微量元素与中药有效化学成分的配合物的研究进展

综述了国内中药中微量元素与有机成分配合物的研究进展，并指出了微量元素与有机成分配合物的研制是开发特效新药的新途径。     

秃叶黄皮树果实中的新三萜化学成分

从秃叶黄皮树(Phellodendron chinense var. glabriusculum Schneid)的果实中分离得到一个新的三萜化合物并用波谱分析鉴定为21α–methylmelianol(21R, 23R)epoxy –24 –hydroxy-21α-methoxyl] triucalla–7, 25–dien–3–one 1,秃叶黄皮树(Phellodendron chinense var. glabriusculum Schneid)果实提取物的乙酸乙酯部分主要含有尼洛替星和苦楝子酮类型的甘遂烷三萜化合物。     

循环制备液相色谱分离芳香新塔花中的化学成分

建立了交替循环和直接循环液相色谱相结合的方法用于制备芳香新塔花中的化学成分.芳香新塔花样品经溶剂提取、柱色谱和中压制备色谱初步分离后得到芳香新塔花的不同馏分.以甲醇-水为流动相,利用双柱交替循环法对组分进行分离,同时,流动相经恒流泵循环输入色谱柱.以馏分Ⅰ和馏分Ⅱ为例,在混合循环模式下分离得到5个化合物.通过核磁共振对其进行鉴定,确定分别为乔松素-7-O-芸香糖苷、白杨素-7-O-芸香糖苷、金合欢素-7-O-芸香糖苷、云杉素和原儿茶酸.实验结果表明,该制备方法分离效率高,节省流动相,是分离天然产物的有效手段.     

蒙椴树皮化学成分的气相色谱-质谱法分析

蒙椴(tilia Mongolia Maxim.)为椴树属植物。在我国,椴树的树皮和根皮用于治疗筋无力、慢性咳嗽、关节炎、风湿等疾病。近几年发现椴树属的蒙椴、籽椴等树种具有显著的抗天牛卵及幼虫的特殊功能^[1]。本文对蒙椴化学成分进行了分析鉴定。     

草玉梅中的化学成分

从草玉梅根部和地上部分甲醇提取物中分离到的8个化合物,其中三萜内酯(7)和三萜皂甙(8)为新化合物.     

食品中的有害化学成分

本文介绍了食品中的有害化学成分、结构、来源,以及食用后的机体反应。介绍了一些防止产生有害成分的措施和除去有害成分的方法。     

高效液相色谱法定量测定采油微生物发酵菌液中的有机酸

采用反相高效液相色谱法(RP-HPLC)在Kromasil C18分析柱上,以0.015 mol/L磷酸二氢钠缓冲液(pH=2.3)和乙腈(体积比为96∶4)的二元流动相分离测定了采油微生物发酵液中的有机酸,流动相的流速为1.0mL/min,采用紫外检测器在210 nm处对有机酸进行测定.结果表明有机酸浓度在0.05～1.5 g/L时其峰面积与相应的质量浓度有良好的线性关系,其r大小等于0.9990,测定结果的RSD都小于4.0%(n=8),平均回收率均为100±4%以内.该方法具有测定结果准确可靠,操作简便快速,重现性好等特点.     

麻疯树叶二氧化碳超临界萃取物的化学成分分析

采用二氧化碳超临界萃取技术(Supercritical Fluid Extraction)及常用的溶剂提取法(Solvent Draw)研究麻疯树叶提取物的化学成分，用气-质联用(GC／MS)方法对分离的化合物进行结构鉴定，应用色谱峰面积归一化法测定各成分的相对百分含量，并对其进行分析。两种提取法结果显示：二氧化碳超临界萃取法具有对有效成分提取完全、效率高、耗时少等优点。     

