A rapid and highly selective method for the estimation of pyro-,tri- and orthophosphates

A rapid, highly selective and simple method has been developed for the quantitative determination of pyro-, tri- and orthophosphates. The method is based on the formation of a solid complex of bis(ethylenediamine)cobalt(III) species with pyrophosphate at pH 4.2-4.3, with triphosphate at pH 2.0-2.1 and with orthophosphate at pH 8.2-8.6. The proposed method for pyro- and triphosphates differs from the available method, which is based on the formation of an adduct with tris(ethylenediamine)cobalt(III) species. The complexes have the composition [Co(en)(2)HP2O7]4H(2)O and [Co(en)(2)H2P3O10]2H(2)O, respectively. The precipitation is instantaneous and quantitative under the recommended optimum conditions giving 99.5% gravimetric yield in both cases. There is no interferences from orthophosphate, trimetaphosphate and pyrophosphate species in the triphosphate estimation up to 5% of each component. The efficacy of the method has been established by determining pyrophosphate and triphosphate contents in various matrices. In the case of orthophosphate, the proposed method differs from the available methods such as ammonium phosphomolybdate, vanadophosphomolybdate and quinoline phosphomolybdate, which are based on the formation of a precipitate, followed by either titrimetry or gravimetry. The precipitation is instantaneous and the method is simple. Under the recommended pH and other reaction conditions, gravimetric yields of 99.6-100% are obtainable. The method is applicable to orthophosphoric acid and a variety of phosphate salts.

X-Ray Structure Of A Ternary Metal-Complex - Copper(Ii) Inosine 5'-Monophosphate Imidazole - Metal-Binding To The N(7) Atom Of The Nucleotide In A Mixed-Ligand System Containing An Aromatic Amine

A ternary metal-nucleotide complex, Na2[Cu(5’-IMP)2(im)o,8(H20)l,2(H20)2h]as~ 1be2e.n4 pHr2ep0a,r ed and its structure analyzed by X-ray diffraction (5’-IMP = inosine 5’-monophos hate; im = imidazole). The complex crystallizes in space group C222, with a = 8.733 (4) A, b = 23.213 (5) A, c = 21.489 (6) 1, and Z = 4. The structure was solved by the heavy-atom method and refined by full-matrix least-squares technique on the basis of 2008 observed reflections to a final R value of 0.087. Symmetry-related 5’-IMP anions coordinate in cis geometry through the N(7) atoms of the bases. The other cis positions of the coordination plane are statistically occupied by nitrogen atoms of disordered im groups and water oxygens with occupancies 0.4 and 0.6, respectively. Water oxygens in axial positions complete the octahedral coordination of Cu(I1). The complex is isostructural with C~S-[P~(S’-IMP),(NH~)~a] m”,o del proposed for Pt(I1) binding to DNA. The base binding observed in the present case is different from the typical ”phosphate only” binding shown from earlier studies on metal-nucleotide complexes containing various other ?r-aromatic amines.

Anomalin. A Dihydropyranocoumarin Derivative from the Plant Lingusticum elatum

The title compound, 9,10-dihydro-8,8-dimethyl-2-oxo-2H,8H-benzo[1,2-b:3,4-b']dipyran-9,10-diyl 2-methyl-2-butenoate, C24H26O7, contains a highly planar coumarin nucleus and a substituted dihydropyran ring (C), which has a distorted half-chair conformation, with an 8 alpha,9 beta orientation. The conformation of ring C is further supported by the two angelyloxy (2-methyl-2-butenoyloxy) substituents at positions C9 and C10, which are cis oriented and thus cannot both occupy equatorial positions with respect to the plane of ring C. The conformations of the two angelyloxy substituents are different, as indicated by their endocyclic torsion angles. The most striking of these angles are O1'-C2'-C4'=C6' and O1'-C2'-C4'-C5' [-137.7 (5) and 43.7 (5)degrees, respectively, in the chain at C10 and 155.8 (5) and -24.7 (9)degrees, respectively in the chain at C9]. These variations are due to two intramolecular hydrogen bonds, namely, C16-H161 ... O1' [C16 ... O1' 3.056 (7) Angstrom] and C7''-H7Y ... O3'' [C7'' ... O3'' 2.955 (12) Angstrom]. The methyl substituents, C15 and C16, at position C8 are alpha and beta oriented, respectively. The crystal structure is stabilized by a weak C4-H41 ... O3' hydrogen bond [C4 ... O3' 3.297 (6) Angstrom] between the screw-related molecules.

