红树尖瓣海莲内生真菌Phomopsis longicolla HL-2232次级代谢产物研究

通过活性追踪的方法,从一株来源于药用红树尖瓣海莲的内生真菌Phomopsis longicolla HL-2232中分离鉴定了5个生物碱类化合物、1个色原酮类化合物以及4个甾醇类化合物,分别鉴定为:6-氨基嘌呤-9-羧酸甲酯(1),腺嘌呤核苷(2),尿嘧啶核苷(3),N,N'-二苯基尿素(4),(2S,2'R,3R,4E,8E,3'E)-2-(2'-羟基-3'-十八碳烯酰胺)-9-甲基-4,8-十八碳二烯-1,3-二醇(5),2-(2'S-羟丙基)-5-甲基-7-羟基对氧萘酮(6),fortisterol(7),(22E)-5α,8α-表二氧麦角甾-6,22-二烯-3β-醇(8),啤酒甾醇(9),β-谷甾醇亚油酸酯(10).其中化合物1为新化合物,化合物5为新天然产物,其碳谱数据至今未曾报道.细胞毒活性表明化合物1~3对肿瘤细胞A549,B16F10,HL-60,MCF-7具有不同程度的抑制活性.其中新化合物1对乳腺癌细胞(MCF-7)的IC50值为14.9μmol·L-1、化合物3对肺癌细胞(A549)的IC50值为8.6μmol·L-1,两者活性强于阳性对照药顺铂.     

千里光中四个新倍半萜的结构

从植物千里光中分得四个新艾里莫芬烷型倍半萜,经仔细的波谱分析和单晶X射线衍射,研究它们的结构分别为为：7β,11-环氧-9α,10α-环氧-8-羰基艾里莫芬烷(1),8-11-过氧-9α,10α-环氧-6-烯-8β-羟基艾里莫芬烷(2),7(11)-烯-9α,10α-环氧-8-羰基艾里莫芬烷(3),6-烯-9α,10α-环氧-11-羟基-8-羰基艾里莫芬烷(4)。活性筛选实验表明化合物1具有促进癌细胞生长作用,化合物2和3具有较好的抗癌活性。     

16,17α-环氧-5α-和5β-孕甾-3β-醇-20-酮和16,17α-环氧-16β-甲基-5α-⊿9(11)-孕甾烯-3β-醇-20-酮的微生物脱氢

16,17α-环氧-5α-和5β-孕甾-3β-醇-20-酮(1,2)用诺卡氏菌脱氢分别得到4,5,6,7和8,5,6,7四个化合物,其中16,17α-环氧-⊿⁴-孕甾烯-3,20-双酮(5)是主要产物.1和2分别用节杆菌脱氢时则均得到两个20α-羟基的不饱和化合物15和16,其中⊿^1,4-双酮16是主要产物.16,17α-环氧-16β-甲基-5α-⊿⁹⁽¹¹⁾-孕甾烯-3β-醇-20-酮(3)用诺卡氏菌脱氢可得到12,13,14三个化合物,其中16,17α-环氧-16β-甲基_-⊿^4,9(11)-孕甾二烯-3,20-双酮(13)是主要产物.综上所述,5α和5β甾族化合物用诺卡氏菌脱氢主要脱去C_4,5两个氢原子形成⊿⁴-烯-3-酮化合物,而采用节杆菌可使C_l,2和C₄,5位同时脱氢形成⊿^1,4-双烯-3-酮化合物.     

三个新甾体皂甙元的结构鉴定

从中药蒺藜Tribulus terrestrisL.(Zygophyllaceae）中分离纯化得到5个 甾体皂甙元，经IR，2D-NMR和MS等波谱技术分别鉴定为：海可皂甙元(1)，25(R)-螺 甾烷-4—烯—3，12—酮(2)，25(R)·螺甾烷—3，5-二烯—12—酮(3)，25(R)-螺 甾烷-4—烯—2β，3α-二羟基—12—酮(4)和25(R)—螺甾烷—24β—羟基-4—烯 —3，12—酮(5)，其中化合物3-5为新化合物．     

匐枝马尾藻的化学成分研究

首次报道从中国北海匐枝马尾藻Sargassum polycystcum分离得到3个纯化合物 ，经过MS，IR，~1H NMR，~(13)C NMR（DEPT），HMQC和HMBC等波谱技术鉴定为： 豆甾-3β-羟基-5，23，25-三烯(1)，3-二下五烷氧基-1，2-丙二醇(2)，24ξ-甲 基胆甾-3β，5α，6β，25-四醇-25-乙酸酯(3)，其中化合物1为新化合物。     

