锌酵母中酵母甘露多糖组分的特征和结构

本文研究从锌酵母中分离出的酵母甘露多糖ＸＰ的特征和结构。ＸＰ经全水解和＾１３ＣＮＭＲ谱显示除甘露糖基外,还有少量Ｌ－鼠李糖基和甲氧基。甲基化分析、过碘酸盐氧化、Ｓｍｉｔｈ降解、乙酰解和部分酸水解显示ＸＰ的主链是１→６连接的甘露糖,侧链是１→２连接的甘露糖。＾１Ｈ及＾１３Ｃ ＮＭＲ谱表明所有糖苷键均为α型,结合元素分析ＸＰ基本是酵母甘露多糖和蛋白质以及锌的络合物。     

长梗千里光中的呋喃雅槛兰型倍半萜

长梗千里光（ＳｅｎｅｃｉｏｋａｓｃｈｋａｒｏｖｉｉＣ．Ｗｉｎｋｌ．）为菊科千里光属的多年生草本植物,广布于甘肃省东南部的灌木丛中及林边草地,四川、青海也有分布［１］。其化学成分未见报道。千里光属植物的主要成分是双稠吡咯啶生物碱和呋喃雅槛兰型倍半萜［２,３］。前者具有抗癌活性,但也有致癌、致畸等毒性［４］。我们从长梗千里光的地上部分分离到两个呋喃雅槛兰型倍半萜（１）和（２）,通过ＵＶ、ＩＲ、ＭＳ、１Ｈ－ＮＭＲ和１３Ｃ－ＮＭＲ等光谱分析,确定化合物１为１α－乙酰氧基－６β－当归酰氧基－１０β－羟基－…     

金顶侧耳多糖PC—4的结构确定与抗肿瘤活性的研究

３％氯乙酸浸提过的金顶侧耳子实体中分离纯化另一水溶性多糖ＰＣ－４。该多糖分子量经为１８９ｋＤ。纸层析与气相层析分析表明其为单一聚糖。经高磺酸氧化,Ｓｍｉｔｈ降解,甲基化,层析,气质联机分析,核磁其振（Ｈ－ＮＭＲ,１３Ｃ－ＮＭＲ）谱及红外光谱测定等,可确定Ｃ－４的主链结构由β－（１→３）糖苷键相连的葡萄糖构成,部份残基Ｃ６,上带有分支。约每５个糖残基有两个侧链,侧链仅为１个葡萄糖残基。     

新雷公藤内酯四醇的研究

从雷公藤（Ｔｒｉｐｔｅｒｙｇｉｕｍ ｗ ｉｌｆｏｒｄｉｉＨｏｏｋ． ｆ．）的叶和根中分离到一个新的环氧二萜内酯化合物,据其理化性质,ＵＶ、ＩＲ、ＭＳ、１Ｈ－ＮＭＲ、１３Ｃ－ＮＭＲ、１３Ｃ－ＮＯＥ、２Ｄ－ＣＯＳＹ、２Ｄ－ＮＯＥＳＹ 和选择性远程ＤＥＰＴ谱等光谱数据分析,并结合分子图形学和分子力学计算确定了它的化学结构,命名为新雷公藤内酯四醇（ｎｅｏｔｒｉｐｔｅｔｒａｏｌｉｄｅ）． 该产物为首次从植物中分得的新化合物     

为一种用途极广的新型材料短梗霉多糖呼吁

短梗霉多糖(Pullulan)是由出芽短梗霉(Aureobasidium pullulans)产生的一种胞 外多糖,其结构为α-1.6糖苷键联结的聚麦芽三糖(为α-1.4键联结的三聚葡萄糖),为中性的线性大分子。其分子量因产生菌和发酵条件的差异而有较大变化,通常为1-100万。短梗霉多糖在水中可无限溶解,其水溶液粘度随浓度和分子量增加而增加,与其它类型多糖相比粘度低得多,浓度10％的分子量10万的短梗霉多糖水溶液粘度仅为30厘泊。     

