Paul I. Forster

Alkaloids and limonoids from Bouchardatia neurococca: systematic significance

Five alkaloids, four beta-indoloquinazoline and one furoquinoline, and four terpenoids, three limonoids and one modified sesquiterpene, have been obtained from the aerial parts of Bouchardatia neurococca (Rutaceae). Two of the alkaloids, 1,2-dihydroxyrutaecarpine and 2-(2-[3-formylindolyl])-(3H)-quinazolin-4-one (bouchardatine), and two of the limonoids, 23-oxo-21xi-hydroxy-21,23-dihydroveprisone (veprisonic acid) and 21-oxo-23xi-hydroxy-21,23-dihydroveprisone (isoveprisonic acid) are new. The pattern of secondary metabolites isolated is rather unusual in the Rutaceae and is reminiscent of Tetradium, a genus with which Bouchardatia has not previously been associated.

Association of cone thermogenesis and volatiles with pollinator specificity in Macrozamia cycads

Cone traits (volatile components and thermogenesis) of three cycad species in the genus Macrozamia were examined for differences related to their specific insect pollinators, the weevil, Tranes spp., or the thrips, Cycadothrips chadwicki. Linalool (>80% of emissions) dominated cone volatile components of M. machinii (Tranes-pollinated) and beta-myrcene was a minor component (<9% of emissions). Volatiles of M. lucida and M. macleayi cones (Cycadothrips-pollinated) were dominated by beta-myrcene (up to 97% of emissions), but no linalool was detected. Pollinator movement into and out of cones coincided with cone thermogenesis and peak odor emission: around sunset for Tranes, and at mid-day for Cycadothrips. Female cone traits were similar to those of their conspecific male cones. Differences in cone traits between Macrozamia species may thus be responsible for conferring pollinator specificity in areas of sympatry.

Pollination of Australian Macrozamia cycads (Zamiaceae): effectiveness and behavior of specialist vectors in a dependent mutualism

Complementary field and laboratory tests confirmed and quantified the pollination abilities of Tranes sp. weevils and Cycadothrips chadwicki thrips, specialist insects of their respective cycad hosts, Macrozamia machinii and M. lucida. No agamospermous seeds were produced when both wind and insects were excluded from female cones; and the exclusion of wind-vectored pollen alone did not eliminate seed set, because insects were able to reach the cone. Based on enclosure pollination tests, each weevil pollinates an average 26.2 ovules per cone and each thrips 2.4 ovules per cone. These pollinators visited similar numbers of ovules per cone in fluorescent dye tests that traced insect movement through cones. Fluorescent dye granules deposited by Cycadothrips were concentrated around the micropyle of each visited ovule, the site of pollen droplet release, where pollen must be deposited to achieve pollination. In contrast, Tranes weevils left dye scattered on different areas of each visited ovule, indicating that chance plays a greater role in this system. Each weevil and 25 thrips delivered 6.2 and 5.2 pollen grains, respectively, on average, to each visited ovule per cone, based on examination of dissected pollen canals. In sum, the pollination potential of 25 Cycadothrips approximates that of one Tranes weevil.

The steam volatile oil of Wollemia nobilis and its comparison with other members of the Araucariaceae (Agathis and Araucaria).

The leaf essential oil of Wollemia nobilis (Wollemi Pine) has been investigated and compared with other members of the family Araucariaceae. All araucaroids examined yielded steam volatile oils in low yields. The oil from Wollemia nobilis was composed mainly of (+)-16-kaurene (60%), together with alpha-pinene (9%) and germacrene-D (8%). Oils from Agathis species endemic to Australia were high in monoterpenes, in contrast to those isolated from extra-Australian species. The major constituents of A. atropurpurea oil were phyllocladene (13%) and 16-kaurene (19%), followed by alpha-pinene (8%) and delta-cadinene (9%). A. microstachya yielded oil in which alpha-pinene (18%) was the major component; the only other components in excess of 5% were myrcene (7%), bicyclogermacrene (6%) and delta-cadinene (6%). A. robusta oil contained spathulenol (37%) and rimuene (6%). Approximately 40% of the oil was unidentified sesquiterpenes. A. australis oil contained 16-kaurene (37%), sclarene (5%) and an unidentified oxygenated diterpene K (12%) as major components; the only other compound in excess of 5% was germacrene-D (9%). 5,15-Rosadiene (60%), and 16-kaurene (7%) were the major constituents of A. macrophylla oil. A. moorei oil was rich in sesquiterpenes, but the only compounds in excess of 5% were allo-aromadendrene (6%), germacrene-D, delta-cadinene (10%), an unidentified sesquiterpene (12%) and 16-kaurene (6%). In A. ovata oil the most significant compounds were caryophyllene oxide (15%) and phyllocladene (39%). Araucaria angustifolia contained germacrene-D (9%) and the diterpenes hibaene (30%) and phyllocladene (20%) as major components of its essential oil. Oils of A. bidwillii, A. columnaris and A. cunninghamii were all low in mono- and sesquiterpenes and high in diterpenes. In the first, hibaene (76%) was the major constituent; the second contained hibaene (9%), sclarene (6%), luxuriadiene (13-epi-dolabradiene)(23%) and two unidentified diterpene hydrocarbons (B) (33%) and (E) (10%). In the last, 16-kaurene (53%) was the most significant component followed by hibaene (29%). A. heterophylla was unusual in that over half the oil was made up of the monoterpenoid alpha-pinene (52%), with phyllocladene (32%) being the only other compound of significance. alpha-Pinene (18%) was a significant component of A. hunsteinii oil; sclarene (11%) and germacrene-D (5%) were the only other compounds present in concentrations of more than 5%. A. luxurians oil was composed of 5,15-rosadiene (20%) and luxuriadiene (13-epi-dolabradiene) (66%), previously unreported from natural sources. The major components of A. montana were phyllocladene (61%) and 16-kaurene (23%). Sclarene (20%), luxuriadiene (19%) and the unidentified diterpene hydrocarbons (B) (25%) and (E) (10%) were the most important constituents of A. muelleri oil. A. scopulorum contained large amounts of 16-alpha-phyllocladanol (41%) as well as luxuridiene (10%) and delta-cadinene and alpha-copaene, both at 6%.

