bluuebunny/crossref_metadata_2025 huggingface dataset:
Co-occurrence of Proteaceae, laterite and related oligotrophic soils: coincidental associations or causative inter-relationships?
Authors: Pate J. S. , Verboom W. H. , Galloway P. D.
Published: September 2002

This communication presents the hypothesis that certain Australian lateritic
and related oligotrophic soils may have been partly derived biotically from
soluble iron-rich complexes generated following secretion of low-molecular
weight organic acids by phosphate-absorbing specialised proteoid (cluster)
roots of proteaceous plants. Subsequent precipitation of the iron is then
pictured as occurring onto the oxide rinds of developing laterite after
consumption of the organic components of the complexes by soil bacteria. The
hypothesis is f irst examined in relation to current theories of origins of
laterites and the extent of the coincidences worldwide in past and present
times between Proteaceae and oligotrophic soil types of lateritic character.
The paper then provides more definitive lines of evidence supporting the
hypothesis, based largely on recent studies by the authors in south-western
Western Australia. This relates to (a) cases of definitive association in
habitats rich in Proteaceae between zones of root proliferation and ferricrete
layers in lateritic soils, (b) proximity in soil profiles between ferric
deposits and current and ancestral root channels, (c) the recovery of
citrate-consuming bacteria from soil profiles and specifically from ferricrete
rinds and horizons accumulating sesquioxide organic matter and (d)
distribution of iron and phosphorus within plant and soil profile components
consistent with ferricrete rinds being generated by rhizosphere-mediated
interactions of plants and microbes under conditions of severely limited
availability of phosphorus. The mode of functioning of proteoid root clusters
is then discussed, especially in relation to exudation of organic acid anions,
uptake of phosphorus and the subsequent fate of organic anions and their metal
ion complexes in the system. An empirically based scheme is presented
indicating flow profiles for phosphorus and iron between soil, ferricrete
rinds and bacterial and plant components. We then discuss possible carbon
costs to proteaceous plant partners when accessing phosphorus under the
nutrient-impoverished conditions typical of heathlands and open woodlands of
Mediterranean-type ecosystems of Western Australia. The paper concludes with a
critical overview of the hypothesis, particularly its implications regarding
possible higher plant: microbial influences shaping soil and landscape
evolution in the regions involved.
History of the family Malpighiaceae in Australia and its biogeographic implications: evidence from pollen
Authors: Martin Helene A.
Published: September 2002

Three pollen types of the family Malpighiaceae have been identified in the
Tertiary fossil record of south-eastern Australia. There are two species of
the family native to Australia and they have the same pollen type. There was
thus a greater diversity of malpighiaceous taxa during the Tertiary than there
is today. The family is found mainly in tropical regions and it is thought
that northern South America was the centre of origin. The restriction of the
two species to coastal north-eastern Australia suggests recent migration into
the area and gives no hint of the long history of the family in Australia.
Seasonal patterns of soil carbon dioxide efflux from a wet-dry tropical savanna of northern Australia
Authors: Chen Xiaoyong , Eamus Derek , Hutley Lindsay B.
Published: September 2002

Soil CO2 efflux rates were measured in a eucalypt open
forest in a tropical savanna of northern Australia, with a portable closed
chamber and CO2 gas analyser. Both abiotic (soil
temperature and water content) and biotic (litterfall and fine-root growth)
factors that may influence soil CO2 efflux were
examined. Daytime rates of soil CO2 efflux rate were
consistently higher than nocturnal values. Maximal rates occurred during late
afternoons when soil temperatures were also maximal and minimum values were
recorded during the early morning (0400–0800 hours). Average soil
CO2 efflux was 5.37 mol m–2
s–1 (range 3.5–6.7 mol
m–2 s–1 during the wet
season and declined to 2.20 mol m–2
s–1 (range 1.2–3.6 mol
m–2 s–1) during the
dry season. The amount of carbon released from soil was 14.3 t
ha–1 year–1, with
approximately 70% released during the wet season and 30% during
the dry season. The rate of efflux was correlated with soil moisture content
and soil temperature only during the wet season, when root growth and
respiration were high. During the dry season there was no correlation with
soil temperature. These results are discussed in relation to the carbon
balance of tropical savannas.
Population dynamics of an arid zone mistletoe (Amyema preissii, Loranthaceae) and its host Acacia victoriae (Mimosaceae)
Authors: Smith Mark Stafford , Reid Nick
Published: September 2002

The principal host of the mistletoe, Amyema preissii,
near Alice Springs is the short-lived, fast-growing tree,
Acacia victoriae. In order to describe the dynamics of
their interaction, the fate, size and phenology of mistletoes were monitored
in natural host stands, infection experiments were conducted to determine
establishment success and growth rates of seedlings, hosts were repeatedly
disinfected in a 14.6-ha paddock surrounded by infected source trees, and
mistletoe reinvasion of disinfected trees was monitored. In the unmanipulated
population of A. victoriae, 46–54% of trees
(> 2 m in height) were infected (5.8–6.7 mistletoes per infected
tree). Establishment percentage of mistletoe seeds deployed on host branches
varied between 11–24% after 12–23 months, and most
naturally-dispersed seedlings established on branches ≤ 20 mm in diameter.
Estimates of natural mistletoe dispersal to uninfected trees varied between 2
and 12 seeds per infected tree over periods of 8–23 months. Examination
of young mistletoes showed that 24% of 122 clumps consisted of more
than one mistletoe, with 27 occurrences of double infection and two
occurrences of triple infection at the same point on the host branch.
Mistletoes grew rapidly: in one sown cohort, plants achieved canopy diameters
of 152–170 cm within 18–23 months, and half were flowering 15
months after germination. In unmanipulated populations, the largest mistletoes
had a maximum canopy diameter of 250 cm and a maximum host branch diameter
proximal to the haustorium of 100 mm, but modal sizes of these measures were
80–120 cm and < 10 mm, respectively.
Turnover in the host population in the disinfection paddock was rapid:
60% of trees died between 1990 and 1995, mortality being balanced by
recruitment. In unmanipulated stands of host trees, larger trees were more
likely to be infected and supported larger numbers of mistletoes per tree than
small trees. Once mistletoes had been removed from trees in the disinfection
paddock, larger trees were still disproportionately infected by reinvading
mistletoes and trees that had been infected previously were more likely to be
reinfected. In order to fully describe the spatial and temporal dynamics of
this host–mistletoe combination, further studies are needed of mistletoe
persistence and mortality through time and annual seed production as a
function of mistletoe size.
Broad-scale environmental relations of floristic gradients in the Mitchell grasslands of Queensland
Authors: Fensham R. J. , Minchin P. R. , Fairfax R. J. , Kemp J. E. , Purdie R. W. , McDonald W. J. F. , Neldner V. J.
Published: September 2002