斜脉暗罗素甲—具有C5—OH的单四氢呋喃环型番荔枝内酯

从斜脉暗罗（Ｐｏｌｙａｌｔｈｉａ ｐｌａｇｉｏｎｅｕｒａ Ｄｉｅｌｓ）的种子中分离到化合物Ｐ４ 及Ｐ５,经ＩＲ、１Ｈ－ＮＭＲ、１３ Ｃ－ＮＭＲ及ＭＳ谱鉴定,Ｐ４ 为海南哥纳香甲素,Ｐ５ 为具有Ｃ５－ＯＨ 的单四氢呋喃环型番荔枝内酯,命名为斜脉暗罗素甲（ｐｌａｇｉｏｎｉｃｉｎ Ａ）。     

长果升麻的化学成分研究

从长果升麻（Ｓｏｕｌｉｅａ ｖａｇｉｎａｔａ）根茎中分离出６种皂甙,经光谱（ＦＡＢ－ＭＳ、１Ｈ－ＮＭＲ、１Ｈ－１Ｈ－ＣＯＳＹ、１３Ｃ－ＮＭＲ、１Ｈ－１３Ｃ－ＣＯＳＹ）分析,分别鉴定为２７－ｄｅｏｘｙａｃｔｅｉｎ（１）,ａｃｔｅｉｎ（２）,２５－０－乙酰升麻醇木糖甙（３）,２５－甲基升麻醇木糖甙（４）,升麻醇木糖甙（５）,２４－ａｃｅｔｙｌｈｙｄｒｏｓｈｅｎｇｍａｎｏｌ ｘｙｌｏｓｉｄｅ（６）,其中     

番荔枝化学成分研究(7)

从番荔枝（Ａｎｎｏｎａ ｓｑｕａｍｏｓａ Ｌ．）种子中得到化合物１、２和４,化合物２和４分别为已知化合物ｍｏｔｒｉｌｉｎ（莫垂林,２）和ｂｕｌｌａｔａｎｏｃｉｎ（布拉他诺辛,４）。化合物１的化学结构经ＩＲ、ＭＳ、＾１Ｈ ＮＭＲ及＾１３Ｃ ＮＭＲ谱分析及其乙酰化物（１ａ）的ＭＳ、＾１Ｈ ＮＭＲ谱分析推定如（１）式并命名为２２－表－莫维查灵（２２－ｅｐｉ－ｍｏｌｖｉｚａｒｉｎ）。     

出芽短梗霉新菌株RM1603产普鲁兰多糖条件优化及多糖分析

目的:出芽短梗霉RM1603是一株高产胞外多糖新菌株,通过优化其产糖条件,鉴定其多糖结构,为进一步开发利用RM1603产胞外多糖奠定理论基础。方法:以RM1603为出发菌株,在单因素分析确定最佳氮源与无机盐的基础上,利用正交试验探究RM1603最佳发酵产糖条件;薄层层析及红外光谱分析确定胞外多糖产物结构。结果:出芽短梗霉菌RM1603的初始多糖产量为28.91g/L,发酵条件优化后产糖量达到65.213g/L,提高了约2.3倍;结构分析表明RM1603的多糖产物为普鲁兰多糖。结论:出芽短梗霉RM1603是一株具有较大产糖优势,极具开发潜力的高产普鲁兰糖新菌株;奠定了开发利用RM1603生产普鲁兰多糖的理论基础。     

阿维菌素高产菌株的选育及阿维菌素B1的鉴定

自阿维链霉菌（Ｓｔｒｅｐｔｏｍｙｃｅｓ ａｖｅｒｍｉｔｉｌｉｓ ＡＴＣＣ３１２７２）中分离出了３种不同类型的菌株,其中只有产灰色了的菌株能产生阿维菌素（Ａｖｅｒｍｅｃｔｉｎｓ）,摇瓶发醇单位约１００μｇ／ｍＬ。从其菌丝体中提取纯化了阿维菌素Ｂ１晶体,其紫外吸收光谱、红外吸收光谱、核磁共振谱Ｈ－ＮＭＲ和＾１３Ｃ－ＮＭＲ）和质与国外报道的一致。Ｓａ－７６菌株又经２次亚硝基胍诱变,筛选出发酵单位２０００     

A nearly idealized 6'-O-methylated iota-carrageenan from the Australian red alga Claviclonium ovatum (Acrotylaceae, Gigartinales)

The polysaccharides extracted from Claviclonium ovatum were studied by a combination of compositional assays, reductive partial hydrolysis, linkage analysis, Fourier Transform infrared (FTIR) spectroscopy, and 13C, 1H, and 13C/1H heteronuclear multiple quantum correlation (HMQC) two-dimensional nuclear magnetic resonance (NMR) spectroscopy. The chemical and spectroscopic data showed that the alkali-modified C. ovatum polysaccharides are composed of a nearly idealized repeating unit of 6'-O-methylcarrabiose 2,4'-disulfate (the repeating unit of 6'-O-methylated iota-carrageenan), although some minor components were also present. The C. ovatum galactans are the most highly methylated carrageenans reported.     

