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Pachysandra is an eastern Asian-North American disjtunct genus with three species, two in eastern Asia (Pachysandra axillaris and Pachysandra terminalis) and one in eastern North America (Pachysandra procurnbens). Although morphological and cytological studies suggest a close affinity of Pprocumbens with P axillaris, molecular data from nuclear and chloroplast DNA regions have provided conflicting signals. In this study, we tested previous phylogenetic hypotheses using sequences of nuclear ribosomal DNA internal transcribed spacers and chloroplast ndhF gene from multiple individuals of each of the three species. We also estimated the time of divergence between eastem Asia and eastern North America. Our results support the morphological and cytological conclusion that P procumbens is more closely related to P axillaris than to P terminalis. The estimated time of divergence of P axillaris and P procumbens was 14.6±5.5 mya, consistent with estimates from many other eastern Asian-North American disjunct genera. The migration of Pachysandra populations from eastern Asia to North America might have occurred by way of the North Atlantic land bridge. 相似文献
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以富贵草(Pachysandra terminalis Sieb.et Zucc.)(以下简称PT)为实验材料,采用开放式浸杀法研究其植物原粉及提取物(PT-Ⅰ)对钉螺的杀灭效果和对鱼类的毒性作用。结果表明PT原粉浓度为17.5 mg/L时,钉螺72 h死亡率为93.4%,120 h死亡率达100.0%;其24、72、120、168 h的LC50分别为42.28、7.20、4.20、3.17 mg/L。PT原粉浓度为75.0 mg/L时,经168 h鱼死亡率为0。使用浓度为35.0、17.5、8.75、4.38 mg/L的PT原粉,分别浸泡1、2、18、42 h时,抑制钉螺上爬率均达到100%。原粉经提取分离得到PT-Ⅰ组分,以1.40 mg/L的PT-Ⅰ组分分别浸杀钉螺24、48、72、96、120 h,钉螺死亡率分别为36.7%、73.3%、96.7%、96.7%、100.0%。表明PT具有很好的杀灭钉螺、抑制钉螺上爬效果,且对鱼毒性较低,是一种较有研究价值的灭螺植物。 相似文献
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Reproductive structures and systematics of Buxaceae 总被引:3,自引:0,他引:3
MARIA VON BALTHAZAR PETER K. ENDRESS 《Botanical journal of the Linnean Society. Linnean Society of London》2002,140(3):193-228
Buxaceae belong to a grade of families near the base of eudicots. Flowers of these families are characterized by a variable number and arrangement of floral organs. In this study, the anthetic structure of the gynoecium and androecium of representatives of all genera of Buxaceae were comparatively studied, and observations on the flowering processes and pollination biology were made. Styloceras and Notobuxus were studied in detail for the first time. Various features of the morphological analysis support our earlier molecular phylogenetic study. Shared reproductive characters among Sarcococca , Pachysandra and Styloceras are the occurrence of two (rarely three) carpels, the lack of interstylar nectaries, a micropyle formed by both integuments, attractive stamens in male flowers, and fleshy fruits. In addition, Styloceras and Pachysandra share a secondary partition in the ovary. Notobuxus does not seem to be clearly distinct from Buxus . Both have a similar inflorescence and perianth structure; female flowers have three carpels, interstylar nectaries, micropyles formed by the inner integument, rudimentary arils, and they develop into capsular fruits; in male flowers stamens are sessile and the central pistillode is lacking in some species. Thus, it is questionable to justify a separation of Buxus and Notobuxus at genus level. The results further strongly support the placement of Buxaceae among basal eudicots. © The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 140 , 193–228. 相似文献
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清香桂碱D和矮陀陀胺碱A,B的结构 总被引:9,自引:0,他引:9
本文报道从国产清香桂(Sarcococca ruscifolta)和金丝矮陀陀(Pachysandra axillaria)植物中分得的三个胺碱型新甾体生物碱清香桂碱 D 和矮陀陀胺碱 A、B 的化学结构,并首次归属了它们的~(13)C NMR 数据。 相似文献
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In this paper, three new alkaloids, sarcorucinine D (1), and paehyaximine A, B (2, 3) were isolated from Sarcococca ruscifolia Stapf and Pachysandra axillaris Franch, respectively. The structures of sarcorucinine D (1) and pachyaximine A, B (2, 3) were elucidated to be 3β-hydroxyl-20α-dimethylamino-5α-pregnane (1); and 3β-methoxyl-20α-dimethylamino-pregne-5-ne (2); and 3β-methoxyl-16-hydroxyl-20α-dimethylaminopregne-5-ne (16-hydroxyl-pachyaxi- mine A) (3), respectively. 相似文献
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This paper describes the chemical structure elucidation of the three new alkaloids isolated from Pachysandra axillarls Franch. They are pachysamine G (20α-dimethylamino-3β-tigloylamino-5α-pregnane), pachysamine H (20α-dimethylamino-3α-N-methyl, benzoylamino-5α-pregnane) and pachysanaximine A (20 α-dimethylamino-3β-methylamino-4β-benzoxyl-5α-pregnane) respectively. Other two compounds were identified as Pachysamine A, B. 相似文献
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Nine new pregnane alkaloids, pachysamines J-R (1-9), together with seven known ones, were isolated from Pachysandra axillaris. The chemical structures of the new alkaloids were elucidated by spectroscopic methods. All the compounds were evaluated for their inhibitory activities against HL-60, SMMC-7721, A-549, SK-BR-3, and PANC-1 cell lines. Compound 15 possessed moderate activities against A-549, SK-BR-3, and PANC-1 cells, with the IC50 values of 11.17, 4.17, and 10.76 μM, respectively. Besides, compound 11 showed cytotoxicities against A-549 cell, with the IC50 values as 24.94 μM. 相似文献
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对国产黄杨科5 种植物作了分类学修订或补充: 将雀舌黄杨归入匙叶黄杨, 中间黄杨归入黄杨, 多毛板凳果归入板凳果, 双蕊野扇花归入羽脉野扇花; 恢复黄杨和尖叶黄杨的原学名;报道宜昌黄杨在湖南的新记录。 相似文献