A large floristic data set was collated from vegetation surveys of Mitchell
(Astrebla spp.) grasslands in Queensland spanning more
than 20 years. The data was ordinated using non-metric multi-dimensional
scaling and a four-dimensional solution could be deciphered. The longest
floristic gradient was clearly aligned with climatic variables associated with
mean annual precipitation. The vector for mean annual temperature was
orientated orthogonally to the primary vector and was strongly correlated
through the ordination space. A grazing vector tentatively derived from the
frequency of species known to be favoured by grazing in Mitchell grasslands
was orthogonal to the major climatic trends. However, the suspected grazing
influence is complicated by the potential influence of sites occurring on
limited areas of limestone habitat representing marginal Mitchell grassland
habitat. A vector derived from the binomial categorisation of landform into
downs and alluvia was clearly aligned with the fourth dimension of the
ordination. Short- and long-term rainfall history variables were generated for
each site from local rainfall records. The oblique trajectory of these
variables through the ordination space tends to suggest that they may be
artefacts of sampling rather than a major independent influence on the
character of Mitchell grasslands. Thus the results at the broad scale of this
study do not conform to previous studies at the paddock scale that emphasise
the influence of climatic fluctuations on the floristic character of Mitchell
grasslands. The results suggest Mitchell grasslands will require conservation
planning and action throughout their geographic range.
Reproductive biology of Ophiopogon xylorrhizus (Liliaceae s.l.): an endangered endemic of Yunnan, Southwest China
Authors: He Tian-hua , Rao Guang-yuan , You Rui-lin
Published: September 2002

Reproductive biology of Ophiopogon xylorrhizus Wang et
Tai was studied from 1995 to 1997 in Mengla County of Yunnan Province,
Southwest China. The small, white or pale pink flowers with stigmas above
anthers appeared from late March to early April in the study years, and
produced abundant pollen, but no nectar. Pollen : ovule ratios were 17 185
± 2175. Every flower opens only once and remains functional for
10–12 h. Pollen remains viable for the same period. During anthesis,
flowers were visited only by single species of thrips
(Taeniothrips sp., Thripidae). No airborne pollen grains
were collected throughout the blooming season, indicating that flowers are not
wind-pollinated. About 28% of stigmas of unopened flowers were found
with germinated pollen grains and seed set took place in single flowers that
were bagged at the bud stage, which indicated autogamy and autonomous
self-pollination. Ovary walls ruptured 4–5 days after fertilisation,
allowing seed production to occur. About 75% of ovules were fertilised
and developed into young seeds, but only 12.5% developed into mature
seeds in open pollination treatments. The remainder of ovules were aborted or
destroyed by insects or animals during the long developmental phase from April
to December. Individuals of O. xylorrhizus commonly
produced a single inflorescence with 2–24 flowers (15.3 ± 6.5,
n = 33), and 1–43 seeds (12.7 ± 6.7,
n = 33) during the study period. Conservation
management for this endangered species is urgently required and
in situ conservation is probably the best method to
conserve this species.
Development of supernumerary buds from the axillary meristem of pea, Pisum sativum (Fabaceae)
Authors: Stafstrom Joel P. , Sarup Vinita B.
Published: September 2002

Leaf axils of higher plants commonly contain vegetative axillary buds, which
are derived from an axillary meristem. The persistence and continued
organogenic activity of the axillary meristem has been studied experimentally
in only two species. Pea (Pisum sativum L.) leaf axils
contain up to four preformed axillary buds. Decapitating plants above Node 5
promoted the development of preformed buds at all nodes. Buds at each node
were removed as soon as they began to grow. These manipulations eventually led
to the growth of all the preformed buds and promoted the development of
supernumerary buds in the axil of each leaf. Adventitious buds were not
observed anywhere on these plants. Examination of leaf axil anatomy and
external morphology indicated that new buds were derived from the axillary
meristem. The axillary meristem at Node 2 was capable of forming at least six
supernumerary buds. ‘Alaska’ plants (Rms-2)
exhibited strong apical dominance whereas WL5951 plants
(rms-2) contained branches at several nodes. Patterns of
bud organogenesis and development were similar in both cultivars.
Genetic systems in the south-west flora: implications for conservation strategies for Australian plant species
Authors: James Sidney H.
Published: September 2002

Is genetic diversity a reliable indicator of evolutionary capability? A
comparative study of genetic systems in Australian native plants, particularly
from south-west Australia, suggests the primitive condition to be
recombinationally capable with low allelic diversity. Diversity has
accumulated in some nursery lineages in association with lethal equivalent
polymorphisms. This generated an elevated evolutionary capability which
allowed escape from the benign nursery into the demanding arid playground.
Lethal equivalent polymorphisms also generate a high genetic load which drives
genetic system evolution towards the minimisation of that load. Many of the
devices which reduce the genetic load, including chiasma localisation at
meiosis and reduced chromosome numbers, are impedimenta to recombination and
they must reduce evolutionary capability. Thus, to correctly interpret the
levels and patterns of genetic diversity within an Australian plant population
system we need to know how its genetic system operates and how much it is
recombinationally impeded. It may be true that in many Australian plant
population systems, the more genetic diversity we see, the less evolutionary
potential there is. Conservation strategies based on a misunderstanding of the
relevance of genetic diversity in population systems may be quite disastrous.
Generic relationships within and between the gymnosperm families Podocarpaceae and Phyllocladaceae based on an analysis of the chloroplast gene rbcL
Authors: Conran John G. , Wood Glenys M. , Martin Peter G. , Dowd Julie M. , Quinn Christopher J. , Gadek Paul A. , Price Robert A.
Published: September 2002