新型肟基取代豆甾类化合物的合成及其抗肿瘤活性

以豆甾醇为原料,通过臭氧化将豆甾醇的C20—C22键断裂,再经过官能团转换,合成了22-肟基取代的单肟基化合物(3和9),6,22-二肟基取代的双肟基化合物(13和14)及3,6,22-三肟基化合物(17),其中涉及4个中间体(5~8)及目标化合物9,13,14和17共8个新化合物,其结构经~1H NMR,~(13)C NMR,IR和HR-MS(ESI)表征。采用MTT法测试了化合物对人胃癌细胞(SGC-7901)、人肝癌细胞(Bel-7404)和人体乳腺癌细胞株(He La)的体外抗肿瘤活性。结果表明,具有22-肟基取代的3-羟基-5-烯结构的豆甾化合物3对受试细胞均有一定活性,IC50分别为34±2μmol·L~(-1),32±1μmol·L~(-1)和38±3μmol·L~(-1)。但是进一步在甾核上引入肟基或羟基的其他几种类型化合物的抗肿瘤活性没有提高。     

长叶暗罗中克罗烷型二萜及其抗炎作用

对长叶暗罗茎的化学成分进行研究,分离得到4个新的克罗烷型二萜类化合物,通过NMR、HR-ESI-MS等多种现代波谱技术鉴定为:2-氧代-14,15,16-降三碳克罗烷-3-烯-13-酸(1)、2-氧代-14,15,16-降三碳克罗烷-3-烯-13-甲酯(2)、2-氧代-14,15,16-降三碳克罗烷-3,11E-二烯-13-酸(3)、2-氧代-16-羟基-克罗烷-3,13Z-二烯-15-酸(4).其中,化合物1～3为降三碳克罗烷型二萜,所有化合物均表现出一定的抗炎活性, IC50值范围为9.24～18.82μmol/L.     

环氧孕甾烯酮的合成与表征

从价格低廉的皂素为起始原料,通过一系列化学反应,合成了不同结构的环氧甾体类药物中间体.以波谱方法进行结构表征,同时对环氧甾体化合物5,6-环氧孕甾-16-烯-20-酮-3β-乙酸酯的单晶进行了结构分析.     

小花金挖耳地上部分萜类成分研究

本文首次报道对小花金挖耳地上部分化学成分的研究工作,采用硅胶柱色谱、Sephadex LH-20凝胶柱色谱、中压柱色谱和薄层制备色谱方法进行分离纯化,从中分离得到8个化合物:(1R,2S,4S,5R)-2,5-二羟基-p-薄荷烷(1),(1S,2S,4R,5S)-2,5-二羟基-p-薄荷烷(2),(3R,4R,6S)-3,6-二羟基-p-1-薄荷烯(3),5αH-桉烷-4(15),11(13)-二烯-12,8β-内酯(4),5α-羟基-桉烷-4(15),11(13)-二烯-12,8β-内酯(5),2α-羟基-5αH-桉烷-4(15),11(13)-二烯-12,8β-内酯(6),4β-羟基-1α,10βH-伪愈创木烷-11(13)-烯-12,8α-内酯(7),4-羰基-1α,10βH-伪愈创木烷-11(13)-烯-12,8α-内酯(8),利用波谱数据和理化性质鉴定了它们的结构.化合物1-3首次从天名精属植物中分离得到.     

海绵Polymastia Sobustia的化学成分研究

首次报道从中国南海海绵Polymas tia sobustia中分离得到5个纯化合物,经过MS,IR,1H NMR,13C NMR (DEPT),HMQC和HMBC等波谱技术鉴定为：豆甾-5-烯-7-羰基-3β-甾醇(1 ),N-(1-羟甲基-2,6-二羟基)十七烷基-5-羟基二十四脂肪酰胺([ ST5”HZ 2),胸腺嘧啶(3),尿嘧啶(4[ ST5”BZ ),对羟基苯甲酸(5);其中化合物1和化合 物2为新化合物。     

