Sue Elizabeth Boyd

Chemical composition of decomposing stumps in successive rotation of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) plantations

Decomposition of stumps in successive rotation of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) plantations was studied using a chronosequence approach. The results showed that decomposition rate constant of Chinese fir stump was 0.02695 as calculated from Olson’s model. The N content of stump increased during the first two-year decomposition. When the dead stump C/N ratio was 463.2 ± 27.3, the stumps started to release N. The pattern of P release was similar to that for N. However, K content of stumps showed a consistent declining trend over time during the whole decomposition.13C nuclear magnetic resonance spectroscopy with cross polarization and magic-angle spinning (13C CPMAS-NMR) was used to analyse organic carbon (C) components in decomposing stumps. The13C CPMAS-NMR spectra of stumps displayed that stump was dominated by cellulose and hemicellulose. The spectra also showed the accumulation of intensity in alkyl C, aromatic C, and carboxyl C spectral regions, which was expected as the labile cellulose and hemicellulose components inO-alkyl C spectral region were selectively decomposed first.

Identification of the novel synthetic cannabimimetic 8-quinolinyl 4-methyl-3-(1-piperidinylsulfonyl)benzoate (QMPSB) and other designer drugs in herbal incense

The identification and structural elucidation of the novel synthetic cannabimimetic 8-quinolinyl 4-methyl-3-(1-piperidinylsulfonyl)benzoate (QMPSB) by GC-MS, LC-MS and NMR is reported. QMPSB was identified in Queensland, Australia on plant material packaged as herbal incense. The identification of QMPSB was initially hampered due to trans-esterification occurring in the extraction solvent. An investigation of the trans-esterification of QMPSB in methanol and ethanol was conducted and analytical data for the respective methyl and ethyl esters are reported. Analytical data is presented for two other compounds detected on seized plant material packaged as herbal incense: the synthetic cannabimimetic 1-[(N-methylpiperidin-2-yl)methyl]-3-(4-methyl-1-naphthoyl)indole (MAM-1220) and the JWH-081 analogue 1-(cyclohexylmethyl)-3-(4-methoxy-1-naphthoyl)indole (CHM-081).

Synthesis, properties and complexation studies on 3-amino-6,6'-dimethyl-2,2'-bipyridine

The new unsymmetrical bipyridyl ligand 6,6′-dimethyl-3-nitro-2,2′-bipyridine was prepared via coupling of 6-methyl-2-trimethylstanniopyridine and 2-chloro-6-methyl-3-nitropyridine in the presence of [Pd(PPh3)2Cl2]. Reduction of the nitro group afforded 3-amino-6,6′-dimethyl-2,2′-bipyridine (L), a model for the central subunit of the antitumour drug streptonigrin. At low temperatures, in [2H6]acetone, L is planar, held in place by a hydrogen bond from the amino group to the pyridyl nitrogen in the adjacent ring. From 1H NMR lineshape analysis the barrier to rotation about the amino–bipyridyl bond (ΔGb‡) was estimated to be ≈38 kJ mol–1 at 200 K. This value is significantly lower than the barrier to rotation about the biaryl bond connecting the aryl rings. In solution, L co-ordinates to CdII, CuI and ZnII as a bipyridyl ligand; in these complexes the chemical shift of the amino group protons shifts upfield to ca.δ 5 compared to L where they resonate at δ 6.5. The crystal structure of [(CdLCl2)2] was determined by X-ray diffraction methods and refined to a residual of 0.027 for 1895 independent observed reflections. The crystals are monoclinic, space group P21/n, a= 9.560(2), b= 16.886(2), c= 9.577(3)A, β= 118.37(2)°. The complex crystallized as a dimer in which each cadmium binds three chloride ligands and a bipyridyl ligand in a distorted trigonal-bipyramidal arrangement. The relevance of these results to the structure and properties of the antitumour drug streptonigrin is discussed.

A spectroelectrochemical investigation of the interaction of diisobutyldithiophosphinate with copper, silver and gold surfaces: I. Raman and NMR spectra of diisobutyldithiophosphinate compounds.

NMR and Raman spectroscopies have been applied to characterise the diisobutyldithiophosphinate (DIBDTPI) compounds of sodium, copper, silver and gold, diisobutyldithiophosphinic acid (DIBDTPIH), and the oxidation product bis(diisobutylthiophosphoryl)disulfide (DIBDTPI)2 in order to provide a basis for investigating the interaction of the flotation collector, NaDIBDTPI, with the coinage metal surfaces. Spectra for the various species in the solid state and in solution obtained by both techniques are interpreted in terms of the symmetry and conformation of the molecule. Raman spectroscopy provides an effective means of distinguishing between coinage metal DIBDTPI compounds and (DIBDTPI)2.

