从薄层层析到天然产物工业制备层析的理论与实践

基于分离理论的共性,通过薄层层析优化难分离物质对的最佳分离条件并直接放大到植物天然产物的工业制备分离。本文对实际应用中的溶剂组成、溶剂强度、溶剂用量及溶剂再利用等问题作了详细论述。最佳溶剂选择性可通过不同溶剂系统在薄层板上所给难分离物质对的最大Rf比值确定;在正相硅胶层析中,主要极性溶剂决定了物质的洗脱顺序;洗脱剂中极少量强极性溶剂(O．5％)或pH值的改变可显著改善拖尾现象;根据Rf值和容量因子(K)及洗脱体积三者之间的关系,Rf在0．1～0．3为用于柱层析的洗脱溶剂强度的最佳范围。     

Isolation and characterization of a cold-active,alkaline, detergent stable α-amylase from a novel bacterium Bacillus subtilis N8

A cold-active alkaline amylase producer Bacillus subtilis N8 was isolated from soil samples. Amylase synthesis optimally occurred at 15°C and pH 10.0 on agar plates containing starch. The molecular weight of the enzyme was found to be 205?kDa by performing SDS-PAGE. While the enzyme exhibited the highest activity at 25°C and pH 8.0, it was highly stable in alkaline media (pH 8.0–12.0) and retained 96% of its original activity at low temperatures (10–40°C) for 24?hr. While the amylase activity increased in the presence of β-mercaptoethanol (103%); Ba²⁺, Ca²⁺, Na⁺, Zn²⁺, Mn²⁺, H₂O₂, and Triton X-100 slightly inhibited the activity. The enzyme showed resistance to some denaturants: such as SDS, EDTA, and urea (52, 65, and 42%, respectively). N8 α-amylase displayed the maximum remaining activity of 56% with 3% NaCl. The major final products of starch were glucose, maltose, and maltose-derived oligosaccharides. This novel cold-active α-amylase has the potential to be used in the industries of detergent and food, bioremediation process and production of prebiotics.     

薄层层析指导下的嗜碱放线菌菌株YIMGQ-14次生代谢产物研究

在微生物资源的开发研究过程中,利用TLC方法,配合TLC数据库的检索,对嗜碱放线菌菌株YIMGQ14的次生代谢产物进行了研究。并从中分离纯化出两个具有生物活性的专利化合物“Umycin C”和“Umycin B”。结果证明：相对于常规的生物活性筛选,TLC法在微生物次生代谢产物研究中具有快速、简便、经济的特点,适合于小量常规筛选的目的。通过进一步对相关的TLC数据库进行构建和补充,将能极大地改善该方法的使用效率。     

Delineating Kocuria turfanensis 2M4 as a credible PGPR: a novel IAA-producing bacteria isolated from saline desert

Indole-3-acetic acid (IAA)-producing bacteria Kocuria turfanensis strain 2M4 was isolated from the rhizospheric soil of halotolerant plant Suaeda fruticosa from a unique saline desert of Little Rann of Kutch, Gujarat, India. Rhizobacteria was bright orange pigmented, gram-positive, coccoid, non-endospore forming, and aerobic in nature. 16S rRNA gene sequence analysis showed that 2M4 isolate matched best with type strain of K. turfanensis HO-9042^T. Isolate optimally produced 38 µg ml^?1 IAA when growth medium was supplemented with 600 µg ml^?1 of L-tryptophan. Thin layer chromatography and Fourier transform infrared spectroscopy analysis were performed to corroborate IAA production. To characterize rhizobacterial isolate as a plant growth-promoting bacteria, it was tested for phosphate solubilization where it solubilized maximum 12 µg ml^?1 phosphate in presence of fructose, produced 53% siderophore units under iron-free minimal MM9 medium and produced 1.8 µmol ml^?1 ammonia in peptone water broth. Plant growth promotion by test isolate was studied on groundnut (Arachis hypogaea L.) under non-saline and saline soil. There was increase by 18% in total plant length and 30% in fresh biomass observed under non-saline control soil. Under saline soil, test isolate showed 17% increase in total length of the plant and 13% increase in fresh biomass.     

