Lipid A structure of Pseudoalteromonas haloplanktis TAC 125: use of electrospray ionization tandem mass spectrometry for the determination of fatty acid distribution

The use of electrospray Ionization (ESI) tandem mass spectrometry (MS/MS) for the structural determination of the lipid A components of the psychrophilic bacterium Pseudoalteromonas haloplanktis TAC 125 is reported. The lipid A contains the classical bisphosphorylated beta-(1' --> 6)-linked D-glucosamine disaccharide with 3-hydroxydodecanoyl residues (12 : 0 (3-OH)) linked both as esters and amides to 2', 3' (distal glucosamine) and 2, 3 positions (proximal glucosamine) of the sugar backbone. The hydroxyl of 12 : 0 (3-OH) fatty acid linked at the 3' position is esterified by a dodecanoyl residue (12 : 0). In addition to the pentaacyl component, a minor tetraacyl lipid A, lacking the acyl residue at position 3, was also found in the lipid A fraction. The advantage of this MS technique for the investigation of the intra-ring fragmentation, which is useful for the determination of fatty acyl residue distribution on each glucosamine unit, is emphasized.     

Chemical structure and biological activity of steroidal saponins from Furcraea gigantea

A new bisdesmosidic furostanol saponin, along with a known spirostanol saponin, furcreastatin, were isolated from Furcraea gigantea Vent. (Agavaceae). The structure of the new saponin was elucidated as 3-[(O-6-deoxy-α-L-mannopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1å 3)-O-[O-β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→2)-O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranosyl)oxy]-(3β, 5α, 25R)-26-(β-D-glucopyranosyloxy)-22-hydroxyfurost-12-one. The structural identification was performed using a combination of spectroscopic techniques and chemical conversions. Furcreastatin showed a powerful haemolytic effect in the in vitro assay, but the new bisdesmosidic furostanol saponin demonstrated only a significant inhibition of the capillary permeability activity.     

Structural characterisation of the core oligosaccharides isolated from the lipooligosaccharide fraction of Agrobacterium tumefaciens A1

Three different oligosaccharide structures from the lipooligosaccharide fraction of Agrobacterium tumefaciens strain A1 were determined by means of chemical and spectrometrical methods. The peculiar feature of this oligosaccharide family consisted of its unusual length, that was very close to the that minimal requested for the external membrane functionality as exemplified from oligosaccharide 3, where the inner core is glycosylated from only one sugar moiety onwards.     

Structural characterization and biological activity of galactoglucan from Castanea mollissima Blume

Abstract

A galactoglucan (HCPA) was extracted from C. mollissima Blume fruits using hot water, which was composed of glucose and galactose, with a molecular weight of 5.5?kDa. Methylation and 1?D, 2?D NMR spectroscopy analysis showed that HCPA contained [→4)-α-D-Glcp(1→], [→4,6)-α-D-Glcp(1→], [→4)-β-D-Galp(1→] and [α-D-Glcp(1→] motifs in a molar ratio of approximately 6.11:1.08:1.00:1.03. HCPA showed a spherical-like structure as detected by scanning electron microscope (SEM). HCPA biological activity was investigated in vitro. The results showed that HCPA inhibited the proliferation of HeLa, MCF-7 and MGC-803 cells, induced HeLa cells apoptosis and arrested cell cycle in G2/M phase of HeLa cells. HCPA also enhanced the viability and phagocytic ability of RAW 264.7 cells and stimulated the production of NO, TNF-α and IL-6. The results demonstrated that HCPA had a potent antitumor and immunomodulating effects in vitro, suggesting its potential use as functional food and drug products.     

