共查询到20条相似文献,搜索用时 15 毫秒
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Xiang-Zhong Huang Yue Liu Shi-Shan Yu You-Cai Hu Jing Qu 《植物学报(英文版)》2007,49(11):1615-1618
A new triterpenoid, 11a.O.trans-p-coumaroyltaraxerol (1), along with 11 known triterpenoids, taraxerone (2), taraxerol (3), 2α,3β,23,24-tetrahydroxyolean-12-en-28-oic acid (4), oleanolic acid (5), β-amyrin (6), 3β,23-dihydroxylursan-12-en- 28-oic acid (7), 2α,3β-dihydroxyursan-12-en-28-oic acid (8), 2α,3β,23-trihydroxyursan-12-en-28-oic acid (9), 2α,3β,24- trihydroxyursan-12-en-28-oic acid (10), u rsolic acid (11), and 3-O-acetylursolic acid (12), was isolated from Craibiodendron henryi W. W. Smith (Ericaceae). The structures of these compounds were elucidated on the basis of spectral evidence. Antioxidant activity and vasodilator effect of compound 1 were assessed. 相似文献
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An examination of the type specimen of Aconitum jiulongense W. T. Wang has shown that it should be reduced to synonymy of A. carmichaeli Debx. 相似文献
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报道了贵州苦苣苔科一新记录属--弥勒苣苔属(Paraisometrum W.T.Wang).该属为中国特有的单型属,仅弥勒苣苔(P.mileense W.T.Wang)一种,分布于云南东南部和广西西部,在贵州省为首次记录.本文对该种进行详细描述,重新确定了该种花冠的颜色为黄色,并提供了野外照片.凭证标本存放于广西植物研究所标本馆(IBK). 相似文献
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Louis N. M. Duysens 《Photosynthesis research》1996,48(1-2):25-29
The impact is discussed here of some experiments by W.A. Aronld and coworkers on photosynthetic research, specifically on that at the Leiden Biophysics Department. These experiments involved the following topics: photosynthetic unit and electronic excitation transfer to a reaction center, chlorophyll luminescence and photosynthesis, and unexpected experimental results as a source of discoveries. 相似文献
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根据对单叶黄荆(Vitex simplicifolia)模式标本的研究,结合在其模式产地的野外调查,发现单叶黄荆与黄荆(V.negundo)并无本质区别,不宜作为独立的种,但其叶片为单叶而且比较稳定,将其降级并组合为黄荆的变种。 相似文献
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Staphylococcal nuclease (SNase) has a single Trp residue at position 140. Circular dichroism, intrinsic and ANS-binding fluorescence, chemical titrations and enzymatic assays were used to measure the changes of its structure, stability and activities as the Trp was mutated or replaced to other positions. The results show that W140 is critical to SNase structure, stability, and function. Mutants such as W140A, F61W/W140A, and Y93W/W140A have unfolding, corrupted secondary and tertiary structures, diminished structural stability and attenuated catalytic activity as compared to the wild type. The deleterious effects of W140 substitution cannot be compensated by concurrent changes at topographical locations of position 61 or 93. Local hydrophobicity defined as a sum of hydrophobicity around a given residue within a distance is found to be a relevant property to SNase folding and stability. 相似文献