The production-influencing factors of extracellular polysacchadde(EPS) from a Strain of lactic acid bacteria and EPS extraction

The influencing factors of extracellular polysaccharide(EPS)produced from a strain of lactic acid bacteria(LAB L15)were studied by using the phenol-H2SO4 method.It was demonstrated that the strain produced EPS at the most amount when it was incubated for 40-48 h and when the pH value was 4 under 30℃.Glucose was the most suitable carbon source for LAB-producing EPS.The rough EPS was obtained from L15 culture after centrifugation,dialysis,deprotein,decoloration,and ethanol-precipitation.The sample was at least composed of two polysaccharides mat were completely different in molecular weight and the amount.The purified EPS was passed through the SephadexG-200 colunm and it showed that it was a sample purified by thin layer chromatography.     

The production-influencing factors of extracellular polysaccharide (EPS) from a strain of lactic acid bacteria and EPS extraction

The influencing factors of extracellular polysaccharide (EPS) produced from a strain of lactic acid bacteria (LAB L15) were studied by using the phenol-H₂SO₄ method. It was demonstrated that the strain produced EPS at the most amount when it was incubated for 40–48 h and when the pH value was 4 under 30°C. Glucose was the most suitable carbon source for LAB-producing EPS. The rough EPS was obtained from L15 culture after centrifugation, dialysis, deprotein, decoloration, and ethanol-precipitation. The sample was at least composed of two polysaccharides that were completely different in molecular weight and the amount. The purified EPS was passed through the SephadexG-200 column and it showed that it was a sample purified by thin layer chromatography. __________ Translated from Microbiology, 2005, 32(4): 85–90 [译自: 微生物学通报, 2005, 32(4): 85–90]     

Mass Spectroscopy and Chromatography of the Trichloromethyl Radical Adduct of Phenyl Ter T-Butyl Nitrone

Positive structural identification of the PBN-trichloromethyl spin adduct in vim was accomplished with the use of high pressure liquid chromatography and/or gas chromatography coupled with mass spectrome-try. Both thin layer and liquid chromatography were used to separate a complex mixture of compounds from rat liver extracts treated with CCI, in vitro and in vivo. Deuterated PBN's (PBN-d, text-butyl deuteration, or PBN-d₁₄; both phenyl and tert-butyl deuteration) were also used to aid in the mass spectral analysis of spin adducts from liver extracts of CCI, exposed rat livers, since the rerr-butyl group fragment ion, C₄D₉+ (m/z = 66) is always present for PBN and PBN spin adducts. In addition, the masses of the ion peaks increase by the amount of deuteration, i.e. an increase of 9 for PBN-d, or PBN-d₁₄ in comparison to normally synthesized PBN.     

Characterization of the chondroitin sulfates in wild type Caenorhabditis elegans

The purpose of this study was to isolate and characterize the GAGs from the wild type nematode Caenorhabditis elegans in preparation for the characterization of the transgenic form constructed by Link [Proc. Natl. Acad. Sci. USA 92 (1995) 9368] which expresses various forms of beta-peptide (or A4 peptide). This peptide forms deposits very similar to the ones found in the neuritic plaques and neurofibrillary tangles in Alzheimer disease (AD). Characterization has been accomplished by degradation with specific enzymes and analysis of the products by TLC and HPLC. The results were compared with earlier works and shown to differ in disaccharide content.     

槲皮素对完整HL-60细胞中肌醇磷脂转换的抑制作用

槲皮素对完整ＨＬ┐６０细胞中肌醇磷脂转换的抑制作用康铁邦梁念慈（广东医学院医用生化研究所,湛江５２４０２３）肌醇磷脂信使系统在生物信号的跨膜传递方面起重要作用,并与细胞增殖及肿瘤形成有密切联系［１～５］,有报道：肿瘤细胞或组织中磷脂酰肌醇４－激酶（Ｐ...     

