John Bremner

• BSc(Hons), PhD, Dip.Chem. Pharmacol.
• Professor Emeritus at University of Wollongong

The reaction of indigo with two equivalents of the electrophile ethyl bromoacetate with caesium carbonate as a base result in the formation of structurally complex polyheterocyclics, including a fused spiroimidazole and a spiro[1,3]oxazino derivative, together with a biindigoid-type derivative, through a convenient one-pot reaction. Further assessm...

Montra Chairat1,2,Email Phattaraporn Thongsamai1 Thamonwan Meephun1 Suwijak Pantanit1 Siritron Samosorn3 Warayuth Sajomsang4 Pattarapond Gonil4 John B Bremner5

Many approaches are being pursued to address the major global health challenge posed by the increasing resistance of pathogenic bacteria to antibacterial agents. One of the promising approaches being investigated includes the design and development of multiple action-based small-molecule antibacterials. Aspects of this broad area have been reviewed...

As part of a project on fused medium-sized ring systems as potential drugs, we have previously demonstrated the usefulness of Density Functional Theory (DFT) to evaluate amine nitrogen-based transannular interactions across the central 10-membered ring in the bioactive dibenzazecine alkaloid, protopine. A range of related hypothetical systems have...

In a continuation of the exploration of indigo cascade reactions, a series of -OMe, -Ph, -Br and -NO2 substituted indigos 1a-i were synthesised to probe electronic effects upon the outcome of allylation cascade reactions. When indigos 1a-i in the presence of base were reacted with allyl bromide, spiroindolinepyridoindolones 17-25 (36-75%) were obta...

Cationic liposomal formulations of the telomeric G-quadruplex stabilizing ligand, 13-(2-naphthylmethoxy)berberine bromide (1), have been developed with the purpose of delivering 1 into the nucleus of cancer cells for potential telomere targeting. Berberine derivative 1 was encapsulated in various cationic lipids 2-4 by the thin film evaporation met...

Polydopamine/Ag (PDA/Ag) nanoparticles were synthesized for methylene blue (MB) removal from aqueous solution as a model dye. These particles were prepared in a modified literature procedure in which polydopamine (PDA) nanoparticles were first prepared via the oxidative polymerization of dopamine (DA) under alkaline conditions in the presence of ox...

Transannular interactions involving a nitrogen and groups Y in ten-membered rings based on the alkaloid protopine were studied by DFT methodology to investigate the potential mimicking of shapes and electrostatic potentials and thus biological activities of fused berberine and related analogues. The methodology was confirmed for protopine (Y=CO) an...

The use of natural dyes for the dyeing of naturally-derived fibres is of economic and cultural importance in many countries and there is thus ongoing research interest in this area. In the current work, the dyeing of eri silk yarn with lac dye was investigated, with both components being accessed in Thailand. While some qualitative studies of this...

There are many possibilities for the future design of new multi-targeted antibacterials based on developing knowledge of synergistic combinations and new modes of action being discovered. This final chapter includes a comparative assessment of the combination, hybrid and prodrug approaches, together with a discussion of the potential for using new...

Added layers of complexity in design are inherent with multi-action agents released from prodrugs, and though challenging, such prodrugs do offer potential advantages over the non-cleavable multi-action hybrids. In particular the pro-moiety of the prodrug can be designed to increase solubility and permeability while the prodrug itself can enable ef...

Multiply active non-cleavable antibacterials constitute a complex molecular design area. The emphasis in this chapter is on design parameters for small molecule triple or higher action single agents based on background information from drug combinations and dual action hybrids. Established multiple action agents or multi-targetingMulti-targeting of...

This chapter sets the basic perspectives for the other chapters in the book. In this context, aspects discussed include the ever-rising global health problem from drug resistant pathogenic bacteria, a basic review of bacterial resistance mechanisms, and the need for innovative solutions to overcome resistance to antibacterials. General ways to achi...

There has been much activity in the area of multiple drug combinations in treating various diseases including bacterially mediated ones. Work in the field is continuing and in this chapter design principles for combinations of separate drugs aimed at more than two types of antibacterial activity or associated activity which contributes to increased...