Molecular composition of recycled organic wastes, as determined by solid-state 13C NMR and elemental analyses

Using solid state (13)C NMR data and elemental composition in a molecular mixing model, we estimated the molecular components of the organic matter in 16 recycled organic (RO) wastes representative of the major materials generated in the Sydney basin area. Close correspondence was found between the measured NMR signal intensities and those predicted by the model for all RO wastes except for poultry manure char. Molecular nature of the organic matter differed widely between the RO wastes. As a proportion of organic C, carbohydrate C ranged from 0.07 to 0.63, protein C from <0.01 to 0.66, lignin C from <0.01 to 0.31, aliphatic C from 0.09 to 0.73, carbonyl C from 0.02 to 0.23, and char C from 0 to 0.45. This method is considered preferable to techniques involving imprecise extraction methods for RO wastes. Molecular composition data has great potential as a predictor of RO waste soil carbon and nutrient outcomes.

Mitsunobu dehydration of N-Boc neomycin B

Reaction of hexa-N-Boc neomycin B with TPP and DIAD in toluene results in the formation of an epoxide in ring IV, not an aziridine or azetidine as previously reported.

Role of oxygen-containing functional groups in forest fire-generated and pyrolytic chars for immobilization of copper and nickel

Char as a carbon-rich material, can be produced under pyrolytic conditions, wildfires or prescribed burn offs for fire management. The objective of this study was to elucidate mechanistic interactions of copper (Cu2+) and nickel (Ni2+) with different chars produced by pyrolysis (green waste, GW; blue-Mallee, BM) and forest fires (fresh-burnt by prescribed fire, FC; aged char produced by wild fire, AC). The pyrolytic chars were more effective sorbents of Cu2+ (∼11 times) and Ni2+ (∼5 times) compared with the forest fire chars. Both cross-polarization (CPMAS-NMR) and Bloch decay (BDMAS-NMR) 13C NMR spectroscopies showed that forest fire chars have higher woody components (aromatic functional groups) and lower polar groups (e.g. O-alkyl C) compared with the pyrolytic chars. The polarity index was greater in the pyrolytic chars (0.99-1.34) than in the fire-generated chars (0.98-1.15), while aromaticity was lower in the former than in the latter. Fourier transform infrared (FTIR) and Raman spectroscopies indicated the binding of carbonate and phosphate with both Cu2+ and Ni2+ in all chars, but with a greater extent in pyrolytic than forest fire-generated chars. These findings have demonstrated the key role of chars oxygen-containing functional groups in determining their sorption capacity for the Cu2+ and Ni2+ in contaminated lands.

Synthesis and characterisation of peripherally functionalised dendritic molecules

A number of peripherally functionalised dendritic molecules were synthesised in almost quantitative yield by a synthetic method involving the reaction between amines and isocyanates. The peripheral functional groups were incorporated by preparing a number of branched subunits, based on tris(hydroxymethyl)aminomethane (TRIS), 1, possessing three nitro, methoxy, methyl or maleimide terminal functionalities. Attachment of these branched units to the core molecules 4,4′-methylenebis(phenyl isocyanate)13 and 1,3,5-benzene triisocyanate20 afforded the corresponding dendritic molecules possessing 6 or 9 peripheral functional groups. Functional group conversions on the dendritic molecules have been successfully carried out, including hydrogenation of the terminal nitro to the corresponding amine and cleavage of the methoxy ether to give the corresponding phenol.

Ethyl 3β-hydroxypregna-5,17(20)-dien-21-oate

In the structure of the title steroid, C23H34O3, the molecules are linked in infinite chains through intermolecular C11(n) O-H...O hydrogen bonds between the hydroxy proton and the ester carbonyl O atom.

Direct Mitsunobu monoesterification of N-protected tobramycin competes with intramolecular pyrrolidine formation in ester prodrug synthesis

Unlike the related aminoglycoside neomycin B, N-protected tobramycin can be selectively esterified at its sole, primary hydroxyl group under Mitsunobu conditions. However, depending on the reaction conditions, the reaction can take a different course with intramolecular cyclization of an N-Boc amine leading to formation of an unusual tobramycin pyrrolidine derivative as the major reaction product.