Browsing by Author "Gammon, David W"
Now showing 1 - 20 of 22
Results Per Page
Sort Options
- ItemOpen AccessBioassay-guided fractionation of Artemisia afra for in vitro antimalarial activity against Plasmodium falciparum(1997) Abrahams, Meryl Arlene; Folb, Peter I; Gammon, David WWith the increase in recent years in the prevalence of malaria, and in drug resistance of Plasmodium falciparum, there has been much interest in natural plant products for new antimalarials with novel modes of action against Plasmodium. Artemisinin or Qinghaosu is one such antimalarial isolated from a Chinese herb, Anemisia annua (Asteraceae) and it is currently undergoing phase I and II clinical trials. The Southern African species, Artemisia afra (African wormwood, wildeals, lengana) is commonly used by local traditional healers for symptoms of malaria, in particular fever. Thus it seemed appropriate to investigate this species for antimalarial activity. Crude petroleum ether soxhlet extracts of Anemisia afra had demonstrated antimalarial activity against Plasmodium falciparum, FCR-3, cultured in vitro. The IC₅₀ values ranged from 5-13μg/ml. The extract from leaves and flowers was then screened against D10 (chloroquine-sensitive) and FAC8 (chloroquineresistant) P. falciparum, in vitro, with IC₅₀ values of 1.03μg/ml and l.5μg/ml respectively. This extract was fractionated by column chromatography using silica gel-60 and the fractions obtained were screened for antimalarial activity. The most active fraction had an IC₅₀ of 0.5μg/ml against D10 and FAC8. Using TLC and HPLC-UV analysis with pure artemisinin as a standard, no artemisinin could be detected in this fraction. This result was confirmed by thermospray LC-MS analyses. Purification of this fraction yielded ultimately a single pure compound; a clear colourless oil identified by MS and NMR analyses as hydroxydavanone. The compound was screened against a variety of P. falciparum strains with varying degrees of sensitivity and resistance to both chloroquine and mefloquine. Their sensitivity against artemisinin was also established. IC₅₀ values obtained for the isolated pure compound against P. falciparum ranged from 0.87 to 2.54μg/ml. The IC₅₀ values obtained for general cytotoxicity of the crude extract and isolated pure compound against RAT-I fibroblast cells were 34.78 ± 8.23 and 6.29 ± 0.95 μg/ml (n=4) respectively. Thus the crude extract and isolated pure compound exhibited a greater antimalarial than cytotoxic effect. Hence, there are implications for A. afra to be used as a phytomedicine for the treatment of malaria. In vivo studies are recommended for hydroxydavanone in order to fully assess its potential for clinical use.
- ItemOpen AccessCharacterization of a unique sulfoxide synthase found in pathogenic trypanosomes(2013) Mashabela, Gabriel Tshwahla Makgotloduwa; Steenkamp, D J; Gammon, David WIncludes abstract. Includes bibliographical references.
- ItemOpen AccessChemical and conformational studies of bacterial cell surface polysaccharide repeating units(2017) Timol, Zaheer; Ravenscroft, Neil Kuttel, Michelle Mary; Gammon, David WAbstract Bacterial cell surface polysaccharides are primarily present as lipopolysaccharides or capsular polysaccharides. They are used by cells for both structure and function and have been shown to be a virulence factor of bacterial pathogens. Cell surface polysaccharides are widely utilised as antigenic components in vaccines and play an important role in the protection against numerous diseases including meningococcal disease and shigellosis. This study is composed of two parts: a computational section, which investigates the capsular polysaccharide (CPS) repeating unit (RU) conformations of meningococcal Y and W CPS vaccines and a second experimental component that involves synthetic studies toward the O-specific polysaccharide (O-SP) RU of Shigella sonnei. The CPS RU of MenY [→6)-α-D-Glc(1→4)-α-D-NeuNAc-(2→] and MenW [→6)-α-D-Gal(1→4)-α-D-NeuNAc-(2→] differ only in the orientation of the C-4 hydroxyl: equatorial in MenY and axial in MenW. However, groups Y and W CPS vaccines have different levels of antibody cross-protection. The purpose of the computational study was to determine if these observed differences may be attributed to CPS RU conformation. Potential of mean force calculations were applied to disaccharide RUs of MenY and MenW, and larger three repeating units (3RU) were simulated with molecular dynamics (MD) in solution. The molecular modelling showed that differences in RU conformation between the meningococcal groups arise primarily due to the structural differences between glucose and galactose; affecting the behaviour and orientation of the 2→6 dihedral linkage. The 2→6 linkages in the MenY 3RU adopt a single preferred orientation and consequently it has a single dominant molecular conformation. In contrast, the 2→6 linkages in the MenW 3RU move frequently between different rotameric conformations resulting in multiple conformational families. These results indicate significant conformational differences between the MenY and MenW CPS RUs, which may account for the different levels of cross-protection observed. The synthetic component was part of a larger study to develop a novel route towards the O-SP RU of S. sonnei for use in biological testing and