Analysis of sequences of the chloroplast gene rbcL for
76 taxa of Podocarpaceae (representing all genera except
Parasitaxus) and five species of Phyllocladaceae were
undertaken with respect to their relationships to each other and to 28
coniferalean outgroup taxa from seven families. The results indicate that
Podocarpaceae are polyphyletic unless expanded to include Phyllocladaceae.
Within Podocarpaceae, Sundacarpus is placed in a clade
with Prumnopitys, and
Falcatifolium is paraphyletic as a basal grade to
Dacrydium. Phyllocladus is in an
unresloved clade with Halocarpus,
Manoao/Lagarostrobos and
Prumnopitys/Sundacarpus. The separation of
Afrocarpus from Podocarpus and its
placement instead as sister to Nageia and
Retrophyllum is supported.
Podocarpus s. str. is monophyletic, with both subgenera
identified, albeit poorly supported. The analysis placed
Lepidothamnus and Saxegothaea in
an unresolved basal polytomy within the family. There were no clear outgroup
relationships with the family. These results differ from the morphological
clades found by Kelch (1997), and disagree strongly with his
18S-sequence-based phylogeny (Kelch 1998). However, jackknife support values
indicate that although the genera are well supported, relationships both
within and between them are not, suggesting that intergeneric relationships in
the family require further study. There is also some congruence between our
results and those of the gymnosperm 18S study by Chaw
et al. (1997), although their study included only three
Podocarpaceae and one Phyllocladaceae species.
Allometric relationships and community biomass estimates for some dominant eucalypts in Central Queensland woodlands
Authors: Burrows W. H. , Hoffmann M. B. , Compton J. F. , Back P. V. , Tait L. J.
Published: September 2002

Allometric equations are presented relating stem circumference to branch,
leaf, trunk, bark, total above-ground and lignotuber biomass for
Eucalyptus crebra F.Muell. (woodland trees),
E. melanophloia Sol. Ex Gaerth. (both woodland and
regrowth community trees) and E. populnea F.Muell.
(woodland trees). There were no significant differences
(P > 0.05) between the slopes of individual lognormal
regression lines plotting stem circumference against total above-ground
biomass for E. crebra,
E. melanophloia and E. populnea.
Root-to-shoot ratios and leaf area indices were also determined for the stands
contributing to each regression. The regressions were then applied to measured
eucalypt stems in the associated plant community to give estimates of each
stand’s component (eucalypt tree fraction only) biomass per hectare.
These eucalypt regressions were next applied to measured stems of each species
on a total of 33 woodland sites in which these eucalypts individually
contributed > 75% of total site basal area. Above-ground
biomass/basal area relationships averaged 6.74 0.29 t
m–2 basal area for 11
E. crebra sites, 5.11 0.28 t
m–2 for 12 E. melanophloia
sites and 5.81 0.11 t m–2 for 10
E. populnea sites. The mean relationship for all sites
was 5.86 0.18 t m–2 basal area. The allometric
relationships presented at both individual tree and stand levels, along with
calculated biomass : basal area relationships, enable ready estimates to be
made of above-ground biomass (carbon stocks) in woodlands dominated by these
eucalypts in Queensland, assuming individual stem circumferences or community
basal areas are known. However, to document changes in carbon stocks (e.g. for
Greenhouse Gas Inventory or Carbon Offset trading purposes), more attention
needs to be placed on monitoring fluxes in the independent variables
(predictors) of these allometric equations.
DNA Interactions and Bacterial Mutagenicity of Some Chromium(III) Imine Complexes and their Chromium(V) Analogues. Evidence for Chromium(V) Intermediates in the Genotoxicity of Chromium(III)
Authors: Dillon Carolyn T. , Lay Peter A. , Bonin Antonio M. , Dixon Nicholas E. , Sulfab Yousif
Published: September 2002

The in vitro DNA interactions and bacterial
mutagenicities of
cis-[CrIII(phen)2(OH2)2]3+
and
trans-[CrIII(salen)(OH2)2]+
and their CrV analogues are reported. At pH 3.3,
cis-[Cr(phen)2(OH2)2]3+
(0.02–2.0 mM) causes negatively supercoiled pUC9 DNA to smear on agarose
gels, with substantial precipitation in the well at ≥1.0 mM. Much weaker
interactions between CrIII and DNA were apparent at pH
7.4. The interactions between DNA and CrV phen complexes
(0.5 mM total Cr, pH 3.3) generated by oxidation of
cis-[Cr(phen)2(OH2)2]3+
(for 10–30 min) resulted in almost complete nicking of form I DNA to
forms II and III DNA. Nicking of form I DNA (≥80%) was also apparent
at pH 7.4 following reaction of DNA with PbO2-oxidized
[Cr(phen)2(OH2)2]3+
(2 mM Cr). Interactions between
trans-[CrIII(salen)(OH2)2]+
and DNA were weaker than those of the CrIII phen complex
at both pH 3.3 and 7.4. The CrV salen derivative (0.5 mM
total Cr) caused the disappearance of form I DNA at oxidation times of ≥10
min and at pH 3.3 with substantial cleavage. While oxidation of
[Cr(salen)(OH2)2]+
by PbO2 was not observed at pH 7.4, the complex was
oxidized by iodosobenzene to produce short-lived
[CrO(salen)]+ that caused DNA smearing on
the agarose gel. In bacterial mutagenicity assays, the
CrIII imine complexes and their
CrV analogues produced similar mutagenic responses,
which were believed to be due to the instabilities of the
CrV species in the bacterial growth medium. While the
spectrum of the mutagenic activities differed between the chromium phen and
salen complexes, both exhibited greatest mutagenicity in
Salmonella typhimurium TA102. These data suggest that
CrV species, generated in vivo by
cellular oxidative enzymes, may be responsible for
CrIII-induced mutagenesis.
New Patulin Derivatives
Authors: Ghisalberti Emilio L. , Hargreaves Jahi R. , Skelton Brian W. , White Allan H.
Published: September 2002

