首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 56 毫秒
1.
栗柄金粉蕨的黄酮成分   总被引:4,自引:0,他引:4  
从湖南省江华瑶族自治县产的栗柄金粉蕨(Onychium lucidum)的地上部分分离得到4个黄酮化合物,经光谱鉴定为:木犀草素-7-葡粮甙(1),3,7-二甲氧基槲皮黄素(2),槲皮黄素-3-葡糖甙(3)和金粉蕨素(4),均为首次从该植物中获得。  相似文献   

2.
深圳双扇蕨(Dipteris shenzhenensis)是仅在深圳分布的极度濒危(CR)植物。对该种占优势群落进行植物群落学研究分析,结果表明:深圳双扇蕨群落共有维管植物49科73属85种,优势种有深圳双扇蕨大头茶(Gordonia axillaris)、谷木叶冬青(Ilex memecylifolia)、竹叶青冈(Cyclobalanopsis neglecta)、吊钟花(Enkianthus quinqueflorus)、豺皮樟(Litsea rotundifolia var. oblongifolia)、芒萁(Dicranopteris pedata);植株个体随着树木高度增加而减少,呈现“倒J”型分布,是亚热带地区明显特点;各生活型物种多样性及均匀度指数呈现“中间高两头低”的态势;对相同地区不同群落物种多样性指数进行T检验,证明不同群落之间多样性水平无显著差异,同属生态演替的稳定阶段;生态位分析揭示了深圳双扇蕨在群落中的生存状态,说明该种并非广布种,对环境要求苛刻且对资源竞争力差,在群落演替中存在灭绝风险;种间联结分析揭示了该物种与其他优势草本的种间关系,找到了可能的互补与竞...  相似文献   

3.
双扇蕨科是一个自然的类群,为单型科,有8种。中国产3种:中华双扇蕨Dipteris chinensisChrist、双扇蕨D.conjugata(Kaulf.)Reinw.和喜马拉雅双扇蕨D.wallichii(R.Br.)T.Moore。云南产2种:中华双扇蕨和喜马拉雅双扇蕨。其中,喜马拉雅双扇蕨为云南分布新纪录。文中列出了国产种类的分类检索表,并均附有彩色图片。  相似文献   

4.
鹿角蕨化学成分的研究   总被引:7,自引:0,他引:7  
从鹿角蕨(Platycerium wallichii Hook.)的干燥叶中分离得到七个成分,利用UV、IR、^13C-NMR、^1H-NMR、MS等光谱方法鉴定出它们的结构,分别为β-谷甾醇(I)、谷甾醇β-D-吡喃葡萄糖苷(Ⅱ)、2-propenoic acid,3-[2,3-dihydro-2-(4-hydroxy-3-methoxyphenyl)-3-(hydroxymethyl)-7-methoxy-5-benzofuramyl]-(Ⅲ)、松脂素(Ⅳ)、松脂素-4′-O-β-D-葡萄糖苷(Ⅴ)、2,5-二羟基苯甲酸甲酯(Ⅵ)、槲皮素3-O-β-吡喃半乳糖苷(Ⅶ)。七个成分均为首次从该种植物中获得。  相似文献   

5.
狗脊化学成分研究   总被引:9,自引:0,他引:9  
从狗脊(Woodwardia japonica(L.f.)Sm)中分离得到五个化合物,经解析,分别鉴定为:山柰素-3-O-α-L-(4-O-乙酰基)鼠李糖基-7-O-α-L-鼠李糖甙(kaempferol3-O-α-L-(4-O-acetyl)rhamnopyranoside-7-O-β-L-rhamnopyranoside)(Ⅰ),山柰素-3-O-α-L-鼠李糖基-7-O-α-L-鼠李糖甙(kaempferol3-O-α-L-rhamnopyranoside-7-O-α-L-rhamnopyanoside)(Ⅱ),狗脊蕨酸(woodwardinic acid)(Ⅲ),β-谷甾醇(β-sitosterol)(Ⅳ),胡萝卜甙(daucosterol)(Ⅴ),这五个化合物均系首次从该植物中获得。  相似文献   

6.
浅裂鳞毛蕨地上部分化学成分研究   总被引:2,自引:0,他引:2  
从鳞毛蕨属植物浅裂鳞毛蕨Dryopteris sublaeta Ching et Hsu.地上部分首次分离得到5个化合物,运用波谱技术确定其结构分别为:β-谷甾醇(1),邻苯二甲酸-双(2-乙基庚基)酯(2),叶绿醇(3),银松素(3,5-二羟基二苯乙烯)(4),3-羟基二苯乙烯-5-O-β-D-葡萄糖苷(5)。  相似文献   