The synthesis of structurally diverse heterocycles for chemical space exploration was achieved via the cascade reactions of indigo with propargylic electrophiles. New pyrazinodiindolodione, naphthyridinedione, azepinodiindolone, oxazinoindolone and pyrrolodione products were prepared in one pot reactions by varying the leaving group (‐Cl, ‐Br, ‐OMs...

This book covers intentional design aspects for combinations of drugs, single-molecule hybrids with potential or actual multiple actions, pro-drugs which could yield multiple activity outcomes, and future possibilities. The approach of the book is interdisciplinary, and it provides greater understanding of the complex interplay of factors involved...

One‐pot domino reactions of indigo with propargyl derivatives produce structurally diverse heterocycles including new pyrazinodiindolodiones, azepinodiindolones, and oxazinoindolones. Mechanistic and DFT studies show propargyl moieties behaving as electrophiles when terminally substituted, thereby competing with leaving groups. Photophysical proper...

Background: Drug resistance and chemotherapy-induced peripheral neuropathy continue to be significant problems in the successful treatment of acute lymphoblastic leukemia (ALL). 5,7-Dibromo-N-alkylisatins, a class of potent microtubule destabilizers, are a promising alternative to traditionally used antimitotics with previous demonstrated efficacy...

The nucleophilic addition of organomagnesium and organolithium species to the cheap and robust natural dye indigo led to desymmetrisation of the heterocyclic nucleus via a Grignard addition-dehydration procedure. Twenty-seven diversely-functionalised [1H,3ꞌH]-3-substituted-2,2ꞌ-diindol-3ꞌ-ones were synthesised by this methodology, with several show...

A new, weakly antibacterial indole alkaloid, named lombine, together with the known alkaloid voacangine, have been isolated from the bark of Voacanga foetida (Bl.) Rolfe (Apocynaceae), a plant used on Lombok Indonesia, for medicinal purposes. A combined chemo- and bio-rational strategy was developed to target this plant for investigation. Lombine w...

The coating of silk yarn with microcrystalline chitosan (MCCh) was carried out using the ultrasonic‐assisted method at a pulsed wave frequency of 80 kHz, which only had a slight impact on the yarn as measured by changes in Young's modulus and percentage of elongation compared with untreated silk. A significant enhancement of lac dye uptake onto MCC...

One of the problems occasionally associated with the use of natural dyes in the dyeing of silk is the susceptibility of the dyed yarn to fading in light. While a number of approaches have been used to address this problem, the use of polydopamine (PDA), a known agent with photo‐protective properties, has not been assessed previously. In this study,...

The base-initiated alkylation of the abundant natural dye indigo 1 with ring-strained electrophiles results in the unprecedented, one-pot synthesis of functionalised dihydropyrazino[1,2-a:4,3-a']diindoles, dihydroepoxy[1,5]oxazocino[5,4-a:3,2-b']diindoles, and dihydrodiazepino[1,2-a:4,3-a']diindoles, resulting from intramolecular ring opening-expan...

Resistance of bacteria to antibiotics is a public health concern worldwide due to the increasing failure of standard antibiotic therapies. Antimicrobial photodynamic inactivation (aPDI) is a promising non-antibiotic alternative for treating localized bacterial infections that uses non-toxic photosensitizers and harmless visible light to produce rea...

As of mid-2017, only one structure of the human immunodeficiency virus (HIV) integrase core domain co-crystallised with an active site inhibitor was reported. In this structure (1QS4), integrase is complexed with a diketo-acid based strand-transfer inhibitor (INSTI). This structure has been a preferred platform for the structure-based design of INS...

Antimicrobial photodynamic inactivation (aPDI) uses photosensitizers (PSs) and harmless visible light to generate reactive oxygen species (ROS) and kill microbes. Multidrug efflux systems can moderate the phototoxic effects of PSs by expelling the compounds from cells. We hypothesized that increasing intracellular concentrations of PSs by inhibitin...

2-Aryl isatogens and their 3-imino derivatives have been extensively studied but to date there have been no reported variants carrying pyrrolyl substituents at the 2-position. This study describes the unexpected synthesis of two novel 3-imino-2-(pyrrol-2-yl) isatogen derivatives upon attempted amide couplings with (E)- or (Z)-3-(3,5-dimethyl-1H-pyr...