HEPT类化合物的QSAR研究

为定量结构／活性相关性研究提取了量子化学参数,拓扑指数Am,分子连接性指数^mxt及疏水性常数,同时应用正交变换和最佳变量子集算法（Leaps-and-Bonds)进行了变量压缩和选择,进而实施了多元回归分析,并由此结果进行了HEPT类化合物（1－[(2-hydroxyethoxy)methyl]-6-(phenylthio)-thymine derivatives)的结构／活性关系的理论解释,进行了人工神经网络法对于该类化合物的活性预测,其结构明显好于多元回归法。     

Effect of the pH of the medium on the chemical shifts in the PMR spectra and on the distribution of the π-electron density

The dependence of the chemical shifts of the ring protons on the pH of the medium for a number of 4-hydroxyquinoline derivatives was studied by means of PMR spectroscopy. The dipolar and uncharged hydroxy forms exist in equilibrium in aqueous solutions. The effect of intramolecular hydrogen bonding on the character of the dependence of the chemical shift on the pH of the medium in the case of 3-piperidinomethyl-4-hydroxyisoquinoline was investigated. The possibility of the separate protonation of the ring nitrogen and the side-chain nitrogen in 3-piperidinomethyl-4-hydroxyisoquinoline was established. The distribution of the -electron density in 4-hydroxyisoquinoline is in good agreement with its chemical behavior.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1546–1549, November, 1971     

Effect of the pH of the medium on the chemical shifts in the PMR spectra and on the distribution of the π-electron density

The dependence of the chemical shift of the ring protons on the pH of the medium for a number of 3-hydroxyquinoline derivatives was studied by PMR spectroscopy. The regions of ionization of the molecules, which correspond to the ranges of acidic, neutral, and alkaline media, were found. In D₂O, 3-hydroxyquinoline is present only in the uncharged hydroxy form. The presence of intramolecular hydrogen bonding in 4-dimethylaminomethyl-3-hydroxyquinoline has a substantial effect on the character of the dependence of the chemical shift on the pH of the medium; the existence of separate protonation of the nitrogen atoms of the ring and the side chain of 4-dimethylaminomethyl-3-hydroxyquinoline was established. The distribution of the -electron density in the 3-hydroxyquinoline molecule is in good agreement with its chemical behavior during electrophilic substitution.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1540–1545, November, 1971.     

液滴荧光传感与计算机联用技术在微量分析中的应用

通过在LS55型荧光-磷光-发光分光光度计上加装液滴产生及调节附件,采用计算机采集与分析处理数据,成功地研制了双通道液滴光化学传感装置.利用葡聚糖凝胶对复合维生素B中不同组分的选择性吸附来达到分离与同时检测的目的,并将其用于复合维生素B药片的分析,取得了满意的结果.     

On the theory underlying the Car-Parrinello method and the role of the fictitious mass parameter

The theory underlying the Car-Parrinello extended-Lagrangian approach to ab initio molecular dynamics (CPMD) is reviewed and reexamined using "heavy" ice as a test system. It is emphasized that the adiabatic decoupling in CPMD is not a decoupling of electronic orbitals from the ions but only a decoupling of a subset of the orbital vibrational modes from the rest of the necessarily coupled system of orbitals and ions. Recent work [J. Chem. Phys. 116, 14 (2002)] has pointed out that, due to the orbital-ion coupling that remains once adiabatic decoupling has been achieved, a large value of the fictitious mass mu can lead to systematic errors in the computed forces in CPMD. These errors are further investigated in the present work with a focus on those parts of these errors that are not corrected simply by rescaling the masses of the ions. It is suggested that any comparison of the efficiencies of Born-Oppenheimer molecular dynamics (BOMD) and CPMD should be performed at a similar level of accuracy. If accuracy is judged according to the average magnitude of the systematic errors in the computed forces, the efficiency of BOMD compares more favorably to that of CPMD than previous comparisons have suggested.     

From the Micro- to the Macro-: Managing the Conservation of the Warship,Vasa

Sweden's famous warship, Vasa, sank on her maiden voyage in August 1628, and remained on the bottom of Stockholm harbour for 333 years. Raised in 1961, she became the first large-scale wooden object to be treated with polyethylene glycol (PEG). In the summer of 2000 a number of acidic salt precipitations were noticed on the surface of the ship and on wooden artefacts in the storerooms. An international research project has been established to look into the causes of this problem and suggest possible re-treatments. Meanwhile projects are underway to monitor movements in the ship, to build a better support system, and to replace the thousands of iron bolts holding the structure together, while a sophisticated new climate system has recently been installed in the museum.