7.
肾蕨的化学成分研究   总被引:2,自引:0,他引:2  
从肾蕨乙醇提取物中分离得到6个化合物,根据理化和光谱分析,鉴定为β-谷甾醇(1)、羊齿-9(11)-烯(2)、齐墩果酸(3)、肉豆蔻酸十八烷基酯(4)、正三十一烷酸(5)和正三十烷醇(6),化合物3~6为首次从该植物中分离得到。  相似文献   

8.
多根硬皮马勃中子实体的化学成分   总被引:2,自引:0,他引:2  
从多根硬皮马勃(Scleroderma polyrhizum Pers.)子实体中分离得到了3个含氮化合物,根据化学和光谱数据,它们的化学结构分别确定为:N,N-dimethylphenylalanine(1),2-N,N,N-trimethyl-phenylalanine(2),2-trimethyl-ammonio-3-(3-indolyl)propionate(3)。上述含氮化合物均首次从多根硬皮马勃中分离得到,其中化合物2首次从高等真菌中分离得到。  相似文献   

9.
从印楝植物内生真菌棘孢曲霉(Aspergillus aculeatus)YM311498的发酵液提取物中分离得到4个化合物,通过波谱技术分别鉴定为大黄酚(1)、大黄素(2)、琥珀酸(3)、柠檬酸二甲酯(4),以上化合物均为首次从该种真菌中分离得到。  相似文献   

10.
大瘤足蕨和镰羽瘤足蕨的化学成分研究   总被引:1,自引:0,他引:1  
对瘤足蕨属中的大瘤足蕨和镰羽瘤足蕨进行化学成分研究,从这两种植物中分离并鉴定了9个化合物,分别是:大波斯菊苷(1)、异山奈甲黄素(2)、astragalin(3)、3β,27-dihydroxylup-12-ene(4)、hydroxyhopanone(5)、plagiogyrin a(6)、androsin(7)、β-谷甾醇(8)、β-胡萝卜苷(9).所有化合物均为首次从这两种植物中分离得到,其中化合物1、4、7、9为这两种植物的共有成分.  相似文献   

11.
Ca2+ efflux from dog red blood cells loaded with Ca2+ using the A23187 ionophore could be separated into two main components: (1) Mg- and ATP-dependent (active transport) and (2) dependent on external Na (K1/2 around 15 mM); at 80 microM internal free Ca the relative magnitudes of these fluxes were 70% and 30% respectively. The Na-dependent Ca2+ efflux had the following additional properties: (i) it was partially inhibited by ATP depletion or preincubation with vanadate, but it was not affected by Mg2+ depletion; (ii) it failed to be stimulated by external monovalent cations other than Na: (iii) it was stimulated by reduction in the internal Na+ concentration. Both active and Na-dependent Ca2+ efflux remained unchanged in hypotonic solutions or in solutions with alkaline pH (8.5). In cells containing ATP and Mg2+, external Ca2+ inhibited Ca2+ efflux (K1/2 around 1 mM); on the other hand, in Mg-free dog red cells external Ca2+ stimulated Ca2+ efflux (K1/2 about 30 microM). In Mg-depleted red cells incubated in the absence of external Na2+, Ca2+ influx as a function of external Ca2+ followed a monotonically saturable function (K1/2 around 20 microM): addition of Na resulted in (i) inhibition of Ca2+ influx and (ii) a sigmoid relationship between flux and external Ca2+. Intracellular Ca2+ stimulated the external Na-dependent Ca2+ efflux along a sigmoid curve (K1/2 around 30 microM); on the other hand the Ca pump had a biphasic response to internal Ca2+: stimulation at low internal Ca2+ (K1/2 between 1 and 10 microM), followed by a decline at internal Ca2+ concentrations higher than 50 microM.  相似文献   

12.
13.
Concanavalin A (Con A) precipitates detergent-solubilized insulin receptors (free of or bound to [125I]insulin) prepared from fat cell membranes resulting in a loss of [125I]insulin binding capacity (or bound hormone) in the soluble fraction. The losses can be recovered by redissolving the precipitates with methyl-α-D-mannoside; the sugar also inhibits precipitation. [125I]insulin also binds to insoluble Con A-occupied receptors. At all concentrations of Con A tested, the initial amounts of free or hormone-bound receptors were completely accounted for by their distribution between soluble and insoluble states. We conclude that Con A and insulin can co-bind to independent sites on the insulin receptor without inhibiting each other and that previously reported decreases in insulin binding to solubilized insulin receptors were likely due to precipitation by Con A of the receptors.  相似文献   

14.
Complexes of labelled proteinases (subtilopeptidase A, trypsin) with serum α1-macroglobulin or α2-macroglobulin are rapidly taken up in vitro by rabbit alveolar macrophages and peritoneal macrophages but not by mixed rabbit peripheral blood leukocytes. Enzyme, not bound to α1 - or α2 -macrogobulin, does not become associated with alveolar macrophages. Chemically inactivated subtilopeptidase A does not bind to α1 - or α2 -microglobulin, does not interact with alveolar macrophages. Blocking experiments confirmed that the interaction of proteinase with alveolar macrophages is complex specific; uptake of labelled complex was prevented by the simultaneous addition of macroglobulin complexes formed with non-labelled subtilopeptidase A, subtilopeptidase B, trypsin or chymotrypsin but not by macroglobulin alone. The findings demonstrate a complex-specific interaction between proteinase-α-macroglobulin complexes and macrophages.  相似文献   

