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ABSTRACT

A glucose/mannose-binding lectin was isolated from seeds of Parkia discolor (Mimosoideae) using affinity chromatography on Sephadex G-100 gel. The protein presented a unique component in SDS-PAGE corresponding to a molecular mass of 58,000 Da, which is very similar to that of a closely related lectin from Parkia platycephala. Among the simple sugars tested, mannose was the best inhibitor, but biantennary glycans, containing the trimannoside core, present in N-glycoproteins, also seem to be powerful inhibitors of the haemagglutinating activity induced by the purified lectin. The protein was characterised by high content of glycine and proline and absence of cysteine. Rabbit antibodies, anti-P. platycephala seed lectin, recognised the P.discolor lectin. However, no cross-reaction was observed when a set of other legume lectins from sub-family Papilionoideae and others from families Moraceae and Euphorbiaceae were assayed with the Parkia lectins. This suggests that Parkia lectins comprise a new group of legume lectins exhibiting distinct characteristics.  相似文献   

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Seeds of the greater celandine (Chelidonium majus L.) contain a lectin which could be isolated using a combination of affinity chromatography on chitin and ion exchange chromatography on sulphopropyl-Sephadex. The purified lectin was partially characterized with respect to its biochemical and physicochemical properties. It is a small dimeric protein composed of two different subunits of Mr 9,500 and 11,500, respectively. Its amino acid composition is typified by high contents of glycine and cysteine. No covalently bound carbohydrate could be detected. Hapten inhibition experiments indicated that the lectin exhibits specificity towards oligomers of N-acetylglucosamine, the potency of inhibition increasing with chain length up to four residues. The greater celandine lectin is the first lectin to be isolated from a species belonging to the plant family Papaveraceae (poppy family). Although it represents a new type of plant lectin, resemblances to phytohemaglutinins from diverse taxonomic origin are obvious.  相似文献   

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秋水仙花生物碱   总被引:2,自引:0,他引:2  
从云南昭通引种欧洲秋水仙花中分离出6个生物碱:秋水仙碱(Ⅰ),2-去甲秋水仙碱(Ⅱ),2-去甲脱羰秋水仙碱(Ⅲ),2-去甲-17-羟基秋水仙碱(Ⅳ),2-去甲-β-光秋水仙碱(Ⅴ),β-光秋水仙碱(Ⅵ)。  相似文献   

6.
本实验研究了从家蝇蛹体内分离的一种凝集素,研究了其免疫调节的性质。首先将收集的家蝇蛹在缓冲液中研磨,得到粗提物,经过亲和吸附、竞争洗脱等步骤得到了纯品。电泳结果表明家蝇蛹凝集素分子量大约为55kD。通过检测巨噬细胞分泌的细胞因子IL-6、IL-12等实验,证明了家蝇蛹凝集素浓度在5μg/mL时对与巨噬细胞分泌IL-6有显著增强作用,家蝇蛹凝集素的浓度在10μg/mL时对巨噬细胞分泌IL-12有显著效果。通过小鼠脾淋巴细胞增殖试验结果可知家蝇蛹凝集素对于混合淋巴细胞增殖有促进作用。以上试验结果说明家蝇蛹凝集素免疫调节作用,为天然免疫增强剂的开发提供了一定的参考依据。  相似文献   

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Lectin from rice     
N-Acetyl-D-glucosamine-binding lectin was isolated and purified from rice by ammonium sulphate fractionation and affinity chromatography using N-acetyl-D-glucosamine linked Sepharose 6B column. It gave a single hand on Polyacrylamide disc gel. It was identified as a glycoprotein. The purified lectin dissociated into two components on Sephadex G-100 column chromatography,-a higher molecular weight fraction not containing any carbohydrate and a lower molecular weight glycoprotein fraction. The apparent molecular weights of these fractions were 85,000 and 14,500. The lectin agglutinated erythrocytes of human A,B,O groups and of several other mammals and its activity was inhibited only by N-acetyl-D-glucosamine. The glycopeptide isolated by pronase digestion of the lectin was homogeneous and did not possess agglutinating activity. It contained about 10% carbohydrate of which xylose, arabinose and glucose were the major components.  相似文献   

8.
Broadly speaking proteomic studies are one of the various techniques of utmost importance for understanding complex biological processes that occur under inductive conditions and revealing the multidimensional aspects of Crocus sativus in biological systems. In order to get an insight into the molecular changes and to characterize the variations in protein expression of C. sativus, a detailed proteomic analysis on one-dimensional gel electrophoresis is one of the basic steps to accomplish. We have compared total protein profiles of C. sativus extracted by three different recipes and analyzed on 10% sodium dodecyl sulfate polyacrylamide gels. Gels were subjected to densitometric analysis for further characterization. Among three different protocols NP-40 extraction buffer recipe resulted in the extraction of proteins most efficiently with minimum background and streaking. There was maximum solubilization of proteins with high efficiency. Such a profile can be used for high precision analysis of differential protein expression. This work is an attempt to assist researchers in effective extraction of proteins from C. sativus. As a researcher faces a perplexing array of choices as where to start we describe a method based on our collective analysis of the different protein protocols. This paper presents a method that could be applied at the outset of any proteomic study.  相似文献   

