竹叶马兜铃化学成分的研究

<正> 竹叶马兜铃Aristolochia bambusifolia.C.F Liang sp.nov.是最近在广西隆林首次发现的马兜铃科马兜铃属植物新种。该属植物大部分为药用或民间有名草药。文献曾报导广西马兜铃属植物有12种,但无此种,民间亦未使用。其化学成分尚未研究过,因此我们对其块根化学成分进行系统研究是很有意义的。     

耳草属植物化学成分及药理活性研究进展

对耳草属植物化学成分、药理作用研究进展进行了综述,为该属植物进一步研究和开发利用提供参考。耳草属植物主要含有环烯醚萜类、黄酮类、蒽醌类、三萜类、生物碱等化学成分,该属植物具有抗肿瘤、调节免疫、肝保护、抑菌、抗炎、抗氧化等多种药理作用。     

马兜铃属植物化学成分及生物活性研究进展

本文从化学成分和生物活性两方面综述了马兜铃属（Ａｒｉｏｓｔｏｌｏｃｈｉａ Ｌ．）植物近十几年来的研究进展,为马兜铃属植物的开发利用提供一定的科学依据。     

橐吾属植物的研究进度

对近年来橐吾属植物的研究文献进行综述,主要内容有该属植物的化学成分、药理作用及其它方面的研究情况。     

马兜铃科探奇

马兜铃科探奇汪劲武在被子植物中,马兜铃科算不上旺族,只有７属３００多种,其中既无栋梁之材,也乏美味佳果,但却有其独到的奇特之处,一些著名的药用种类自古就广为人知。中国有６０多种马兜科植物,全国各地都有分布。囚禁媒人的奇花马兜铃科种类最多的属是马兜铃属...     

橐吾属植物药用研究概况

对近20年来国产橐吾属植物的药用研究文献进行综述,主要内容有该属植物的化学成分、药理作用及民间应用的情况。     

中国马兜铃属植物的药用资源

马兜铃属(Aristolochia Linn. )隶属于马兜铃科(Aristolochiaceae),全世界有400多种,主产于热带和亚热带,我国有50多种,主产西南地区,其中大部分种类是常用中药和草药,还有些种类于产区民间入药。本文根据笔者过去三年中对我国马兜铃属植物的调查所得资料,选入27种国产马兜铃属药用植物,按有关内容整理而成,供本属药用植物的深入研究与开发利用方面参考(见表1)。     

寻骨风化学成份的研究

从马兜铃属植物寻骨风(Aristolochia mollisstma Hance)的茎叶中分离得10种结晶性成份。经鉴定为:马兜铃酸 A、香草酸、马兜铃酸 D、马兜铃内酰胺、6-甲氧基马兜铃内酰胺、棕榈酮、三十醇、β-谷甾醇、β-谷甾醇-D-葡萄糖甙和硬脂酸。动物试验表明,马兜铃酸 A 具有明显的抗早孕作用。     

葫芦叶马兜铃化学成分的分离

<正> 葫芦叶马兜铃Aristolochia cucurbitoides C.F.Liang系马兜铃科马兜铃属植物,为宿根性多年生草质藤本,具圆形肉质根。分布于广西百色地区。民间用于止痛。其化学成分尚未见详细报导。我们对产自广西隆林县的样品,进行了化学成分的分离。现介绍其主要药用成分之一马兜铃酸的分离,葫芦叶马兜铃根中含粗马兜铃酸0.15％左右。经薄层、紫外光谱、红外光谱与已知马兜铃酸比较鉴定,其结果一致。为了进一步证明是马兜铃酸,经用锌粉醋酸在油浴中回流,得到黄绿色马兜铃内酰胺C_(18)H_(11)O_4N与已知马兜铃内酰胺的薄层、紫外光谱、红外光谱对照基本一致。证明葫芦叶马兜铃根中分离出来的黄色微针状结晶是马兜铃酸(Aristolochic acid)。     

