Chloropupukeanolides C-E: cytotoxic pupukeanane chlorides with a spiroketal skeleton from Pestalotiopsis fici

Chloropupukeanolides C–E ( 8 – 10 ), three highly functionalized secondary metabolites featuring a novel spiroketal skeleton derived from the chlorinated tricyclo‐[4.3.1.0^{3, 7}]‐decane (pupukeanane) and the 2,6‐dihydroxy‐4‐methylbenzoic acid moieties, were isolated from the scale‐up fermentation extract of the plant endophytic fungus Pestalotiopsis fici. The constitutions of compounds 8 – 10 were elucidated primarily by NMR experiments. Their relative configurations were deduced by analogy to metabolites 4 – 6 , which were previously isolated from the same fungus. The absolute configuration of 8 was assigned by X‐ray crystallography and those of 9 and 10 by quantum‐chemical CD calculations. Biogenetically, chloropupukeanolides C–E ( 8 – 10 ) are presumably derived from the same oxidation‐induced Diels–Alder reaction pathway as compounds 1 and 4 – 7 , via the putative biosynthetic precursors 2 and 3 . The opposite configurations of the complete “Southern parts” of 8 and 9 suggests that this Diels–Alder reaction is stereochemically not very selective. Compounds 8 – 10 showed significant cytotoxicity against a small panel of human tumor cell lines and weak activities against the pathogens of tropical diseases.     

Ikirydinium A: a new indole alkaloid from the seeds of Hunteria umbellata (K. Schum)

Chemical investigations into samples of Hunteria umbellata (K. Schum) collected in Osun State, Nigeria, led to the discovery of a new indole alkaloid, ikirydinium A, featuring an unprecedented 3-alkylpyridinium-indole-2-carboxylate scaffold. Ikirydinium A was found to exhibit antimicrobial activity (IC₅₀ 0.6 μM) against Bacillus subtilis ATCC 6051. The involvement of a common intermediate in the biosynthesis of ikirydinium A and vinblastine is hypothesized.     

(E)‐Ethyl 3‐(3,4‐dihydroxyphenyl)prop‐2‐enoate: a natural polymorph extracted from Aristotelia chilensis (Maqui)

The natural title compound, C₁₁H₁₂O₄, extracted from the Chilean native tree Aristotelia chilensis (Maqui), is a polymorph of the synthetic E form reported by Xia, Hu & Rao [Acta Cryst. (2004), E 60 , o913–o914]. Both rotational conformers are identical from a metrical point of view, and only differ in the orientation of the 3,4‐dihydroxyphenyl ring with respect to the rest of the molecule, which leads to completely different crystal structure arrangements and packing efficiencies. The reasons behind both reside in the different hydrogen‐bonding interactions.     

Structure elucidation and NMR assignments for two amide alkaloids from a Mangrove endophytic Fungus (No. ZZF-22)

The structure elucidations and complete (1)H and (13)C NMR assignments are reported for two new natural products: 3-benzylidene-8,8a-dihydroxy-2-methyl-hexahydro-pyrrolo[1,2-a]pyrazine-1,4-dione(1) and 4-hydroxy-6-(hydroxy-phenyl-methyl)-N-(3-methyl-butyryl)-nicotinamide (2). Both of these secondary metabolites were isolated from the fermentation medium of a Mangrove endophytic fungus. High resolution electron impact mass spectrometry (HREIMS), FT-IR Spectroscopy and NMR experiments including gCOSY, gHMQC, gHMBC and NOE were used for determination of the structures and assignments of the amide alkaloids.     

Taichunamides: Prenylated Indole Alkaloids from Aspergillus taichungensis (IBT 19404)

Seven new prenylated indole alkaloids, taichunamides A–G, were isolated from the fungus Aspergillus taichungensis (IBT 19404). Taichunamides A and B contained an azetidine and 4‐pyridone units, respectively, and are likely biosynthesized from notoamide S via (+)‐6‐epi‐stephacidin A. Taichunamides C and D contain endoperoxide and methylsulfonyl units, respectively. This fungus produced indole alkaloids containing an anti‐bicyclo[2.2.2]diazaoctane core, whereas A. protuberus and A. amoenus produced congeners with a syn‐bicyclo[2.2.2]diazaoctane core. Plausible biosynthetic pathways to access these cores within the three species likely arise from an intramolecular hetero Diels–Alder reaction.     