The hypothesis that the dried, ground biomass of the red marine alga Gracilaria tenuistipitata could be used for the efficient removal of lac dye from aqueous solution was assessed in this work. The effects of parameters such as initial pH, biosorbent dosage, contact time, initial dye concentration, and temperature on the biosorption capacity of th...

From library screening of synthetic antimicrobial peptides, an O-allyltyrosine-based tripeptide was identified to possess inhibitory activity against HIV-1 integrase (IN) exhibiting an IC50 value of 17.5 μM in a combination 3'-processing and strand transfer microtitre plate assay. The tripeptide was subjected to structure-activity relationship (SAR...

Thirty two new binaphthyl-based, functionalized oxazole and thiazole peptidomimetics and over thirty five novel leucine-containing intermediate oxazoles and thiazoles were prepared in this study. This includes the first examples of the direct C-5 arylation of an amino acid dipeptide-derived oxazole. Moderate to excellent antibacterial activity was...

Flavonoid constituents from the aqueous extract of the stems of Combretum latifolium Blume sourced in Thailand have potential use as dyestuffs for cotton dyeing. In an effort to improve current natural dyeing methods with this extract, further aspects of the process were studied. It was found that, before equilibrium was reached, an increase in tem...

The allylation of indirubin produced the expected indolic N′-allylindirubin and N,N′-diallylindirubin derivatives in moderate yields, together with the corresponding N-substituted isatin products. At higher temperatures, the base-initiated reaction with allylic halides yielded spiroindolinepyrido[1,2-a]indolediones in a one-pot cascade reaction seq...

Diversity-directed synthesis based on the cascade allylation chemistry of indigo, with its embedded 2,2'-diindolic core, has resulted in rapid access to new examples of the hydroxy-8a,13-dihydroazepino[1,2-a:3,4-b']diindol-14(8H)-one skeleton in up to 51% yield. Additionally a derivative of the novel bridged heterocycle 7,8-dihydro-6H-6,8a-epoxyaze...

Using a common 1-(1-phenylethenyl)-1,2,3,4-tetrahydroisoquinoline precursor to the required ylide or N-oxide intermediate, the Stevens [2,3] and analogous Meisenheimer [2,3] sigmatropic rearrangements have been applied to afford concise syntheses of phenyl -substituted representatives of each of the reduced 1H-3-benzazonine and 4,3-benzoxazonine sy...

Berberine–INF55 hybrids are a promising class of antibacterials that combine berberine and the NorA multidrug resistance pump inhibitor INF55 (5-nitro-2-phenylindole) together in one molecule via a chemically stable linkage. Previous studies demonstrated the potential of these compounds for countering efflux-mediated antibacterial drug resistance b...

Concise synthetic routes to 2H-benzo[b]thieno[3,2-b][1,5]oxazocin-6(3H)-one, and the new benzo[b]thieno[3,2-b][1,5]oxazonin-7(2H)-one and 2H-benzo[b]thieno[3,2-b][1,5]oxazecin-8(3H)-one systems, have been developed based on intramolecular nucleophilic displacement in the key ring forming step.

Current antibiotics for treating Clostridium difficile infections (CDI), that is, metronidazole, vancomycin and more recently fidaxomicin, are mostly effective but treatment failure and disease relapse remain as significant clinical problems. The shortcomings of these agents are attributed to their low selectivity for C. difficile over normal gut m...

The base-induced propargylation of the dye indigo results in the rapid and unprecedented one-pot synthesis of highly functionalized representatives of the pyrazino[1,2-a:4,3-a']diindole, pyrido[1,2-a:3,4-b']diindole and benzo[b]indolo[1,2-h]naphthyridine heterocyclic systems, with the last two reflecting the core skeleton of the anticancer/antiplas...

The present invention relates to compositions comprising 5-fluorouracil, or a pharmaceutically acceptable salt or analogue thereof, folinic acid, or a pharmaceutically acceptable salt thereof and a cyclodextrin, or a pharmaceutically acceptable salt or derivative thereof. The invention also relates to methods for the treatment of cancer using such...

To further expand the structure–cytotoxic activity relationships of isatin derivatives and to reduce flexibility in substituent groups at nitrogen, 20 analogues incorporating a ring system between the N1 and C7 atoms of isatin were prepared using a variety of synthetic strategies. This yielded pyrroloindole-, pyrroloquinoline-, pyrroloacridine-, py...