Two new derivatives of patulin (1), the dimer (2) arising from cycloaddition
at the 3,4-double bond, and 3,4-dihydroxypatulin acetonide (4), from attempted
epoxidation with dimethyldioxirane, have been characterized. The structure of
(2) was established by a single-crystal low-temperature X-ray study, while
that of (4) was deduced from spectroscopic studies.
Studies on the Nature and Strength of Pt . . .H(-N) Interactions. The Crystal Structures of Chloro[N-(2-aminoethyl)-N-(2-ammonioethyl)ethane-1,2-diamine]platinum(II) Chloride and Dichloro[4,7-diaza-1-azoniacyclononane]platinum(II) Tetrachlor
Authors: Davies Murray S. , Fenton Ronald R. , Huq Fazlul , Ling Edwina C. H. , Hambley Trevor W.
Published: September 2002

Two complexes, namely,
chloro[N-(2-aminoethyl)-N-(2-ammonioethyl)ethane-1,2-diamine]platinum(II)
chloride {[PtCl(tren+H)]Cl2}
and dichloro[4,7-diaza-1-azoniacyclononane]platinum(II)
tetrachloroplatinate(II)–water (1/2)
{[PtCl2(tacn+H)]2[PtCl4]·2H2O},
have been prepared and structurally characterized by single-crystal X-ray
diffractometry as part of a study of the nature and strength of
Pt···H(–N) interactions. Crystals of
[PtCl(tren+H)]Cl2 are monoclinic, space
group P21/c,
a 8.293(2), b 14.396(6),
c 11.305(3) Å, β 107.34(2)º, Z 4, and the
structure has been refined to a residual of 0.042 based on 1631 reflections.
Crystals of
[PtCl2(tacn+H)]2[PtCl4]·2H2O
are monoclinic, space group
P21/a, a
12.834(4), b 8.206(4), c 13.116(8)
Å, β 93.01(4)˚, Z 2, and the structure has been refined to a
residual of 0.035 based on 1974 reflections. In
[PtCl(tren+H)]2+, the protonated
amine forms hydrogen bonds with chloride anions and no close contacts with the
metal ion. In
[PtCl2(tacn+H)]+,
a short intramolecular contact is observed between the metal and the
protonated amine and the results of molecular mechanics modelling are
consistent with there being a Pt···H hydrogen bond.
Molecular mechanics modelling of
[PtCl(tren+H)]2+ and
[PtCl2(dien+H)]+
shows that the protonated amines could readily form close contacts with the
metal. It is concluded that there is evidence for the formation of
Pt···H(–N) hydrogen bonds but these bonds are very
weak, being similar or lower in energy than
Cl···H(–NPt) hydrogen bonds.
Metallo-β-cyclodextrins of 6A-(2-(2-(2-Aminoethylamino)-ethylamino)ethylamino)-6A-deoxy-β-cyclodextrin and 6A-Deoxy-6A-(1,4,7,10-tetraazacyclododecan-1-yl)-β-cyclodextrin: Their Formation and Complexation of (R)- and (S)-Tryptophan and Tryptophanate in Aqueous Solution
Authors: Kean Suzanna D. , Easton Christopher J. , Lincoln Stephen F.
Published: September 2002

The binary metallo-β-cyclodextrins formed by
6A-(2-(2-(2-aminoethylamino)ethylamino)ethylamino)-6A-deoxy-β-cyclodextrin,
[M(βCDtrien)]2+, where
M2+ = Ni2+,
Cu2+ and Zn2+, are
characterized by log(K/dm3
mol-1) = 11.500.02, 10.700.07 and 9.400.01,
respectively, in aqueous solution at 298.2 K and I
= 0.1 mol dm-3 (NaClO4),
where K is the stability constant. For those formed by
6A-deoxy-6A-(1,4,7,10-tetraazacyclododecan-1-yl)-β-cyclodextrin,
[M(βCDcyclen)]2+, where
M2+ = Cu2+ and
Zn2+,
log(K/dm3
mol-1) = 13.610.02 and 11.620.04, respectively.
The ternary metallo-β-cyclodextrins formed by
[M(βCDtrien)]2+ and
(R)- and (S)-tryptophanate,
[M(βCDtrien)((R)-Trp)]+
and
[M(βCDtrien)((S)-Trp)]+
are characterized by log(K/dm3
mol-1) = 6.900.04 and 6.790.04, 8.20.3 and
7.90.2, and 6.640.08 and 7.010.07, respectively, where
M2+ = Ni2+,
Cu2+ and Zn2+. For the
ternary metallo-β-cyclodextrins formed by
[M(βCDcyclen)]2+ and
(R)- and (S)-tryptophanate,
[M(βCDcyclen)((R)-Trp)]+
and
[M(βCDcyclen)((S)-Trp)]+,
log(K/dm3
mol-1) = 6.840.06 and 6.850.06, and 4.950.05 and
4.940.04, respectively, where M2+ =
Cu2+ and Zn2+. Other
binary and ternary metallo-β-cyclo-dextrins are also formed. Binary
complexes formed by the substituted β-cyclodextrins
are exemplified by
βCDcyclen.(R)-Trp- and
βCDcyclen.(S)-Trp- for which
log(Kd/m3
mol-1) = 3.690.04 and 3.950.03, respectively.
These data are discussed together with those from the literature
characterizing other metallo-β-cyclodextrin and substituted
β-cyclodextrin systems.
The Synthesis of Ventilone A
Authors: Piggott Matthew J. , Wege Dieter
Published: September 2002