酵母甘露聚糖硫酸酯化前后结构与生物活性比较研究

对酵母甘露聚糖及硫酸酯化酵酯母甘露聚糖的相对分子质量、红外光谱、离子色谱、比旋光度、IO4^-氧化、SO4^2-含量、Smith降解、电泳及THP－1细胞分泌IL-la的水平等进行了测定，结果表明，硫酸酯化后相对分子质量增加，IR光谱[α]D^20均有明显变化，电泳迁移加快，IO4^-氧化甲酸生成量减少，硫酸酯化位置在非还原末端，C（3）对碱位置稳定，Smith降解结果表明硫酸化前后基本结构无明显变化。硫酸酯化前后样品对THP－1细胞分泌IL－1a水平影响差异显，对IL-6,IL-8,TNFa,IL-2亦有影响。     

Synthesis,structure and biological activity of four new picolinohydrazonamide derivatives

Four new picolinohydrazonamide derivatives, namely, 6‐methyl‐N′‐(morpholine‐4‐carbonothioyl)picolinohydrazonamide, C₁₂H₁₇N₅OS, 6‐chloro‐N′‐(morpholine‐4‐carbonothioyl)picolinohydrazonamide methanol monosolvate, C₁₁H₁₄ClN₅OS·CH₃OH, 6‐chloro‐N′‐(4‐phenylpiperazine‐1‐carbonothioyl)picolinohydrazonamide, C₁₇H₁₉ClN₆S, and 6‐chloropicolinohydrazonamide, C₆H₇ClN₄, have been synthesized and characterized by NMR spectroscopy and single‐crystal low‐temperature X‐ray diffraction. In addition, their antibacterial and anti‐yeast activities have been determined. The first three compounds adopt the zwitterionic form in the crystal structure regardless of the presence or absence of solvent molecules in the structure. They also adopt the same symmetry, i.e. P2₁/c (P2₁/n), unlike the fourth structure which is chiral and has the space group P2₁2₁2₁. For all the studied cases, intermolecular N—H…O and N—H…N hydrogen bonds play an essential role in the formation of the structures.     

双乙酰二茂铁缩肼基二硫代甲酸甲酯Schiff碱的合成、晶体结构和生物活性(英文)

用双乙酰二茂铁和肼基二硫代甲酸甲酯为起始原料,制备了含二茂铁的Schiff碱配体[(CH3)SSCNHN=C(CH3)(C5H4)]2Fe.利用元素分析以及红外光谱和单晶X射线衍射分析了产物的组成、化学特征及晶体结构,并测定了其生物活性.结果表明,标题化合物对Ec9706食管癌细胞株具有适度的生长抑制活性.     

Telomerase Inhibitors from Cyanobacteria: Isolation and Synthesis of Sulfoquinovosyl Diacylglycerols from Microcystis aeruguinosa PCC 7806

By using the Telospot assay, 27 different extracts of cyanobacteria were evaluated for telomerase inhibition. All extracts showed varying, but significant activity. We selected Microcystis aeruguinosa PCC 7806 to identify the active compound and a bioassay guided fractionation led us to isolate mixtures of sulfoquinovosyl diacylglycerols (SQDGs), which were identified by 2D NMR and MS/MS experiments. Pure SQDG derivatives were then synthesized. The IC₅₀ values of pure synthetic sulfoquinovosyl dipalmitoylglycerol and the monopalmitoylated derivative against telomerase were determined to be 17 and 40 μM , respectively. A structure–activity relationship study allowed the identification of compounds with modified lipophilic acyl groups that display improved activity.     

水杨醛缩2-芴胺席夫碱的合成、晶体结构及生物活性

芴在煤焦油中的含量为1%～2%,全国每年可从中提取1.4万吨芴.芴是一种带有荧光的片状化合物,作为一种新型的发光材料主要用于制备芴基金属化合物、有机光导体、树脂、染料、Ziegler-Natta催化剂的给电子体等.     

Structural features of chitin from Aral crustaceans and use of chitosans based on it

Structural features of chitin from Aral crustaceans and chitosan based on it are examined using x-ray diffraction and IR spectroscopy. Their biological activities on encapsulated cotton seeds are determined.Institute of Polymer Chemistry and Physics, Academy of Sciences of the Republic of Uzbekistan, Tashkent, 700128, ul. A. Kodirii, 76, fax 144 26 61. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 97–99, March–April, 2000.     

聚异戊二烯基三胺的合成及生理活性评价

设计、合成了一系列聚异戊二烯基三胺化合物,目标化合物结构均经过核磁共振谱、质谱及元素分析确认;利用MTT法测试了目标化合物对人白血病细胞K562和人肝癌细胞Bel-7402的体外抗肿瘤活性.结果表明,目标化合物对两种肿瘤细胞的生长均有较强的抑制活性.     