Role of dicarboxylate linkers in Mn-III-salicylaldoximate based extended structures: synthesis, structures, and magnetic behavior

Four new oxo-centered Mn-III-salicylaldoximate triangle-based extended complexes (Mn6O2)-O-III(salox)(6)(EtOH)(4)(phda)](n)(saloxH(2))(n)(2H(2)O)(n) (1), (Mn6O2)-O-III(salox)(6)(MeOH)(5)(5-I-isoph)](n)(3MeOH)(n) (2), (Mn6O2)-O-III(salox)(6)(MeOH)(4)(H2O) (5-N-3-isoph)](n)(4MeOH)(n) (3) and (Mn3NaO)-Na-III(salox)(3)(MeOH)(4)(5-NO2-isoph)](n)(MeOH)(n) (H2O)(n) (4) salox=salicylaldoximate, phda=1,3-phenylenediacetate, isoph=isophthalate] have been synthesized under similar reaction conditions. Single crystal X-ray structures show that in 1, only one type of Mn-6 cluster is arranged in 1D, whereas in 2 and 3 there are two types of clusters, differing in the way the triangle units are joined and assembled. In complex4, however, the basic building structure is heteronuclear and based on Mn-3 units extended in 2D. Susceptibility measurements (dc and ac) over a wide range of temperatures and fields show that the complexes1, 2, and 3 behave as single molecule magnets (SMMs) with S=4ground state, while 4 is dominantly antiferromagnetic with a ground spin state S=2. Density functional theory calculations have been performed on model complexes to provide a qualitative theoretical interpretation for their overall magnetic behavior.

An enolato-bridged dinuclear Cu(II) complex with a coumarin-assisted precursor: a spectral, magnetic and biological study

A new, phenoxo-bridged Cu-II dinuclear complex Cu-2(L)(2)(DMF)(2)] (1) has been obtained by employing the coumarin-assisted tridentate precursor, H2L, benzoic acid(7-hydroxy-4-methyl-2-oxo-2H-chromen-8-ylmethylene)-hydrazide]. Complex 1 has been systematically characterized by FTIR, UV-Vis, fluorescence and PR spectrometry. The single crystal X-ray diffraction analysis of 1 shows that the geometry around each copper ion is square pyramidal, comprising two enolato oxygen atoms belonging to different ligands (which assemble the dimer bridging the two metal centers), one imine-N and one phenolic-O atoms of the Schiff base and one oxygen atom from the DMF molecule. The temperature dependent magnetic interpretation agrees with the existence of weak ferromagnetic interactions between the bridging dinuclear Cu(II) ions. Both the ligand and complex 1 exhibit anti-mycobacterial activity and considerable efficacy towards M. tuberculosis H37Rv ATCC 27294 and M. tuberculosis H37Ra ATCC 25177 strains. The cytotoxicity study on human adenocarcinoma cell lines (MCF7) suggests that the ligand and complex 1 have potential anticancer properties. Molecular docking of H2L with the enoyl acyl carrier protein reductase of M. tuberculosis H37R(v) (PDB ID: 4U0K) is examined and the best docked pose of H2L shows one hydrogen bond with Thr196 (1.99 angstrom).