2-Amino-3,6-dimethoxy-4,5-methylenedioxybenzoic acid (12) was prepared from
1,4-dimethoxy-2,3-methylenedioxybenzene (8) via the isatin (11). The benzyne
generated from (12) was intercepted with
3-acetyl-2-ethoxy-4-[(4-methoxyphenoxy)methyl]furan (4) to give the
naphthol (27), which on treatment with cericammonium nitrate gave the dimethyl
ether of ventilone A(29). Demethylation with boron tribromide then
affordedventilone A (1).
Synthesis of Medium and Large Cyclic Amines in Rhodium-Catalysed Reactions of Aminoalkenes with H2/CO
Authors: Bergmann David J. , Campi Eva M. , Jackson W. Roy , Patti Antonio F. , Saylik Dilek
Published: September 2002

Rhodium-catalysed reactions of N-benzyl- or
N-alkyl-aminoalkenes (6) with
H2/CO can give cyclic amines (7) (7–13 ring
size) in good to excellent yields when BIPHEPHOS is used as a ligand.
Hydrogenation of the aminoalkene becomes a competing reaction for the smaller
rings but can be overcome by using a H2/CO gas ratio
of 1 : 5. Reactions of 2-alkenyloxybenzylamines (13) gave 9-, 12- and
17-membered rings (14) in 30–40% yield, but dimer formation (16)
and/or hydrogenation were competing reactions. Similar reactions of
alkenylamides and ortho-alkenylanilines gave only
non-cyclized amino aldehydes as products in low isolated yields.
X-Ray Crystallographic Structures of Biologically Active Trishomocubanes of the Types Pentacyclo[5.4.0.02,6.03,10.05,9]undecylamines and 4-Azahexacyclo[5.4.1.02,6.03,10.05,9.08,11]dodecane
Authors: Hambley Trevor W. , Knott Robert , Kassiou Michael , Christie MacDonald J.
Published: September 2002

The structures of three trishomocubanes of types pentacyclo[5.4.0.0
2,6 .0 3,10 .0
5,9 ]undecylamines and 4-azahexacyclo[5.4.1.0
2,6 .0 3,10 .0
5,9 .0 8,11 ]dodecanes have
been determined. These ligands have demonstrated high selectivity and affinity
for the sigma binding site, a molecular binding site important in the study of
neurological disorders. The three compounds reported are members of an
extensive series of ligands under investigation in a search for more
efficacious pharmaceuticals. Compound (3) crystallized in the monoclinic space
group C2/c with
a 15.821(8), b 22.407(10),
c 11.032(6) Å, β 115.15(3)°,
V 3540(3) Å 3 ,
Z 8, and was refined to an R value
of 0.054 on 1161F. Compound (4) crystallized in the
triclinic, space group P1, a
11.278(3), b 13.139(2), c 7.444(2)
Å, α 104.54(1), β 107.85(2), γ 68.51(1)°,
V 964.9(4) Å 3 ,
Z 2, and was refined to an R value
of 0.061 on 1939F. Compound (6) crystallized in the
monoclinic space group P2 1
/c, a 9.971(4),
b 11.989(4), c 12.993(5)
Å, β 108.68(3)°, V 1471(1)
Å3 , Z 4, and was
refined to an R value of 0.060 on
1303F. The results are in accord with the hypothesis
that the spatial relationship between the amine group and the hydrophobic
regions of the molecule are important determinants of binding at the sigma
site.
Crystal Structures of Tris(hydroxamato) Complexes of Iron(III)
Authors: Failes Timothy W. , Hambley Trevor W.
Published: September 2002

The crystal structures of
[Fe(aha)3]·1.5H2O
and
[Fe(bha)3]·3H2O
(ahaH = acetohydroxamic acid, bhaH = benzohydroxamic acid) have
been determined.
[Fe(aha)3]·1.5H2O
crystallizes in the monoclinic space group
P21/ c
(a 19.169(4), b 8.5738(3),
c 12.257(3) Å, α = γ =
90°, β 92.255(4)°). The two isomeric forms
(fac and mer) cocrystallize. The
structure of
[Fe(bha)3]·3H2O
is as reported previously (monoclinic,
P21/n,
a 12.9998(16), b 13.2196(16),
c 14.1154(17) Å, α = γ =
90°, β 90.809(2)°) but with improved refinement giving an
R value of 0.03 compared to 0.12. In each complex the
geometry of the Fe centre is octahedral but with significant distortion.
4-O-Methylconhypoprotocetraric Acid, a New β-Orcinol Depsidone from the Lichen Xanthoparmelia competita
Authors: Elix John A. , Wardlaw Judith H.
Published: September 2002

The depsidone 4-O-methylconhypoprotocetraric acid
(8-hydroxy-3-methoxy-1,4,6,9-tetramethyl-11-oxo-11H-dibenzo[b,e][1,4]-dioxepin-7-carboxylic
acid) (4) has been isolated from the lichen
Xanthoparmelia competita together with usnic acid and
4-O-methylhypoprotocetraric acid (3). The structure of
compound (4) followed from a combination of spectroscopic data.
Structural Properties of a Dimeric Phenylcyanamidocopper(I) Complex, [{Cu(PPh3)2(C6H5NCN)}2]
Authors: Ainscough Eric W. , Brodie Andrew M. , Healy Peter C. , Waters Joyce M.
Published: September 2002