高效薄层色谱测定湛江等鞭金藻培养过程脂质变化

【目的】研究湛江等鞭金藻(Isochrysis zhangjiangensis)由氮元素丰富至限制培养过程中脂质成分的变化。【方法】利用高效薄层色谱(HPTLC)分离分析微藻中脂质。【结果】随着培养基中营养物质的消耗,细胞逐渐处于胁迫状态,在这种状态下,细胞大量积累贮存脂质—甘油三脂(TAG),组成生物膜系统的单半乳糖甘油二脂(MGDG)、硫代异鼠李糖甘油二脂(SQDG)、磷脂酰甘油(PG)和磷脂酰胆碱(PC)含量降低,而游离脂肪酸(FFA)、甘油二脂(DAG)、双半乳糖甘油二脂(DGDG)、磷脂酰肌醇(PI)和磷脂酰乙醇胺(PE)则相对稳定。【结论】HPTLC可作为一种简便、可靠的微藻中脂质分离分析方法,为研究微藻油脂代谢途径以及甘油三脂(TAG)的调控积累提供有效手段。     

一株细菌儿茶酚型铁载体分泌的影响因素研究

采用两种新的高分辨率的薄层层析（TLC）方法对一株土壤细菌S1在3种不同培养基上产生的儿茶酚型铁载体进行了分析。结果表明：不同培养基对铁载体的产生影响较大,在3种不同的培养基上菌株S1产生不同的儿茶酚铁载体,其中仅在1种培养基上S1能够分泌2,3-二羟基苯甲酸（2,3-DHBA）。同时,还分析了Al^3＋对S1分泌的儿茶酚型铁载体总量的影响,结果表明：Al^3＋能显著刺激铁载体的分泌,并且能抵消一定浓度范围内的Fe^2＋对铁载体分泌的抑制作用,KMB培养液中产生的4种儿茶酚铁载体中有3种和Al^3＋有较强的螯合力．     

DETECTION OF CHLOROPHYLL C1 AND MAGNESIUM-2,4-DIVINYLPHEOPORPHYRIN A5 MONOMETHYLESTER IN CRYPTOPHYTES1

Three different chlorophyll (chl) c-type pigments were isolated from two cryptophyte species by silica thin-layer chromatography or polyethylene high-performance liquid chromatography. Chroomonas sp. Hansgirg contained chl c₁ and magnesium-2,4-divinylpheoporphyrin a, mono-methylester; chl c₂ and magnesium-2,4-divinylpheoporphyrin a₅ monomethylester were found in Cryptomonas maculata (syn. Rhodomonas maculata Butcher). These identifications were based on spectral characteristics and on comparison with reference pigments isolated from the synurophycean Synura petersenii Korshikov and the prasinophyte Mantoniella squamata Manton & Park. Neither of the cryptophyte species contained chl c₁ and chl c₂. The significance of chl c₁ as a major pigment and the occurrence of magnesium-2,4-divinylpheoporphyrin a₅ monomethylester in cryptophytes are discussed.     

黄褐毛忍冬生药学鉴定研究

黄褐毛忍冬具有消炎、抗菌、免疫调节等多种功效,但容易与忍冬属其他物种混淆,通过生药学研究将为黄褐毛忍冬的鉴定工作和药材标准的制定提供科学依据。该文采用植物学鉴定、显微镜观察、薄层色谱鉴定和分子鉴定的方法从植物学性状、药材显微特征、薄层色谱和ITS(internal transcribed spacer)序列特征等方面对黄褐毛忍冬进行了专属性特征鉴定。结果表明：(1)黄褐毛忍冬花朵横切面分泌细胞较多,花瓣外表面有黄褐色腺毛;花冠表皮上层细胞为多角形,蚌形花粉囊对开,花粉粒形状规则,有三角形和卵圆形两种,油室椭圆形。(2)粉末显微检测发现中柱鞘纤维呈短棱形;木栓细胞棱角明显,呈浅黄色;木纤维呈粗短的棱形,偶见有弯曲;网纹导管较多,细胞腔密布草酸钙方晶。(3)薄层色谱显示黄褐毛忍冬花中三柰酚含量较高,三柰酚可作为黄褐毛忍冬的检视成分。(4)基于ITS序列系统聚类结果显示,ITS序列可以作为DNA条形码将黄褐毛忍冬、灰毡毛忍冬、华南忍冬和金银花准确地区分。上述结果表明黄褐毛忍冬生药学特征明显,该研究为黄褐毛忍冬药材鉴定、成分分析和质量标准制定提供了参考。