聚合物膜离子选择性电极的制备与性能研究

聚合物膜离子选择性电极具有选择性高、使用简便、价格低廉等优点，在环境监测中日益受到人们的关注。这类电极的响应特性主要取决于聚合物膜相中起分子识别作用的离子载体的选择性。本文设计合成了一系列对重金属离子具有高选择性的有机配体，并将其作为电中性离子载体应用于银、汞、锌、铬等离子选择性电极中，实现了对重金属离子的高选择性测定。此外，我们对海水中有机物质的紫外线消解进行了研究，优化了消解条件，采用离子选择性电极技术实现了对海水中重金属污染物的快速检测。具体内容如下： 1、以硫氮杂冠醚为离子载体的银离子选择性电极制备及性能研究。 合成了一系列硫氮杂冠醚配体，通过优化反应条件，提高了反应产率，简化了产物处理过程。将此类冠醚作为离子载体用于银离子选择性电极的制备，并讨论了冠醚环大小、冠醚环的韧性以及硫原子个数对电极选择性的影响。在此研究基础上，利用沉淀-溶解平衡法调节内充液主离子浓度，采用冠醚9，10，12，13，24，25-六氢-5H，15H，23H-二苯[b，q][1，7，10，13，19，4，16]五硫二氮二十三环-6，16 (7H，17H)-二酮环作为低检出限银离子选择性电极载体，通过优化电极的内充液和聚合物膜组份，测得最低检出限为2.2×10-10 M，电极电位响应斜率为54.5 mV/dec.，线性范围为1.0×10-9-1.0×10-5 M，电极使用寿命为一个月。采用标准加入法，成功实现了自来水中银离子浓度的测试，并以该电极作为指示电极，以硝酸银溶液为滴定剂，成功滴定了I-、Br-和Cl-离子的混合液。 2、以1，2，4-三唑衍生物为离子载体的汞离子选择性电极的制备及性能表征。 设计合成了一种基于1，2，4-三唑的希夫碱结构化合物，3，5-二(二硫代甲酸苄酯肼基-2-亚甲胺基苯氧甲基)-1-(四氢-2H-吡喃)-1H-1，2，4-三唑，并成功用作中性载体实现对汞离子的测定。在最佳膜组分条件下，以该化合物作为载体的汞离子选择性电极的检出限为2.6×10-7 M Hg2+，电极电位响应斜率为29.3±0.3 mV/dec.，线性范围为1.0×10-6-3.0×10-4 M。该电极使用寿命为2个月，在pH 2.6-5.2范围内测试不受酸度影响。以该电极为指示电极，以EDTA为滴定剂，可准确滴定溶液中汞离子的浓度。 3、以希夫碱结构化合物为离子载体的锌离子选择性电极的制备及性能研究。 本文设计了一种含吡啶杂环的希夫碱结构化合物(E)-N'-(吡啶-2-亚甲胺基)-2-((E)-吡啶-2-亚甲胺基)苯甲酰肼，并成功用作离子载体实现对锌离子的测定。在最佳膜组分条件下，以该化合物为载体的锌离子选择性电极的检出限为7.4×10-7M Zn2+，电极电位响应斜率为25.9 mV/dec.，线性范围为1.0×10-6-1.0×10-3 M。该电极使用寿命为3个月，在pH 3.4-5.8范围内测试不受酸度影响。以该电极为指示电极，以EDTA为滴定剂，可准确滴定溶液中锌离子的浓度。 4、紫外光在线消解技术用于离子选择性电极测试海水中重金属离子的研究。 海水中重金属离子大多以络合物形式存在，而离子选择性电极只对游离态金属离子响应，因此要实现离子选择性电极测试海水中的重金属，首先必须使金属离子从络合物中游离出来。紫外光消解方法相对于其它海水预处理手段是一种清洁的样品预处理方法。我们以模拟海水为考察对象，考察了盐度、酸度、有机物浓度对消解效率的影响，并在优化消解条件的基础上对实际海水进行消解，利用离子选择性电极成功实现了海水中铜离子浓度的测试，测试值与ICP-MS数值一致。 5、合成希夫碱结构罗丹明B衍生物作为载体和分子探针用于Cr3+离子的检测。 设计合成了希夫碱结构罗丹明B衍生物2-亚甲胺基-8-乙酯基喹啉-罗丹明。荧光法显示，在化合物对铬离子(III)有较好的选择性，进而我们将该化合物作为分子探针进行了详细的研究。结果表明，分子探针与铬离子配位比为1:1，铬离子响应的线性范围是8.0×10-7-8.0×10-5 M，检测下限为1.9×10-7 M。电化学测试结果显示，基于该化合物为载体的离子选择性电极对铬离子(III)的选择性较差。

Chemical Constituents from Fruit Hulls of Garcinia mangostana ( Cuttiferae

从山竺(Garcinia mangostana)果壳中分离得到6个化合物,通过MS,1D 1NMR以及与文献对照鉴定它们为4个(口山)酮类化合物:α-mangostin(1),β-mangostin(2),γ-mangostin(3),5,9-dihydroxy-8-methoxy-2,2-dimethyl-7-(3-methylbut-2-enyl)-2H,6H-pyrano-[3,2-b]-xanthen-6-one(4),以及表儿茶素(epicatechin,5)和一个双苄类化合物egonol(6).其中化合物5和化合物6为首次从该植物中分离得到.对化合物1～5进行抗HIV-1 RT活性筛选结果表明,化合物2和化合物5在浓度200 μg/ml的条件下,其对HIV-1 RT抑制率分别为41.97%和47.72%;同一实验结果显示化合物1,3和4没有抑制HIV-1 RT作用.

