中国繁缕属的一些分类问题

研究了36种中国产繁缕属(Stellaria)植物,根据模式材料或仅根据原描述,将已合格发表的1组、1系、12种、4变种和1变型首次归并到有关各类,依次列举入异名录中,其中有1移属。讨论了各种错误鉴定,同时对于选择性状、设想进化过程和分布记录均有讨论。     

西沙群岛植物资源调查

西沙群岛主要的植被类型是常绿珊瑚岛林、灌木林或滨海植被。本区有植物89科224属340种,其中大型真菌6科11属22种,地衣1种,蕨类4科4属5种,被子植物78科208属312种。根据其经济用途,划分为10个类型,主要资源植物有药用植物、蜜源植物、食用植物、观赏植物等。西沙群岛的植物区系与海南岛十分相似,属、种的相似性指标分别为98.46％和94.09％。泛热带分布的属是本区系中最大的部分,占总属数的70.00％。最后对西沙群岛植物资源的保护和利用进行了讨论。     

侧金盏花属（Adonis L.）植物花粉形态研究

本文利用光学显微镜和扫描电镜对国产9种1变种及外国产8种侧金盏花属植物的花粉形态进行了研究,认为该属的花粉可以划分为2个大类型,这与根据外部形态分类划分的两个组是吻合的。另外根据本届花粉形态的变异,又将其中的1个大类型划分为4个亚类型。为进一步讨论该属的系统关系提供依据。 侧金盏花属植物是隶属于毛莨科毛莨族中的一个小属,约有30余种,分布于欧、亚大陆。我国有10种、1变种和2变型,分布于西南、西北、东北和山西等省区。本属植物的花粉形态过去在文献上曾有一些记载,如R.P.Wodhouse(1936)对本属的夏侧金盏花A.aestivalis)和A.vernalis进行了研究。《中国植物花粉形态》(1960)一书仅借助于光学显微镜描述了侧金盏花(A.amurensis)的花粉形态。T.Santisuk(1979)对本属12种(其中有4种产中国)的花粉形态进行了观察研究。但是,以上学者只是对本属植物的花粉形态作了轮廓性和描述和简单的讨论。他们报道该属的花粉为椭圆形或球形,具三沟、沟长而狭,轮廓不显著,沟膜具颗粒状雕纹;外壁分二层,外层厚,表面具刺状雕纹等。本文对国产的9种1变种以及外国的8种花粉形态分别利用了光学显微镜和扫描电镜进行了观察研究。     

江西三清山珍稀濒危植物考察研究

三清山有珍稀濒危植物33种,隶属30属22科,其中蕨类植物1科1属1种,裸子植物6科12属12种;被子植物15科17属20种。主要讨论了三清山珍稀濒危植物地理分布及保护。     

粤北韶关早石炭世大塘期牙形刺

作者发现了广东韶关早石炭世大塘期一些牙形刺,其中石磴子组11属20种(包括1新种和1新亚种),梓门桥组8属9种,并与国内外一些地区相当的牙形刺带进行了比较和讨论。对重要的台型牙形刺和新种作了简要描述。根据牙形刺的面貌,梓门桥组中下部可能属早石炭世。     

猕猴桃科的花粉形态及其系统位置的探讨

本文作者用光学显微镜和扫描电镜(少数种类用透射电镜)对猕猴桃科Actinidia- ceae(按照Cronquist 1981和Dahlgren 1983的概念)的猕猴桃属Actinidia(15种)、藤山柳 属Clematoclethra(5种)和水东哥属Saurauia(3种)植物的花粉形态进行了观察,并与山茶科 Theaceae(7属9种)和山柳科Clethraceae(1属1种)的花粉进行了对比分析。根据花粉的 资料,并综合分析有关的外部形态、胚胎和化学方面的特征,讨论了猕猴桃科的范围,以及这个 科的系统位置。     

江苏北部下第三系戴南组的盘星藻化石及其沉积环境的初步分析

本文记述了江苏北部兴化县下第三系戴南组盘星藻化石1属、15种、2变种,其中5新种。根据盘星藻生态条件的分析,对戴南组的沉积环境进行了讨论。     

中国的骨碎补科

本文讨论了骨碎补科属的划分问题,承认了骨碎补属、钻毛蕨属、雨蕨属和大膜盖蕨属。小膜盖蕨属和阴石蕨属的种类被并入到了骨碎补属。中国计有骨碎补科植物3属14种,其中骨碎补属12种,雨蕨属1种,大膜盖蕨属1种。     

