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1.
岩豆凝集素的圆二色性与生物学活性关系的研究   总被引:1,自引:0,他引:1  
岩豆凝集素(MDL)的远紫外圆二色性谱(CD谱)显示216-217nm处的单一负峰。此时MDL分子含有16.2%的α螺旋,46.3%的β折叠和37.5%的无规卷曲。pH9.0时负峰红移至220nm,且在217-222nm处的峰值几乎相同;在20-40℃范围内,CD谱的变化甚微;60℃时谱峰蓝移;在80℃或100℃时,212nm处出现一大负峰。1mol/L或2mol/L脲时,MDL的CD谱已发生明显变化,二级结构单元也有变化,凝集兔红细胞的活性也随之减弱;随脲浓度的增加,MDL的谱峰蓝移,最终在212nm处出现大负峰。当胍浓度为0.75mol/L时,MDL的CD谱即有明显变化和活性丧失;胍浓度继续增加,CD谱逐渐成为特征的无规卷曲的谱形。在pH9.0、温度超过80℃、脲或胍浓度分别高于2mol/L和0.75mol/L时,MDL的CD谱发生显著变化的同时,其凝集兔红细胞的生物学活性全部丧失,分子的二级结构单元也发生很大改变。  相似文献   
2.
岳春雷  江洪  魏伟 《生态学报》2001,21(7):1204-1207
研究了分布于开阔地和辽东栎林下短柄五加无性系种群拆散方式、无性系的形态可塑性和分株的死亡年龄,研究结果表明,开阔地上无性系分株的扩散方式为稀疏线型,根茎长度、无性系分株数目,林下和开阔地差异显著,根茎分枝角度、无性系根茎总长无显著性差异。林下分株的死亡年龄显著小于开阔地上无性系分株的死亡年龄。  相似文献   
3.
The extract of the stem bark of Siberian ginseng, Acanthopanax senticosus Harms (ASH), is believed to play a body-coping role in stress through a brain noradrenergic mechanism. The present study was carried out to investigate the effect of ASH on the neuronal activation patterns of c-Fos expression in the rat brain. With ASH administration, c-Fos accumulated in both the supraoptic nuclei (SON) and paraventricular nuclei (PVN), which regulate stress response. Only the caudal regions in the nucleus of the solitary tract (NTS), a locus innervating both the SON and PVN, were activated. Such a neuro-anatomical pattern associated with ASH suggests the possible involvement of these stress-related brain loci.  相似文献   
4.
本文研究红毛五加多糖不同组分(AHP-I、AHP-II、AHP-III)对小鼠腹腔巨噬细胞免疫调节功能的影响,为进一步阐明红毛五加多糖对小鼠免疫调节作用机制奠定基础。采用不同浓度的3种多糖组分作用于小鼠腹腔巨噬细胞,测定其对巨噬细胞吞噬中性红、释放NO能力、分泌IL-6、TNF-α、IL-1β水平的影响。最后结果是红毛五加多糖的3种不同组分对小鼠免疫细胞有不同的刺激能力。其中,AHP-II可极其显著地增强吞噬细胞的吞噬功能,促进其合成NO,促进巨噬细胞细胞因子的分泌。因此红毛五加多糖能激活小鼠腹腔巨噬细胞,其中,AHP-II是最重要的作用组分。  相似文献   
5.
This study investigated the effect of butanol extract of AS (ASBUE) on atherosclerosis in apolipoprotein E-deficient (ApoE−/−) mice. The mice were administered ASBUE (390 or 130 mg/kg/day) or rosuvastatin (RSV) via oral gavage for eight weeks. In ApoE−/− mice, ASBUE suppressed the abnormal body weight gain and improved serum and liver biochemical indicators. ASBUE remarkably reduced the aortic plaque area, improved liver pathological conditions, and lipid metabolism abnormalities, and altered the intestinal microbiota structure in ApoE−/− mice. In the vascular tissue of ASBUE-treated mice, P-IKKβ, P-NFκB, and P-IκBα levels tended to decrease, while IκB-α increased in high fat-diet-fed atherosclerotic mice. These findings demonstrated the anti-atherosclerotic potential of ASBUE, which is mediated by the interaction between the gut microbiota and lipid metabolism and regulated via the Nuclear Factor-kappa B (NF-κB) pathway. This work paves the groundwork for subsequent studies to develop innovative drugs to treat atherosclerosis.  相似文献   
6.
短柄五加大,小孢子发生和雌,雄配子体发育的研究   总被引:4,自引:2,他引:4  
王仲礼  田国伟 《植物研究》1998,18(2):177-183
短柄五加花药5枚,每个花药四个花粉囊。小孢子母细胞减数分裂时,胞质分裂为同时型,产生正四面体形的四分体。花药壁由表皮、药室内壁、中层和绒毡层四层细胞组成,其发育类型为双子叶型。腺质绒毡层,其细胞为二核。三细胞型花粉。子房5室,每室两个胚珠,上胚珠败育,下胚珠可育。下胚珠倒生,具单珠被,厚珠心。大孢子母细胞减数分裂形成线性排列的四个大孢子,雌配子体发育属蓼型。开花当天,花粉散开,雌配子体尚未成熟,处  相似文献   
7.
