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Control of liver fluke infections remains a significant challenge in the livestock sector due to widespread distribution of drug resistant parasite populations. In particular, increasing prevalence and economic losses due to infection with Fasciola hepatica is a direct result of drug resistance to the gold standard flukicide, triclabendazole. Sustainable control of this significant zoonotic pathogen, therefore, urgently requires the identification of new anthelmintics. Plants represent a source of molecules with potential flukicidal effects and, amongst their secondary metabolites, the diterpenoid abietic acids can be isolated in large quantities. In this study, nineteen (19) chemically modified abietic acid analogues (MC_X) were first evaluated for their anthelmintic activities against F. hepatica newly excysted juveniles (NEJs, from the laboratory-derived Italian strain); from this, 6 analogues were secondly evaluated for their anthelmintic activities against adult wild strain flukes. One analogue, MC010, was progressed further against 8-week immature- and 12-week mature Italian strain flukes. Here, MC010 demonstrated moderate activity against both of these intra-mammalian fluke stages (with an adult fluke EC

R- and S-Glycerol mycolates derived from single synthetic α-, keto- and methoxy-mycolic acids are described.

An efficient synthetic approach to tri-arabino di-mycolates, using structurally defined synthetic α-, keto and methoxy mycolic acids is described.

Mycobacterium tuberculosis, the causative agent of tuberculosis, is on the rise again in step with the HIV/AIDS pandemic. Characteristically, M. tuberculosis features a hydrophobic cell envelope conferring resistance to degradation by host defences and impeding drug entry. This review focuses on mycolic acids, the distinctive cornerstone lipids of that cell envelope. The structure of these α-alkyl-β-hydroxy fatty acids is discussed along with their relation to pathogenicity. From the uniqueness of their structures and biosynthesis, rationales to target enzyme complexes involved in mycolic acid biosynthesis are discussed. The uniqueness of mycolic acids is also the basis of their application for immunodiagnosis of tuberculosis, an application showing renewed promise. Finally, emerging insights into the role of mycolic acids in the host–pathogen interaction are discussed, ascribing to mycolic acids a function in promoting cellular immune defences but also immune tolerance and the formation of foam macrophages.

Some single enantiomers of epoxy-mycolic acids containing an α-methyl-trans-alkene or a cis-cyclopropane are synthesized.

The isolation of cellulose from wheat straw was studied using a two-stage process based on steam explosion pre-treatment followed by alkaline peroxide post-treatment. Straw was steamed at 200 degrees C, 15 bar for 10 and 33 min, and 220 degrees C, 22 bar for 3, 5 and 8 min with a solid to liquid ratio of 2:1 (w/w) and 220 degrees C, 22 bar for 5 min with a solid to liquid ratio of 10:1, respectively. The steamed straw was washed with hot water to yield a solution rich in hemicelluloses-derived mono- and oligosaccharides and gave 61.3%, 60.2%, 66.2%, 63.1%, 60.3% and 61.3% of the straw residue, respectively. The washed fibre was delignified and bleached by 2% H2O2 at 50 degrees C for 5 h under pH 11.5, which yielded 34.9%, 32.6%, 40.0%, 36.9%, 30.9% and 36.1% (% dry wheat straw) of the cellulose preparation, respectively. The optimum cellulose yield (40.0%) was obtained when the steam explosion pre-treatment was performed at 220 degrees C, 22 bar for 3 min with a solid to liquid ratio of 2:1, in which the cellulose fraction obtained had a viscosity average degree of polymerisation of 587 and contained 14.6% hemicelluloses and 1.2% klason lignin. The steam explosion pre-treatment led to a significant loss in hemicelluloses and alkaline peroxide post-treatment resulted in substantial dissolution of lignin and an increase in cellulose crystallinity. The six isolated cellulose samples were further characterised by FT-IR and 13C-CP/MAS NMR spectroscopy and thermal analysis.

The synthesis and dehydrohalogenation of diethyl halocyclopropane-1,1-dicarboxylates prepared from diethyl ethylidene- and benzylidenemalonates are described.

3-(2 S -Heptylcycloprop-1 S -yl)propanoic acid 2-phenylethanamide was synthesised from cis -cyclopropan-1,2-dimethanol via enzymatic desymmetrisation of the dibutyrate; it gave identical NMR spectroscopic data to those reported for grenadamide but had an equal and opposite absolute rotation, indicating that the latter is the 2 R ,1 R -enantiomer.