峨眉山自然分布的马兜铃科药用植物

马兜铃科植物在峨眉山较为常见,其中不少种类为常用中药或著名的民间草药。如马兜铃、淮通、宜宾防已、朱砂莲、西南细辛、前叶细辛等等。多年来,笔者结合药用植物教学、实习,多次上山进行调查、采集标本百余份,经查阅资料,鉴定整理,该科植物在峨眉山共有2属11种1变种,全供药用[2]1马兜铃科药用植物在峨眉山的自然分布峨眉山植被主要按垂直分布不同,通常划分为4个区。马兜铃科药用植物的自然分布如下。1．l高山草甸区包括金顶、长坡、千佛项,万佛项等地,海拔3000米以上,为寒温带气候。植被为高山草甸,以箭竹、杜鹃属为优势种。…     

诱导子对藏红花悬浮培养细胞生产藏红花色素的影响

考察壳聚糖（chitosan）、壳寡糖（chitosanoligosaccharides,COS）、茉莉酸甲酯（methyljasmonate,MJ）、水杨酸（salicylicacid,SA）和Cu2＋等诱导子对藏红花悬浮培养细胞生长和藏红花色素合成的影响。结果表明：在实验考察浓度范围内,壳寡糖（1～500mg／L）和较低浓度壳聚糖（≤10mrdL）、MJ（≤10μmol／L）、SA（≤10μμmol／L）和Cu2＋（≤1μmoL／L）对细胞生长无显著影响;较高浓度壳聚糖（≥100mg／L）、MJ（≥100μmol／L）、SA（≥100μmoL／L）和cu“（≥10μmoL／L）显著抑制细胞生长。5种诱导子对藏红花色素合成的诱导效果不同,并且与诱导子作用浓度和添加时间有关。MJ诱导效果最好,在细胞培养第0天添加终浓度100仙moL／LMJ,藏红花色素含量（以1克干细胞计）达到28．57mg,比对照提高177．9％。其次是cu“,在细胞培养第4天添加终浓度500μmoL／LCu2＋,色素含量达到19．82mg,比对照提高108．2％。再次是壳聚糖和壳寡糖,在细胞培养第14天分别添加终质量浓度100mg／L壳聚糖和壳寡糖,色素含量分别达到18．33和17．39mg,比对照提高69．1％和69．0％。最后是SA,在细胞培养第14天添加终浓度10μmoL／LSA,色素含量达到14．65mg,比对照提高45．4％。     

Exchange of ribosomal proteins among the ribosomes of Escherichia coli.

Summary The exchange of ribosomal proteins among ribosomes of E. coli has been measured, using a density label technique. As expected most of the proteins do not exhange appreciably. However a substantial fraction of each of proteins S1, S2, S21, L7/L12, L9, L10, L11, L26 and L33 is found to exchange, but exchange of S1, S2, L7/L12, L10, L11 and L26 is found to occur in vitro after lysis of the cells, and therefore it is not possible to say whether or not these proteins also exchange in vivo. In contrast S21, L9 and L33 do not exchange after lysis of the cells and we therefore conclude that these proteins exchange in vivo. The maximum level of exchange of S21, L9 and L33 is attained so rapidly that we were unable to show whether or not it was dependent on protein synthesis.     

Non-ionic detergent affects the conformation of a functionally active mutant of Bcl-X(L)

We found that a mutant, Bcl-X(L)(F131V), which was previously reported to have impaired binding capacity, can bind to Bax almost as strongly as wild-type Bcl-X(L). In the absence of detergent, the Bcl-X(L)(F131V) mutant adopts the same conformation as wild-type Bcl-X(L), as determined by circular dichroism spectroscopy and size-exclusion chromatography. However, non-ionic detergent induces a conformational change in the Bcl-X(L)(F131V) mutant and causes it to lose Bax-binding capacity. Wild-type Bcl-X(L), on the other hand, is more resistant to detergent-induced effects and retains its ability to bind Bax in the presence of detergent. Since it has been shown that the Bcl-X(L)(F131V) mutant has nearly the same anti-apoptotic activity as wild-type Bcl-X(L), it would be likely that the Bcl-X(L)(F131V) mutant can adopt the wild-type conformation, rather than the detergent-induced conformational state and can bind to Bax in vivo. Therefore, our data demonstrated that non-ionic detergent can have unpredicted effects on protein conformation, differential effects on wild-type and mutant Bcl-X(L) proteins in this case and may cause complications in the interpretation of in vitro binding studies.     