NMR study of the metabolic 15N isotopic enrichment of cyanophycin synthesized by the cyanobacterium Synechocystis sp. strain PCC 6308

1H, 13C and 15N nuclear magnetic resonance (NMR) spectroscopy has been used to characterize cyanophycin, a multi-l-arginyl-poly-[l-aspartic acid] polypeptide from the cyanobacterium Synechocystis sp. strain PCC 6308. 1H, 13C and 15N chemical shifts and 1JHN and 1JCN coupling constants were measured in isolated 15N-labeled cyanophycin, and showed chemical shift values and J-couplings consistent with the reported polypeptide structure. 15N enrichment levels were determined from the extent of 1H-15N J-coupling in 1H NMR spectra of cyanophycin. Similar experiments using 13C-15N coupling in 13C NMR spectra were not useful in determining enrichment levels.     

Acetylation and silylation of piperidine solubilized sporopollenin from pollen of Typha angustifolia L

Silyl and acetyl derivatives of sporopollenin from the pollen of Typha angustifolia L. were prepared. The derivatized products were readily soluble in piperidine-d11 and could be investigated employing one- and two-dimensional proton and carbon NMR (nuclear magnetic resonance) spectroscopy (1H,1H-COSY and 13C,1H-HETCOR techniques). For the first time, a two dimensional 13C,1H-HETCOR NMR spectrum of a sporopollenin could be obtained. The results underline the importance of derivatization techniques for obtaining two dimensional 13C-NMR spectra of sporopollenins. Moreover, piperidine turns out to be a more suitable solvent for sporopollenins than 2-aminoethanol, as it allows for higher solubilities, being important for 2D-NMR investigations. From the HETCOR and COSY spectra of the silylated and the acetylated Typha samples the occurrence of aliphatic polyhydroxy compounds as well as phenolic OH groups became evident.     

Two-dimensional 1H/13C heteronuclear chemical shift correlation spectroscopy of lipid bilayers.

Using solid-state magic angle spinning nuclear magnetic resonance (NMR) techniques, we have obtained two-dimensional (2D), 1H/13C chemical shift-correlated spectra of liquid crystalline 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC) bilayers in 30 wt% PO4/D2O buffer. Linewidths in both the 13C and the 1H dimensions were less than 0.3 ppm wide. The 2D spectrum consists of chemical shift correlations between all resolvable, directly bonded 13C-1H pairs and exhibits considerably greater spectral dispersion than either ID 1H or 13C MAS spectra. This approach promises to be an important tool in structural studies of biological membranes.     

2D NMR metabonomic analysis: a novel method for automated peak alignment

MOTIVATION: Comparative metabolic profiling by nuclear magnetic resonance (NMR) is showing increasing promise for identifying inter-individual differences to drug response. Two dimensional (2D) (1)H (13)C NMR can reduce spectral overlap, a common problem of 1D (1)H NMR. However, the peak alignment tools for 1D NMR spectra are not well suited for 2D NMR. An automated and statistically robust method for aligning 2D NMR peaks is required to enable comparative metabonomic analysis using 2D NMR. RESULTS: A novel statistical method was developed to align NMR peaks that represent the same chemical groups across multiple 2D NMR spectra. The degree of local pattern match among peaks in different spectra is assessed using a similarity measure, and a heuristic algorithm maximizes the similarity measure for peaks across the whole spectrum. This peak alignment method was used to align peaks in 2D NMR spectra of endogenous metabolites in liver extracts obtained from four inbred mouse strains in the study of acetaminophen-induced liver toxicity. This automated alignment method was validated by manual examination of the top 50 peaks as ranked by signal intensity. Manual inspection of 1872 peaks in 39 different spectra demonstrated that the automated algorithm correctly aligned 1810 (96.7%) peaks. AVAILABILITY: Algorithm is available upon request.     