The facile synthesis of seven new dicationic tripeptide benzyl ester derivatives, with hydrophobic group variations in the C-terminal amino acid component, is described. Moderate to good activity was seen against Gram-positive bacteria in vitro. One cyclohexyl-substituted compound 2c was tested more widely and showed good potency (MIC values rangin...

In the course of studies on hybrid antibacterials incorporating 2-aryl-5-nitro-1H-indole moieties as potential bacterial NorA efflux pump inhibitors, the compound 1-[2-(5-nitro-1H-indol-2-yl)phenyl]methylpyridinium chloride (2) was synthesized and structurally characterized. This pyridinium chloride salt crystallized in the monoclinic space group P...

Tumor-specific delivery of ligand-directed prodrugs can increase the therapeutic window of chemotherapeutics by maintaining efficacy whilst decreasing toxic side effects. We have previously described a series of synthetic N-alkylated isatin cytotoxins that destabilize microtubules and induce apoptosis with 10-fold greater potency than conventional...

The compact synthesis of a new ring fused benzo[b]thieno derivative with an embedded nine-membered ring system via ring closing metathesis methodology is described. The preparation of the novel 11H-benzo[b]thieno[2,3-c]pyrrolo[2,3-a]indol-11-one via palladium-mediated oxidative cyclisation of benzo[b]thien-2-oyl indole derivatives is also reported.

Flavonoid constituents from the aqueous extract of the leaves of Eupatorium odoratum, an invasive weed in Thailand, have potential use as dyestuffs for cotton dyeing. It was found that cotton yarn, which was pretreated with a chitosan solution (with and without a crosslinking glyoxal solution), followed by dyeing with E. odoratum extract in the pre...

The synthesis of eleven novel antibacterial agents is reported. The structures are based on a C-2-symmetric binaphthyl scaffold which holds two identical chains consisting of a short linker, a basic amino acid and a small hydrophobic side chain. Antibacterial activity is revealed for a number of derivatives down to an MIC of 2 mu g/mL (2 mu M) agai...

As part of a programme investigating antibacterial cyclic macrocycles containing a cationic amino acid with an internal aromatic hydrophobic scaffold, we previously reported a macrocycle anchored at the 3,3'-positions of a 1,1'-binaphthyl unit. This was prepared via key intermediates containing an internal allylglycine and an allyl-substituted bina...

In this study a series of isatin-based, pH-sensitive aryl imine derivatives with differing aromatic substituents and substitution patterns were synthesised and their acid-catalysed hydrolysis evaluated. These derivatives were functionalised at the C3 carbonyl group of a potent N-substituted isatin cytotoxin and were stable at physiological pH but r...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

This paper reports the compact synthesis of two isomeric dual-action hybrid antimicrobials where the 13-position of the antibacterial berberine has been linked via 3'- and 4'-methylene bridges to INF55 (5-nitro-2-phenylindole), an inhibitor of the bacterial NorA multidrug-resistance pump.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ESI mass spectrometry was used to assess the binding of 13-substituted, 5-nitro-2-phenylindolyl- and 2-naphthalenyl-based berberine derivatives to inter- and intramolecular G-quadruplex DNA molecules. In contrast with the parent berberine, the compounds showed selectivity for quadruplex over duplex DNA and stabilised the quadruplex structure. They...

5-Fluorouracil (5-FU) in combination with its synergistic biomodulator folinic acid maintains a pivotal position in cancer chemotherapy. However, clinical limitations such as phlebitis and catheter blockages persist with the administration of these drugs in combination, and are associated with reduced efficacy and/or quality of life for patients. W...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The plant Aconitum orochryseum Stapf. (Ranunculaceae) is employed together with other plants in Bhutanese traditional medicine and is indicated for malaria-associated fever. To study the in vitro antiplasmodial activity of atisinium chloride, the major alkaloid from Aconitum orochryseum. Atisinium chloride was extracted and purified from aerial par...

A compact synthesis of 15 new binaphthyl-based dicationic tripeptoids and one biphenyl based dicationic tripeptoid is described. Fourteen of these tripeptoids resulted from variation of the C-2' ether substituent of the binaphthyl unit. An O-iso-butyl ether binaphthyl derivative was found to be the most active against Staphylococcus aureus (MIC 1.9...

