滇黄芩再生植株中黄酮类化合物的组织化学定位及黄芩苷的含量测定

应用植物组织化学定位方法,研究了组织培养滇黄芩再生植株中黄酮类化合物的积累分布状态;并且通过HPLC对滇黄芩再生植株中黄芩苷的含量进行测定。结果表明,滇黄芩再生植株黄酮类化合物主要存在于营养器官的表皮和皮层,以及茎、叶腺毛中。同时,测定再生植株中黄芩苷的含量表明,地下部分(根)含量为0.12%;地上部分(茎、叶)含量为0.43%。     

黄芩的结构与黄芩苷含量的关系

应用解剖学、组织化学定位和植物化学技术,研究了一、二年生黄芩（Scutellaria baicalensis Georgi）营养器官的结构特征与黄芩苷积累的关系。结果表明：黄芩各营养器官的结构类似于一般草本双子叶植物,黄芩苷主要分布在各器官的薄壁组织细胞内,其中以维管组织的薄壁细胞为多。器官间含量的不同表现为根〉叶〉茎,这与其结构特征相对应,根中维管组织所占比例最大,其中薄壁组织细胞又占主要部分,故根中黄芩苷含量最高。说明根部是黄芩苷的主要贮存部位,符合黄芩以根入药的传统。不同生长期黄芩苷含量测定结果表明,两年生营养生长前期春季根内含量最高,所以春季采挖为好。     

黄芩的结构与黄芩苷含量的关系

应用解剖学、组织化学定位和植物化学技术,研究了一、二年生黄芩(Scutellaria baicalensis Georgi)营养器官的结构特征与黄芩苷积累的关系.结果表明:黄芩各营养器官的结构类似于一般草本双子叶植物,黄芩苷主要分布在各器官的薄壁组织细胞内,其中以维管组织的薄壁细胞为多.器官间含量的不同表现为根>叶>茎,这与其结构特征相对应,根中维管组织所占比例最大,其中薄壁组织细胞又占主要部分,故根中黄芩苷含量最高.说明根部是黄芩苷的主要贮存部位,符合黄芩以根入药的传统.不同生长期黄芩苷含量测定结果表明,两年生营养生长前期春季根内含量最高,所以春季采挖为好.     

滇黄芩的研究进展及作为黄芩药用的探讨

滇黄芩(Scutellaria amoena C. H.Wright)为黄芩属药用植物,具有消炎、抗病毒、抗肿瘤等药用价值.黄芩作为正品在我国大部分地区药用,学术界对其已有较广泛而深入的研究;然而,滇黄芩作为我国西南地区地道药材,尚未受到足够重视.对滇黄芩的研究进展进行综述,并与黄芩(S. baicalensis Georgi)进行比较:二者形态结构的差异可作为对原植物及药材进行鉴别的科学依据,化学成分及含量的差异则显示滇黄芩部分有效成分含量高于黄芩.表明滇黄芩具有极大的研究价值及开发潜力.     

滇黄芩毛状根的诱导及其黄芩苷含量测定

本文利用发根农杆菌A grobacterizum rhizogenes1.2556感染滇黄芩再生苗的茎段和叶片,建立了毛状根培养及其植株再生体系。毛状根可直接从受伤的茎、叶外植体表面产生,在无外源激素的MS固体和液体培养基上自主生长,表现出典型的发根特征。毛状根茎段的诱导率较叶片高,最高可达到14.44%;经rolB基因PCR分析和甘露碱纸电泳检测,证明Ri质粒T-DNA已整合到滇黄芩基因组中并表达;毛状根在附加6-BA2mg/L和NAA0.2mg/L的MS固体培养基上直接诱导不定芽,并在MS培养基上生根,形成再生植株。获得的毛状根系经MS液体培养基培养30d后通过HPLC都能检测到黄芩苷,其中1个转化系黄芩苷含量为2.59%,是药材黄芩的0.20倍,而从3年单位时间黄芩苷生成量计算,毛状根是药材黄芩的7.18倍。本研究建立的毛状根培养体系,将对滇黄芩转基因技术的完善和利用毛状根生产黄芩苷的生物转化提供了实验基础。     