液驱式间歇浸没培养系统的研制

本文以菩提树为培养对象，采用改进的液驱式间歇浸没培养技术进行组织培养实验。为了更准确，精密地控制培养条件我们研制了间歇浸没式植物培养箱；为了提高培养效率，降低成本，我们对现有培养系统和方法进行了改进。鉴于液驱式间歇浸没培养半开放等培养特点，容易造成雪崩式污染。通过调查污染来源，研究各种物理化学生物杀菌抑菌方法的特点，以及对各个培养环节的消毒能力，建立了一套适合菩提树间歇浸没无糖培养的污染控制操作规程，为进一步大规模的商业化生产打下坚实的基础。 研究结果表明， 1、利用液驱式间歇浸没系统装置(简写为TD-TIB)进行组织培养，效率更高，成本更低。 液驱式间歇浸没培养与RITA和TIB相比，简单易操作，能耗低，效率高，成本低。与间歇浸没式植物培养箱配合使用，能够精密控制环境培养参数，包括温湿度，二氧化碳氧气的全程自动化检测控制 ，能够实现远程实时控制。利用液驱式培养方法生根后的培养苗自养光合能力强，驯化时间短，成活率高，芽多，健壮。 2、操作规程能够控制半开放间歇浸没培养中的污染问题。 从对紫外，臭氧，酒精，抗生素，杀菌剂以及过滤等污染控制方法的研究我们得出，任何一种消毒杀菌方法都不能控制系统的污染，只有结合培养系统环节和消毒方法的特点，把各种方法有机组合起来才能控制半开放条件下的污染。预处理是整个控制过程的关键。按照该操作规程，在2min/2h的间歇频率下的无糖间歇培养中，30天内成功实现了菩提树的生根驯化实验，培养液无污染。 间歇浸没培养技术与污染控制技术相结合实现了小范围的规模化培养，为大规模自动化组织培养技术奠定了坚实的基础。

Structure of an unexpected trimer from the reaction of ageratochromene II with aluminum chloride

A new trimer from the reaction of ageratochromene [1] (6,7-dimethoxy-2,2-dimethyl-1-benzopyran) with anhydrous aluminum chloride was shown to be 3,4-dihydro-6,7-dimethoxy-2,2-dimethyl-3-(6',7'-dimethoxy-2',2'-di-methyl-2H-1-benzopyran-4'-yl)-4-(3" 4"-dihydro-6", 7"-dimethoxy-2",2"-dimethyl-2H-1-benzopyran-3"-yl)-2H-1-benzopyran. Its structure was confirmed by NMR (H-1, C-13, DEPT-135. COSY, HMBC, HSQC, TOCSY and NOESY), IR, mass spectra and elemental analysis. Copyright (C) 2002 John Wiley Sons, Ltd.

Studies on synergistic extraction of Sc(III) with HBTMPTP and Cyanex 925

The synergistic extraction of Sc(III) from H2SO4 solution with bis(2, 4, 4-trimethylpentyl)monothiophosphinic acid(HBTMPTP, HL) and branched chain alkyl phosphine oxide mixture (Cyanex 925, B) in n-hexane has been investigated, The results indicated that synergistic effect was showed in low acidity (c(H2SO4) < 0.25 mol/L). The composition of the extracted complex of Sc(III) has been determined to be Sc(HL2)(2)B-3(SO4)(1/2) by the method of slope analysis, The mechanism of the synergistic extraction of Sc(III) may be : Sc3+ + 2(HL)(2(O)) + 3B((O)) + 1/2SO(4)(2-)reversible arrow(K12)Sc(HL2)(2)B-3(SO4)(1/2(O)) + 2H(+) ScL(HL2)(2(O)) + 3B((O)) + H+ + 1/2SO(4)(2-)reversible arrow(beta')Sc(HL2)(2)B-3(SO4)(1/2(O)) + 1/2(HL)(2(O)) Sc(SO4)(1.5)B-2(O) + B-(O) + 2(HL)(2(O))reversible arrow(beta')Sc(HL2)(2)B-3(SO4)(1/2(O)) + 2H(+) + SO42- Their equilibrium constants have been calculated to be lgK(13)=6.77+/-0.12, lg beta'=7.71, lg beta '' = 0.10, respectively, The IR spectra and FAB-MS of the saturated synergistic extraction complex of Sc(III) have been discussed as well.