南京大学、中国科学院南京地质古生物研究所联合举办藻类培训班

本文重点研究了抚顺煤田早第三纪地层下部玄武岩凝灰岩夹B 组煤层中的孢粉组合,经统计约有100余种,描述了18属、35种,其中1新属、20新种。对孢粉组合的成份、特征进行了分析,详细讨论了这一组合代表的地质时代为古新世,并讨论了这一孢粉植物群所属植物区和它们所反映的气候特点。     

中国棋子豆属的订正

本文结合花粉形态和叶脉结构特征讨论了棋子豆属（Cylindrokelupha） 的范围,并指出该属荚果圆柱形或近圆柱形,果瓣厚、直,种子较大为圆柱状,充满荚果空间等特征是独特的和稳定的,将之归入其它属（如合欢属,Archidendron属）是不妥的。经研究得出,该属在中国有10种,其中包括1新种和1新记录种。     

A comparative study on structural elucidation of sialyl oligosaccharides by mass spectrometry with fast atom bombardment, electrospray ionization, and matrix assisted laser desorption/ionization.

To establish a new protocol for sensitive detection and structural characterization of sialyl oligosaccharides, their sensitivities and structural information from mass spectrometry and tandem mass spectrometry with FAB-, ESI-, and MALDI were evaluated in detail. Among these ionization methods, FAB-MS and FAB-MS/MS gave reproducible and predictable spectra carrying information on sequence and branching of sialyl oligosaccharides after derivatization with 2-aminopyridine (PA). With both positive and negative ion modes, their structural elucidation promises to be straightforward, MS/MS spectra being measurable at as low as 200 pmol. Thus, this method constitutes a powerful tool for sensitive detection and structural characterization of limited quantities of sialyl oligosaccharides by FAB-MS and FAB-MS/MS.     

A Comparative Study on Structural Elucidation of Sialyl Oligosaccharides by Mass Spectrometry with Fast Atom Bombardment,Electrospray Ionization,and Matrix Assisted Laser Desorption/Ionization

To establish a new protocol for sensitive detection and structural characterization of sialyl oligosaccharides, their sensitivities and structural information from mass spectrometry and tandem mass spectrometry with FAB-, ESI-, and MALDI were evaluated in detail. Among these ionization methods, FAB-MS and FAB-MS/MS gave reproducible and predictable spectra carrying information on sequence and branching of sialyl oligosaccharides after derivatization with 2-aminopyridine (PA). With both positive and negative ion modes, their structural elucidation promises to be straightforward, MS/MS specta being measurable at as low as 200 pmol. Thus, this method consitutes a powerful tool for sensitive detection and structural characterization of limited quantities of sialyl oligosaccharides by FAB-MS and FAB-MS/MS.     

Negative ion fast atom bombardment-tandem mass spectrometry for structural analysis of isoprenoid diphosphates

Applicability of negative ion fast atom bombardment (FAB)-tandem mass spectrometry (MS/MS) was examined in trace mixture analyses and structural assignments of some isoprenoid diphosphates. Negative ion FAB-MS spectra using a glycerol matrix of these isoprenoid diphosphates showed predominantly molecular ions (M-H)- together with fragment ions at m/z 177 (H3P2O7)-, 176 (H2P2O7)-, 159 (HP2O6)-, and 79 (PO3)- which were characteristic of the diphosphate ester moiety. The molecular ions did not overlap with peaks arising from any impurities even when crude sample such as butanol extracts from enzymatic reaction mixtures were directly analyzed without any purification. Moreover, collisionally activated dissociation spectra of the molecular ion showed many structurally significant fragment ions which enabled us to elucidate the structures of such irregular alkyl chain moieties as those having a homoisoprenoid skeleton or substituted structures. These studies indicate that negative ion FAB-MS/MS is a simple and useful technique for trace mixture analysis and structure elucidation of isoprenoid diphosphates.     

Analysis of gangliosides using fast atom bombardment mass spectrometry

The native gangliosides GM3, GM1, Fuc-GM1, GD1a, GD1b, Fuc-GD1b, GT1b and GQ1b were analysed by fast atom bombardment mass spectrometry (FAB-MS) in the negative ion mode in a matrix of thioglycerol. After permethylation the same gangliosides were analysed by electron impact (EI) and FAB-MS in the positive ion mode. The negative ion mass spectra furnished information on the molecular weight, the ceramide moiety and the sequence of carbohydrate residues. The sites of attachment and the number of sialic acids present could be deduced directly from the pattern of sequence ions. After addition of sodium acetate positive ion FAB-spectra of the permethylated samples show intense pseudomolecular ions M + Na, that provide evidence on the homogeneity of the samples. In addition, the ceramide part, the oligosaccharide moiety obtained after cleavage of the glycosidic bond of the hexosamine residue, the whole carbohydrate chain and the sialic acids are represented by specific fragment ions. With EI-MS further information can be obtained on the sphingosine and fatty acid components of the ceramide residue. The data show, that the combination of soft ionization mass spectrometry with classical EI-MS gives valuable information on the structure and homogeneity of gangliosides. The method is also applicable to the structural elucidation or quantitation of more complex gangliosides or glycolipid mixtures using only micrograms of material.     