9.
Summary Paraffin sections of seven cases of nephroblastoma and one case of clear cell sarcoma were stained with a battery of eleven lectins conjugated to horseradish peroxidase. Lectin staining revealed similarities between blastema and stroma with respect to their content of glycoconjugates whereas blastema and epithelial cells exhibited major differences. In general, blastema and stroma contained glycoconjugates with terminal or penultimate -galactose, glycoconjugates having either biantennary or triantennary N-linked sugar chains or both, sialoglycoconjugates, and occasionally glycogen. Epithelial cells also showed these complex carbohydrates but stained additionally for terminal disaccharide galactose-(13)-N-acetylgalactosamine, terminal -galactose and terminal -N-acetylgalactosamine. Furthermore, staining with three fucose-binding lectins revealed that the linkage between terminal -fucose residues to the constituent oligosaccharide chains varied between epithelial cells, blastema and stroma. In general, the distribution and content of glycoconjugates in tumour cells comprising clear cell sarcoma resembled that in blastema and stroma of nephroblastoma. Other findings included differences in content of glycosubstance between cuboidal and columnar cells within the same tumour. Also observed were variations between a primary tumour and its metastasis with respect to the occurrence of certain complex carbohydrates.  相似文献   

10.
The pistil of Colchicum is syncarpous, the carpels having open sutures or well-marked commissures and many bitegmic ovules of variable orientation. Although the vascularization of the carpel is also variable, there are usually three dorsal bundles and three alternate, septal bundles at the base of the pistil, with occasionally some placental bundles at that level. More often the placental bundles, differentiating basipetally, appear to establish connections with the septal bundles higher up, at the lowermost ovular insertion level. The septal bundles divide in two more frequently in pistils in which the carpellary suture is open than in those in which it is closed.  相似文献   

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A new species, Colchicum leptunthum K. Perss. (Colchicaceae), endemic to north-east Turkey, is described. The species is early spring-5owering (± winter-5owering), and has soboliferous corms, a feature it shares with only eight other species of the genus. The chromosome number is 2 n = 18.  相似文献   

13.
从黄果西番莲(Passiflora edulisSims)压榨果汁中分离得到一个新的内酯类成分,波谱技术鉴定其结构为西番莲内酯。该化合物未显示对DPPH自由基的清除活性。  相似文献   

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A new phenylpropanediol, (2S)-3, 3-di-(4-hydroxy-3-methoxyphenyl)-propane-1, 2-diol (1), along with a known compound, shizukanolide E (2) were isolated from the water extract of the whole plants of Sarcandra glabra. The structure was elucidated on the basis of extensive NMR, MS, and ORD spectral analysis.  相似文献   

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从青海产鄂西香茶菜(Isodon henryi)的叶中分离得到1个新的苯取代二酮,利用波谱技术鉴定其结构.同时,还得到了8个已知化合物.  相似文献   

16.
中华青荚叶的一个新果糖酯   总被引:1,自引:0,他引:1  
从山茱萸科中华青荚叶( Helwingia chinensis )的乙醇提取物中分离得到一个新果糖酯和十个已知化合物.通过现代波谱技术分别鉴定为:2- O -(E)-咖啡酰-3- O -(3, 5-二甲氧基香豆酰)-α-D-呋喃果糖甙(1),2- O -β-D-呋喃果糖基α-D-异吡喃糖酯(2),甘草甜素(3),4′-羟基-7- O -葡萄糖-2, 3-二羟黄酮甙(4),黄豆甙(5),5-葡萄糖芹菜甙(6),7- O -葡萄糖芹菜甙(7),4- O -葡萄糖香豆酸(8), 葡萄糖咖啡酸(9), 3β-赤杨醇(10), 薯蓣皂甙3- O -{α-L-鼠李糖吡喃糖基(1→2)-[α-L-阿拉伯呋喃糖基(1→3)]-β-D-葡萄糖吡喃糖} (11).  相似文献   

17.
从披针叶胡颓子(Elaeagnus lanceolata)的干燥枝叶中分离得到19个化合物,其中isoamericanol B(1)为一新化合物,经波谱学方法鉴定其结构为rel-(7′Z)-(7β,8α)-3-methoxy-4,9′-dihydroxy-3′,7-epox-y-8,4′-oxyneolign-7′-ene。  相似文献   

18.
从云南怒江产的长鞭红景天(Rhodiola fastigiata (Hook. f. et Thoms.) S. H. Fu)根茎中分离得到13个化合物,它们的结构通过波谱和化学方法得到鉴定.其中,化合物1被鉴定为新的葡萄糖甙(2-O-β-D-吡喃葡糖基-3-甲基-戊酸甲酯),命名为长鞭红景天素甲,化合物2和 5~9首次从该植物中分离得到.  相似文献   

19.
Chaenomeles sinensis lectin (CSL) was isolated from Chinese quince fruit by affinity chromatography. The molecular weight of native CSL was estimated to be 16 kD by gel filtration chromatography. This lectin was found to contain approximately 57% carbohydrates. The molecular weight of deglycosylated CSL was estimated to be 3.6 kD by tricine-SIDS-PAGE under reduced conditions. Our results suggest that CSL may be a homodimer. The hemagglutinating activity of CSL was inhibited by N-acetyllactosamine and chicken ovalbumin, and it was drastically decreased at pH levels of 9.0 or greater. CSL may be a useful tool for the purification of glycoconjugates.  相似文献   

20.
长鞭红景天中一个新的葡萄糖甙   总被引:3,自引:0,他引:3  
从云南怒江产的长鞭红景天 (Rhodiolafastigiata (Hook .f.etThoms.)S .H .Fu)根茎中分离得到 13个化合物 ,它们的结构通过波谱和化学方法得到鉴定。其中 ,化合物 1被鉴定为新的葡萄糖甙 (2_O_β_D_吡喃葡糖基_3_甲基_戊酸甲酯 ) ,命名为长鞭红景天素甲 ,化合物 2和 5~ 9首次从该植物中分离得到  相似文献   

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