A growth factor (TJF) for a malo-lactic fermentation bacterium has been isolated from tomato juice, and found to be a β-glucoside. The NMR spectra of TJF and its acetate revealed that the glucosyl residue linked to the hydroxyl group at C-2′ or C-4′ of d- or l-pantothenic acid moiety. Then, 2′-O-(β-d-glucopyranosyl)-dl-pantothenic acid (I), 4′-O-(β-d-glucopyranosyl)-dl-pantothenic acid (II) and 4′-O-(β-d-glucopyranosyl)-d(R)-pantothenic acid (II-a) were synthesized, and Il-a and 4′-O-(β-d-glucopyranosyl)-l-pantothenic acid (II-b) were obtained by the optical resolution of the acetate of II. Among the above compounds, II-a was identical with natural TJF regarding to the biological activity, NMR and ORD spectra, and thin-layer chromatography.  相似文献   
8.
刺五加传粉生物学研究   总被引:13,自引:0,他引:13  
本文报道刺五加Eleutherococcus seticosus(Rupr.et Maxim.)Maxim的花朵酬物、访花者类别、访花 者在花序上的访花行为、访花频率及传粉效果。主要结果如下:(1)每朵雄花可提供的报偿是58 000~ 81 000粒花粉,5.5~8.0 µl/d×2~4d花蜜。每朵雌花仅可提供4.0~8.0µl/d× 2~3 d花蜜,不能提 供花粉。每朵两性花可提供19 000~54 000粒花粉和7.0~10.0 µl/d× 2~6 d花蜜。(2)花粉提供者 (雄花和两性花)提供报偿的日期是开花后1~3天,花粉接受者(雌花和两性花在柱头外翻变白时)是 开花后5~7或7~9天,这进一步证实了剌五加雄蕊先熟。另外,花粉提供者提供花蜜的时间在一天中 是8:30至15:30,其高峰是9:00~15:00;花粉接受者提供花蜜的时间在一天中是10:30至16:30,其高 峰是11:00~16:00。这种时间差异可能是刺五加影响传粉者流向(从花粉提供者到花粉接受者)的关键 因素。(3)在刺五加花朵上记录到的访花昆虫有50余种,分别隶属于膜翅目、鳞翅目、鞘翅目、双翅目和 半翅目。在不同天气、不同生境、不同性别的植株记录到的访花频率及高峰时间不同:花粉提供者的 访花高峰早于花粉接受者的;雄株上的访花频率高于雌株的;两性株接受花粉时的访花频率高于提供花 粉时的;而天气越晴朗,刺五加地块(patch)越大,则访花频率越高;每日接受光照越早,访花高峰越早。 (4)从传粉效果看,刺五加种子的形成完全依赖于传粉昆虫的活动。其中,蜂类,如熊蜂、花蜂、切叶蜂、胡蜂和蜜蜂等是最有效的传粉者,其它昆虫如粉蝶、食蚜蝇、寄蝇和鳃角金龟等对传粉也有帮助。  相似文献   
9.
High frequency somatic embryogenesis of Eleutheorcoccus chiisanensis was achieved through suspension culture of embryogenic cells in hormone-free Murashige and Skoog liquid medium supplemented with 30 g sucrose l−1. Cotyledonary somatic embryos were germinated and converted into plantlets using 20 μM gibberellic acid which were then grown in a 10 l airlift bioreactor. HPLC analysis revealed the accumulation of eleutheroside B, E and E1 in the embryos and plantlets. Thus mass production of embryos and plantlets of E. chiisanensis can be achieved in liquid cultures and the biomass produced may become an alternative source of eleutherosides.  相似文献   
10.
Ling You X  Seon Yi J  Eui Choi Y 《Protoplasma》2006,227(2-4):105-112
Summary. Eleutherococcus senticosus zygotic embryos were pretreated with 1.0 M mannitol or sucrose for 3–24 h. This pretreatment resulted in a high frequency of somatic-embryo formation on hormone-free medium. All the somatic embryos developed directly and independently from single epidermal cells on the surface of zygotic embryos after plasmolyzing pretreatment. Scanning electron microscopic observation revealed that the epidermal cells of hypocotyls rapidly became irregular and showed a random orientation before somatic-embryo development commenced. At the same time, the epidermal cells in the untreated control remained regular. Callose concentration determined by fluorometric analysis increased sharply in E. senticosus zygotic embryos after plasmolyzing pretreatment but remained low in the untreated control. Aniline blue fluorescent staining of callose showed that the plasmolyzing pretreatment of zygotic embryos resulted in heavy accumulation of callose between the plasma membrane and cell walls. On the basis of these results, we suggest that plasmolyzing pretreatment of zygotic embryos induces the accumulation of callose, and the interruption of cell-to-cell communication imposed by this might stimulate the reprogramming of epidermal cells into embryogenically competent cells and finally induce somatic-embryo development from single cells. Correspondence and reprints: Division of Forest Resources, College of Forest Sciences, Kangwon National University, Chunchon 200-701, Republic of Korea.  相似文献   
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