穿心莲内酯硒化物的研究

穿心莲主要有效成分为穿心莲内酯、穿心莲新内酯、脱氧穿心莲内酯、脱水穿心莲内酯等,在临床上的疗效已有报道^[1-2],关于它的抑制肿瘤效果,国内外均未见报莲。硒抑制肿瘤的作用,已有报道^[3],硒是人体不可缺少的微量元素^[3]。我们采用穿心莲内酯与亚硒酸钠加成的方法^[4],制成水溶性的穿心莲内酯硒化物,经动物试验得到抑瘤活性显著的效果(见表1)。     

穿心莲内酯的电化学研究

用单扫描示波极谱法在０．０５ｍｏｌ／ＬＮＨ４ＣＬ＋０．２５ｍｏｌ／ＬＮＨ３．Ｈ２Ｏ中，穿心链内酯有一灵敏的还原峰，２５℃时，峰电位为－１．６０Ｖ（ｖｓ．ＳＣＥ），峰电流与浓度在０．０１～１．２ｍｇ／Ｌ和１．４～２６ｍｇ／Ｌ范围内有良好的线性关系，检测限为６ｎｇ／ｍＬ。用本法测定天然中药穿心链中总内酯的含量，其结果令人满意。实验证明穿心链内酯的电极过程为可逆的逐级电子过程，Ｈ２Ｏ２可催化该还原峰，另     

Oxidation/reduction studies with forskolin

Oxidation/reduction reactions were carried out with forskolin and its derivatives. The structures of the skeletally rearranged products obtained are reported.     

两个穿心莲内酯苷的波谱学研究

利用柱色谱对穿心莲地上部分的提取物进行分离,得到3,14-二去氧穿心莲内酯苷和14-去氧穿心莲内酯苷。利用核磁共振氢谱(1H-NMR)、碳谱(13C-NMR)以及双量子滤波相关谱(DQFCOSY)、总相关谱(TOCSY)、异核多量子相干谱(HMQC)、异核多键相关谱(HMBC),解析这两个化合物的结构。确定了1H-NMR的氢信号和13C-NMR的碳信号的归属,并且用NOESY对3,14-二去氧穿心莲内酯苷的立体结构进行了研究。     

穿心莲内酯衍生物的合成研究进展

穿心莲内酯是中药穿心莲的主要二萜类活性成分之一. 近年来药物及有机化学工作者发现穿心莲内酯及其衍生物具有抗肿瘤, 抗HIV, α-葡萄糖苷酶抑制等活性, 由于其广泛的药理活性而倍受人们的关注. 作者对穿心莲内酯衍生物的合成进行了综述.     

Oxidation of nitroxyl radicals: electrochemical and computational studies

We have developed azaadamantane-type nitroxyl radicals (AZADOs) and azabicyclo-type nitroxyl radicals (ABNOs) as highly active alcohol oxidation catalysts. Herein, the electrochemical properties of these nitroxyl radicals were investigated by measuring their formal potentials using cyclic voltammetry (CV). The redox potentials were rationalized with the aid of density functional theory (DFT) calculations. A good correlation between the experimental redox potential and the DFT-computed energy differences (ΔE) between nitroxyl radicals and oxoammonium species was obtained, which shows the effectiveness of DFT in predicting the redox potentials of nitroxyl radicals. Redox potential appears to be an important factor of catalytic activity.     

Oxidation studies of Indian reduced activation ferritic martensitic steel

The paper reports the oxidation behaviour of Indian variety of reduced activation ferritic martensitic steel (RAFMS) proposed to be used as a first wall material in test blanket module in ITER and future fusion reactors. Oxidation of first wall can occur in case of a catastrophic leak in the vacuum vessel of fusion reactor. The oxidation of Indian RAFMS was done at 450–650 °C. Long-term oxidation for 25, 50 and 100 h was studied at 550 °C. A mass gain/unit area vs time was plotted and oxidation kinetics determined. The cross section SEM of the oxidised RAFMS was done. The SEM micrographs showed two distinct layers of oxides that have formed with total thickness of around 10 µm. Glancing-angle XRD showed that the top layer is essentially a mixture of magnetite and haematite. A strong enrichment of Cr is visible in a narrow band below the top layer near the scale/alloy interface. It was found that formation of this Cr-rich spinel mid-layer ensures the short-term and long-term oxidation resistance of IN-RAFMS in case of any accidental leak in fusion reactor conditions.     