A suite of twelve assays has been used to ‘fingerprint’ dissolved organic matter (DOM). The assays were applied directly to filtered natural water samples. Temperature, pH and conductivity accounted for the environmental conditions on-site. Bulk carbon characteristics were assayed by measuring UV absorbance at 200 and 240 nm, colour in grade Hazen, DOC (dissolved organic carbon), fluorescence (excitation 370 nm, emission 450 nm) and the complexation of phenol itself. Measuring hydroxybenzenes (‘monophenolics’), polyhydroxybenzenes (‘polyphenolics’) and total phenolics with the Gibbs, Prussian Blue and Folin–Ciocalteau assays, respectively, determined the phenolics pool. The methodology was tested on six freshwater sites in North Wales chosen to provide differences in vegetation, land-use and water chemistry and sampled once during each season. A novel approach for the presentation of the data has been developed that combines all range normalised assay results for each site and each season within one polar plot, hence the term ‘fingerprint’. The data was also analysed using principal component factor analysis. Assays characterised as determining the chemical properties of DOM contributed to Factor 1 and explained 59% of the variation in the data. Assays apparently determined by the water matrix, contributed to Factor 2 and explained 20% of the variation within the data. The factor scores obtained for each site showed more variation for assays relating to the chemical properties of DOM than to the surrounding water matrix. The methodology was found to detect chemical changes within DOM for each site throughout the year and different responses for different sites.

Intramolecular reaction of methylenecarbenes (carbenoids), derived by reaction of 1,1 -dibromoalkenes and methyllithium, with 5,6-related C–H bonds leads to cyclopentenes when there is an alkoxy or amino substituent on C-5, but no reaction occurs at a 4,5-related C–H bond when there is a heteroatom on C-4; when there is an alkylthio group either on C-4 or C-5 attack occurs on sulphur and the alkyl group is lost, leading to a 2,3-dihydrothiophene or a 3, 4-dihydro-2H-thiopyran respectively. If a heteroatom-hydrogen bond is present at the 5,6-position a formal insertion occurs at that bond leading to 2,3-dihydropyrroles, 2,3-dihydrofurans or 2,3-dihydrothiophenes.

A series of esters of cyclopropene fatty acids, including sterculic, malvalic and sterculynic acids, has been prepared by alkylation of the corresponding 1-lithiocyclopropenes.

1-Lithio-1,3-dimethylcyclopropene has been obtained in optically active form in five steps from tiglic acid and trapped with electrophiles to produce, among others, optically active 1,3-dimethylcyclopropene.

1,1,2-Tribromocyclopropanes undergo 1,2-debromination with a dialkyl phosphite and either a trialkylamine or sodium hydride to form the corresponding 1-bromocyclopropene.

Iodination of selected 1-allyl- or 1-benzyl-cyclopropenes with electron-donating groups on the substituent leads to 2-iodo-1-iodomethyl-1 -vinyl or 1-arylcyclopropanes.

The title compound, methyl 8-chlorobicyclo­[7.1.0]deca-1,8-dien-4-yn-2-carboxylate C12H11ClO2, crystallizes with two chemically equivalent and essentially geometrically and conformationally identical molecules in the asymmetric unit. A cyclopropane ring is fused to a nine-membered ring such that it is flanked by two double bonds and the presence of a triple bond in the larger ring generates considerable strain, evidenced in the marked non-linearity of the alkyne unit [165.2 (2)–168.4 (2)° at the carbon atoms] and the wide angles within the nine-membered ring at the ring fusion atoms [153.09 (10)–155.5 (2)°].

The dichloro- and dibromocarbene adducts of chloroprene and 2,3-dichlorobutadiene are readily dehalogenated by reaction with methyllithium to give 1-halo-2-vinylcyclopropenes which on further lithium-halogen exchange give synthetically useful 1-lithio-2-vinylcyclopropenes. Trapping of 1-lithio-2-(1-chlorovinyl)cyclopropene with methyl chloroformate leads to a very unusual cyclononadienyne.

1 Dehydrohalogenations of Halogenated Cyclopropanes 2 Elimination of Halogen 3 1,2-Elimination of a Trialkylsilylhalide 4 Eliminations Leading to Cyclopropa-Aromatics 5 1,1- and 1,3-Elimination Leading to Cyclopropenes 6 1,3-Dehalogenation of 1-Halo-2-Halomethylcyclopropanes 7 Eliminations Leading to Bicyclo[1.1.0]but-1(3)-enes 8 1,2- and 1,3-Eliminations in Quadricyclanes 9 Dehalogenation and Dehydrohalogenation of Halogenated Cyclopropenes Keywords: dehydrohalogenations of halogenated cyclopropanes; halogen elimination; eliminations involving carbon–halogen bonds; gas phase dehalogenations; dehalosilylation; gas phase elimination; bicyclopropene and spiropentadine preparation; eliminations leading to cyclopropa-aromatics

Intramolecular insertion of single enantiomers of cyclopropylidenes into 5,6-related CH bonds adjacent to nitrogen has been used to obtain enantiomerically pure methanoproline and a number of analogues with a high degree of one- or two-fold asymmetric induction.

Intramolecular interaction of vinylcarbenes derived from 1,2-dichlorocyclopropenes with isoxazoles or bicyclic isoxazolines can lead to a rearrangement with the formation of 1-azafulvenes or derived 2-alkenoylpyrroles.

Reaction of 2-acyloxymethyl or 2-acylaminomethyl-1,1-dibromocyclopropanes with methyllithium at −90°C leads to selective bromine-lithium exchange and intramolecular cyclisation to give a 1-bromo-3-oxa- or 1-bromo-3-aza-bicyclo[3.1.0]hexan-2-ol.