黄孢原毛平革菌突变株抗碳氮营养阻遏产漆酶碳氮生理调控机理

【目的】通过比较不同碳氮营养及其消耗对产漆酶的影响,了解白腐菌模式种黄孢原毛平革菌解除营养阻遏产漆酶代谢的生理生态特性,揭示白腐菌合成漆酶的碳氮生理调控机理。【方法】分别利用限碳限氮(CL-NL)、限碳富氮(CL-NS)、富碳限氮(CS-NL)与富碳富氮(CS-NS)4种条件培养黄孢原毛平革菌野生型(WT)与突变株,比较两者产漆酶动力学、菌体生长、葡萄糖与氨氮消耗差异及其相关性来揭示解除营养阻遏产漆酶调控生理特性,明确C、N营养对产漆酶的生理调控途径。【结果】突变菌株除消耗速率比野生型略慢外,两者氨消耗趋势一致,但对葡萄糖的消耗比野生型快且氨氮浓度对葡萄糖的消耗影响不大。在CL-NL、CL-NS、CS-NL、CS-NS 4种培养条件下,野生型分别在培养后期的第11、14、19和19天的次生代谢时期产生0.107、0.029、12.84和18.05U/L漆酶,启动漆酶合成及酶峰值出现的时间与基质中葡萄糖耗尽或接近耗尽的时刻,或同氨氮消耗至最低值的时刻相对应;与WT产漆酶特性不同,突变株产漆酶伴随整个培养过程且均有两个产酶高峰,分别在培养的第8、7、12天和12天出现298.83、343.14、271.22、251.49U/L漆酶第一个产酶高峰,在培养的第12、13、19和19天产生257.69、298.78、213.81、216.93U/L漆酶的第二个产酶高峰。碳氮营养对产酶的影响显示:两菌株只要初始碳源浓度相同(限碳或富碳),各自产酶动力学趋势基本一致;相反,即使初始氮源浓度相同但其产酶动力学趋势却不同,说明碳源对黄孢原毛平革菌产漆酶的影响比氮源更为重要。【结论】野生型黄孢原毛平革菌产漆酶受碳或氮饥饿调控,碳、氮各自独立发挥作用且在不同的营养条件下由不同营养素所调控,如在限碳条件下产漆酶主要由葡萄糖饥饿启动,而在富碳条件下则由氨氮饥饿所激发,以碳或氮菌体负荷表示是否达到启动酶合成的调控阀值比单纯碳或氮浓度更为合理。突变菌株漆酶合成的启动不受碳、氮营养所阻遏,可能涉及一个全局调控的改变,解除了漆酶合成的营养阻碍。     

Genome organization and characterization of mycobacteriophage Bxb1

Mycobacteriophage Bxb1 is a temperate phage of Mycobacterium smegmatis. The morphology of Bxb1 particles is similar to that of mycobacteriophages L5 and D29, although Bxb1 differs from these phages in other respects. First, it is heteroimmune with L5 and efficiently forms plaques on an L5 lysogen. Secondly, it has a different host range and fails to infect slow-growing mycobacteria, using a receptor system that is apparently different from that of L5 and D29. Thirdly, it is the first mycobacteriophage to be described that forms a large prominent halo around plaques on a lawn of M. smegmatis. The sequence of the Bxb1 genome shows that it possesses a similar overall organization to the genomes of L5 and D29 and shares weak but detectable DNA sequence similarity to these phages within the structural genes. However, Bxb1 uses a different system of integration and excision, a repressor with different specificity to that of L5 and encodes a large number of novel gene products including several with enzymatic functions that could degrade or modify the mycobacterial cell wall.     