Flavone C-glycosides from Scleranthus uncinatus

Two flavone C-glycosides, 5,7,4'-trihydroxy-3'-methoxyflavone-8-C-beta-D-xylopyranoside-2"-O-glucoside, 5,7-dihydroxy-3'-methoxy-4'-acetoxyflavone-8-C-beta-D- xylopyranoside-2"-O-glucoside and one known maltol beta-D-glucopyranoside were isolated for the first time from the Scleranthus uncinatus and their structures deduced by high field 1D and 2D 400 MHz NMR and (+) FAB-MS spectra.     

Structures of Sarcorucinine D and Pachyaximine A,B

In this paper, three new alkaloids, sarcorucinine D (1), and paehyaximine A, B (2, 3) were isolated from Sarcococca ruscifolia Stapf and Pachysandra axillaris Franch, respectively. The structures of sarcorucinine D (1) and pachyaximine A, B (2, 3) were elucidated to be 3β-hydroxyl-20α-dimethylamino-5α-pregnane (1); and 3β-methoxyl-20α-dimethylamino-pregne-5-ne (2); and 3β-methoxyl-16-hydroxyl-20α-dimethylaminopregne-5-ne (16-hydroxyl-pachyaxi- mine A) (3), respectively.     

Structure of syringotoxin, a bioactive metabolite of Pseudomonas syringae pv. syringae

The covalent structure of syringotoxin, a bioactive metabolite of Pseudomonas syringae pv. syringae isolates, pathogenic on various species of citrus trees, has been deduced from 1D and 2D 1H- and 13C-NMR spectra combined with extensive FAB-MS data and results of some chemical reactions. Similarly to syringomicins and syringostatins, produced by other plant pathogenic strains of P. syringae pv. syringae, syringotoxin is a lipodepsinonapeptide. Its peptide moiety corresponds to Ser-Dab-Gly-Hse-Orn-aThr-Dhb-(3-OH)Asp-(4-Cl)Thr with the terminal carboxy group closing a macrocyclic ring on the OH group of the N-terminal Ser, which in turn is N-acetylated by 3-hydroxytetradecanoic acid.     

环烯醚萜甙的快速原子轰击质谱和场解吸质谱研究

环烯醚萜甙是植物界分布较广泛的一类配糖体成分,极性较大,用通常的电子轰击质谱测试不能得到分子离子信息,且离子碎片零碎,难以进行结构解析。本文对２５个不同类型的环烯醚萜甙进行正,负离子快速原子轰击质谱和场解吸质谱分析,并讨论这两种质谱新技术在环烯醚萜甙类化合物结构解析中的应用。     

Structural elucidation of novel degradation product of brotizolam

When the drug product of brotizolam (1) is decomposed according to the interview form and patent, hydrolysate (2) is obtained, but its physicochemical data are still missing. To elucidate the structure based on a spectroscopic approach, the above-mentioned degradation product was isolated and applied to the structural analysis. As a result, the structure of decomposed product was found to be different from that of 2. In this report, its isolation and structure elucidation by NMR and MS spectra are described.     

Solution structure of C-terminal Escherichia coli translation initiation factor IF2 by small-angle X-ray scattering

Initiation of protein synthesis in bacteria involves the combined action of three translation initiation factors, including translation initiation factor IF2. Structural knowledge of this bacterial protein is scarce. A fragment consisting of the four C-terminal domains of IF2 from Escherichia coli was expressed, purified, and characterized by small-angle X-ray scattering (SAXS), and from the SAXS data, a radius of gyration of 43 +/- 1 A and a maximum dimension of approximately 145 A were obtained for the molecule. Furthermore, the SAXS data revealed that E. coli IF2 in solution adopts a structure that is significantly different from the crystal structure of orthologous aIF5B from Methanobacterium thermoautotrophicum. This crystal structure constitutes the only atomic resolution structural knowledge of the full-length factor. Computer programs were applied to the SAXS data to provide an initial structural model for IF2 in solution. The low-resolution nature of SAXS prevents the elucidation of a complete and detailed structure, but the resulting model for C-terminal E. coli IF2 indicates important structural differences between the aIF5B crystal structure and IF2 in solution. The chalice-like structure with a highly exposed alpha-helical stretch observed for the aIF5B crystal structure was not found in the structural model of IF2 in solution, in which domain VI-2 is moved closer to the rest of the protein.