Walker's pronouncing dictionary of the English language. Abridged for the use of schools, containing ... principles of English pronunciation with the proper names that occur in the sacred Scriptures; to which is ... added a selection of geographical proper names and derivatives.

Mode of access: Internet.

Walker's pronouncing dictionary of the English languge : abridged for the use of schools : containing a compendium of the principles of English pronunciation with proper names that occur in the sacred scriptures : to which is likewise added, a selection of geographical proper names and derivatives.

Mode of access: Internet.

Boron trifluoride and its derivatives /

References: p. 256-290.

Designing supramolecular structures from models of cyclic peptide scaffolds with heterocyclic constraints

Cyclic peptides containing oxazole and thiazole heterocycles have been examined for their capacity to be used as scaffolds in larger, more complex, protein-like structures. Both the macrocyclic scaffolds and the supramolecular structures derived therefrom have been visualised by molecular modelling techniques. These molecules are too symmetrical to examine structurally by NMR spectroscopy. The cyclic hexapeptide ([Aaa-Thz](3), [Aaa-Oxz](3)) and cyclic octapeptide ([Aaa-Thz](4), [Aaa-Oxz](4)) analogues are composed of dipeptide surrogates (Aaa: amino acid, Thz: thiazole, Oxz: oxazole) derived from intramolecular condensation of cysteine or serine/threonine side chains in dipeptides like Aaa-Cys, Aaa-Ser and Aaa-Thr. The five-membered heterocyclic rings, like thiazole, oxazole and reduced analogues like thiazoline, thiazolidine and oxazoline have profound influences on the structures and bioactivities of cyclic peptides derived therefrom. This work suggests that such constrained cyclic peptides can be used as scaffolds to create a range of novel protein-like supramolecular structures (e.g. cylinders, troughs, cones, multi-loop structures, helix bundles) that are comparable in size, shape and composition to bioactive surfaces of proteins. They may therefore represent interesting starting points for the design of novel artificial proteins and artificial enzymes. (C) 2002 Elsevier Science Inc. All rights reserved.

Use of derivatives in public sector organisations

The present paper develops and tests a model explaining public sector derivative use in terms of budget discrepancy minimization. The model is different from private sector models. Private sector models do not readily translate into the public sector, which typically faces different objectives. Hypotheses are developed and tested using logistic regression over a sample of Australian Commonwealth public sector organizations. It is found that public sector organization derivative use is positively correlated with liabilities and size consistent with the hypotheses concerning budget discrepancy management.

The reaction of 8-amino-p-menthene derivatives with electrophiles

Attempts to ring-close the nitrogen atom of 8-amino-p-menth-1-ene and of N-substituted 8-amino-p-menth-1-enes onto the C1 - C2 double-bond carbons has led to a range of bicyclo[2.2.2] and bicyclo[3.2.1] products, together with the novel bicyclo[4.3.1]-1,3-oxazepine 9.

Management motivation for using financial derivatives in Australia

This study takes a direct approach to determine management motivation for the use of financial derivatives. We survey a sample of Australian firms on attitudes to derivative use and financial risk management. Management views are sought on the importance of a series of theoretical reasons for using derivatives. Generally, we find that managers are focused on the broad reduction of risk and volatility of cash flows and earnings in using derivatives. Specific issues such as reducing bankruptcy costs, debt levels and taxation are not considered as important. A further interesting result from this research is that even though firms may use derivatives they may not necessarily hedge all of their annual exposures across different financial risks. This helps explain the inconsistency of results in many empirical studies on the determinants of derivative use.