左旋葡聚糖的制备与在生物技术领域的应用

左旋葡聚糖(LGA)作为一种极具潜力的新糖源,既可以加酸水解为葡萄糖后间接用于微生物发酵,也可以被真菌或细菌甚至构造的基因工程菌直接代谢,目前已经在发酵上展现出良好的应用前景。此外,LGA还可作为碳源,生产生物乙醇、丁二酸等。目前制备LGA普遍采用生物质热解法,该方法存在能耗高、产率低、产物难以提取等缺点,应努力发展在溶剂体系中分解纤维素制备LGA的方法以提高产率。今后的研究应致力于开发微生物代谢LGA的新过程、新方法、新菌种,为LGA的高效利用提供坚实基础。     

发酵液中香兰素的反相高效液相色谱分析方法研究

建立了测定发酵液中香兰素含量的反相高效液相色谱方法。采用Symmetry C18柱(5μm,4.6 mm i.d.×150 mm),以V(甲醇)∶V(水)=35∶65为流动相,流速为1.0 mL/min,紫外检测波长为280 nm,柱温为室温,进样量10μL。香兰素在5.0~1000 mg/L范围内,峰面积与质量浓度呈良好的线性关系,相对标准偏差RSD为0.68%,回收率在99.88%~100.28%之间。该方法适用于微生物发酵法合成香兰素的质量控制及发酵工艺的改进。     

Properties of a thermostable nonspecific fructofuranosidase produced by cladosporium cladosporioides cells for hydrolysis of Jerusalem artichoke extract

Thermostable invertase (E.C. 3.2.1.26) and inulinase 2,1-beta-D-fructan fructanohydrolase (E.C. 3.2.1.7) activities were produced by Cladosporium cladosporioides grown on sucrose, inulin, yam extract, or Jerusalem artichoke. The ratio I (inulinase)/S(invertase) activity was between 0.31 and 0.36. Both activities had high temperature optima (60 degrees C) and were stable during pretreatment for 4.5 h at this temperature. Whole cells of C. cladosporioides were used for batch fructose production from Jerusalem artichoke extract at several concentrations. With the highest extract concentration used (260 g total sugars/L), total hydrolysis was achieved in 150 min at 60 degrees C. Thin-layer chromatography of the enzymatic hydrolysis of inulin and Jerusalem artichoke extract showed that from the beginning of the reaction, fructose was the only product released. This suggests an exoaction mechanism, beta-D-fructofuranoside fructohydrolase [E.C. 3.2.1.2.6].     

Three New Coumarins from Micromelum integerrimum

Micromelum integerrimum (Rutaceae) is a shrub growing in Yunnan Province. Leaves and barks of this plant have been used for the treatment of dysentery, and arthritis1. Previous researches revealed that this plant contained coumarins2-8. Micromelin, the main chemical constituent of this plant, showed significant inhibition against leukaemia P-388 cell line (T/C 149% at 10 mg/kg) but was inactive in lower doses, and also showed significant activity (T/C 228% at 1.25 mg/kg) against Lewis lung…     

Four New Diterpenoids from Isodon leucophylla

IsodonleucoPhyll(Dunn)Hara(Labiatae),distributedinthenorthwestareaofYunnanProvince,isusedasfolkmedicineforitsantibacterialandanti-inflanimatoryactivitybylocalpractitioners'.Fromtheleavesofthisplant,fournewent-kauranetypediterPenoids,baiyecrystalA'C1'3andePi-baiyecrystalC4,wereisolated.Thispaperpresentstheirsimctureelucidation.BaiyecrystalA1C26H34O1owasdeterminedbyHRMS(5O6.2157,calc5o6.2l52).Itsmassspectrumshowedthatthemolecularion(wt5O6)was58amumorethanthatofeffusaninD5',aknownkaureno…     