Reliability of unfamiliar, multijoint, uni- and bilateral strength tests: effects of load and laterality

To better understand the reliability of unfamiliar multijoint strength tests, 16 resistance-trained men performed maximum velocity uni- (1 leg [1L]) and bilateral (2 legs [2L]) lifts on an unfamiliar semiprone leg squat machine with loads equivalent to 40 and 70% of maximum isometric force on 2 separate occasions. Peak force was highly reproducible between testing occasions at the heavy load under both uni- and bilateral conditions (intraclass correlation coefficient [ICC](1L70%) = 0.91, ICC(2L70%) = 0.92), was slightly reduced in the light load bilateral condition (ICC(2L40%) = 0.85), and was significantly (p < 0.05) reduced in the light load unilateral condition (ICC(1L40%) = 0.57). Test reliability was not related to total load lifted (2L 70% > 1L 70% > 2L 40% > 1L 40%) or to the peak force developed during the tests (2L 70% > 1L 70% = 2L 40% > 1L 40%), but it was somewhat related to the time taken to attain peak force (2L 70% = 1L 70% > 2L 40% > 1L 40%). To obtain reliable strength data from athletes, more familiarization seems to be needed when they perform modified versions of common multijoint strength tests, or unfamiliar strength tests, under light load, unilateral conditions. The marked differences in reliability resulting from variation in loading conditions suggests that the reliability of a test needs to be reestablished when it is modified, before it is used to assess athlete/subject strength performance.     

羊草与灰色赖草F1代细胞悬浮系的建立及植株再生

本研究以羊草(L eym us ch inensis)与灰色赖草(L eym us cinereus)杂种F1代幼穗为外植体诱导愈伤组织,在3.0 m g/L 2,4-D M S培养基上继代1次后,转入不同浓度激素(2,4-D、IAA、KT)配比和不同浓度蔗糖的M S液体培养基进行振荡培养,建立杂种F1代细胞悬浮系和植株再生体系.结果表明,细胞悬浮培养时,M S 1.0 m g/L2,4-D 0.1 m g/L KT 4%蔗糖的液体培养基最佳;悬浮细胞分化时,1.0 m g/L 2,4-D 0.1 m g/L KT 4%蔗糖 M S和1.0 m g/L 2,4-D 4%蔗糖 M S培养的悬浮细胞在1.0 m g/L NAA 0.5 m g/L KT M S分化培养基上的绿苗分化率分别达到83%和80%.细胞悬浮系及再生体系的建立为杂种F1代育性恢复的研究奠定了基础.     

Three new species of Leptolalax from Thailand (Amphibia, Anura, Megophryidae)

Three new megophryid species, Leptolalax melanoleucus, L. fuliginosus, and L. solus, are described from southwestern and southern Thailand on the bases of acoustic and morphological characteristics. Leptolalax melanoleucus and L. fuliginosus are similar to L. pelodytoides from northern Thailand, but differ from it completely in advertisement call characteristics and ventral color. Leptolalax solus is similar to L. heteropus from peninsular Malaysia, but differs from it by advertisement call, as well as by some body proportions. The distributional pattern of Leptolalax within Thailand is discussed.     

Loss of LINE-1 activity in the megabats

LINE-1 (L1) retrotransposons are the most abundant type of mammalian retroelement. They have profound effects on genome plasticity and have been proposed to fulfill essential host functions, yet it remains unclear where they lie on the spectrum from parasitism to mutualism. Their ubiquity makes it difficult to determine the extent of their effects on genome evolution and gene expression because of the relative dearth of animal models lacking L1 activity. We have isolated L1 sequences from 11 megabat species by a method that enriches for recently inserted L1s and have done a bioinformatic examination of L1 sequences from a 12th species whose genome was recently shotgun sequenced. An L1 extinction event appears to have occurred at least 24 million years ago (MYA) in an ancestor of the megabats. The ancestor was unusual in having maintained two highly divergent long-term L1 lineages with different levels of activity, which appear, on an evolutionary scale, to have simultaneously lost that activity. These megabat species can serve as new animal models to ask what effect loss of L1 activity has on mammalian genome evolution and gene expression.