physicochemical characterisation for vaccine development. The O-SP RU of S. sonnei is →4-α-L-AltNAc-(1→3)-β-D-FucNAc4N(1→. The multi-step synthesis was performed using known methodology as well as methods developed by the research group. The key 2,3-oxazolidinone protected intermediate was successfully synthesised in good yields and due to time constraints the final product synthesised was two steps away from the protected FucNAc4N residue. Additional studies were performed on the 2,3-oxazolidinone intermediate as part of a divergent synthesis strategy toward the AltNAcA residue of S. sonnei. Reactions were conducted whereby β and α derivatives of the 2,3-oxazolidinone intermediate were successfully synthesised in large scale and good yields for further studies to be performed by the group. i
- ItemOpen AccessDesign and synthesis of potential inhibitors of enzymes involved in the biosynthesis and utilisation of mycothiol(2012) Watermeyer, Nicholas D; Gammon, David W; Steenkamp, DanielThis thesis describes the synthesis of several naphthoquinone- and carbazole-1,4-quinone-derived conjugates of a mycothiol-like scaffold designed to act as redox cycling subversive substrates of the enzyme, Mtr, or potentially inhibit other mycothiol-dependent or biosynthetic enzymes, in order to develop novel antitubercular lead compounds. The expression and purification of Mtr, as well as the attempts made towards the cloning and expression of active Mycobacterial glyoxalase I, in order to generate enzymes on which to assay the synthesised molecules, are also described. Linking of the quinone functionalities to the mycothiol-like scaffold, phenyl-1-thio-Dglucosamine, was envisaged to facilitate delivery of this class of redox active molecules to the active-site of the mycothiol enzymes. Successful completion of the synthesis of naphthoquinone conjugates of this scaffold was not achieved due to a persistent side reaction that took place during an N-tert-butoxycarbonyl deprotection step. However, this unexpected result led to the discovery of a new synthetic route to benzo[g]indoles and benzo[h]quinolines. This route differs from traditional quinoline and indole syntheses in that the aromatic C-N bond is generated by a condensation reaction between a quinone carbonyl and an aliphatic amine, rather than via the traditional condensation of an aromatic amine with a distal carbonyl group.
- ItemOpen AccessDetermination of a robust metabolic barcoding model for chemotaxonomy in Aizoaceae species : expanding morphological and genetic understanding(2016) Hilgart, Amelia; Gammon, David W; Farrant, Jill MThe use of metabolic fingerprints as taxonomic markers is becoming more common. Many studies have found that by comparing the vast metabolic fingerprints of closely related species to each other, secondary metabolites tend to be unique to the samples of individual species and are identified in clustering algorithms as the variables responsible for species-specific clustering. A holistic approach to metabolic fingerprinting was thus employed to assess the stability of various metabolomic markers and finally to distinguish taxonomically difficult Aizoaceae species. Many secondary metabolites are not constitutively produced. Because at least some Aizoaceae species facultatively use crassulacean acid metabolism (CAM), there was a potentially interesting molecular switch that could be monitored for transitions in metabolic fingerprints. In order to contextualise the changes in carbon uptake, 20 different climate, nutrient, physiological, and other variables were monitored over the course of 12 months to build up a store of species-specific information to use in model optimisation across 5 Aizoaceae species (Galenia africana, Aridaria noctiora, Carpobrotus edulis, Ruschia robusta, and Tetragonia fruticosa) using two Crassulaceae species as CAM controls (Cotyledon orbiculata and Tylecodon wallichii ). Metabolic fingerprints of the leaves of various Aizoaceae species were generated using LC/TOFMS, following which Principal Components Analysis (PCA) was used to identify the LC-MS ions which distinguished the species from each other, or in statistical terms, were informative. Once isolated, this subset of informative data was established as metabolic barcodes for the identification of the study species. A machine learning algorithm, Random Forest, was used to build a classification model based on the metabolic barcodes which was then trained on various trends from the factors monitored over the year. The use of these trends in the development of a classification model based on metabolic barcodes resulted in a highly robust classification model for species identification. Clustering analysis of a subset of ions which corresponded to compounds previously isolated from Aizoaceae species did not show species-specific clustering and was inevitably biased by compounds from species with a greater number of studies focusing on compound isolation. Ideally, this model should be expanded to include other species from the Aizoaceae family to further check robustness of the model. Application of this model to these and other species could facilitate not only species identification and distribution, but also the identification of novel chemical constructs associated with particular species.