15.
Four new species of the genus Aristolochia (Aristolochiaceae) are described as new from China. They are Aristolochia austrochinensis C. Y. Cheng & J. S. Ma, A. caulialata C. Y. Wu, A. salweenensis C. Y. Cheng & J. S. Ma, and A. kunmingensis C. Y. Cheng &J. S. Ma. A naturalized species, A. ringens Vahl is also reported.  相似文献   

16.
The genus, Ainsliaea DC. from China is revised in this paper. Three species, A. nana Y. C. Tseng, A. pingbianensis Y. G. Tseng and A. trinervis Y. C. Tseng, are newly described; two species, A. chapaensis Merr. and A. angustifolia Hook. f. et Thoms. ex C. B. Clarke are new records for China and two new combinations, A. apteroides (Chang) Y. C. Tseng and A. macrocephala (Mattf.) Y. C. Tseng, are made. In addition, one species, A. hypoleuca Diels ex Limpr. and four varieties, A. bonatii Beauverd var. arachnoidea Beauverd, A. pteropoda DC. var. leiophylla Franch., A. elegans Hemsl. var. tomentosa Mattf. and A. glabra Hemsl. var. tenuiculis (Mattf.)Chang, are reduced to synonyms.  相似文献   

17.
本文报道链格孢属的2个新种:寄生在苦木科(Simaroubaceae)臭椿[Ailanthusaltissima(Mill.)Swingle]上的臭椿链格孢(Alternariaailanthispnov),寄生在桦木科(Betulaceas)黑桦(BetuladahuricaPall.)上的桦木链格孢(A.betalaesp.nov.),2个新组合:豆链格孢[A.azukiae(Hara)comb.nov.],蔷薇生链格孢[A.rosicola(Rao)comb.nov.]和1个新名称红花链格孢(A.carthami-tinctoriinom.nov)。文中为新种提供了拉丁文简介、描述和图。模式标本保藏在山东农业大学植物病理标本室(HSAUP)。  相似文献   

18.
蔡峻  赵敬钊 《蛛形学报》1998,7(1):48-53
实验室恒温条件下,研究了园蛛属3种园蛛——角园蛛(Araneus cornutus),叶斑园蛛(A.sta),大腹园蛛(A.ventricosus)的各龄幼蛛。描述它们各自的形态特征;指出它们之间的形态差异。  相似文献   

19.
Endogenous gibberellins (GAs) were extracted and purified from apical buds of Eucalyptus nitens (Deane and Maid.) Maid. and the cambial region of E. globulus (Labill.). then analysed by capillary gas chromatography-mass spectrometry. GA1 GA19 GA20 and GA29 were identified by full scan mass spectra. Kovats retention indices and high resolution selected ion monitoring. Using deuterated internal standards. GA1. GA19. GA20 and putative GA29 and GA53 were quantified in the apical buds, while GA4. GA8. GA9 and GA44 were shown to be either absent or present at very low levels. From the cambial region. GA1 and GA20 were quantified at levels of 0.30 ng (g fresh weight)-1 and 8.8 ng (g fresh weight)-1 respectively. These data suggest that the early 13-hydroxylation pathway is the dominant pathway for GA biosynthesis in Eucalyptus .  相似文献   

20.
Infection with Helicobacter pylori strains harboring determinants of pathogenicity may lead to a strong inflammatory response in gastric mucosa. In this work, we examined the frequency of the cagA, vacA and iceA genotypes in H. pylori strains isolated from Brazilian patients and correlated these with the clinical manifestations. H. pylori was isolated from 165 patients [30 with non-ulcer dyspepsia cases (NUD); 93 peptic ulcer disease (PUD): 31 gastric ulcers (GU) and 62 duodenal ulcer disease (DU); 18 with erosive gastritis (EG); and 24 gastroesophageal reflux disease (GERD)]. Allelic variants of cagA, vacA and iceA were identified using the polymerase chain reaction. More than one H. pylori strain was detected in 28 cases (17%), and these were excluded from the statistical analysis. We were unable to confirm an association between iceA status and clinical outcome. There was a strong association between the genotype cagA-positive vacA s1 and PUD. However, logistic regression analysis showed that vacA s1 was the only predictive factor for PUD (OR=4.19; 95% CI 1.95-8.98). The presence of the less virulent strain vacA s2 was related to GERD (OR=8.59; 95% CI 2.85-25.91). Our results support the hypothesis that virulent strains may protect against the development of GERD.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号