Acaricidal and cytotoxic activities of extracts from selected genera of Australian Lamiaceae.

Abstract Crude foliar extracts of 67 species from six subfamilies of Australian Lamiaceae were screened by whole organism contact toxicity on the polyphagous mite Tetranychus urticae Koch (Acari: Tetranychidae) by using a Potter precision spray tower. Cytotoxicity assessments against insect cell lines from Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) and Drosophila melanogaster (Meigen) (Diptera: Drosophilidae) also were made. The Spodoptera cell line was more susceptible to extracts than the Drosophila cell line. No direct correlation was observed between the two screening methods, but several interesting relationships were identified. Extracts from subfamilies Ajugoideae, Scutellarioideae, Chloanthoideae, Viticoideae and Nepetoideae showed acaricidal activity, whereas only those from Ajugoideae and Nepetoideae displayed potent cytotoxic effects. A range of activities was observed for the 25 species of Plectranthus, 14 of which showed moderate-to-high contact toxicity against T. urticae. Overall, the lowest toxicity was observed for extracts from the plant subfamily Prostantheroideae, which showed little contact toxicity or cytotoxicity for the 18 extracts studied.

Leaf Oils of the Genus Backhousia (Myrtaceae)

ABSTRACT The leaf oils of eight described and one undescribed species of Backhousia were examined by GC and GC/MS. The major components of the five suspected chemotypes of B. angustifolia F. Muell. were 1,8-cineole, (E)-β-ocimene, angustifolenone, angustifolionol, dehydroangustione and angustione. B. anisata Vickery was found to exist in two chemotypes in whch the major compound was either (E)-anethole or methyl chavicol. The oil from B. bancroftii F. M. Bailey & F. Muell., which varied quantitatively between trees, contained octyl acetate (0.3–61.7%), dodecyl acetate (0.2–21.0%), dodecanol (trace-22.9%), decyl acetate (0.5–39.0%), decanol (0.1–17.4%), 2,4,6-trimethoxy-3- methylacetophenone (trace-23.0%) and a novel compound, bancroftinone (6-hydroxy-2,4-dimethoxy-3-methylacetophenone) (trace-90.0%) as its major constituents. B. citriodora F. Muell. was found to exist as two chemotypes in which either citral or citronellal predominated. The major constituents of B. hughesii C. T. White were β-bisabolene (...

Female flowers and systematic position of Picrodendraceae (Euphorbiaceae s.l., Malpighiales)

This is the first comparative study of floral structure of the recently established new family Picrodendraceae (part of Euphorbiaceae s.l.) in Malpighiales. Nine species of eight (out of ca. 28) genera were studied. Female flowers are mainly completely trimerous, and in such flowers the perianth consists of one or two whorls of sepals. A floral disc (which probably functions as a nectary) is mostly present. The free parts of the carpels are simple (unbranched) in all ten species studied. Each carpel contains two crassinucellar, anatropous or hemitropous, epitropous (antitropous) ovules, which are covered by a large obturator. The inner integument is thicker than the outer (equally thick in two species studied), and commonly both integuments form the micropyle. In mature ovules the vascular bundle commonly branches in the chalaza, with the branches extending to the base of the inner integument but not entering it. A nucellar cap and, less often, a nucellar beak is formed. Floral structure supports the close relationship of Picrodendraceae with Phyllanthaceae and Euphorbiaceae s.str. within Malpighiales, as suggested (but not yet strongly supported) by some recent published molecular analyses. These three families share a unique combination of characters, including (1) unisexual, apetalous trimerous flowers, (2) crassinucellar ovules with a nucellar beak, (3) a large obturator, and (4) explosive fruits with carunculate seeds.