- ItemOpen AccessDevelopment of an alternative synthesis of 2-acetamido-2-deoxy-L-altruronic acid: an unusual sugar found in the O-specific polysaccharide of Shigella sonnei(2017) Anderson, Kirstin P C; Gammon, David W; Ravenscroft, NeilA new synthetic route has been explored for the preparation of derivatives of 2-acetamido-2-deoxy-L-altruronic acid (L-AltNAcA). This is a rare sugar found together with 2-acetamido-4-amino-2,4-dideoxy-D-fucose(D-FucNAc4N) in the repeating unit of Shigella sonnei. Derivatives are needed inter alia for chemical and spectroscopic calibration standards, and as building blocks for preparing oligomeric subunits of the O-polysaccharide antigen for possible incorporation into a synthetic glycoconjugate vaccine. Two synthetic routes were investigated. The first route successfully repeated a published four step sequence converting diacetone-D-glucose to 1,6-anhydro--L-idopyranose in a 38% yield overall, and a further selective benzylation at O-3. Attempts to discriminate between O-2, O-3 and O-4 using low temperature acylation or alkylation conditions were unsuccessful, but modest selectivity for the 4-benzoate was observed in a Bu₂SnO-mediated benzoylation, although this product could not be easily separated from other mono-benzoates. The second route started from N-acetyl-D-glucosamine which was successfully converted in the first step to 2-methyl-(1,2-dideoxyl-5,6-O-isopropylidene-α-D-glucofurano)-[2,1-d]-2-oxazoline. The oxazoline and dioxolane units could be selectively manipulated in a series of steps to afford 2-acetamido-2-deoxy-3-O-benzyl-6-O-t-butyldimethylsilyl-α-D-glucofuranosyl acetate in a 41% yield over four steps. This is a key synthetic intermediate in which the 5-OH is available for the required inversion step. During this study, an unusual minor side-product, 1,6-anhydro-2-acetamido-O-acetyl-2-deoxy-3-O-benzyl-α-D-glucofuranose, was isolated. While this was also a potentially useful intermediate, having only the 5-OH unprotected, it proved not possible to find conditions for optimizing this product. Inversion of configuration at C-5 in the 6-O-silylated glucofuranose was attempted via the 5-O-triflate and 5-O-mesylate: the triflate formed but was displaced in situ by the solvent pyridine to give an unusual 5-pyridinium derivative, while the mesylate was stable but unreactive towards subsequent SN2 inversion. These outcomes were attributed to the steric congestion imposed by the combination of the 3,4-cis-disubstitution of the furanose ring and the very bulky silyl substituent at O-6. While the goal of preparing L-AltNAcA was not achieved via these approaches, useful insights have been contributed towards the ongoing study.
- ItemOpen AccessDevelopment of new methodologies for functionalizing glycals and 1,2-cyclopropanated sugars, and applications in the synthesis of inhibitors of enzymes in the Mycobacteria(2006) Kinfe, Henok Hadgu; Gammon, David WTuberculosis (TB) is a contagious respiratory disease caused by Mycobacterium tuberculosis. Due to lack of an efficient and short-term treatment of TB, the bacterium has become resistant to the first line antibiotics and the disease has ranked next to HIV/AIDS. A low molecular weight thiol called myctothiol protects the bacteria from many foreign stress factors and secures its survival. Studies have shown the mycothiol-deficient bacteria are hypersensitive to external stresses and hence inhibition of the biosynthesis of mycothiol could be a drug lead against TB.