The X-ray crystal structure determination of
bis[-(phenylcyanamido)bis(triphenylphosphine)copper(I)],
[{Cu(PPh3)2(C6H5NCN)}2],
(1) is reported. The complex has a centrosymmetric dimeric structure with the
phenylcyanamide ligands bridging the copper atoms in a -1,3-fashion. The
structure is compared with that of the 4-methylphenylcyanamido complex,
[{Cu(PPh3)2(4-MeC6H4NCN)}2]
(2), and the differences observed in the Cu–P bond lengths compared with
changes in the solid state 31P cross-polarization
magic-angle spinning (CPMAS) spectra of the two complexes.
Chromatography on Cation Columns: a Much-Neglected Method of Separation
Authors: Angyal S. J.
Published: September 2002

Chromatography on a column of cations immobilized on a cation-exchange resin is particularly suitable for the separation of polyhydroxy compounds, particularly carbohydrates. Neodymium is recommended as the cation of choice.
Current Chemistry: Synthetic Opal as Two-Dimensional and Three-Dimensional Nanotemplates
Authors: White Paul A. , Heales Lindsey , Barber Richard L. , Pham Khoa N. , Turney Terence W.
Published: September 2002

Manuscript received: 3 October 2001.
Final version: 7 January 2002.
Evidence for Efficient Unpromoted Regioselective Reactions of Vicinal and Non-Vicinal Diols
Authors: Fraser-Reid B. , Lopez J. C. , Anilkumar G. nair , Lopez J. C. , Nair L. G. , Gomez A. , Uriel C. , Radhakrishnan K. V.
Published: September 2002

A 1965 publication from Angyal's laboratory reported that the cis-vicinal diol group of tetra-O-benzyl myo-inositol reacted regioselectively, sometimes exclusively, with acylating agents at the equatorial OH, but with alkylating agents at the axial OH. Recent reports by Fraser-Reid and coworkers showed that such selectivities were also found for the trans-1,3-diol of tetra-O-benzyl myo-inositol, as well as the C2-C4 hydroxyls of a di-O-allyl mannopyranoside. In addition, the latter workers reported that regioselectivities could be extended to glycosidation reactions. Thus, n-pentenyl ortho ester (NPOE) and 2-O-acyl n-pentenyl glycoside (NPGAC) donors reacted preferentially, if not exclusively, at the equatorial OH, whereas 2-O-alkyl counterparts (NPGALK) gave mixtures, usually with major glycosidation occuring at the axial OH. The present manuscript examines several vicinal diols, and reports that the NPOE and (NPGAC) donors frequently react at only one of the two hydroxy groups in good yield, whereas the corresponding benzylated donor (NPGALK) is less discriminating, and frequently gives lower yields. In a key experiment to examine the basis of the selectivity, it was found that the highly hindered C3 OH of 4,6-O-benzylidene methyl a-D-altropyranoside was selectively glycosylated with NPOE in 92% yield, thereby establishing that the glycosidation preference is not due to steric hindrance.
A Novel Compound Enniatin G from the Mangrove Fungus Halosarpheia sp. (strain #732) from the South China Sea
Authors: Lin Y. , Wang J. , Wu X. , Zhou S. , Vrijmoed L. L. P. , Jones E. B. G.
Published: September 2002

A novel cyclic depsipeptide, enniatin G, together with enniatins B and B4 were isolated from the mangrove fungus Halosarpheia sp.(strain 732) from the South China Sea. Their structures were determined by analysis of spectroscopic data, mainly two-dimensional nuclear magnetic resonance experiments. Enniatin G exhibited activity against Heps 7402, ED50 12mg/mL.
Partial Etherification Reactions of Cavitand Phenol Bowls
Authors: Barrett E. S. , Irwin J. L. , Picker K. , Sherburn M. S.
Published: September 2002

Reactions between the C4v-symmetrical cavitand tetraphenol (2), various bases, and less than 4 molar equivalents of alkyl halides result in the generation of statistical mixtures of the five possible ether products along with unreacted starting material. Useful quantities of monoalkoxytriphenol (8), A,B-dialkoxydiphenol (9) and trialkoxymonophenol (11) are obtained by controlling the reaction stoichiometry and the desired products can, in general, be isolated by straightforward chromatographic means.
Synthesis and X-Ray Structure of a Heterovalent, Cycloaurated Pentafluorophenylgold(I)/Pentafluorophenylgold(III) Complex
Authors: Bennett M. A. , Bhargava S. K. , Mohr F. , Welling L. L. , Willis A. C.
Published: September 2002

The heterovalent gold(I)/gold(III) complex [(C6F5)AuI(μ-2-Ph2PC6H3-6-Me)AuIII(C6F5){η2-(6-MeC6H3-2-PPh2)}] has been prepared and structurally characterized by X-ray crystallography. It shows square planar stereochemistry at AuIII incorporating a four-membered chelate ring and linear arrangement at AuI. The compound is a rare example of a heterovalent complex containing an aryl ligand on each gold atom.
A Chemoenzymatic Synthesis of Differentially Protected D-Talose Derivatives
Authors: Banwell M. G. , Edwards A. J. , Lambert J. N. , Ma X. H. , Watson K. G.
Published: September 2002

The synthesis of the D-talose derivatives (10)-(14) from the readily available and enantiomerically pure cis-1,2-dihydrocatechol (2) is described. The structures of compounds (7) and (13) have been established by single-crystal X-ray analyses.
Formation of Regular Honeycomb-Patterned Porous Film by Self-Organization
Authors: Stenzel M. H.
Published: September 2002

Regular honeycomb-structured porous films can be prepared by the casting of a polymer solution under humid conditions. The origin of these pores is `empty' water droplets, which condense from the humid atmosphere onto the solution. The water droplets self-organize into a regular array and serve as a highly regular template for the precipitating polymer. The pore size can be controlled by the casting conditions as well as by the polymer used. A spherical-shaped polymer is required to support a high regularity. These specially designed polymers can easily be prepared by controlled radical polymerization techniques.
The Facile Production of N-Methyl Amino Acids via Oxazolidinones
Authors: Aurelio Luigi , Brownlee Robert T. C. , Hughes Andrew B. , Sleebs Brad E.
Published: September 2002