台风海面风场的动力分析、四维同化及数值试验

台风是最具破坏性的海洋大气系统。台风及其引起的沿海强风暴潮和海上巨浪不仅给沿海地区人民的生命财产造成严重的损失，而且对海上交通运输、军事活动、海洋工程和渔业都带来严重影响。准确的台风海面风场是获得比较真实的海浪、风暴潮等海洋现象的关键所在。由于不准确的海面初始场和台风海面风场数值模式中物理过程不完善等问题，模拟预报台风海面风场的精度达不到要求，极大的影响了海浪、风暴潮等海洋过程的模拟预报精度。因此获得准确真实的台风海面风场不仅对国民经济的顺利健康发展起到至关重要的作用，而且会很好地促进海浪、风暴湖等过程的研究。中尺度大气数值模式MM5在灾害性天气的预报研究方面具有重要的地位，并在暴雨研究方面取得了成功。在本论文中，我们结合气象工作者和海洋学者在台风研究中的不同侧重点，耦合自由大气和边界层过程，考察海气相互作用对台风海面风场的作用，首次将MM5应用于台风海面风场的研究之中，这对台风海面风场的研究来说是一个新的起点。本论文在MM5中，将中国国家气象中心中期预报谱模式T63／T106分析和预报场与常规地面和探空观测资料相结合，合理调整模式参数(海面粗糙度等参数)，建立了一套适用于中国区域的台风海面风场的模拟、预报系统。本论文利用改造过的中尺度大气数值模式MM5对两个台风个例：9608号台风(HERB)和9711号台风(WINNIE)进行数值试验。对海面风场而言，海气热通量交换对海面风场发挥着重要作用。因此本论文研究海面热量通量交换对9608号台风的强度和中心位置的影响，这也是以前国内台风数值模式中疏于考虑的方面。最后将模式模拟风场用于波浪的模拟研究之中，考察模拟海面风场在海洋环境研究中应用的有效性；并与目前国内较先进的LAGFD-WIN海面动力风场模式对比，检验MM5在台风海面风场研究中的性能。研究结果表明，MM5较好的反映出台风特性，并且优于LAGFD-WIN海面动力风场模式结果。在考察台风不稳定扰动特征时，我们区别于以往的本征值方法，利用中尺度二维扰动模式，由MM5提供9711号台风数值试验结果作为扰动模式的初始场，从动力学角度研究台风过程的扰动特征。初始资料问题对台风模式的预报模拟精度来说是一个最大、最重要的问题。因此改善、弥补模式初始场所造成的不足是本研究论文的重点工作之一。目前，在国内关于MM5中的四维资料同化(FDDA)方案试验刚刚起步。在本论文中，我们成功的启动MM5的四维资料同化方案：分析逼近和观测逼近。我们改造模式，同时启动这两种逼近方法，充分发挥探空资料和地面观测资料各自的优越性，I探索不同尺度、不同类型的资料在台风海面风场的应用。尝试卫星高度计风场资料溶于MM5中的同化方案中，这是本研究论文的另一个创新之处。本文的主要结论是(1)对两个台风个例：9608号台风(HERB)和9711号台风(WINNIE)进行了控制试验(CNTL)研究，分析台风模拟过程的温度距平、海平面气压及海面风场分布特点。研究表明，两个台风过程分别在不同高度上具有暖中心结构；模拟出的两个台风环流都呈现出台风的非对称及涡旋型态，模拟出的台风强度令人满意。对移动路径来说，对9608号台风过程，12h模拟台风路径误差为1.3个纬度，0.7个经度，而24h的模拟误差则为0.4个纬度，0.2个纬度；而对于9711号台风过程，其12h模拟台风路径误差为1.2个纬度，1.6个经度；24h路径误差为1.9个纬度，1．5个经度；36h模拟路径误差为3.2个纬度，2.8个经度。我们认为，由于9711号台风过程不准确的初始场，9711号台风模拟路径精度逊色于9608号台风过程的结果。(2)9608号台风过程中感热通量和潜热通量交换，在台风中心附近，热通量较小，但在台风周围，存在热通量的高值压，随着台风强度的减弱，热量通量交换也随之减小。在海面上始终是海水给大气提供热量。海面潜热通量总为正通量，并且都大于相应时刻的感热通量，表明水汽通量对台风系统比感热通量更重要。在分析热通量在不同下垫面演变特征时发现，在下午2h左右，在水陆交界处的次之，上最大，陆地上最小。感热通量在陆地下垫面上最大，其峰值出现而在水域上的最小，对于潜热通量则是水域(3)应用9608号台风的模拟海面风场到海浪的数值模拟研究中，发现由于台风海面风场分布的不对称性(在台风前进方向的右侧风速最大)，也因此造成了海浪有效波高分布的不对称性，同时在台风影响的右前方也传播得较远。随着台风海面风场减弱，风浪能量也逐渐消耗，有效波高也逐渐降低。(4)在台风发展的动力学特征研究方面，首先从不稳定扰动理论角度出发，讨论了台风发展的条件，得到了和天气学分析的台风形成发展条件一致的判据；在台风不稳定扰动的数值试验方面，针对9711号台风过程进行了数值试验，数值试验结果表明：扰动环流型以倾斜的扰动特征出现，并略向西倾斜，这是发展型的扰动型态；促使中尺度扰动发展和维持的能源主要来自于基本流场的有效位能和扰动场的有效位能。(5)利用标准探空资料和卫星高度计风场资料，在MM5中对9608号台风进行了七个试验：一个控制试验，三个分析逼近试验(AW，AWTQ，ATQ)，两个观测逼近试验(IWT，IW)和一个同时进行分析和观测逼近的试验(AWTQ+IWT)。七个试验中海平面气压场都形成了闭合低压中心，海面风场具有台风的气旋型态，再次证明MM5对台风的模拟能力；在定量的描述上，AWTQ+IWT试验较好地模拟出台风的中心位置和强度。因此联合有相对好的垂直分辨率的探空资料以及相对于探空资料有好的时间和水平分辨率的地面资料，能有效地提高台风海面风场的模拟预报精度。由于没有同化SLP的观测资料到模式中，SLP成为确定FDDA有效程度的有力手段。我们发现同时同化风场和质量场(温度场和湿度场)的试验AWTQ对风场和质量场均有一致的正面影响；对由强烈动力作用和大尺度强迫的台风过程，风场优于质量场。试验AWTQ，AW和ATQ的结果表明在风场中只有非常少的质量场诱导信息。试验ATQ，IWT对风场，海平面气压场具有负面影响。而利用包含常规气象观测资料无法拥有的海面风场信息的高度计风场资料，仅进行风场同化的IW试验，对海面气压场有非常好的效果。结果表明而AW，AWTQ，IW，AWTQ+IWT在24h模拟期间，则对SLP的平均RMS有明显的减小，分别约为3％，9％，12％和8％。