- ItemOpen AccessThe development of S-glycosylcysteine derivatives for use in glycan-binding assays(2017) Williams, Matthew; Gammon, David WThis dissertation concerns the development of a synthetic route towards novel cysteine-based glycan-binding probes, for incorporation into glycoarrays and or similar applications used in assays of glycan-recognition phenomena. The need to systematically characterize the glycome and decipher the range of glycosylation patterns found in living cells, has prompted the development of molecular tools such as glycoarrays and related systems for immobilizing defined carbohydrate structures. The preparation of these probes requires access to building blocks where the core structure has defined glycans together with appropriate linkers, and the amino acid cysteine is explored here as one such structure. In particular, this dissertation describes the synthesis of a S-glucosylcysteine derivative SGC, or methyl N-(6-aminohexanoyl)-S-(β-D-glucopyranosyl)-L-cysteinate trifluoroacetate 67, as well as its 2-acetamido analogue SAGC, or methyl N-(6-aminohexanoyl)-S-(2-acetamido-2-deoxy-β-D-glucopyranosyl)-L-cysteinate trifluoroacetate 74. The first approach involved initial preparation of N-(4-azidobutanoyl)-L-cysteine 12 and attempted reaction of this with 1,2,3,4,6-penta-O-acetyl-β-D-glucopyranose 3 to form the initial target of this dissertation, bis-glucoside 13. This was not successful, but repetition of the reported reaction involving the use of N-acetyl-L-cysteine 4 provided a modest yield of partially purified bis-glucosyl cysteine (BGC, 1). A mechanism for this one-pot, sequential bis-glucosylation is proposed. The limitations of the one-pot procedure led to investigation of alternative methods for the step-wise introduction of sugar units to the cysteine core. For this purpose the cysteine derivative, methyl N-(6-((tert-butoxycarbonyl)amino)hexanoyl)-L-cysteinate 40, was prepared and reacted with 3 to obtain a fully protected precursor of the target SGC. However, inefficiencies in this procedure led to investigation of an alternative strategy for preparation of SGC.
- ItemOpen AccessAn ethnobotanical, phytochemical and metabolomics investigstion of plants from the Paulshoek Communal Area, Namaqualand(2014) Wheat, Nicola M; Gammon, David W; Hoffman, Timm; Chibale, KellyThe aim of this thesis is to investigate medicinal plants from different perspectives in an attempt to arrive at a new, integrated and streamlined method for the discovery of bioactive secondary metabolites of plant origin. This will be done through a focused study of the traditionally used medicinal plants of the Paulshoek region of Namaqualand and a demographic study of the people who use them. Trends in traditional medicinal plant choice will be investigated and methods of traditional knowledge acquisition and transfer will be examined. Additional assessment of bioactivity and trends in bioactivity will be conducted and a variety of physico-chemical and computational techniques will be used to determine the major metabolites present in selected plant species. These different approaches to medicinal plants will be brought together in a single holistic method put forward as a possible way of conducting future studies into discovering active metabolites for potential drug development.
- ItemOpen AccessIdentification of Antimycobacterial Natural Products from a Library of Marine Invertebrate Extracts(2022-01-28) Acquah, Kojo Sekyi; Beukes, Denzil R; Seldon, Ronnett; Jordaan, Audrey; Sunassee, Suthananda N; Warner, Digby F; Gammon, David WTuberculosis (TB) remains a public health crisis, requiring the urgent identification of new anti-mycobacterial drugs. We screened several organic and aqueous marine invertebrate extracts for their in vitro inhibitory activity against the causative organism, Mycobacterium tuberculosis. Here, we report the results obtained for 54 marine invertebrate extracts. The chemical components of two of the extracts were dereplicated, using 1H NMR and HR-LCMS with GNPS molecular networking, and these extracts were further subjected to an activity-guided isolation process to purify the bioactive components. Hyrtios reticulatus yielded heteronemin 1 and Jaspis splendens was found to produce the bengamide class of compounds, of which bengamides P 2 and Q 3 were isolated, while a new derivative, bengamide S 5, was putatively identified and its structure predicted, based on the similarity of its MS/MS fragmentation pattern to those of other bengamides. The isolated bioactive metabolites and semi-pure fractions exhibited M. tuberculosis growth inhibitory activity, in the range
- ItemOpen AccessMycothiol disulfide reductase as a drug target(2010) Mavumengwana, Vuyo Bhongolethu; Steenkamp, D J; Gammon, David WIncludes abstract. Includes bibliographical references (leaves 154-171).
