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| | 1. |
2005 Nov 9 |
Exploration of phylogenetic data using a global sequence analysis method
Chapus, Dufraigne, Edwards, Giron, Fertil, Deschavanne
BMC Evol Biol 2005 Nov 9;5:63. published online before print
Abstract
Molecular phylogenetic methods are based on alignments of nucleic or peptidic sequences. The tremendous increase in molecular data permits phylogenetic analyses of very long sequences and of many species, but also requires methods to help manage large datasets.
[Pubmed: 16280081]
| | 2. |
2006 Feb 16 |
New terpenoids from Amentotaxus formosana.
Chen HL, Wang LW, Su HJ, Wei BL, Yang SZ, Lin CN
Org. Lett. 2006 Feb 16;8(4):753-6.
Abstract
[structure: see text] Amentoditaxone (1), possessing an unprecedented diterpenoid skeleton, along with two new terpenoids, amentotaxin WC (2) and amentotaxone (3), were established by extensive analysis of spectroscopic data.
[Pubmed: 16468759]
| | 3. |
2005 Oct 25 |
Low genetic diversity and significant population structuring in the relict Amentotaxus argotaenia complex (Taxaceae) based on ISSR fingerprinting.
Ge XJ, Zhou XL, Li ZC, Hsu TW, Schaal BA, Chiang TY
J. Plant Res. 2005 Dec;118(6):415-22. Epub 2005 Oct 25.
Abstract
Amentotaxus, a genus of the Taxaceae, represents an ancient lineage that has long existed in Eurasia. All Amentotaxus species experienced frequent population expansion and contraction over periodical glaciations in Tertiary and Quaternary. Among them, Amentotaxus argotaenia complex consists of three morphologically alike species, A. argotaenia, Amentotaxus yunnanensis, and Amentotaxus formosana. This complex is distributed in the subtropical region of mainland China and Taiwan where many Pleistocene refugia have been documented. In this study, genetic diversity and population structuring within and between species were investigated based on the inter-simple sequence repeats (ISSR) fingerprinting. Mean genetic diversity within populations was estimated in three ways: (1) the percentage of polymorphic loci out of all loci (P) (2) Nei's unbiased expected heterozygosity (He), and (3) Shannon's index of phenotypic diversity. For a total of 310 individuals of 15 populations sampled from the three species, low levels of ISSR genetic variation within populations were detected, with P=4.66-16.58%, He=0.0176-0.0645 and Hpop=0.0263-0.0939, agreeing with their seriously threatened status. AMOVA analyses revealed that the differences between species only accounted for 27.38% of the total variation, whereas differences among populations and within populations were 57.70 and 14.92%, respectively, indicating substantial isolation between the patch-like populations. A neighbor-joining tree identified a close affinity between A. yunnanensis and A. formosana. Genetic drift due to small population size, plus limited current gene flow, resulted in significant genetic structuring. Low levels of intra-populational genetic variation and considerable inter-populational divergence were also attributable to demographic bottlenecks during and/or after the Pleistocene glaciations.
[Pubmed: 16247653]
| | 4. |
2005 Apr |
New phenylpropane and anti-inflammatory diterpene derivatives from Amentotaxus formosana.
Wang LW, Su HJ, Day SH, Tsao LT, Yang SZ, Wang JP, Lin CN
Planta Med. 2005 Apr;71(4):344-8.
Abstract
One new diterpene, 8(14),15-sandaracopimaradiene-2alpha,3beta,18-triol (1), two new phenylpropane derivatives, i.e., (E)-methyl 2-(3,4-methylene-dioxyphenyl)-3-methoxypropenoate (2) and (E)-2-(3,4-methylene-dioxyphenyl)-3-methoxypropenoic acid (3), and two known diterpenes, ent-8(14),15-sandaracopimaradiene-2alpha,18-diol (4) and 8(14),15-sandaracopimaradiene-2alpha,18,19-triol (5), were isolated from the heartwoods and barks of Amentotaxus formosana, respectively. The anti-inflammatory activity of the diterpenes 1, 4, and 5 was assessed in vitro by determining their inhibitory effects on the chemical mediators released from mast cells, neutrophils, macrophages, and microglial cells. Compounds 1, 4, and 5 showed significant concentration-dependent inhibitory effects on the release of beta-glucuronidase from rat neutrophils in response to formyl-Met-Leu-Phe/cytochalasin B (fMLP/CB) with IC50 values of 5.5 +/- 1.8, 8.4 +/- 2.9 and 19.2 +/- 3.3 microM, respectively. Compounds 1 and 5 also showed significant concentration-dependent inhibitory effects on superoxide anion generation in rat neutrophils stimulated with fMLP/CB and phorbol 12-myristate 13-acetate (PMA) with IC50 values of 12.6 +/- 1.2 and 9.4 +/- 1.7, and 10.7 +/- 3.3 and 12.9 +/- 0.9 microM, respectively.
[Pubmed: 15856411]
| | 5. |
2002 Jan |
Lanostanoids of Amentotaxus formosana.
Su HJ, Day SH, Yang SZ, Chiang MY, Lin CN
J. Nat. Prod. 2002 Jan;65(1):79-81.
Abstract
Three lanostanoids, 3beta-methoxycycloartan-24(24(1))-ene (1), 3beta,23beta-dimethoxycycloartan-24(24(1))-ene (2), and 3beta,23beta-dimethoxy-5alpha-lanosta-24(24(1))-ene (3), were isolated from the leaves of Amentotaxus formosana. The structures of new compounds 2 and 3 were determined by NMR and MS studies, and the structure of 3 was further confirmed by X-ray crystallographic analysis.
[Pubmed: 11809073]
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