狭叶柴胡营养器官中柴胡皂苷和黄酮类化合物的积累部位及含量比较

采用植物解剖学、组织化学定位和紫外分光光度计分析方法,对狭叶柴胡各营养器官(根、茎、叶)的结构特征、营养器官中柴胡皂苷和黄酮类化合物的积累部位及其含量进行比较研究。结果表明:(1)狭叶柴胡根由周皮、中柱鞘薄壁组织和次生维管组织组成,茎由表皮、皮层和维管柱组成,叶为等面叶结构,其营养器官的结构均表现出对旱生环境的适应性。(2)组织化学定位显示,柴胡皂苷在狭叶柴胡根中主要分布在维管形成层和次生韧皮部及次生木质部靠近维管形成层的木薄壁细胞中,在茎中主要分布在表皮、皮层、维管形成层及韧皮薄壁细胞中,在叶中主要分布于表皮和叶肉中;狭叶柴胡的黄酮类化合物在茎中主要分布于表皮、棱角处的厚角组织及部分皮层细胞中,在叶中主要分布于表皮和位于叶缘及下表皮内的厚角组织中,在根内分布很少。(3)定量分析表明,柴胡总皂苷在狭叶柴胡根、茎、叶中的含量分别为2.635%、1.045%和0.981%;而黄酮类化合物在根、茎、叶中的含量分别为0.032%、1.212%和2.259%;定量分析结果与组织化学实验结果相符。研究表明,柴胡总皂苷在狭叶柴胡的根中含量最高,支持《中国药典》以根入药的结论;而且狭叶柴胡叶中的黄酮类化合物含量较高,建议对狭叶柴胡的叶进行综合开发利用。     

卵叶远志营养器官的结构及远志皂苷的组织化学定位和含量测定

应用植物解剖学、组织化学定位和高效液相色谱法,研究了卵叶远志各营养器官的结构、远志皂苷积累分布状态及含量变化。结果表明．卵叶远志的根包括周皮和次生维管组织两部分．周皮发达,次生韧皮部较厚,韧皮薄壁细胞为其主要成分。次生木质部中导管和纤维发达,导管分布密度较大。茎包括表皮、皮层、维管柱三部分,在皮层与韧皮部之间具有一圈排列紧密的厚壁细胞．推测这圈厚壁细胞具有质外体屏障作用．可保护茎组织免受干旱的伤害。叶为异面叶。根茎的结构表现为旱生特点。组织化学显示远志皂苷在根中分布在次生韧皮部和栓内层：在茎中分布在表皮、皮层和次生韧皮部细胞中：在叶中则分布在叶肉组织和表皮中。根的次生韧皮部为皂苷积累储存的主要场所。高效液相测定结果显示营养器官中都有远志皂苷元的积累．根中的含量高．茎叶中含量较低．说明卵叶远志地上部分也有药用价值。根据不同发育时期根和茎叶中皂苷元的动态变化趋势．建议在5月份（花果期）进行卵叶远志的采收。     

北柴胡营养器官中主要化学成分的组织化学定位及其含量比较

应用植物解剖学、组织化学定位和植物化学方法,研究了北柴胡各营养器官中柴胡皂苷和黄酮类化合物的积累分布状态及其含量变化。结果表明,柴胡皂苷在根中分布在中柱鞘和次生韧皮部中;在茎中主要分布在表皮、棱角处的厚角组织以及位于皮层和髓中的分泌道的上皮细胞中;在叶中,则分布在表皮细胞和整个叶肉组织中。而黄酮类化合物在茎中分布在表皮、棱角处的厚角组织、皮层、髓射线和髓鞘细胞中;在叶中,则主要分布在表皮和位于上下表皮内的厚角组织中。同时,北柴胡中柴胡总皂苷在根、茎、叶中的含量的变化规律为根>叶>茎;而总黄酮在根、茎、叶中的含量的变化规律为叶>茎>根;且在叶中含量相当高,从而为北柴胡的综合利用提供依据,对合理利用药材和保护北柴胡资源也有一定意义。     