Hydrothermal Synthesis and Structure Analysis of a Chromium Complex [Cr(aea)]2(OH)2(aea=N-(2-Aminoethyl)aspartate)

A dimeric chromium compound has been synthesized by hydrothermal method and characterized by IR,EPR spectra and TG-DTA technique.The title compound [Cr(aea)]2(OH)2(aea=N-(2-aminoethyl)aspartate)crystallizes in monoclinic,space group P21/c with a=8.9393(10),b=6.7198(7),c=14.6791(16)(A),β=91.0580(10)°,V=881.63(17)(A)3,Z=2,Mr=486.34,Dc=1.832g/cm3,F(000)=500,μ=1.296 mm-1,R=0.0271 and wR=0.0756.Single-crystal X-ray structural analysis indicates that the title compound consists of two Cr(aca)units linked by two bridging hydroxyl groups.The geometry around each chromium center is approximately octahedral and completed by two hydroxyls and a quadridentate ligand which is formed when ethylenediamine reacts with maleie acid.     

Hydrothermal Synthesis and Structure Analysis of a Chromium Complex [Cr（aea）]2（OH）2 （aea = N-（2-Aminoethyl）aspartate）

A dimeric chromium compound has been synthesized by hydrothermal method and characterized by IR, EPR spectra and TG-DTA technique. The title compound [Cr（aea）]2（OH）2 （aea = N-（2-aminoethyl）aspartate） crystallizes in monoclinic, space group P21/c with a = 8.9393（10）, b = 6.7198（7）, c = 14.6791（16） A, β = 91.0580（10）°, V= 881.63（17） A3, Z= 2, Mr = 486.34, De= 1.832 g/cm3, F（000） = 500,μ = 1.296 mm-1, R = 0.0271 and wR = 0.0756. Single-crystal X-ray structural analysis indicates that the title compound consists of two Cr（aea） units linked by two bridging hydroxyl groups. The geometry around each chromium center is approximately octahedral and completed by two hydroxyls and a quadridentate ligand which is formed when ethylenediamine reacts with maleic acid.     

Synthesis and bifunctional asymmetric organocatalysis of helical poly(phenylacetylene)s bearing cinchona alkaloid pendants via a sulfonamide linkage

Four novel helical poly(phenylacetylene)s with amino‐functionalized cinchona alkaloid pendant groups connecting to the phenyl rings through a sulfonamide linkage were synthesized by the polymerization of the corresponding phenylacetylene monomers using Rh⁺(2,5‐norbornadiene)[(η⁶‐C₆H₅)B^?(C₆H₅)₃] (Rh(nbd)BPh₄) as the catalyst. The optically active sulfonamide‐linked polymers adopted a helical conformation with an excess of one‐handedness as supported by the appearance of the induced Cotton effects in the main‐chain chromophore regions, and efficiently catalyzed the enantioselective methanolytic desymmetrization of a cyclic anhydride and aza‐Michael addition of aniline to chalcone, thereby producing the corresponding optically active products up to 86% enantiomeric excess. However, their enantioselectivities from the methanolytic desymmetrization were slightly lower than those catalyzed by the corresponding cinchona alkaloid‐bound monomers. On the other hand, during the asymmetric aza‐Michael addition, a unique enhancement of the enantioselectivity was observed for several sulfonamide‐linked helical polymers, and thus affording a remarkably higher enantioselectivity compared to those of the corresponding monomers and nonhelical polymers bearing the identical cinchona alkaloid residues. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2869–2879     

Synthesis of Bis(indole) Alkaloids from Arundo donax: The Ynindole Diels–Alder Reaction,Conformational Chirality,and Absolute Stereochemistry

Bis(indole) alkaloids from Arundo donax were synthesized using the first ynindole Diels–Alder reaction. The alkaloids are chiral, having stable enantiomeric conformations with half‐lives of racemization of t_1/2=4150–25100 seconds at room temperature. Their absolute stereochemistry was determined using the exciton chirality method.     

Dawson结构聚金属氧酸盐有机-无机复合物[{Y(DMSO)5(H2O)3}{Y(DMSO)8}][P2W18O62]·2DMSO·2H2O的合成、性质及晶体结构

以α-H6P2W18O62·nH2O,Y2O3,DMSO(二甲亚砜)为原料合成了Dawson结构聚金属氧酸盐有机-无机复合物犤狖Y(DMSO)5(H2O)3狚狖Y(DMSO)8狚犦犤P2W18O62犦·2DMSO·2H2O(1),化合物晶体属于单斜晶系,P21/c空间群,Mr=5803.06,a=1.7614(4)nm,b=3.1527(6)nm,c=2.1523(4)nm,β=90.40(3)°,V=11.963(4)nm3,Dc=3.222g·cm-3,μ=18.566mm-1,Z=4,F(000)=10464。由17342个可观测衍射点犤I≥2σ(I)犦用于精修所有的结构参数,得一致性因子R=0.0745,wR=0.1438。结构解析表明,化合物中两个Y3+离子的配位环境均为八配位的畸变双冠三棱柱构型。CV行为研究表明,标题化合物中阴离子(pH=5.5)存在五步还原过程,得电子数依次为1,1,1,1,2。化合物的IR光谱和X-射线衍射结果表明,固态条件下配阳离子与杂多阴离子之间存在较强的相互作用。     

Crystallographic report: Diaquacadmium bis(iminodiacetato)cobaltate,a two‐dimensional heterometallic network

In the title compound, each Cd(H₂O)₂²⁺ is linked to two carboxyl and two carbonyl oxygen atoms, all belonging to different [(NC₄H₅O₄)₂Co]^2? moieties, to furnish a two‐dimensional heterometallic network. Both metal atoms display octahedral coordination. The layers are further held together by hydrogen bonding interactions. Copyright © 2003 John Wiley & Sons, Ltd.     