Reaction of a range of 1-bromocyclopropenes with diazo-compounds leads to pyrazoles which ring-open to pyridazines in reasonable yield.

Simple chiral building blocks 1-(R)- and 1-(S)-2,2-dibromocyclopropanecarboxylic acids and 2-(R)-bromo-1-(S)-cyclopropanecarboxylic acids and their 1-methyl analogues, have been obtained on a preparatively useful laboratory scale.

Reaction of Diels-Alder adducts of 1-bromo-2-bromomethylcyclopropene and either 1,3-dienes or furans with butyl lithium leads to a 1,3-dehalogenation to produce [4.1.1]propellanes. The oxygen bridged propellane derived from furan reacts with a second mol.equiv. of butyllithium by cleavage of the bridge with allylic rearrangement and the formation of a cis-3-butyl-[4.1.1]propell-4-en-2-ol. © 1997 Elsevier Science Ltd.

(1S,2S)-2[(S)-Amino(4-methoxyphenyl)methyl]cyclopropan-1-ol together with a range of racemic 2-(2-aminoalkyl)-1-hydroxycyclopropanes were prepared by a stepwise procedure involving a 1,3-dipolar cycloaddition of a nitrile oxide to a cyclopropene followed by reduction of the derived bicycle.

Reaction of gem -dibromocyclopropanes with ethylmagnesium bromide at ambient temperature leads to very high yields of allenes; when cyclopropylidene–allene ring opening is suppressed, alternative carbenic products are observed, although other reactions compete. When the reactions are carried out at −60°C, a 1-bromo-1-(bromomagnesio)-cyclopropane is formed which may be trapped by a number of electrophiles.

We report the syntheses of a single enantiomer of an unprotected ketomycolic acids containing a cis-cyclopropane and of related hydroxy-mycolic acids.

In this study, we investigated the physicochemical properties of the cellulosic preparations obtained from both untreated perennial ryegrass leaves and de-juiced leaves. It was found that treatment at 22 degrees C with 18% NaOH and 18% KOH for 2h, and 10% NaOH and 10% KOH for 16 h yielded 28.2%, 28.8%, 22.7%, 23.4%, respectively, of 'cellulose' residue from untreated ryegrass leaves and 35.7%, 36.8%, 32.8% and 34.6%, respectively, from the de-juiced leaves. For each cellulosic fraction, the glucose content was 71.6%, 69.6%, 67.8%, 66.7%, 69.7%, 68.6%, 63.9% and 61.7%, respectively. The structure of the cellulose samples was examined using FTIR and CP/MAS (13)C NMR spectroscopy and X-ray diffraction. The cellulosic preparations were free of bound lignin except for noticeable amounts of residual hemicelluloses (28.4-38.3%), and had intrinsic viscosities between 275.1 and 361.0 mL/g, along with molecular weights from 144,130 to 194,930 g/mol. This study found that the cellulose samples isolated from both de-juiced ryegrass leaves and the untreated leaves had a much lower percent crystallinity (33.0-38.6%) than that from wood-based fibres (60-70%) and had much shorter fibres (0.35-0.49 mm) than those of either cereal straws, bagasse or wood. In addition, a partial disruption of the hydrogen bonds and microfibrils may occur during the de-juicing process by mechanical activity, which results in a decreased cellulose crystallinity and fibre length. These findings are significant in relation to hydrolysing ryegrass cellulose for bio-ethanol production.

Sequential three-stage treatments with 80% EtOH containing 0.2% NaOH, 2.5% H 2 O 2 –0.2% EDTA containing 1.5% NaOH and 2.5% H 2 O 2 –0.2% TAED containing 1.0% NaOH at 75 °C for 3 h released 8.0% and 10.4%, 79.1% and 77.0% and 12.9% and 12.5% of the original hemicelluloses from perennial grass and cocksfoot grass, respectively. It was found that the four alkaline peroxide-soluble hemicellulosic fractions contained higher amounts of xylose (33.4–38.2%), uronic acids (9.3–15.3%) and rhamnose (3.0–3.9%), but were lower in glucose (25.1–28.3%), galactose (13.3–15.3%) and mannose (0.4–1.5%) than those of the two alkaline EtOH-soluble hemicellulosic fractions in which glucose (32.9–36.0%), xylose (20.1–22.6%), arabinose (14.1–21.4%), galactose (16.6–19.9%), mannose (4.1–9.9%) and uronic acids (3.4–7.4%) were the major sugar components. 13 C NMR spectroscopy confirmed that all the six hemicellulosic fractions were composed of galactoarabinoxylans, 4- O -methylglucuronoarabinoxylans and β-glucan. In addition, the studies showed that the four alkaline peroxide-soluble hemicellulosic fractions were more linear and acidic and had larger molecular weights ( M w , 28,400–38,650 g mol −1 ) than those of the two alkaline EtOH-soluble hemicellulosic fractions ( M w , 16,460–17,420 g mol −1 ).