光果甘草营养器官结构及其总黄酮的组织化学定位和含量研究

应用植物解剖学、组织化学和植物化学方法,对光果甘草各营养器官的结构、总黄酮的组织化学定位和含量差异进行了研究.结果显示:(1)光果甘草叶为异面叶,由表皮、叶肉和叶脉组成.叶表皮具腺毛,叶肉中具胶囊细胞,主脉发达;茎由表皮(周皮)、皮层、维管柱组成,其髓中具有粘液细胞;根由周皮、次生维管组织组成,周皮具厚木栓层,次生维管组织中次生木质部和纤维发达.(2)黄酮类物质在叶中分布在表皮、腺毛、胶囊细胞、厚角组织和韧皮部和木质部中的薄壁细胞中;茎中分布在周皮、韧皮部和粘液细胞中;在根中则分布在周皮中.(3)不同营养器官中黄酮类物质含量存在差异:叶＞根茎＞主根＞茎.(4)温度的下降促使黄酮类物质从地上合成器官向地下储藏器官的转运.建议每年可在果熟期和枯萎期之间采挖药材,地上部分收割也作药用,综合利用光果甘草资源.     

多穗金粟兰营养器官的形态结构及组织化学研究

采用植物解剖学和组织化学定位方法研究多穗金粟兰（Chloranthus multistachysPei）营养器官的显微结构及萜类和黄酮类化合物在营养器官中的分布规律。结果表明：多穗金粟兰的根皮层细胞排列不整齐,液泡化明显,细胞间隙较大,有散在石细胞分布;茎皮层细胞排列不整齐,在韧皮部外方包围有少数几层束状纤维束;叶为异面叶,栅栏组织和海绵组织分化明显,叶片上、下表皮均无毛被,气孔器多为不规则型。组织化学定位结果显示萜类和黄酮类化合物分布在根的皮层、茎的皮层及韧皮部细胞中。     

On the algorithms for determining the primary structure of biopolymers

The algorithm for determining the primary structure of biopolymers from complete and partial digests are analyzed. The problem of determining the primary structure is formulated in the form of the problem of word reconstruction in the limits of which the corresponding algorithms are analyzed. Difficulties arising in constructing the algorithms for determining the primary structure of nucleic acids from a partial digest are discussed. They seem to be due to the extensive testing of variants. When there is a certain scheme of the initial data from a partial digest we propose an economical testing (searching) algorithm. The scheme of an effective algorithm for reconstruction of the primary structure fromN complete digests is given.     

The similarity of the primary structure and homology of rhodopsin, beta-adrenoreceptor and muscarinic cholinoceptor

Computer analysis has been made of the primary structure of 6 different types of receptor proteins: rhodopsin, adrenoreceptor, muscarinic acetylcholine receptor, insulin receptor, nicotinic cholinoreceptor, and bacteriorhodopsin. The aim of the present investigation was to elucidate, at least partially, to what extent insignificant similarity in the primary structure of rhodopsin, muscarinic cholinoreceptor and adrenoreceptor is due to divergent, but not convergent, evolution. Nicotinic cholinoreceptor, bacteriorhodopsin and insulin receptor were chosen for comparison with rhodopsin, adrenoreceptor and muscarinic cholinoreceptor since each of these proteins exhibits this or that structural or functional property which is common for rhodopsin, adrenoreceptor or muscarinic cholinoreceptor; on the other hand, nicotinic cholinoreceptor, bacteriorhodopsin and insulin receptor differ from other receptor proteins by their molecular mechanisms. Comparison of the primary structure of rhodopsin, adrenoreceptor and muscarinic cholinoreceptor on the one hand, and insulin receptor, nicotinic cholinoreceptor and bacteriorhodopsin on the other indicates that only the former exhibit similar primary structure, whereas insulin receptor, nicotinic cholinoreceptor and bacteriorhodopsin show no similarity neither in their primary structure, nor in the primary structure of rhodopsin and other receptor proteins which are similar to the latter with respect to their mode of action. The data obtained indicate that similarity in the primary structure between rhodopsin, muscarinic cholinoreceptor and adrenoreceptor is a consequence of divergent, not convergent, evolution; in other words, these receptor proteins are homologous.     