NMR of fd coat protein

The conformations of the major coat protein of a filamentous bacteriophage can be described by nuclear magnetic resonance spectroscopy of the protein and the virus. The NMR experiments involve detection of the ¹³C and ¹H nuclei of the coat protein. Both the ¹³C and ¹H nuclear magnetic resonance (NMR) spectra show that regions of the polypeptide chain have substantially more motion than a typical globular protein. The fd coat protein was purified by gel chromatography of the SDS solubilized virus. Natural abundance ¹³C NMR spectra at 38 MHz resolve all of the nonprotonated aromatic carbons from the three phenylalanines, two tyrosines, and one tryptophan of the coat protein. The α carbons of the coat protein show at least two different classes of relaxation behavior, indicative of substantial variation in the motion of the backbone carbons in contrast to the rigidity of the α carbons of globular proteins. The ¹H spectrum at 360 MHz shows all of the aromatic carbons and many of the amide protons. Titration of a ¹H spectra gives the pKas for the tyrosines.     

Preparation and properties of an Fe(III)-complex with an Amadori compound derived from L-tyrosine

The complexation of Fe(III) with an Amadori compound derived from L-tyrosine was studied. The isolated complex was characterized by elemental analyses, Fourier transform infrared (FTIR) and 13C nuclear magnetic resonance (NMR) spectroscopy. Analyses indicate that the ligand is coordinated through the amino and carboxylate groups of the tyrosine part of the molecule.     

Assignment of the 13C nuclear magnetic resonance spectrum of a short DNA-duplex with 1H-detected two-dimensional heteronuclear correlation spectroscopy.

Proton-detected 1H-13C heteronuclear correlated spectroscopy [( 1H,13C]-COSY) was used to establish relations between the carbon-13 and proton nuclear magnetic resonance chemical shifts in the hexadeoxynucleoside pentaphosphate d-(GCATGC)2. Using the previously established sequence-specific proton NMR assignments, sequence-specific assignments were thus obtained for nearly all proton-bearing carbons. This approach offers a new criterion for distinguishing between the proton NMR lines of purines and pyrimidines, based on the different proton-carbon-13 coupling constants. Furthermore, the adenine ring carbon 2 has a unique carbon-13 chemical shift, which enables a straightforward identification of the adenine C2H resonances by [1H,13C]-COSY.     

1H- and 13C-NMR, FTIR, UV-VIS, ESI-MS, and PM5 studies as well as emission properties of a new Schiff base of gossypol with 5-methoxytryptamine and a new hydrazone of gossypol with dansylhydrazine

A new Schiff base of gossypol with 5-methoxytryptamine (GSTR) and a new hydrazone of gossypol with dansylhydrazine (GHDH) have been synthesized and studied by Fourier transform infrared (FTIR), 1H and 13C nuclear magnetic resonance (NMR), ultraviolet-visible (UV-VIS), electrospray ionization-mass spectroscopy (ESI-MS) as well as the parametric method PM5. The spectroscopic methods have provided clear evidence that GSTR exists in chloroform solution as an enamine-enamine tautomer, whereas GHDH is present in chloroform as a N-imine-N-imine tautomer. The fluorescence spectra of both compounds indicate that their quantum yield of fluorescence is increased by one or two orders of magnitude compared to that of pure gossypol. The ESI-MS spectra of the 1:1 mixtures of GSTR or GHDH with formic acid have demonstrated that both compounds exist as protonated monomers in the gas phase, whereas GHDH can also exist in a stable protonated dimeric structure. The structures of the stable tautomers are calculated and visualized using the PM5 semiempirical method. The intra- and intermolecular hydrogen bonds within these structures are discussed.     

NMR studies of melanins: characterization of a soluble melanin free acid from Sepia ink.

This paper deals with the nuclear magnetic resonance characterization of a soluble derivative (melanin free acid) of Sepia melanin obtained by a peroxidative treatment of the parent (insoluble) species. High resolution 13C and 15N solid state NMR spectroscopies allow the assessment of the chemical changes occurring in the macromolecule upon solubilization. 1H and 13C NMR solution spectra are discussed in light of the results obtained from the solid state spectra. Furthermore, the coordination properties of melanin have been investigated through 27Al NMR spectroscopy and proton relaxation enhancement studies of the paramagnetic gadolinium complex of melanin free acid. Through these experiments it has been possible to evaluate the molecular reorientational time tau R (and from it an estimated molecular weight close to 20 KDa) and the strength of the metal-macromolecule interaction.