穿心莲中7种微量元素的形态分析

采用传统煎煮法对穿心莲中的铁、锰、铜、锌、铝、硼和锶7种微量元素进行提取,用0.45 μm微孔滤膜分离提取液中的可溶态与悬浮态;用LSA-10大孔吸附树脂分离可溶态中的有机态与无机态;并用正辛醇-水分配体系在模拟人体胃肠酸度的条件下,将可溶态中各待测元素分离为醇溶态和水溶态;采用电感耦合等离子原子发射光谱法(ICP-A...     

Oxidation studies on some natural monoterpenes: Citral, pulegone, and camphene

Citral extracted from Cymbopogon citratus (Gramineae) was subjected to photochemical epoxidation with hydrogen peroxide to obtain a mixture of epoxy derivatives at the C²=C³ and C⁶=C⁷ double bonds. The thermal oxidation of citral with m-chloroperoxybenzoic acid at room temperature gave only the corresponding 6,7-epoxy derivative as a mixture of E and Z isomers with respect to the C²=C³ double bond. Photosensitized oxygenation of citral in the presence of tetraphenylporphyrin, Rose Bengal, or chlorophyll lead to a mixture of two isomeric hydroperoxides, (2E)-6-hydroperoxy-3,7-dimethylocta-2,7-dienal and (2E,5E)-7-hydroperoxy-3,7-dimethylocta-2,5-dienal. Epoxidation of pulegone isolated from Penny royal oil (Mentha pulegium, Lamiaceae) with hydrogen peroxide under irradiation with a sodium lamp lead to a mixture of cis- and trans-isomeric 2,2,6-trimethyl-1-oxaspiro[2.5]octan-4-ones, whereas under conditions of photosensitized oxygenation two hydroperoxide derivatives, 2-(1-hydroperoxy-1-methylethyl)-5-methylcyclohex-2-en-1-one and 2-hydroperoxy-5-methyl-2-(1-methylethenyl)cyclohexan-1-one, were also formed. Camphene reacted with hydrogen peroxide under irradiation to give a mixture of the corresponding endo- and exo-epoxy derivatives and camphor, while its thermal oxidation with m-chloroperoxybenzoic produced only the two former. Published in Russian in Zhurnal Organicheskoi Khimii, 2008, Vol. 44, No. 6, pp. 825–833. The text was submitted by the authors in English.     

穿心莲内酯的溶剂浮选

应用溶剂浮选法对穿心莲乙醇提取液中的穿心莲内酯进行分离富集,优化了穿心莲内酯的浮选条件.实验表明:浮选溶剂为乙酸乙酯,水相与有机相体积比为2: 1,加入水相体积4%的乙醇,溶液pH 7,氮气流速200 mL/min,浮选时间40 min为最佳浮选条件.在最佳实验条件下,穿心莲内酯平均收率为94.1%; RSD为1.1%,平均标准加入回收率95.1%; 富集倍数为9.7倍.溶剂浮选法分离穿心莲内酯不仅能得到满意的回收率和富集倍数,并能有效地除去水溶性杂质,提高目标物纯度.与溶剂萃取法相比, 溶剂浮选法能节约有机溶剂和操作时间.     

A New Glucuronidated Metabolite of Andrographolide in Human

A new andrographolide metabolite 1 was isolated from human urine samples after oral administration. The structure was determined to be 3-carbonylandrographolide-19-O-β-D-glucuronide on the basis of chemical evidences and spectral analysis, especially by 2D-NMR techniques.     

穿心莲内酯NO供体衍生物的合成

利用协同前药原理, 在穿心莲内酯衍生物的结构上引入硝酸酯, 合成了硝酸酯NO供体新化合物9个, 以期找到生物利用度更高、抗癌作用更好的新药; 目标化合物结构经¹H NMR, ¹³C NMR和MS确证.     