Trypanosoma congolense: structure and molecular organization of the surface glycoproteins of two early bloodstream variants

The complete primary structures of two variant specific glycoproteins (VSGs) of the nannomonad Trypanosoma (N.) congolense are presented. These coat proteins subserve the function of antigenic variation. The secondary structure potentials of both VSGs have been calculated. The amino acid sequences and secondary structure potentials of these VSGs have been compared with the primary structures and secondary structure potentials of several Trypanosoma brucei complex VSGs. In homologous regions, the T. brucei complex VSGs show a pattern of sharply contrasting secondary structure potentials. It has been suggested previously that this pattern gives rise to different folding structures in different members of this polygene protein family. Thus, different short regions of the polypeptide sequence are exposed as antigenic "caps" on the solvent-exposed surface of intact trypanosomes. A sharply contrasting secondary structure potential pattern is also found in regions of the two T. congolense VSGs. However, there is little homology of primary structure between each of the two T. congolense VSGs and any member of the T. brucei complex VSG polygene family whose primary structure has been determined.     

Symmetric primary and tertiary structure mutations within a symmetric superfold: a solution, not a constraint, to achieve a foldable polypeptide

In previous studies designed to increase the primary structure symmetry within the hydrophobic core of human acidic fibroblast growth factor (FGF-1) a combination of five mutations were accommodated, resulting in structure, stability and folding kinetic properties similar to wild-type (despite the symmetric constraint upon the set of core residues). A sixth mutation in the core, involving a highly conserved Met residue at position 67, appeared intolerant to substitution. Structural analysis suggested that the local packing environment of position 67 involved two regions of apparent insertions that distorted the tertiary structure symmetry inherent in the beta-trefoil architecture. It was postulated that a symmetric constraint upon the primary structure within the core could only be achieved after these insertions had been deleted (concomitantly increasing the tertiary structure symmetry). The deletion of these insertions is now shown to permit mutation of position 67, thereby increasing the primary structure symmetry relationship within the core. Furthermore, despite the imposed symmetric constraint upon both the primary and tertiary structure, the resulting mutant form of FGF-1 is substantially more stable. The apparent inserted regions are shown to be associated with heparin-binding functionality; however, despite a marked reduction in heparin-binding affinity the mutant form of FGF-1 is surprisingly approximately 70 times more potent in 3T3 fibroblast mitogenic assays. The results support the hypothesis that primary structure symmetry within a symmetric protein superfold represents a possible solution, rather than a constraint, to achieving a foldable polypeptide.     

Primary structure of inorganic polyphosphate/ATP-NAD kinase from Micrococcus flavus,and occurrence of substrate inorganic polyphosphate for the enzyme

The gene encoding an inorganic polyphosphate/ATP-NAD kinase was cloned from Micrococcus flavus, and its primary structure was analyzed. Alignment of the primary structure with those of other characterized NAD kinases revealed candidate amino acid residues, mainly charged ones, that would be related to inorganic polyphosphate use. The alignment also showed that the primary structure found carried a protruding C-terminal polypeptide. Although the C-terminal polypeptide was demonstrated to be dispensable for the kinase activities, and was proposed to be removed in M. flavus, the entire primary structure including the C-terminal polypeptide was homologous with that of the ATP synthase beta chain. The inorganic polyphosphate used by the inorganic polyphosphate/ATP-NAD kinase as a phosphoryl donor was isolated from cells of M. flavus, suggesting that the ability of the enzyme to use inorganic polyphosphate is of physiological significance and is not an evolutionary trait alone.     

白鲜根的发育解剖学研究

应用半薄切片、常规石蜡切片并结合离析法,对药用植物白鲜(Dictamnus dasycarpus Turcz.)根的发生发育过程进行了研究。结果表明:白鲜根的发生发育过程包括4个阶段,即原分生组织阶段、初生分生组织阶段、初生结构阶段以及次生结构阶段。原分生组织位于根冠内侧及初生分生组织之间,衍生细胞分化为初生分生组织。初生分生组织由原表皮、基本分生组织以及中柱原组成。原表皮分化为表皮,基本分生组织分化为皮层,中柱原分化为维管柱,共同组成根的初生结构;在初生结构中,部分表皮细胞外壁向外延伸形成根毛,皮层中分布有油细胞,内皮层有凯氏带,初生木质部为二原型或偶见三原型,外始式;根初生结构有髓或无。次生结构来源于原形成层起源的维管形成层的活动以及中柱鞘起源的木栓形成层的活动;白鲜次生韧皮部宽广,其中多年生根中可占根横切面积的85%,另外除基本组成分子外,还分布有油细胞;周皮发达,木栓层厚;初生皮层、次生木质部和次生韧皮部薄壁细胞中常充满丰富的淀粉粒。     