Quantitative adsorption kinetic and equilibrium parameters for indigo carmine dyeing of silk were studied using UV-visible absorption spectroscopy. The effect of initial dye concentration, contact time, pH, material to liquor ratio (MLR), and temperature were determined to find the optimal conditions for adsorption. The mechanism of adsorption of i...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The alkaloidal components of the Bhutanese medicinal plant Corydalis calliantha Long, which is used for the treatment of malaria, have been assessed. Four known alkaloids, protopine (1), scoulerine (2), cheilanthifoline (3) and stylopine (4) are reported from this plant for the first time. The protopine alkaloid, protopine, and the tetrahydroprotob...

A urokinase targeting conjugate of 2'-deoxy-5-fluorouridine (5-FUdr) was synthesized and tested for tumor-cell selective cytotoxicity in vitro. The 5-FUdr prodrug 2'-deoxy-5-fluoro-3'-O-(3-carboxypropanoyl)uridine (5-FUdrsuccOH) containing an ester-labile succinate linker was attached to the specific urokinase inhibitor plasminogen activator inhibi...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

An efficient synthesis of 29 new binaphthyl-based neutral, and mono- and di-cationic, peptoids is described. Some of these compounds had antibacterial activities with MIC values of 1.9-3.9microg/mL against Staphylococcus aureus. One peptoid had a MIC value of 6microg/mL against a methicillin-resistant strain of S. aureus (MRSA) and a MIC value of 2...

Hybrid antimicrobials containing an antibacterial linked to a multidrug resistance (MDR) pump inhibitor make up a promising new class of agents for countering efflux-mediated bacterial drug resistance. This study explores the effects of varying the relative orientation of the antibacterial and efflux pump inhibitor components in three isomeric hybr...

The allylation of indigo results in the one-step synthesis of two unique complex heterocyclic systems: a spiroindoline–pyridoindolone arising from the addition of three allyl moieties and a fused pyridoindolo-azepinoindolone generated from the addition and subsequent cyclisation of two allyl moieties. The structures of these novel heterocycles are...

(Figure Presented) Superbugs stalled! Two newly designed synthetic dicationic peptoids (see one example; red O, blue N, green Cl) show promising in vitro bactericidal activity against a range of Gram-positive pathogens, including organisms resistant to vancomycin, methicillin, and linezolid, with only slow development of resistance. Moreover their...

Silk yarn was dyed with morin (2′,3,4′,5,7-pentahydroxyflavone) by using alum as mordant. In order to optimize the process, three methods of dyeing involving: pre-mordanting, simultaneous mordanting, and post-mordanting were assessed and compared with a mordant-free process. The adsorption of alum-morin dye onto silk fibers indicated that the adsor...

5-Fluorouracil in combination with its biomodulator folinic acid maintains a pivotal position in current anticancer treatment regimens. However, limitations in clinical management persist with the administration of these drugs. These limitations are associated with the use of a high pH to maintain 5-fluorouracil in solution, resulting in high rates...

An efficient synthesis of four new acyclic and four new cyclic binaphthyl-based cationic peptoids is described. These compounds had anti-bacterial activities with MIC values of 4-62 microg/mL against Staphylococcus aureus.

Conjugation of the NorA substrate berberine and the NorA inhibitor 5-nitro-2-phenyl-1H-indole via a methylene ether linking group gave the 13-substituted berberine-NorA inhibitor hybrid, 3. A series of simpler arylmethyl ether hybrid structures were also synthesized. The hybrid 3 showed excellent antibacterial activity (MIC Staphylococcus aureus, 1...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Changes to ecosystem abiotic parameters are regarded as possible mechanisms facilitating plant invasion and community composition shifts. This study compared the hydrophobic chemical signatures of soil from exotic bitou bush (Chrysanthemoides monilifera spp. rotundata) invaded, indigenous acacia (Acacia longifolia var. sophorae) dominated and bare...

A compact and regioselective approach to 2-substituted isoflav-3-enes based on a preformed 2-unsubstituted isoflavene is described. Isoflavene oxidation by hydride ion abstraction to the corresponding isoflavylium salt using trityl hexafluorophosphate followed by nucleophilic addition to the 2-position resulted in the introduction of a range of sub...

