Methyl 2-cyano-3,11-dioxo-18β-olean-1,12-dien-30-oate (β-CDODA-Me) and methyl 2-cyano-3,11-dioxo-18α-olean-1,12-dien-30-oate (α-CDODA-Me ) isomers are synthetic analogs of the naturally occurring triterpenoid glycyrrhetinic acid. The activity of these compounds as selective peroxisome proliferator-activated receptor γ (PPARγ) agonists and as cytotoxic anticancer agents has been investigated in colon, prostate and pancreatic cancer cells. In colon cancer cells β-CDODA-Me arrested the growth at G2/M and this was accompanied by decreased expression of Sp1, Sp3 and Sp4 protein and mRNA and several Sp-dependent genes including survivin, vascular endothelial growth factor (VEGF), and VEGF receptor 1 (VEGFR1 or Flt-1). β-CDODA-Me also inhibited tumor growth in athymic nude mice bearing RKO cells as xenografts. β- CDODA-Me decreased expression of microRNA-27a (miR-27a), and this was accompanied by increased expression of two miR-27a-regulated mRNAs, namely ZBTB10 (an Sp repressor) and Myt-1 which catalyzes phosphorylation of cdc2 to inhibit progression of cells through G2/M. In LNCaP prostate cancer cells induction of two proapoptotic proteins namely nonsteroidal anti-inflammatory drug- activated gene-1 (NAG-1) and activating transcription factor-3 (ATF-3) was PPARγ independent and required activation of kinases. β-CDODA-Me also decreased the levels of androgen receptor (AR) and prostate-specific antigen (PSA) mRNA and protein levels. Thus the cytotoxicity of β- CDODA-Me involved multiple pathways that selectively activate growth inhibitory and proapoptotic responses. Betulinic acid (BA), an inhibitor of melanoma is a pentacyclic triterpenoid natural product that induces apoptosis and antiangiogenic responses in tumors derived from multiple tissues. However, the underlying mechanism of action of BA is unknown. In LNCaP prostate cancer cells, BA acts as a novel anticancer agent by inducing proteasome-dependent repression of Sp proteins and Sp- dependent genes. The anticancer activity of the 2-cyano substituted analogs of BA, CN-BA and its methyl ester, CN-BA-Me was also investigated in colon and pancreatic cancer cells. Both CNBA and CN-BA-Me were highly cytotoxic and activated PPARγ and induced several receptor-mediated responses. The results clearly demonstrated that both the PPARγ agonist activities of CN-BA and CN-BA-Me were structure-, response-/gene- and cell context-dependent suggesting that these compounds are a novel class of selective PPARγ modulators with potential for clinical treatment of prostate, colon and pancreatic cancer.

Thesis (M. Sc.)--University of Hong Kong, 1971. / A paper entitled Structures of three C32 triterpenoids from Neolitsea pulchella, by W.H. Hui and others, in pocket. Typewritten.

Thesis (M. Sc.)--University of Hong Kong, 1973. / Includes reprints of 2 papers entitled Further C32 triterpenoids from Neolitsea pulchella by W.S. Chan and W.H. Hui, from Journal of the Chemical Society, 1973, and Triterpenoids and sterols from three Millettia species of Hong Kong, by W.H. Hui and others, from Phytochemistry, v.12, 1973, in pocket.

An extract of the sponge <i>Rhabdastrella globostellifera</i> was active in an assay measuring stabilization of the binding of DNA with DNA polymerase β. From this extract, four isomalabaricane triterpenoids were isolated and characterized, three of which were active in the binding assay. All compounds were active in the A2780 ovarian cancer cell line assay. Bioassay-guided fractionation of an extract of a sponge of species <i>Dysidea</i> using the A2780 bioassay yielded the known scalarane sesterterpenoid heteronemin in good yield. Four derivatives of heteronemin were prepared semisynthetically from the natural product, tested for their bioactivity, and their structure-activity dependence was observed. Bioassay guided-fractionation of an extract of a <i>Tuemoya</i> sp. green alga, using an assay for inhibitors of the enzyme Tie2 kinase, afforded a two sulfated cycloartanol triterpenoids. Both the major and minor compounds were identified by spectroscopic methods. Bioassay-guided fractionation of an extract of <i>Petalonyx parryi</i> yielded three known oleanane triterpenoids which inhibited the lyase domain of DNA polymerase β. The structures were confirmed by NMR spectroscopic techniques. This is the first reported study of the chemical components of <i>Petalonyx parryi</i>. As part of our antitumor natural product drug discovery efforts, several extracts were selected for bioassay-guided fractionation based on their activity in initial in vitro screens. A new dereplication method using aminopropyl SPE cartridges was applied to six of these extracts, and four of the extracts were dropped due to the presence of long-chain fatty acids (LCFAs). We present results for the testing and application of this SPE-based method for LCFA dereplication. The cell cycle kinase Chk1 is an interesting target for the development of agents which might potentiate DNA damaging agents. Typical assays for Chk1 involve the use of expensive or radioactive reagents. To facilitate the development of new assays using shorter peptide substrates, small libraries of peptides have been synthesized and tested for their activity as Chk1 substrates. Several of the substrates synthesized displayed activity in the Chk1 assay. / Ph. D.