A range of oxazolidinones derived from N-carbamoyl
α-amino acids were prepared by an efficient method as key intermediates
in the synthesis of N-methyl amino acids and peptides.
The method was readily applied to most α-amino acids except those with
basic side chains. The oxazolidinones were converted by reductive cleavage
into N-methyl α-amino acids.
Anticipating Molecular Polarity. III.A Graph-Theoretical Approach to Semiempirical pi-Polarizations of Non-Alternant Monocycles and Bicycles
Authors: Frederiksen Mathias Ugelstad , Langler Richard Francis , Staples Mark Andrew , Verma Sachin Dev
Published: September 2002

A straightforward graph-theoretical approach to anticipating PM3 semiempirical
molecular orbital π-polarizations for non-alternant monocycles and
bicycles is described. This approach allows one to see the relationship
between hydrocarbon structural relatives and their calculated polarities.
The Structure and Stereochemistry of Coronatoquinone, a New Pyranonaphthazarin from the Lichen Pseudocyphellaria coronata.
Authors: Ernst-Russell Michael A. , Elix John A. , Chai Christina L. L. , Rive Megan J. , Wardlaw Judith H.
Published: September 2002

A new pyranonaphthazarin, coronatoquinone
[(1S)-1,5,8,10-tetrahydroxy-7-methoxy-3-methyl-6,9-dihydro-1H-naphtho[2,3-c]pyran-6,9-dione]
(1), has been isolated from the lichen
Pseudocyphellaria coronata. The structure of
coronatoquinone (1) was established by spectroscopic methods and its absolute
configuration determined from chiroptical measurements.
Approaches to the High-Throughput Synthesis of Analogues of Dihydroaeruginoic Acid
Authors: Loughlin Wendy A. , Knevitt Scott A. , Hosking Rachel E. , Marshall Raymond L.
Published: September 2002

A solution-phase synthesis of dihydroaeruginoic acid (1) was identified for
its application towards the high-throughput synthesis of analogues of
dihydroaeruginoic acid (1). Development of a solid-phase synthesis of
dihydroaeruginoic acid (1) was examined. Simple analogues (11a–f) of
dihydroaeruginoic acid (1) were obtained by using solution-phase
high-throughput synthesis.
Investigations into the Chemistry of Some 1,6-Epithio and 1,6-Episeleno ß-D-Glucopyranoses
Authors: Skelton Brian W. , Stick Robert V. , Tilbrook D. Matthew G. , White Allan H. , Williams Spencer J.
Published: September 2002

Derivatives of 1,6-dideoxy-1,6-epithio-β-D-glucopyranose have been shown
to undergo oxidation reactions to afford the corresponding sulfoxides and
sulfones. The sulfoxides participate in Pummerer reactions to afford the
corresponding α-acetoxy sulfides which were then oxidized further. None
of the sulfoxides, sulfones or α-acetoxy sulfides prepared were
particularly efficient glycosyl donors. Also presented are crystal structures
of 1,6-dideoxy-1,6-epithio-β-D-glucopyranose
S,S-dioxide and
1,6-dideoxy-1,6-episeleno-β-D-glucopyranose, interesting analogues of
1,6-anhydro-β-D-glucopyranose.
Synthesis of the Syributins and Formal Total Synthesis of Syringolide 1.
Authors: Di Florio Romina , Rizzacasa Mark A.
Published: September 2002

A synthesis of syributins 1 (5) and 2 (6) from D-glyceraldehyde acetonide (12)
and furans (14) and (15) is described. Compounds (5) and (6) are cometabolites
of the novel non-proteinaceous C-glycosidic elicitor
molecules the syringolides 1 (1) and 2 (2). Under a variety of acidic
conditions, the intermediate butenolides (9) and (10) provided syributins 1
(5) and 2 (6). Similar results have been reported by Honda and coworkers who
converted butenolide (20) into syringolide 1 (1). Since compound (20) was also
synthesized by the present new route, a formal synthesis of syringolide 1 (1)
has been achieved.
Application of biochemical studies to improving nitrogen fixation
Authors: Vance C. P. , Lamb J. F. S.
Published: September 2002

Improvement of symbiotic nitrogen fixation requires a multidisciplinary
approach with a comprehensive program ranging from microbial ecology to plant
breeding and genomics. Achievement of symbiotic nitrogen fixation requires at
least 100 genes from each partner interacting in a favorable environment. The
more information that we obtain from applied and fundamental studies of
Rhizobium–legume and
Frankia–non-legume symbioses, the greater are our
chances to extend nitrogen fixation to non-fixing species. Studies with
alfalfa (Medicago sativa L.) aimed at improving
symbiotic nitrogen fixation have resulted in significant advances in germplasm
development, plant biochemistry, microbial ecology and the understanding of
plant genes involved in nodule nitrogen and carbon metabolism. However,
translation to field improvement of symbiotic nitrogen fixation has proven
elusive.
Weed interference reduces yield of coppiced tea tree (Melaleuca alternifolia)
Authors: Virtue J. G. , Sutton B. G. , Murtagh G. J. , Cousens R. D.
Published: September 2002

The effects of weeds on the oil yield of tea tree,
Melaleuca alternifolia (Maiden and Betche) Cheel, were
examined in 6 field experiments. Tea tree is grown in plantations as a coppice
crop, being annually harvested for its leaf oil. Plots were maintained with
and without weed control between successive harvests. Weed interference
significantly reduced leaf biomass yield of regrowth tea tree in 5 of 6
experiments, with a mean yield loss of 25%. Yield losses ranged from 9
to 47%, and these were correlated with weed biomass remaining at
harvest. Weed interference did not significantly affect leaf oil
concentration, or its chemical composition.
Genetic and environmental influences on beef tenderness
Authors: Robinson D. L. , Ferguson D. M. , Oddy V. H. , Perry D. , Thompson J.
Published: September 2002