Njaoamine I,a cytotoxic polycyclic alkaloid from the Haplosclerida sponge Haliclona (Reniera) sp.

A new cytotoxic polycyclic alkaloid containing a quinoline moiety, njaoamine I (1) has been isolated from the methanol extract of the sponge Haliclona (Reniera) sp. collected at Okuza Island, Tanzania. The structure of compound 1 was determined by 1D and 2D NMR and HRMS data analysis. Its relative configuration was elucidated by a NOESY experiment and confirmed by comparison of its NMR spectral data to those of njaoamines A–H. Moreover, njaoamine G (2) was also detected by LC/MS analysis of the methanol extract. Njaoamine I (1) displays cytotoxic activity against a panel of three human tumor cell lines in the micromolar range.     

Synthesis and Crystal Structure of a Novel Ion-pair Compound Consisting of 1-（4-Bromobenzyl）pyridinium Cation and 7,7,8,8-Tetracyanoquinodimethanide Anion

The title compound [BrBzPy][TCNQ] （BrBzPy^＋=1-（4-bromobenzyl）pyridinium cation, TCNQ = 7,7,8,8-tetracyanoquinodimethanide anion） was synthesized by the reaction of [BrBzPy]Br and LiTCNQ in ethanol solution and its structure was determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c with a = 14.067（3）, b = 7.3089（14）, c = 23.796（4）A, β = 122.011（9）°, V= 2074.6（7）A^3, Z = 4, C24H15BrN5, Mr = 453.32, Dc = 1.451 g/cm^3,μ = 2.002 mm^-1, S = 1.047, F（000） = 916, R = 0.0398 and wR = 0.0921. The most prominent structural features are the completely segregated stacking columns of the TCNQ- anions and [BrBzPy]^＋ cations. In a TCNQ column, the centroid-to-centroid distances of the neighboring anions of TCNQ are 3.2693 and 4.9464 A, respectively.     

Synthesis and Crystal Structure of a Novel Ion-pair Compound Consisting of 1,3-Bis（4-cynobenzyl） Imidazole Cation and 7,7,8,8-Tetracyanoquinodimethanide Anion

A novel compound [(CNBz)2Im]2(TCNQ)3(CH3CN)((CNBz)2Im = 1,3-bis(4-cyano-benzyl) imidazole cation,TCNQ-1 = 7,7,8,8-tetracyanoquinodimethanide anion) was synthesized by the reaction of [(CNBz)2Im]Br and LiTCNQ in water and its structure was determined by single-crystal X-ray diffraction.The crystal belongs to monoclinic,space group P21/c with a = 10.1823(17),b = 20.292(3),c = 16.952(3) ,β = 104.73(0)°,V = 3387.6(10)3,Z = 4,C39H24N11,Mr = 646.69,Dc = 1.268 g/cm3,μ = 0.080 mm-1 and F(000) = 1340.The structure was solved by direct methods and refined to R = 0.0596 and wR = 0.0911 for 2690 observed reflections(Ⅰ 2σ(Ⅰ)).The most prominent structural feature is that there are two types of TCNQ entries(TCNQ-1 and TCNQ0) in agreement with the IR spectra analysis of the compound.     

Synthesis and Structure of a Hydrogen-bonding Assembled Three-dimensional Supramolecular Indium(III) Compound Involving One-dimensional Helices

The title compound [In(H2ip)(pdc)(H2O)] (H3ip = 5-hydroxyisophthalic acid, H2pdc = pyridine-2,6-dicarboxylic acid) has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/c with a = 13.830(8), b = 6.488(4), c = 17.632(10) , β = 92.510(10)°, C15H10InNO10, Mr = 479.06, V = 1580.6(15) 3, Z = 4, Dc = 2.013 g/cm3, F(000) = 944, μ = 1.557 mm-1, the final R = 0.0413 and wR = 0.0793 for 2950 observed reflections with I > 2σ(I). The In(III) ion is seven-coordinated in a slightly distorted penta-bipyramidal geometry. The mixed ligands connect the In(III) ions into 21 helical chains along the [010] direction, and the hydrogen bonds assemble the chains into a three-dimensional supramolecular network.