新型穿心莲内酯环磷酸酯类衍生物的合成及其抗肿瘤活性

以穿心莲内酯为先导化合物,在其3-位和19-位进行结构修饰,设计并合成了8个新型的穿心莲内酯环磷酸酯类衍生物(3a~3h),其结构经FT-IR和ESI-MS表征。用MTT法研究了3a~3h的体外抗肿瘤活性。结果表明:11,12-脱水(-1-对甲氧基苯酚)-3,19-环磷酸酯穿心莲内酯(3g)对舌癌细胞(Tca-8113)的抑制作用最强,用药量为1.0×10-4mol·L-1时,3g的抑制率为35.16%。     

Synthesis of Andrographolide Cyclophosphate Derivatives and Their Antitumor Activities

A series of cyclophosphate andrographolide derivatives were synthesized from andrographolide, the cytotoxic constituent of the plant Andrographis paniculata. The derivative (P_R, P′_S)‐5 and (P_S, P′_S)‐6 were synthesized and the proposed mechanism for their formation was discussed. The structures of all compounds were elucidated by IR, NMR, MS (ESI), and HR‐MS. The stereochemistry of 6 was confirmed by X‐ray analysis. All the derivatives were tested for antitumor activity in vitro, and some of them showed good results.     

Oxidation of phenol and hexanol in their binary mixtures on illuminated titania: Kinetic studies

Kinetics of phenol and hexanol oxidation on illuminated TiO₂ was studied both in separate solutions and in mixtures. It was found that the kinetic behavior of the components of the binary mixtures could be well described using kinetic constants estimated for the single-component solutions.     

Volumetric studies in oxidation-reduction reactions: Oxidation with chloramine-t. indirect determinations

Chloramine-T has been used as an oxidizing agent in hydrochloric acid medium for the indirect volumetric determination of hydrogen peroxide, lead dioxide, selenium dioxide, sodium formate, potassium meta-periodate, potassium permanganate and potassium dichromate using iodine monochloride as a catalyst, prcoxidizer and an indicator. Chloroform is coloured pink owing to the liberation of iodine during the titration and becomes very pale yellow at the end-point because of the formation of iodine monochloride.     

Potentiometric studies in oxidation-reduction reactions: Oxidation with chloramine-b. indirect determinations

Chloramine-B has been used as an oxidising agent to determine indirectly potassium iodate, potassium metaperiodate, potassium, bromate, potassium dichromate, hydrogen peroxide, chloramine-T and potassium permanganate by a potentiometric method. An excess of potassium iodide added to each of the substances in an acid medium is titrated back with a standard solution of chloramine-B, using platinum foil as an oxidation-reduction electrode coupled with a saturated calomel electrode through an agar-agar potassium chloride bridge.     

Elicitation of Andrographolide in the Suspension Cultures of Andrographis paniculata

Andrographis paniculata belonging to the family Acanthaceae produces a group of diterpene lactones, one of which is the pharmaceutically important??andrographolide. It is known to possess various important biological properties like anticancer, anti-HIV, anti-inflammatory, etc. This is the first report on the production of andrographolide in the cell suspension cultures of Andrographis paniculata by ??elicitation??. Elicitation was attempted to enhance the andrographolide content in the suspension cultures of Andrographis paniculata and also to ascertain its stimulation under stress conditions or in response to pathogen attack. The maximum andrographolide production was found to be 1.53?mg/g dry cell weight (DCW) at the end of stationary phase during the growth curve. The biotic elicitors (yeast, Escherichia coli, Bacillus subtilis, Agrobacterium rhizogenes 532 and Agrobacterium tumefaciens C 58) were more effective in eliciting the response when compared to the abiotic elicitors (CdCl₂, AgNO₃, CuCl₂ and HgCl₂). Yeast has shown to stimulate maximum accumulation of 13.5?mg/g DCW andrographolide, which was found to be 8.82-fold higher than the untreated cultures.