Characterization of the human cytochrome P450 forms involved in metabolism of tamoxifen to its alpha-hydroxy and alpha,4-dihydroxy derivatives

Tamoxifen is a known hepatocarcinogen in rats and is associated with an increased incidence of endometrial. cancer in patients. One mechanism for these actions is via bioactivation, where reactive metabolites are generated that are capable of binding to DNA or protein. Several metabolites of tamoxifen have been identified that appear to predispose to adduct formation. These include alpha-hydroxytamoxifen, alpha,4-dihydroxytamoxifen, and alpha-hydroxy-N-desmethyltamoxifen. Previous studies have shown that cytochrome P450 (P450) enzymes play an important role in the biotransformation of tamoxifen. The aim of our work was to determine which P450 enzymes were capable of producing a-hydroxylated metabolites from tamoxifen. When tamoxifen (18 or 250,mu M) was used as the substrate, P450 3A4, and to a lesser extent, P450 2D6, P450 2B6, P450 3A5, P450 2C9, and P450 2C19 all produced a metabolite with the same HPLC retention time as alpha-hydroxytamoxifen at either substrate concentration tested. This peak was well-separated from 4-hydroxy-N-desmethyltamoxifen, which eluted substantially later under the chromatographic conditions used. No alpha,4-dihydroxytamoxifen was detected in incubations with any of the forms with tamoxifen as substrate. However, when 4-hydroxytamoxifen (100,mu M) was used as the substrate, P450 2B6, P450 3A4, P450 3A5, P450 1B1, P450 1A1, and P450 2D6 all produced detectable concentrations of a,4-dihydroxytamoxifen. These studies demonstrate that multiple human P450s, including forms found in the endometrium, may generate reactive metabolites in women undergoing tamoxifen therapy, which could subsequently play a role in the development of endometrial cancer.

Tuning the photophysical behavior of luminescent cyclam derivatives by cation binding and excited state redox potential

The emission from two photoactive 14-membered macrocyclic ligands, 6-((naphthalen-1-ylmethyl)-amino)trans-6,13-dimethyl- 13-amino- 1,4,8,11 -tetraaza-cyclotetradecane (L-1) and 6-((anthracen-9-ylmethyl)-amino)trans-6,13 -dimethyl - 13 -amino- 1,4,8, 1 1-tetraaza-cyclotetradecane (L-2) is strongly quenched by a photoinduced electron transfer (PET) mechanism involving amine lone pairs as electron donors. Time-correlated single photon counting (TCSPC), multiplex transient grating (TG), and fluorescence upconversion (FU) measurements were performed to characterize this quenching mechanism. Upon complexation with the redox inactive metal ion, Zn(II), the emission of the ligands is dramatically altered, with a significant increase in the fluorescence quantum yields due to coordination-induced deactivation of the macrocyclic amine lone pair electron donors. For [ZnL2](2+), the substituted exocyclic amine nitrogen, which is not coordinated to the metal ion, does not quench the fluorescence due to an inductive effect of the proximal divalent metal ion that raises the ionization potential. However, for [ZnL1](2+), the naphthalene chromophore is a sufficiently strong excited-state oxidant for PET quenching to occur.

Aspergillazines A-E: novel heterocyclic dipeptides from an Australian strain of Aspergillus unilateralis

Biological and chemical pro ling of an Australian strain of the fungus Aspergillus unilateralis (MST-F8675), isolated from a soil sample collected near Mount Isa, Queensland, revealed a complex array of metabolites displaying broad chemotherapeutic properties. Noteworthy among these metabolites were a unique series of highly modified dipeptides aspergillazines A-E, incorporating a selection of unprecedented and yet biosynthetically related heterocyclic systems. Co-occurring with the aspergillazines was the recently described marine-derived fungal metabolite trichodermamide A (cf. penicillazine), whereas re-fermentation of A. unilateralis in NaCl (1%) enriched media resulted in co-production of the only other known example of this structure class, the marine-derived fungal metabolite trichodermamide B. Further investigation of A. unilateralis returned the known terrestrial fungal metabolite viridicatumtoxin as the cytotoxic and antibacterial principle, together with E-2-decenedioic acid, ferulic acid, (7E,7'E)-5,5'-diferulic acid and (7E,7'E)-8,5'-diferulic acid. The aromatic diacids have previously been reported from the chemical and enzymatic (esterase) treatment of plant cell wall material, with their isolation from A. unilateralis being their first apparent reported occurrence as natural products. Structures for all metabolites were determined by detailed spectroscopic analysis and, where appropriate, comparison to literature data and/or authentic samples.