Mechanical tenderness measurements of M. longissimus
(LM) and M. semitendinosus (ST) were analysed from 1392
tropically adapted (Brahman, Belmont Red and Santa Gertrudis) cattle grown out
and finished in both tropical and temperate environments, and 2408 temperate
breed (Angus, Hereford, Murray Grey and Shorthorn) cattle grown out and
finished in a temperate environment. Groups of cattle from both environments
were managed under 2 finishing systems (pasture and feedlot) to market
liveweights of 400, 520 (steers and heifers) and 600 kg (steers only).
Carcasses were electrically stimulated and care was taken to minimise stress
before slaughter.
Estimated genetic variation (GV) of compression of unaged LM and ST muscles
was 0.006 and 0.018 kg2 respectively in tropically
adapted and 0.004 and 0.009 kg2 in temperate breeds
(phenotypic means 1.7, 2.1, 1.6, 2.1 kg; heritabilities,
h2 = 0.16, 0.24, 0.10, 0.16). Estimated GV for LM
and ST shear force was 0.24 and 0.12 kg2 in tropically
adapted and 0.06 and 0.02 kg2 in temperate breeds (means
4.3, 4.6, 4.0 and 4.7 kg; h2 = 0.38, 0.40, 0.11,
0.06). Genetic correlations among shear and compression forces of the ST and
LM ranged from 0.28 to 0.95 in tropically adapted and –0.20 to 0.60 in
temperate breeds. The fixed effects model (market, finish, breed, birth herd,
management group and interactions) explained about half the variation in
compression measurements, but only 16% and 27% of the variation
of LM shear force in tropically adapted and temperate breeds.
The relatively low genetic variation and inconsistent genetic correlations in
temperate breeds suggest genetic improvement in tenderness may be less
important than effective pre- and post-slaughter management protocols. The
higher additive genetic variances and moderate heritabilities in tropically
adapted breeds suggest genetic improvement is possible but this will be most
effective if combined with effective control of slaughter protocols.
Application of DNA fingerprinting for the classification of selected almond [Prunus dulcis (Miller) D. A. Webb] cultivars
Authors: Woolley F. M. , Collins G. G. , Sedgley M.
Published: September 2002

Almond cultivars developed in Australia are thought to have descended from 2
breeding lines, 1 from hard-shelled Spanish/Jordan types, and the other
from paper-shell Californian types. However, the precise derivation of many
individual Australian cultivars is uncertain. Randomly amplified polymorphic
DNA (RAPD) was used to estimate the genetic similarities between 50 accessions
of almond cultivars derived from Australia, California, Europe and the Middle
East, and individual accessions of Prunus orientalis
(Miller) D. A. Webb and Prunus webbii (Spach) Vieh.
Amplification products were analysed using the simple matching coefficient and
the unweighted pair group method with arithmetic averages to cluster
individuals into a dendrogram. Cultivars known to have originated in Europe or
the Middle East clustered in a different group from those known to have
originated in California confirming the 2 suspected breeding lines. The origin
of some common Australian commercial cultivars was inferred by their placement
on the dendrogram, and the possible parentage of some Australian selections is
discussed.
Communication, education and training strategies to deliver CRC outcomes to beef industry stakeholders
Authors: Bindon B. M. , Burrow H. M. , Kinghorn B. P.
Published: September 2002

At the commencement of the Cooperative Research Centre for the Cattle and Beef
Industry (Meat Quality) participating scientists were encouraged to anticipate
the methods and channels that might be used to deliver the Cooperative
Research Centre’s research outcomes to beef industry end-users. This
important step was seen as the completion of the process, which began with the
beef industry issue, leading then to formulation of the Cooperative Research
Centre concept, initiation of the research program, completion of research and
finally commercialisation or delivery of products and processes to industry.
This paper deals with techniques, institutions and commercial arrangements
employed to achieve delivery and adoption of diverse outcomes of the
Cooperative Research Centre.
Investigating structural stability using the soil water characteristic curve
Authors: Barlow K. , Nash D.
Published: September 2002

Soil physical properties, including infiltration, strength, water storage and
aeration, affect the productivity of agricultural land. This paper
investigated the stability of soil structure to chemical disruption, using the
soil water characteristic curve. The soil water characteristic was determined
twice on intact soil cores of an acidic mesotrophic, red Ferrosol (Gn4.11) and
an acidic, eutrophic, grey Dermosol (Gn4.51). Saturated NaCl or deionised
water was used to wet the soil cores between each determination.
Despite the variability associated with undisturbed soil cores, significant
differences were detected in the soil water characteristic curves both within
and between soil types. The ability to detect differences in the soil
structure of the Ferrosol and Dermosol, both Emerson class 8, suggests this
technique could be used to determine the chemical stability of soils with
minimal mechanical disruption of the structure.
Counts versus categories: choosing the more appropriate weed scoring method
Authors: Rew L. J. , Alston C. L. , Harden S. , Felton W. L.
Published: September 2002

Weed sampling can be a time consuming and repetitive task if populations are
to be adequately monitored. In situations where there are a range of species
densities, high numbers of samples are required, and/or where the sample
area is large, it may be appropriate to group weed densities into ordinal
categories. An ordinal system is outlined in which weed densities were
categorised into 8 groups. Weed species composition and density were assessed
using the category and count methods, on 10 fields in northern New South
Wales. A multinomial distribution was used within a generalised linear model
framework, to assess the validity of the category method. A simulation study
was also conducted to assess the performance of the 2 scoring methods. The
main difference between the count and category predictions is that count data
produce a population mean, whereas ordinal scores provide a mean within a
categorical range. Collecting categorical data is less time consuming,
particularly for higher weed densities. However, the simulations showed that
to determine significant differences between population means required more
samples using the category method (15–30) compared with less than
20 for the count method, assuming a satisfactory study power of 0.9. The
category method is reliable, particularly where general trends or baseline
information are required from the data. When the population density is low and
more detailed information is required, counts are a more appropriate
methodology.