Azepines and their benz-fused derivatives have commanded a considerable amount of synthetic interest. This is particularly true of the latter systems because of their continuing pharmacological significance. Ring synthesis by ring construction is the dominant general approach, although a number of new ring transformation strategies have been develo...

Prof. John Bremner is Professor of Organic Chemistry in the Department of Chemistry, University of Wollongong, Australia. He is a graduate of the University of Western Australia and the Australian National University. After being a Research Fellow at Harvard University, he returned to Australia in 1968 to an academic appointment in Chemistry at the...

Prof. John Bremner is Professor of Organic Chemistry in the Department of Chemistry, University of Wollongong, Australia. He is a graduate of the University of Western Australia and the Australian National University. After being a Research Fellow at Harvard University, he returned to Australia in 1968 to an academic appointment in Chemistry at the...

As part of a program investigating cyclic peptides with an internal aromatic hydrophobic scaffold as potential novel anti-bacterial agents, we explored the synthesis of simple tyrosine-based systems. These were prepared via key intermediates containing internal allylglycine and allyltyrosine residues for subsequent ring closing metathesis reactions...

A compact three-step synthesis of a new fused bisindole system isomeric with the heterocyclic skeleton present in the marine natural product iheyamine A has been achieved. The structure of the synthetic product was confirmed by a single-crystal X-ray structure.

Background: Vancomycin is a glycopeptide that binds to the terminal D-Ala-D-Ala dipeptide of peptidoglycan precursors, abrogating cell wall synthesis. Resistance to vancomycin is a recognised clinically significant problem, resulting from substitution of D-lactic acid for the terminal D-Ala, with loss of affinity for vancomycin. A series of compoun...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

An efficient synthesis of two new N-acetyl-4'-arylphenylalanines is described together with their incorporation into a number of cationic peptoid antibacterial agents, one of which had an MIC of 7.8 microg/mL against Staphylococcus aureus.

The synthesis of 22 2-aryl-1H-indoles, including 12 new compounds, has been achieved via Pd- or Rh-mediated methodologies, or selective electrophilic substitution. All three methods were based on elaborations from simple indole precursors. SAR studies on these indoles and 2-phenyl-1H-indole in Staphylococcus aureus as NorA efflux pump inhibitors in...

A range of N-phenethyl, N-phenacyl, and N-(1- and 2-naphthylmethyl) derivatives of 5,7-dibromoisatin 2 were prepared by N-alkylation reactions. Their activity against human monocyte-like histiocytic lymphoma (U937), leukemia (Jurkat), and breast carcinoma (MDA-MB-231) cell lines was assessed. The results allowed further development of structure-act...

Chemical interference is increasingly suggested as a mechanism facilitating exotic plant invasion and plant community composition. In order to explore this further, we employed a comprehensive extract-bioassay technique that facilitated detection and demarcation of phytotoxicity, direct allelopathy and indirect allelopathy of bitou bush (Chrysanthe...

Betulinic acid, oleanolic acid and ursolic acid have been modified at the C-3 position to cinnamate-based esters and in vitro antimycobacterial activity against Mycobacterium tuberculosis H(37)Ra has been determined. The results indicated that modification of the parent structures of betulinic acid, oleanolic acid and ursolic acid to the p-coumarat...

Allelopathy has been suggested as a mechanism promoting the monoculture formation of some invasive exotic plants. Previous studies have shown that hydrophobic extracts of the roots and soil of exotic bitou bush (Chrysanthemoides monilifera spp. rotundata (DC.) T. Norl.) inhibited the seedling growth of five Australian native plants, including the d...

The structure of the complex formed between Al(III) (alum) and brazilein in aqueous solution was investigated using UV-visible spectroscopy. The molar ratio method and Job's method of continuous variation were applied to ascertain the stoichiometric composition of the complex in aqueous solution. A 1:2 complex was indicated by both methods. A struc...

Adsorption and thermodynamic studies of lac dyeing on cotton pretreated with chitosan were investigated under dyeing conditions of pH 3.0, a material to liquor ratio (MLR) of 1:100 and a contact time of 3 h. Batch equilibrium studies showed that the adsorption of lac dye on cotton pretreated with chitosan could be described by the Langmuir isotherm...