Synthesis of bioreductive esters from fungal compounds

Four new bioreductive esters (7-10) have been synthesized. Their structures composed of trimethyl lock containing quinone propionic acid with an ester linkage to the fungal cytotoxic compounds; preussomerin G (1), preussomerin I (2), phaseolinone (3) and phomenone (4). The synthesized esters are aimed to act via reductive activation specifically at the cancer cells, resulting from hypoxia and overexpression of reductases. Hence, the toxicity will be lessened during distribution across the normal cells. The anticancer activity was determined in cancer cell lines with reported reductase i.e., BC-1 cells and NCI-H187 as well as in non-reductase containing cancer cells; KB cells. When considering each cell lines, result showed that structure modification giving to 7-10 led to less cytotoxicity than their parent compounds (1-4). Both 7 and 8 were strongly cytotoxic (IC50 < or = 5 microg/ml) to NCI-H187, whereas 9 and 10 were moderately cytotoxic (IC50 = 6-10 microg/ml) to BC-1 cells. Additional study of stability of represented phenolic ester (8) and an alcoholic ester (9) were performed. Result illustrated that both 8 and 9 were stable in the presence of esterase. Therefore, the cytotoxicity of the synthesized compounds (8-10) might be due to partial bioreductive activation in the cancer cells.     

Fatty acid derivatives from the halotolerant fungus Cladosporium cladosporioides

Halotolerant fungus Cladosporium cladosporioides OUCMDZ‐187 was isolated from the mangrove plant Rhizophora stylosa collected in Shankou, Guangxi Province of China. Three new fatty acid esters cladosporesters A–C ( 1 – 3 ) and 5 new fatty acids cladosporacids A–E ( 4 – 8 ) were isolated from the ethyl acetate extract of the fermentation broth of OUCMDZ‐187 in a hypersaline (10% salt) medium. Their structures were elucidated by UV, IR, MS, specific rotation, and 1D and 2D NMR data.     

713A, a new metabolite isolated from a fungal strain 713

A new compound named 713A was isolated from the fermentation broth of a fungal strain 713. The structure of 713A was elucidated by spectroscopic methods. In the screening for interleukin-6 (IL-6) receptor antagonist, 713A exhibited inhibitory activity to the binding of IL-6 and IL-6 receptor with an IC50 value of 8.6 microM.     

Three new pterocarpans from the aerial parts of Abrus Precatorius

Abstract

Three new pterocarpans, named abrusprecatins A-C (1–3), along with three known ones, namely medicarpin (4), maackiain (5), and 4-hydroxy-3-methoxy-8,9-methylenedioxypterocarpan (6) were isolated from the aerial parts of Abrus precatorius. The structures of these compounds were established by extensive analysis of mass spectrometric data, 1?D and 2?D NMR spectroscopic data. In addition, the absolute configurations were determined by a combination of single crystal X-ray diffraction analysis and circular dichroism spectroscopy.     

Biochemical properties of Cu/Zn-superoxide dismutase from fungal strain Aspergillus niger 26

The fungal strain Aspergillus niger produces two superoxide dismutases, Cu/Zn-SOD and Mn-SOD. The primary structure of the Cu/Zn-SOD has been determined by Edman degradation of peptide fragments derived from proteolytic digests. A single chain of the protein, consisting of 153 amino acid residues, reveals a very high degree of structural homology with the amino acid sequences of other Aspergillus Cu/Zn-SODs. The molecular mass of ANSOD, measured by MALDI-MS and ESI-MS, and calculated by its amino acid sequence, was determined to be 15821 Da. Only one Trp residue, at position 32, and one disulfide bridge were identified. However, neither a Tyr residue nor a carbohydrate chain occupying an N-linkage site (-Asn-Ile-Thr-) were found. Studies on the temperature and pH dependence of fluorescence, and on the temperature dependence of CD spectroscopic properties, confirmed that the enzyme is very stable, which can be explained by the stabilising effect of the disulfide bridge. The enzyme retains about 53% of its activity after incubation for a period of 30 min at 60 degrees C, and 15% at 85 degrees C.     

Japonicones A-C: Three lindenane sesquiterpenoid dimers with a 12-membered ring core from Chloranthus japonicus

Japonicones A–C (1–3), three new dimeric lindenane-type sesquiterpenoids featuring a rare 12-membered ring framework, were isolated from the whole plants of Chloranthus japonicus Sieb. Their structures and absolute configurations were unequivocally established by a combination of spectroscopic data, ECD calculation, and X-ray crystallography. Compounds 1–3 were evaluated for their DNA Topoisomerase Ⅰ (Top1) inhibitory, cytotoxic, and antibacterial activities.