Micro/nanoreservoirs for controlled release of active species in smart functional coatings

This work reports one possible way to develop new functional coatings used to increase the life time of metallic structures. The functionalities selected and attributed to model coatings in the frame of this work were corrosion protection, self-sensing and prevention of fouling (antifouling). The way used to confer those functionalities to coatings was based on the encapsulation of active compounds (corrosion inhibitors, pH indicators and biocides) in micro and nanocontainers followed by their incorporation into the coating matrices. To confer active corrosion protection, one corrosion inhibitor (2-mercaptobenzothiazole, MBT) was encapsulated in two different containers, firstly in silica nanocapsules (SiNC) and in polyurea microcapsules (PU-MC). The incorporation of both containers in different models coatings shows a significant improvement in the corrosion protection of aluminum alloy 2024 (AA2024). Following the same approach, SiNC and PU-MC were also used for the encapsulation of phenolphthalein (one well known pH indicator) to introduce sensing properties in polymeric coatings. SiNC and PU-MC containing phenolphthalein acted as corrosion sensor, showing a pink coloration due to the beginning of cathodic reaction, resulting in a pH increase identified by those capsules. Their sensing performance was proved in suspension and when integrated in coatings for aluminium alloy 2024 and magnesium alloy AZ31. In a similar way, the biocide activity (antifouling) was assigned to two polymeric matrices using SiNC for encapsulation of one biocide (Dichloro-2-octyl-2H-isothiazol-3-one, DCOIT) and also SiNC-MBT was tested as biocide. The antifouling activity of those two encapsulated compounds was assessed through inhibition and consequent decrease in the bioluminescence of modified E. coli. That effect was verified in suspension and when incorporated in coatings for AISI 1008 carbon steel. The developed micro and nanocontainers presented the desired performance, allowing the introduction of new functionalities to model coatings, showing potential to be used as functional additives in the next generation of multifunctional coatings.

