA-MB-231. The extracts from the stipes showed stronger inhibitory activities on cancer cell proliferation than those from pilei. Furthermore, the extracts from the whole fruiting body and stipe of G. lucidum possessed strong antitumor effects on the nude mice bearing MCF-7 xenografts and the BALB/c mice bearing sarcoma S-180 allografts as well as strong immunomodulatory effects in terms of stimulating splenic lymphocyte proliferative responses. The oral administrations of spores and spore oil did not show significant inhibition on MCF-7 xenografts growth but they inhibited sarcoma allografts growth effectively. / The strong biological effects of the stipe of Ganoderma and the stroma of Cordyceps were showed for the first-time. This study sheds light on how the fruiting bodies of Ganoderma or Cordyceps should be used to achieve the most out of their pharmacological properties. This study also demonstrated the novel application of Cordyceps in promoting secretion in human airway submucosal glands, which reinforces the rationale of using this fungus for treating respiratory diseases. / Yue Gar Lee Grace. / "August 2006." / Advisers: Leung Ping Chung; Kwok Pui Fung; Bik San Clara Lau. / Source: Dissertation Abstracts International, Volume: 68-03, Section: B, page: 1584. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 318-340). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Thesis (M.Tech.: Biotechnology)-Dept. of Biotechnology, Durban University of Technology, 2007 xv, 136 leaves / The chemical and biological properties of the essential oil from Cymbopogon validus were investigated. Hydro-distillation was used to extract the oil from C. validus, the flower-heads, leaves, culms and rhizomes. The percentage oil yields obtained from the plant organs varied from 0.05 to 1.23%, with the greatest concentration found in the flower-heads and rhizomes, 1.23 and 1.12% respectively. A sensory evaluation of the oil revealed that the essential oil was slightly murky, pale yellow in colour, had a strong turpentine-like smell and remained liquid at room temperature. The oxidative stability of C. validus oil was evaluated by determining its Rancimat induction period (negative), peroxide value (60.56 meq/kg), iodine value (84.55), percentage free fatty acids (0.19%) and percentage cholesterol (3.03%). These results indicated that the oil was highly susceptible to oxidation. Chromatographic profiles of the oils from C. validus, as well as the plant organs were generated using gas chromatography-mass spectroscopy (GC-MS). Predominant compounds present in the oil included alpha-Cubebene, Camphene, Geraniol, Limonene, Myrcene, Palmitic acid and Sabinene. C. validus essential oil was also investigated for its antimicrobial (disk diffusion), antioxidant (1, 1-Diphenyl-1-Picrylhydrazyl (DPPH) assay), anti-inflammatory (5-lipoxygenase assay), anti-mosquito properties (insecticidal, larvicidal and repellency assays) and toxicity profile (Brine shrimp and Ames assays). The oil showed poor antimicrobial activity and inhibited the growth of only Gram positive bacteria with a minimum inhibitory concentration (MIC) of 0.0625 (vol/vol) for Bacillus, Micrococcus and Staphylococcus species. The oil also exhibited excellent antioxidant activity, scavenging more than 80% of DPPH free radicals and possesses anti-inflammatory activity (IC50=190 ppm). C. validus oil showed good adulticidal activity (53.7% mortality) and excellent larvicidal (100% mortality) and repellent activity (100% repellency) against Anopheles arabiensis mosquitoes. At high concentrations, the oil was toxic to brine shrimp larvae. However, when diluted it was safe and the minimum inhibitory concentration was 0.0001(vol/vol). The absence of revertant colonies at all essential oil concentrations in the Ames test suggest that the oil is not mutagenic. These results lead the way for exploiting C. validus oil as a multi-functional agent that has antibacterial, anti-oxidant, anti-inflammatory, and anti-mosquito properties.