Structure and stability effects of mutations designed to increase the primary sequence symmetry within the core region of a β-trefoil

Human acidic fibroblast growth factor (FGF-1) is a member of the beta-trefoil hyperfamily and exhibits a characteristic threefold symmetry of the tertiary structure. However, evidence of this symmetry is not readily apparent at the level of the primary sequence. This suggests that while selective pressures may exist to retain (or converge upon) a symmetric tertiary structure, other selective pressures have resulted in divergence of the primary sequence during evolution. Using intra-chain and homologue sequence comparisons for 19 members of this family of proteins, we have designed mutants of FGF-1 that constrain a subset of core-packing residues to threefold symmetry at the level of the primary sequence. The consequences of these mutations regarding structure and stability were evaluated using a combination of X-ray crystallography and differential scanning calorimetry. The mutational effects on structure and stability can be rationalized through the characterization of "microcavities" within the core detected using a 1.0A probe radius. The results show that the symmetric constraint within the primary sequence is compatible with a well-packed core and near wild-type stability. However, despite the general maintenance of overall thermal stability, a noticeable increase in non-two-state denaturation follows the increase in primary sequence symmetry. Therefore, properties of folding, rather than stability, may contribute to the selective pressure for asymmetric primary core sequences within symmetric protein architectures.     

黄芩根的解剖学研究

用常规石蜡切片方法对黄芩(Scutellaria baicalensis Georgi)一、二年生主根的发育及结构进行解剖学研究。结果表明,黄芩根的发育可分为原分生组织、初生分生组织、初生结构和次生生长等4个阶段。原分生组织由3群原始细胞组成,其细胞具有典型分生组织的细胞学特征;初生分生组织包括根冠原、表皮原、皮层原和中柱原,其中根冠原和表皮原具有相同的起源。初生结构由表皮、皮层和中柱组成。初生木质部为二原型。次生生长主要是由维管形成层和木栓形成层的活动完成,木栓形成层起源于中柱鞘细胞。二年生黄芩主根的主要结构与一年生的基本相同,其不同之处为:二年生主根的周皮增厚,次生木质部中木纤维成群分布,出现木间木栓;维管射线为多列且明显;在近周皮的韧皮部内出现包围石细胞的木栓环组织。     

黄芩根的解剖学研究

用常规石蜡切片方法对黄芩(Scutellaria baicalensis Georgi)一、二年生主根的发育及结构进行解剖学研究.结果表明,黄芩根的发育可分为原分生组织、初生分生组织、初生结构和次生生长等4个阶段.原分生组织由3 群原始细胞组成,其细胞具有典型分生组织的细胞学特征;初生分生组织包括根冠原、表皮原、皮层原和中柱原,其中根冠原和表皮原具有相同的起源.初生结构由表皮、皮层和中柱组成.初生木质部为二原型.次生生长主要是由维管形成层和木栓形成层的活动完成,木栓形成层起源于中柱鞘细胞.二年生黄芩主根的主要结构与一年生的基本相同,其不同之处为:二年生主根的周皮增厚,次生木质部中木纤维成群分布,出现木间木栓;维管射线为多列且明显;在近周皮的韧皮部内出现包围石细胞的木栓环组织.     

Structure elucidation of glycoprotein glycans and of polysaccharides by NMR spectroscopy

The applicability of 1H-NMR spectroscopy for the determination of the primary and tertiary structure of carbohydrate-containing molecules is demonstrated. For classes of known compounds the characterization can be based on chemical shifts observed in 1D NMR spectra with or without the aid of a computer database. For more complex structure determinations 2D NMR techniques are required. Here the application of 2D NMR is demonstrated for the primary structure determination of two bacterial exopolysaccharides, for the spatial structure determination of a disaccharide and a glycoprotein hormone.