Essential Oils from the Leaves of Some Queensland Annonaceae

Abstract The leaf oils of seven species from the family Annonaceae, growing in Queensland, Australia, have been examined. Artabotrys sp. (Claudie River B.Gray 3240) produced oil in poor yield in which unidentified oxygenated sesquiterpenes accounted for approximately 80% of the oil. Uvaria rufa gave an oil rich in sesquiterpenes, in which the principal component was a-humulene (50%), while in Uvaria concava the principal component was spathulenol (32%). Benzyl benzoate was also present (5%) in U. rufa. In Cyathostemma micranthum the principal components were caryophyllene oxide (26%), spathulenol (11%) and benzyl benzoate (4%). The oil of Mitrephora zippeliana existed in two forms in which either monoterpenes were more prominent with a-pinene (13%) and β-pinene (15%) being the major components together with the sesquiterpenes caryophyllene oxide (10%), spathulenol (10%) and β-caryophyllene (8%), or sesquiterpenes were prominent with β-caryophyllene (18%), α-humulene (7%), γ-curcumene (4%), bicyclogermacrene (4%), ar-curcumene (5%), caryophyllene oxide (3%) and spathulenol (5%) being the principal components. Goniothalamus australis presented a leaf oil that contained significant amounts of both mono-and sesquiterpenes; one sample contained pinocarvone (10%) and trans-pinocarveol (17%) as the principal monoterpenes, while a second collection contained α-pinene (10–11%) as the principal component. Cananga odorata gave a leaf oil in which the major components were β-caryophyllene (34–52%), sabinene (1–20%), α-humulene (6–11%) and a-pinene (1–17%).

Major clades of Australasian Rutoideae (Rutaceae) based on rbcL and atpB sequences.

Background Rutaceae subfamily Rutoideae (46 genera, c. 660 species) is diverse in both rainforests and sclerophyll vegetation of Australasia. Australia and New Caledonia are centres of endemism with a number of genera and species distributed disjunctly between the two regions. Our aim was to generate a high-level molecular phylogeny for the Australasian Rutoideae and identify major clades as a framework for assessing morphological and biogeographic patterns and taxonomy. Methodology/Principal Findings Phylogenetic analyses were based on chloroplast genes, rbcL and atpB, for 108 samples (78 new here), including 38 of 46 Australasian genera. Results were integrated with those from other molecular studies to produce a supertree for Rutaceae worldwide, including 115 of 154 genera. Australasian clades are poorly matched with existing tribal classifications, and genera Philotheca and Boronia are not monophyletic. Major sclerophyll lineages in Australia belong to two separate clades, each with an early divergence between rainforest and sclerophyll taxa. Dehiscent fruits with seeds ejected at maturity (often associated with myrmecochory) are inferred as ancestral; derived states include woody capsules with winged seeds, samaras, fleshy drupes, and retention and display of seeds in dehisced fruits (the last two states adaptations to bird dispersal, with multiple origins among rainforest genera). Patterns of relationship and levels of sequence divergence in some taxa, mostly species, with bird-dispersed (Acronychia, Sarcomelicope, Halfordia and Melicope) or winged (Flindersia) seeds are consistent with recent long-distance dispersal between Australia and New Caledonia. Other deeper Australian/New Caledonian divergences, some involving ant-dispersed taxa (e.g., Neoschmidia), suggest older vicariance. Conclusions/Significance This comprehensive molecular phylogeny of the Australasian Rutoideae gives a broad overview of the group’s evolutionary and biogeographic history. Deficiencies of infrafamilial classifications of Rutoideae have long been recognised, and our results provide a basis for taxonomic revision and a necessary framework for more focused studies of genera and species.

Low isozymic differentiation among five species of the Macrozamia heteromera group (Zamiaceae)

Abstract Starch gel electrophoresis was employed to estimate the levels of genetic variation among five entities of the Macrozamia heteromera (Zamiaceae) group which can be recognised on morphological grounds. A total of 168 specimens were assayed for 12 enzyme systems coded by 16 loci. Low levels of genetic variation were observed with 10 of the 17 loci (58%) being monomorphic. Mean percent polymorphic loci ( P =26%), number of alleles per locus ( A =1.3) and expected heterozygosity ( H e =0.06) were all low. Although notably morphologically different, the species are very similar genetically. The overall G st value of 0.10 and the high genetic identity value of (range 0.92–0.97) suggest that these species are either recently evolved or they are depauperate in genetic variation due to inbreeding.