Antrodia camphorata is a Taiwan-unique fungus which grows on the walls inside the core of decayed Cinnamomum kanehirae. Antrodia camphorata provides many bioactive substance and it is cultivated mainly via mycelium nowadays. First section of this research is focused on Antrodia camphorata (CCRC-35716) in liquid cultivation medium and the changes within extracellular polysaccharides, trierpenoids, pH and growth. It also uses HPLC to analyze the differences of mycelium triterpenoids. This experiment showed when Antrodia camphorata was cultivated in PDB liquid medium for 14 days; it had the highest extracellular polysaccharides (0.23

Thesis (Ph. D.)--University of Hong Kong, 1972. / Reprints of 2 papers by H.R. Arthur and the author from Australian journal of chemistry, 1968 and 1969, in pocket. Offset from typescript.

Thesis (M. Sc.)--University of Hong Kong, 1969. / Offprints of An examination of the Euphorbiaceae of Hong Kong, pts. III and VI, by W.H. Hui and the author in pocket. Typewritten.

Six new compounds were isolated from the aerial and root parts of S. viridis L. cv. Blue Jeans. Two new triterpenoids, lup-20(29)-ene-2α-acetate-3β-ol, and lup-20(29)-ene-2α-ol-3β-acetate were found in the aerial part together with lup-20(29)-ene-2α-3β-diol, ursolic acid, oleanolic acid, β-sitosterol and β-sitosterol glucoside. Three new diterpenoids, 1-oxomicrostegiol, viroxocane, viridoquinone, together with five known diterpenoids, ferruginol, salvinolonyl 12-methyl ether, microstegiol, 7α-acetoxy-14-hydroxy-8,13-abietadiene-11,12-dione and 7α,14-dihydroxy-8,13-abietadiene-11,12-dione were found in roots. 1-Docosyl ferulate, 2'',3''-di-O-acetyl-martynoside and a mixture of 2-(4'-alkoxy-phenyl) ethyl alkanoates were also isolated from roots. Seven caffeic acid derivatives, five flavonoid glycosides, and salidroside were found in the crude aerial fraction. Four caffeic acid derivatives were known phenylpropanoids, i.e. trans-, cis-verbascoside, leucosceptoside A and martynoside, which are now reported in the genus Salvia for the first time. The others were caffeic acid, rosmarinic acid and 6-O-caffeoyl-glucose. A new flavonoid glycoside, luteolin-7-O-α-rhamnopyranosyl-(1→6)-β-galactopyranoside was also identified in the aerial part with four known flavone glycosides: luteolin-7-O-β-glucopyranoside, luteolin-7-O-β-galactopyranoside, luteolin-7-O-rutinoside and apigenin-7-O-β-glucopyranoside. Verbascoside (acteoside), which is a major component in this plant, showed a significant protective effect against UVA induced damage in a human skin fibroblast model in vitro. It exhibited 1.4 fold protective effect against UVA induced necrosis with 1.4 fold higher in cell survival. 50 μM Verbascoside showed the same protective effect as 100 μM DFO at a high intensity UVA dose (500 kJ/m2). Further determination of organelle specific protection suggested a mechanism of action in mitochondria. Two terpenoids, lup-20(29)-ene-2α-acetate-3β-ol and 7α,14-dihydroxy-8,13-abieta-diene-11,12-dione, exhibited antibacterial activity against Enterococcus faecalis with MIC 50 μM. Microstegiol was also active against Staphylococcus aureus with MIC 50 μM. Ursolic acid, oleanolic acid and ferruginol showed appreciable antibacterial activity against three Gram-positive bacteria, Staphylococcus aureus, Enterococcus faecalis, and Bacillus cereus with MIC 12.5-50 μM. The other diterpenoids were active against all three Gram-positive bacteria with MIC 100-200 μM. None of crude fractions was active against three Gram-negative bacteria, Klebsiella pneumoniae, Proteus vulgaris, and Escherichia coli.