- ItemOpen AccessNew synthetic routes to functionalized 2-C-alkylglucosides, precursors of potential inhibitors of mycothiol biosynthesis in the Mycobacteria(2011) Muganza, Freddy Munyololo; Gammon, David WThis thesis was concerned with the design and synthesis of compounds which are either substrate-mimics or inhibitors of MshB, a N-deacetylase involved in the biosynthesis of mycothiol in the Mycobacteria, including M. tuberculosis, the causative agent of TB. Mycothiol is a low molecular weight thiol produced by Mycobacteria as a defense against oxidative stress and xenobiotics, and the enzymes involved in its biosynthesis are postulated to be viable drug targets.
- ItemOpen AccessPharmacognostic study of 5 medicinal plant species from Western Cape Province (South Africa) for anti-tubercular activity(2006) Bamuamba, Kapinga Benoit; Meyers, Paul; Gammon, David W; Franca, Marie-Geneviève DijouxIn our search for new anti-tuberculosis lead molecules, five medicinal plant species, Olea capensis (L.l, Tulbaghia alliacea (L.), Inula graveolens (L.), Leyssera gnaphaloides (L.), and Buddleja saligna (L.) were collected in Cape Town and surrounding area and investigated for antimycobacterial activity following report of their therapeutic use in traditional medicine to treat infectious diseases such as tuberculosis. A bioassay guided fractionation of the acetone/water (4:1) crude extracts of O. capensis (leaves) and T. alliacea (rhizomes) showed no activity against Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 252923, and Mycobacterium aurum A+. In contrast, the orgamc fractions (hexane, dichloromethane) of the acetone/water (4: 1) crude extracts of 1. graveolens, L. gnaphaloides, and B. saligna exhibited significant activity against M. tuberculosis H37Rv, M. avium 25291, M. microti ATCC 19422, and M. scrofulaceum ATCC 19987. The isolation and structure determination of the bioactive led to the identification of pentacyclic triterpenoids, ursolic acid (UA) and oleanolic acid as major antitubercular constituents of B. saligna, L. gnaphaloides, and 1. graveolens. The in vitro cytotoxicity assays of the isolated bioactive constituents showed no cytotoxicity against Chinese Hamster Ovarian (CHO) cells line. Subsequently, given the pharmaceutical value of the above finding, a survey on structure activity of pentacyclic triterpenoids was conducted. It was was found, for instance that selective substitutions at C-3 and/or C-28 and the double bond at UA, OA and betulinic and (1) BA) were made in order to improve anti-tumour and anti-HIV activity. However, thought a great number of modified bioactive pentacyclic triterpenoids is reported, none was tested against Mtb. Therefore, this study also explored a new synthetic route (scheme 1) toward a generation of (5), which may allow improving antitubercular, anti-HIV or anti-tumour activity, and/or specificity.
- ItemOpen AccessPhytochemical studies on traditional medicinal plants with antimalarial activities(1997) Chen, Dianne Tzu-Hsiu; Gammon, David W; Campbell, William EThe active antimalarial principles of three traditional medicinal plants, Passerina obtusifolia (Thymelaeaceae), Tetradenia riparia (Labiatea) and Xerophyta retinervis (V elloziaceae) were investigated by employing bioassay guided fractionation. Two novel compounds and five known constituents were isolated from the active fractions of these three plants. The types of compounds isolated included: three triterpenoids (20(29)-Lupene-3α,28- diol (30), 20(29)-Lupene-3α, 16β,28-triol (32) and 3β-Hydroxy-20(29)-Lupen-28-oic acid (42)); two diterpenoids (8-Abietene-7 β,13 β -diol (45) and cariocal (51)); one flavonoid ( 5-Hydroxy:.4' ,6, 7-trimethoxyflavone ( 44)) and one flavonolignan ( 11-0- acetyl hydnocarpin (62)). In addition, one analogue of 7α-hydroxyroyleanone (41) (which was previously isolated from T riparia and was found to be the active antimalarial principle of the plant) was prepared.