Syntheses,crystal structures and biological activity of the dialkytin complexes based on 2-oxo-3-phenylpropionic acid salicyloylhydrazone

Three new dialkytin complexes, {[o-OH–C₆H₄(O)C=N–N=C(CH₂Ph)COO](n-Bu₂Sn)}_n (1), {[o-OH–C₆H₄(O)C=N–N=C(CH₂Ph)COO](MeOH)(p-MeC₆H₅CH₂)₂Sn}₂ (2), and {[o-OH–C₆H₄(O)C=N–N=C(CH₂Ph)COO](EtOH)(C₆H₅CH₂)₂Sn}₂ (3), were synthesized by reactions of 2-oxo-3-phenylpropionic acid salicyloylhydrazone with the corresponding diorganotin(IV) complex, respectively. All the complexes were characterized by IR, ¹H, ¹³C, ¹¹⁹Sn NMR spectra, elemental analysis, X-ray single crystal diffraction and TGA. For in vitro antitumor activities, complexes were evaluated by the MTT assay against three human cancer cell lines (NCI-H460, HepG2 and MCF7) and human cell line (HL7702). The results showed that 1 may be a better potential candidate for further chemical optimization and cancer therapy than 2 and 3. The interactions between the complexes and calf thymus DNA were studied; the interaction of 1 with calf thymus DNA was intercalation, 2 and 3 were intercalation and electrostatic binding.     

邻烷氧基羰基苯磺酰胺衍生物的合成、表征及生物活性

磺酰胺类化合物是继磺酰脲与咪唑啉酮除草剂之后开发的乙酰乳酸合成酶 (ＡＬＳ)抑制剂的另一重要领域 ,已筛选出一些高活性的新品种[1～ 3] 。为寻找新的性能优良的活性物质 ,进一步研究活性与结构的关系 ,本文设计将磺酰胺类和酰胺类除草剂的基本骨架用一个亚甲基 ＣＨ2 连结起来 ,相当于在磺酰脲桥链中间插入了一个亚甲基 ,共合成了 1 6个新的邻烷氧基羰基苯磺酰胺衍生物( 2ａ～ 2ｐ) ,并初步测试了它们的生物活性。1　实验部分1 1　仪器和试剂ＪＥＯＬＦＸ 90Ｑ型、ＢＲＵＫＥＲＡＣ Ｐ2 0 0型核磁共振仪 ,ＴＭＳ为内标 ;Ｓｈｉｍａｄ…     

硝基苯酰基硫脲衍生物的合成与生物活性研究

酰氨基硫脲类化合物具有很好的生物活性,如消炎、抗菌、抗结核、抗癌、杀菌、杀虫及植物生长调节等[1-8],也是重要的有机合成中间体[9-12].因此,随着新型农药的开发研究,酰氨基硫脲类化合物又成为药物开发的热点之一.     

Synthesis and characterization of organotitanium substituted heteropolytungstosilicates and their biological activity

Tris-, di-(organotitanium) substituted tungstosilicates α、β-[(CpTi)3(SiW9O37)]7- and γ-[(Cp-Ti)2(SiW10O38)]6- were prepared by the reaction of Cp2TiCl2 (Cp = η5-C5H5) with α、β-SiW9O349- (noted α、β-SiW9), γ-SiWO368- (noted γ-SiW10) . The products were characterized by means of elemental analysis, IR, 1H NMR, 183W NMR and polarography. 183W NMR spectra of the complexes support the stoichiometry of the new heteropolyanions and the probable retention of the A-XWg or γ-SiW10 units. And the organotitanium substituted compounds showed promising in vitro antitumor activity in two of human tumor cell lines.     

Water-Soluble Polysaccharides from Narcissus poeticus and Their Biological Activity

A homogeneous native acetylated glucomannan of molecular weight 32000 was isolated from bulbs of N. poeticus. A linear chain polymer consisting of -14-bound D-manno- and D-glucopyranoses was found using periodate and chromic oxidation and methylation. The glucomannan has low toxicity and exhibits distinct hypolipidemic activity.