New diterpenes from Araucaria cunninghami

Eleven labdane diterpenes, nine of which are new compounds, were identified in the oleoresin of Araucaria cunninghami.     

Neutral diterpenes from Araucaria bidwilli

Five ent-labdane diterpenes were isolated from the neutral fraction of the resin of Araucaria bidwilli. Three of them, previously unknown, were     

Diterpenes from Baccharis species

The aerial parts of Baccharis minutiflora afforded in addition to known compounds eight new ent-kaurane derivatives, one being a homo kaurane, while the aerial parts of B. alatemoides gave two pairs of epimeric clerodane derivatives, which, however, had to be modified chemically before they could be separated. The stereochemistry of these diterpenes could not be elucidated with certainty.     

Diterpenes from Koanophyllon species

The investigation of two Koanophyllon species afforded, in addition to known compounds, several new diterpenes, two new geranylgeraniol derivatives and four diterpenes, most probably closely related to clerodanes; their structures, however, could not be deduced with certainty. The chemotaxonomic situation of this genus is discussed briefly.     

Clerodane and labdane diterpenoids from Baccharis species

The investigation of eight Baccharis species afforded, in addition to known compounds, five new clerodanes, three labdane derivatives and a nor-diterpene as well as one hydroperoxide derived from 4α-hydroxygermacra-1(10), 5-diene. The structures were elucidated by spectroscopic methods. The structures of esters isolated previously from B. cassinaefolia have to be revised. Chemotaxonomic aspects are discussed briefly.     

New labdane diterpenes from Araucaria cooki

Eight new and seven known labdane diterpenes were identified in the oleoresin of Araucaria cooki.     

Diterpenes from Croton salutaris

The twigs of Croton salutaris afforded three new acyclic diterpenes and a new tricyclic diterpene as well as a known compound, sonderianol. The structures of three acyclic diterpenes [(10E)-3,12-dihydroxy-3,7,11,15-tetramethyl-1,10,14-hexadecatrien-5,13-dione, (6E,10E)-3,12-dihydroxy-3,7,11,15-tetramethyl-1,6,10,14-hexadecatetraen-5,13-dione and (6Z,10E)-3,12-dihydroxy-3,7,11,15-tetramethyl-1,6,10,14-hexadecatetraen-5,13-dione] and a tricyclic diterpene [12-hydroxy-13-methylpodocarpa-9,11,13-trien-3-one] were determined by spectral methods.     

The diterpene acids in the bled resins of three pacific kauri, Agathis vitiensis, A. Lanceolata and A. Macrophylla

The composition of the diterpene acids in the bled resins of three kauri pines, Agathis vitiensis from Fiji, A. lanceolata from New Caledonia, and A. macrophylla from the Solomon Islands has been determined by extraction, methylation and chromatography. The results are compared with Agathis species from Australia and New Zealand.     

Diterpenes and tetranorditerpenes from Acritopappus species

The investigation of four Acritopappus species afforded twenty-three new diterpenes of the labdane or kolavane type and three tetranorditerpenes as well as two new benzofuran derivatives and a hydroxybicyclogermacrene. The structures were elucidated by spectroscopic methods and by some chemical transformations. Though the absolute configuration were not established in all cases, most probably all diterpenes were ent-labdanes or kolavanes (clerodanes). The chemotaxonomic importance of this investigation is discussed briefly.     

Five diterpenes and other constituents from nine Baccharis species

The investigation of nine Baccharis species afforded, in addition to known compounds, three new clerodane derivatives related to bacchotricuneatin B, two ent-labdane derivatives, two 3-acetoxyflavanones, a benzofuran derivative and a chromene. The overall picture of the chemistry of this large genus is still not very clear.     

Diterpenes of Larix oleoresins

Oleoresins from most species of the genus Larix have been analysed by GLC for their diterpene composition. Common to all are the abietadiene and isopimaradiene acids usual in Pinaceae with the corresponding aldehydes and alcohols in small amounts. Epimanool also occurs in all, but larixol and its acetate is confined to L. decidua and L. gmelini, and epitorulosol to the remainder. In the hybrid L. Xeurolepis both of these last two compounds are present.     

Somatic embryogenesis in Araucaria angustifolia

Immature and mature zygotic embryos were used as source of explants for induction of somatic embryogenesis in Araucaria angustifolia. Embryogenic cultures (EC) were only obtained from immature zygotic embryos. Basic medium, carbon source, and genotype showed a significant influence on the formation of stage I somatic embryos (SE). When EC were submitted to maturation conditions, SE continued their individual development until stage II, but mature embryos were not obtained. Proteins secreted by embryogenic cultures were, to a certain degree, genotype specific and included an extracellular class IV chitinase and β-1-3-glucanase.     

Diterpenes and kawalactone from the rhizomes of Amomum uliginosum J.Koenig

Seven compounds, including three labdane diterpenes (1, 4, 6), one bisnorlabdane diterpene (2), one steroid (3), one sesquiterpene (5) and one kawalactone (7) were isolated from the rhizomes of Amomum uliginosum J.Koenig. Compounds 1–4, 6 and 7 were firstly isolated from the genus Amomum. This work represented the first phytochemical study on this plant. The chemotaxonomic significance of these compounds was summarized.     

Diterpenes with a new carbon skeleton from Printzia Laxa

The aerial parts of the South African composite Printzia laxa contain two manoyl oxides and three clerodane derivatives together with two further acids, which belong to a new type of diterpene, biogenetically closely related to the clerodanes. The structures have been elucidated by spectroscopic methods. The constituents may indicate some relationship of Printzia to the tribe Astereae.     

Characterization of nuclear microsatellites in New Caledonian Araucaria species

Thirteen of the world's 19 species of Araucaria are endemic to the Pacific Ocean island of New Caledonia. In order to investigate the evolutionary biological processes underlying the radiation of the genus on the island we have developed a set of nuclear microsatellite loci. Using a membrane enrichment procedure, five loci have been developed (four derived from A. subulata DNA and one from A. rulei DNA) which amplified in A. columnaris. PCR products of the expected size were also produced in a very limited sample of eight other New Caledonian Araucaria species tested.     

Diterpenes and sesquiterpenes from the bark of Taxus yunnanensis

Two taxane-type diterpenes, 10beta-acetoxy-2alpha,5alpha,7beta,9alpha-tetrahydroxytaxa-4(20),11-dien-13-one and 2alpha-acetoxy-9alpha-benzoyloxy-5alpha,7beta,10beta,15-tetrahydroxy-11(15-->1)- abeotaxa-4(20),11-dien-13-one, and two new drimane-type sesquiterpenes, 1beta-acetoxy-7-drimen-11alpha-ol-12,11-lactone and 1beta-acetoxy-11,12-epoxy-6-drimen-8alpha,11alpha-diol, were isolated from the bark of Taxus yunnanensis together with 35 known taxane-type diterpenes, a known drimane-type sesquiterpene and a known flavanone.