- ItemOpen AccessProgress in the synthesis of stabilized glycoconjugate vaccine candidates against Neisseria meningitides group A(2003) Kinfe, Henok Hadgu; Gammon, David W; Ravenscroft, NeilMeningitis is the inflammation of the lining membranes of human brains and spinal cord. It is a deadly disease that has claimed millions of lives throughout the world in particular in developing countries. Neisseria meningitidis serogroup A is among the leading causative agents of meningitis in Sub-Saharan Africa. Its capsular polysaccharide antigen consists of a homopolymer of a-(1
- ItemOpen AccessReplacement of homogeneous acids in the conversion of meta-phenylenediamine to resorcinol by Heterogeneous Analogues(2001) Brack, Bryan; Van Steen, Eric; Gammon, David WResorcinol is an important building block in the pharmaceutical, adhesion and dye industry. A number of different processes for the production of resorcinol are available with each synthesis route having intrinsic advantages and disadvantages that differ from one process to another. A viable route to resourcinol in South Africa is via meta-dinitrobenzene due to the large-scale production of nitrobenzene from benzene. Since meta-dintrobenzene is formed as a side-product during the production of nitrobenzene and is hydrogenated quite easily, the acid hydrolysis of MPDA to resorcinol will be considered during this investigation.
- ItemOpen AccessSEAmester – South Africa’s first class afloat(2016) Dorrington, Rosemary A; Fawcett, Sarah; Gammon, David W; Henry, Tahlia; Hermes, Juliet; Hölscher, Beate; d’Hotman, Jethan; Meiklejohn, Ian; Morris, Tammy; Pinto, Izidine; du Plessis, Marcel; Roman, Raymond; Saunders, Clinton; Shabangu, Fannie W; de Vos, Marc; Walker, David R; Louw, GavinThe International Society for Burns Injuries (ISBI) has published guidelines for the management of multiple or mass burns casualties, and recommends that 'each country has or should have a disaster planning system that addresses its own particular needs.' The need for a national burns disaster plan integrated with national and provincial disaster planning was discussed at the South African Burns Society Congress in 2009, but there was no real involvement in the disaster planning prior to the 2010 World Cup; the country would have been poorly prepared had there been a burns disaster during the event. This article identifies some of the lessons learnt and strategies derived from major burns disasters and burns disaster planning from other regions. Members of the South African Burns Society are undertaking an audit of burns care in South Africa to investigate the feasibility of a national burns disaster plan. This audit (which is still under way) also aims to identify weaknesses of burns care in South Africa and implement improvements where necessary.
- ItemOpen AccessStereoselective synthesis 2-C-alkylglucosides, potential inhibitors of mycobacterial MshB and related enzymes(2010) Muhunga, Denis Ngumbu; Gammon, David WTuberculosis (TB) is one of the world's most deadly diseases and kills approximately 1.7 million people each year. The developing resistance of TB to the two most common anti-TB drugs (isoniazid and rifampicin) proves the urgency of the current situation. The MshB reducing agent exclusively in the actinomycetes is used as a model for the development of new anti-TB drugs. It was shown that the stereoselectivity synthesis of C-2 alkyl glucoside gave a key intermediate for the suitable synthesis of glycosyl donors. In addition, we achieved the preparation of D-inositol derivative chirally pure and having the hydroxyl at the 1-position. However, the attempted glycosylation reaction failed to give the desired product.
- ItemOpen AccessThe study of aldol condensation of ketones using zoelites as catalysts(2001) Motsoetsoe, Phalali; Gammon, David W; Van Steen, EricIn this investigation, zeolites HZSM-5 (Si/Al: 22), HZSM-5 (Si/A: 45), H-Beta and H-USY were evaluated as catalysts for aldol condensation reactions of acetone and cyclohexanone and the results compared with those using H₂SO₄. Cross-aldol condensation reactions of acetone and benzaldehyde were also performed.
- ItemOpen AccessSynthesis of analogues of mycothiol as possible inhibitors of enzymes in the biosynthesis of mycothiol(2003) Mudzunga, Theophilus Thivhulawi; Gammon, David WMycobacterium tuberculosis is the causative agent of tuberculosis and is a leading pathogenic cause of death worldwide. The rise of mycobacterial resistance to common antituberculars such as isoniazid and rifampicin, along with the lethal alliance of HIV and M. tuberculosis co-infection, has led to interest in developing novel, effective, non-toxic antituberculosis agents.