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Three new cytotoxic diterpenoids reniformin A, B and C, have been isolated from the leaves of Rabdosia latifolia var. reniformis Z. W. Xue et X. W. Wang. Their structures were established as (1), (2), and (3) by spectroscopic and chemical data respectively. 相似文献
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用气相色谱保留指数定性法、色谱-质谱-计算机联用测定和标准品迭加法分析了木里香橼叶精油的化学成分。从分离出的59个色谱峰中鉴定了31个化合物。其中主要成分是柠檬烯(31.730%)、芳樟醇(1.554%)、香茅醛(23.383%)、香茅醇(1.189%)、橙花醇(11.777%)、香叶醛(16.544%),乙酸香茅酯(1.427%)、乙酸橙花酯(2.258%)、乙酸香叶酯(4.714%)等。把木里香橼叶油与木里香橼果皮油与云南野香橼叶油分别作了比较。结果表明木里香橼叶油中含氧化合物醇、醛、酯的含量相当高,是精油的主要成分,可能作为进口橙叶油的较好的代用品,是一种很有潜力的天然香料资源。 相似文献
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采用光谱法和胰酯酶分解法对大果木姜子油酯中分得的结晶C—I组成进行了分析,结果表明C—I是由11种甘油三酯组成。其中2-位为月硅酸的甘油三酯占91.80%,1,3-位脂肪酸主要为癸酸和月桂酸,甘油三酯的组成中,CLC占62.24%,LLC占24.50%。 相似文献
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Aster ageratoides var. pendulus W. P. Li & G. X. Chen, a new variety of Aster (Asteraceae) from Shimen County, northwestern Hunan, China, is described. The variety is similar to A. ageratoides var. laticorymbus (Vant.) Hand.-Mazz., from which it differs by having pendent stem, basal leaves and lower stem leaves purple beneath, stem leaves linear, hispid above, and broader phyllaries. The new variety is also possibly similar to A. ageratoides var. micranthus Ling in the linear leaves and white ligules, but differs by having the phyllaries green at apex, 1.25–1.75 mm wide, and the obvious creeping underground rhizomes. 相似文献
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桂西和黔南中三叠世珊瑚 总被引:1,自引:0,他引:1
文内描述中三叠世安尼阶(Anisian)珊瑚化石分别采自桂西田阳板纳组和黔南贵阳青岩青岩组。板纳组珊瑚群中建立Pentasmilia guangxiensisgen.etsp.nov.,该新属种有5条第一周期原生隔片甚至有5条第二周期后生隔片,以此不同于有6条第一周期原生隔片和有6条第二周期后生隔片的石珊瑚类(scleractinians)的珊瑚。产于板纳组的另一新属种Radiophyllia astylatusgen.etsp.nov.,其隔片的排列格式与前人归纳的隔片周期插入示意图甚似,但它却发生在中生代最早期(Anisian)珊瑚的骸体内。文中还对青岩组的Pamiroseris silesiaca作了重新描述。 相似文献
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20 0 3年在沈阳的三裂叶豚草 (AmbrosiatrifidaL .)上发现了苍耳柄锈菌三裂叶豚草专化型 (PucciniaxanthiiSchwein .f.sp .ambrosia trifidaeS .W .T .Batra) ,这是在我国三裂叶豚草上发现的一种新病菌。试验采用扫描电镜和透射电镜对该锈菌的冬孢子和吸器的形态结构进行了观察。 相似文献
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报道生于夹竹桃科(Apocynaceae)植物上的链格孢新种2个、新变种2个,即络石链格孢(Alternaria trachelospermi T.Y Zhang,X,F,Lin et W.Q.Chen)、细极链格孢络石生变种[A.tenuissima(Neesex Fr.)Wiltshirevar.trachelospermicola T.Y.Zhang,X.F.LinetW.Q.Chen]、细极链格孢长春花变种[A.tenuissima(NeesexFr.)Wiltshirevar.catharanthiT,Y.ZhangetX.F.Lin]和长春花生链格孢(A.catharanthicolaT.Y.Zhang),及生于番木瓜科(Caricaceae)植物上的番木瓜链格孢(A.caricae T.Y.Zhang,W.Q.Chen et X.F.Lin).新种和新变种均有拉丁文特征描述,并附绘图.新分类单位的模式标本分别存放在西北农业大学真菌标本室(HMUABO)和山东农业大学植物病理标本室(HSAUP). 相似文献
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报道了云南苦苣苔科一新记录属——单座苣苔属(Metabriggsia W.T.Wang)。该属为中国特有属,仅单座苣苔(Metabriggsia ovalifolia W.T.Wang)和紫叶单座苣苔(Metabriggsia purpureotincta W.T.Wang)2种,分布于广西西部、北部及贵州南部,在云南的发现对研究其地理与区系有重要的意义。 相似文献