Isokibdelones: Novel heterocyclic polyketides from a Kibdelosporangium sp.

The isokibdelones are an unprecedented family of polyketides produced by an Australian isolate of a rare actinomycete, Kibdelosporangium sp. The structures of the isokibdelones were assigned by spectroscopic analysis and chemical interconversion. A proposed biosynthesis requires a novel molecular twist that generates an unprecedented heterocyclic system and differentiates the isokibdelones from their kibdelone co-metabolites. SAR analysis on the isokibdelones further defines the anticancer pharmacophore of these novel polyketides.

Synthesis and characterization of Pd(II) and Pt(II) complexes with triazolopyrimidine derivatives: The crystal structure of [Pd2L2Cl4] where L=5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine

The Pd(II) and Pt(II) complexes with triazolopyrimidine C-nucleosides L-1 (5,7-dimethyl-3-(2',3',5'-tri-O-benzoyl-beta-D-ribofuranosyl-s-triazolo)[4,3-a]pyrimidine), L-2 (5,7-dimethyl-3-beta-D-ribofuranosyl-s-triazolo [4,3-a]pyrimidine) and L-3 (5,7-dimethyl[1,5-a]-s-triazolopyrimidine), [Pd(en)(L-1)](NO3)(2), (Pd(bpy)(L-1)](NO3)(2), cis-Pd(L-3)(2)Cl-2, [Pd-2(L-3)(2)Cl-4]center dot H2O, cis-Pd(L-2)(2)Cl-2 and [Pt-3(L-1)(2)Cl-6] were synthesized and characterized by elemental analysis and NMR spectroscopy. The structure of the [Pd-2(L-3)(2)Cl-4]center dot H2O complex was established by Xray crystallography. The two L-3 ligands are found in a head to tail orientation, with a (PdPd)-Pd-... distance of 3.1254(17) angstrom.L-1 coordinates to Pd(II) through N8 and N1 forming polymeric structures. L-2 coordinates to Pd(II) through N8 in acidic solutions (0.1 M HCl) forming complexes of cis-geometry. The Pd(II) coordination to L-2 does not affect the sugar conformation probably due to the high stability of the C-C glycoside bond. (c) 2006 Elsevier B.V. All rights reserved.

A comparison of the excretion rate of endogenous purine derivatives in the urine of Bos indicus and Bos taurus steers

Estimates of microbial crude protein (MCP) production by ruminants, using a method based on the excretion of purine derivatives in urine, require an estimate of the excretion of endogenous purine derivatives (PD) by the animal. Current methods allocate a single value to all cattle. An experiment was carried out to compare the endogenous PD excretion in Bos taurus and high-content B. indicus ( hereafter, B. indicus) cattle. Five Holstein - Friesian ( B. taurus) and 5 Brahman (> 75% B. indicus) steers ( mean liveweight 326 +/- 3.0 kg) were used in a fasting study. Steers were fed a low-quality buffel grass (Cenchrus ciliaris; 59.4 g crude protein/kg dry matter) hay at estimated maintenance requirements for 19 days, after which hay intake was incrementally reduced for 2 days and the steers were fasted for 7 days. The excretion of PD in urine was measured daily for the last 6 days of the fasting period and the mean represented the daily endogenous PD excretion. Excretion of endogenous PD in the urine of B. indicus steers was less than half that of the B. taurus steers ( 190 mu mol/kg W-0.75. day v. 414 mu mol/kg W-0.75. day; combined s.e. 37.2 mu mol/kg W-0.75. day; P< 0.001). It was concluded that the use of a single value for endogenous PD excretion is inappropriate for use in MCP estimations and that subspecies-specific values would improve precision.