La vigne (Vitis vinifera) est sensible à un grand nombre de maladies. Les politiques de limitation des traitements phytosanitaires font qu'aujourd'hui, les viticulteurs ne disposent d'aucun moyen de lutte contre certains bioagresseurs. C'est le cas des maladies du bois causées par des complexes fongiques nécrosant les ceps et du court noué, maladie virale transmise par des nématodes. La vigne est une espèce végétale connue pour sa production particulière de métabolites secondaires en réponse à des infections. Dans le cadre de cette thèse, nous nous sommes intéressés aux phytoanticipines, préformées dans les plantes et dont le potentiel de toxicité envers des agents pathogènes est intéressant, c’est le cas des triterpénoïdes. Les objectifs de cette thèse ont donc été dans un premier temps d'estimer la capacité de la vigne à produire de tels composés. Pour cela, la composition en triterpénoïdes de différents organes et de différents cépages a été analysée. Nous avons pu montrer que la composition générale en triterpénoïdes est caractéristique de chaque cépage et de chaque organe. Dans une deuxième partie, 9 gènes impliqués dans la synthèse de triterpènes chez la vigne ont été identifiés et leur expression a été évaluée dans différents organes, chez différents cépages et sous différentes conditions de stress biotique et abiotique. Cette étude exploratoire nous donne des pistes pour mettre en corrélation l'expression de certaines triterpène synthases avec la production différentielle de certains triterpènes à la surface des feuilles de différents cépages. Enfin, nous nous sommes intéressés aux triterpènes glycosylés, les saponines, afin d'évaluer leur potentiel dans la lutte contre certaines maladies majeures de la vigne pour lesquelles aucun traitement n'est actuellement disponible. Pour cela, l'efficacité de saponines issues de la gypsophile et du quillaja a été testée contre certains champignons associés aux maladies du bois ainsi que contre les nématodes vecteurs des virus du court noué. Nous avons pu mettre en évidence que les souches de champignons testées étaient capables de contourner la toxicité des saponines, tandis qu'un tel traitement était rapidement efficace pour lutter contre les nématodes. Afin de vérifier l'innocuité de ce traitement pour l'environnement, les doses efficaces ont été testées et n'ont pas eu d'impact significatif sur différents bioindicateurs. / Vitis vinifera is susceptible to many pathogens. These past few years, treatment policies led to the withdrawal of many pesticides. Renee, no chemical treatments are available to treat some grapevine diseases such as the grapevine trunk diseases caused by fungi complexes and the grapevine fanleaf degeneration, a viral disease transmitted from grapevine to grapevine by vector nematodes. Grapevine is known for the production of secondary metabolites as a response to pathogen infections. In this work, we focused on phytoanticipins such as triterpenoids, that are found as preformed compounds and that confer a basal resistance level to plants. First, a chemical analysis was made on the triterpenoid composition of some grapevine cultivars and organs. This study revealed that the triterpenoid composition is specific to the V. vinifera cultivar and the organ. In a genomic approach, 9 candidate genes involved in the triterpene biosynthesis were identified and their expression was studied in different organs, varieties and biotic or abiotic stress conditions. This explorative study shows correlations between gene expression and differential triterpene production at the leaf surface of the different varieties. In the last part of this study, the use of glycosylated triterpenes, also called saponins, as a substitution solution to withdrawed treattnents against major grapevine diseases was tested. Therefore, the efficiency of saponins extracted from gypsophila and quillaja was tested against fungi associated to grapevine trunk diseases and some nematodes vector of the grapevine fanleaf degeneration. These tests evidenced that the fungi were able to avoid saponins toxicity, whereas such treatment was efficient to kill nematodes. In order to evaluate the effect of the treatment on the environment, the efficient doses were tested and bad no significant impact on some bioindicators.

Analysis of cuticular wax from Kalanchoe daigremontiana leaves was performed to identify the constituent components within the wax, determine how these changed during leaf ontogenesis, and discover how they were distributed within the cuticle. Analysis of extracted cuticular wax by gas chromatography, mass spectrometry, and comparison with authentic standards led to the identification of triterpenoids including glutinol, friedelin, germanicol, epifriedelanol, glutinol acetate and β-amyrin as well as very long chain fatty acid (VLCFA) derivatives including alkanes, primary alcohols, aldehydes, fatty acids, and alkyl esters. Cuticular wax composition in young K. daigremontiana leaves was dominated by triterpenoids, which made up over 70% of the lipid soluble compounds. During leaf ontogenesis, wax composition changed to include a higher proportion of VLCFA derivatives, which made up approximately 50% of cuticular wax in mature leaves. The most abundant triterpenoids in the wax were glutinol and friedelin, both fairly uncommon pentacyclic triterpenoids with a complex proposed biosynthetic mechanism. Tritriacontane (C33 alkane) was the most abundant compound within the VLCFA derivatives. Cuticular wax accumulation was found to correspond well to leaf growth, with both processes slowing at the same time. Variations in the ratio of friedelin-like compounds to glutinol-like compounds during leaf ontogenesis suggest the presence more than one active triterpenoid synthase enzyme in the leaves of K. daigremontiana. VLCFA compounds were found mainly in the epicuticular wax on both the adaxial and abaxial surfaces, while triterpenoids were relatively more abundant in the intracuticular layer. Two different epicuticular wax crystal forms were observed by scanning electron microscopy (SEM) which can be described as platelets with sinuate margins and twisted ribbons. Based on SEM and chemical data as well as previous reports of crystal composition, it is hypothesized that each crystal type has a unique composition, with the platelets containing one or more triterpenoids and the twisted ribbons containing alkanes and other VLCFA derivatives. Confirmation of this hypothesis will have to await further investigation. This research provides information that will aid in the larger goals of characterizing a glutinol or friedelin synthase and understanding the gradients established within epicuticular and intracuticular wax layers.