Syntheses of two new 1D and 3D networks of Cu(II) and Co(II) using malonate and urotropine as bridging ligands: Crystal structures and magnetic studies

Two new metal-organic based polymeric complexes, [Cu-4(O2CCH2CO2)(4)(L)].7H(2)O (1) and [CO2(O2CCH2CO2)(2)(L)].2H(2)O (2) [L = hexamethylenetetramine (urotropine)], have been synthesized and characterized by X-ray crystal structure determination and magnetic studies. Complex 1 is a 1D coordination polymer comprising a carboxylato, bridged Cu-4 moiety linked by a tetradentate bridging urotropine. Complex 2 is a 3D coordination polymer made of pseudo-two-dimensional layers of Co(II) ions linked by malonate anions in syn-anticonformation which are bridged by bidentate urotropine in trans fashion, Complex 1 crystallizes in the orthothombic system, space group Pmmn, with a = 14,80(2) Angstrom, b = 14.54(2) Angstrom, c = 7.325(10) Angstrom, beta = 90degrees, and Z = 4. Complex 2 crystallizes in the orthorhombic system, space group Imm2, a = 7.584(11) Angstrom, b = 15.80(2) Angstrom, c = 6.939(13) Angstrom, beta = 90.10degrees(1), and Z = 4. Variable temperature (300-2 K) magnetic behavior reveals the existence of ferro- and antiferromagnetic interactions in 1 and only antiferromagnetic interactions in 2. The best fitted parameters for complex 1 are J = 13.5 cm(-1), J = -18.1 cm(-1), and g = 2.14 considering only intra-Cu-4 interactions through carboxylate and urotropine pathways. In case of complex 2, the fit of the magnetic data considering intralayer interaction through carboxylate pathway as well as interlayer interaction via urotropine pathway gave no satisfactory result at this moment using any model known due to considerable orbital contribution of Co(II) ions to the magnetic moment and its complicated structure. Assuming isolated Co(II) ions (without any coupling, J = 0) the shape of the chi(M)T curve fits well with experimental data except at very low temperatures.

A chromene and prenylated benzoic acid from Piper aduncum

In addition to nerolidol, 2',6'-dihydroxy-4'-methoxydihydrochalcone, methyl 2,2-dimethyl-8-(3'-methyl-2'-butenyl)-2H-1-chromene-6-carboxylate, methyl 2,2-dimethyl-2H-1-chromene-6-carboxylate and methyl 8-hydroxy-2,2-dimethyl-2H-1-chromene-6-carboxylate, two new natural products were isolated from the leaves of Piper aduncum, 2,2-dimethyl-2H-1-chromene-6-carboxylic acid and 3-(3',7'-dimethyl-2',6 '-octadienyl)-4-methoxybenzoic acid. The structures of the isolates were established based on analysis of spectroscopic data, including ES-MS. The DNA-damaging activity of the isolated compounds was also investigated against mutant strains of Saccharomyces cerevisiae. (C) 1999 Elsevier B.V. Ltd. All rights reserved.

Biosynthetic origins of the isoprene units of gaudichaudianic acid in Piper gaudichaudianum (Piperaceae)

The biosynthesis of (2S)-2-methyl-2-(4'-methyl-3-pentenyl)-8-(3-methyl-2-butenyl)-2H-1-benzopyran-6-carboxylic acid (gaudichaudianic acid), the major metabolite in leaves and roots of Piper gaudichaudianum Kunth (Piperaceae), has been investigated employing [1(-13) C]-D-glucose as precursor. The labelling pattern in the isolated gaudichaudianic acid was determined by quantitative 13 C NMR spectroscopy analysis and was consistent with involvement of both mevalonic acid and 2-C-methyl-D-erythritol-4-phosphate pathways in the formation of the dimethylallyl- and geranyl-derived moieties. The results confirmed that both plastidic and cytoplasmic pathways are able to provide isopentenyl diphosphate units for prenylation of p-hydroxybenzoic acid. (c) 2007 Elsevier Ltd. All rights reserved.