Supramolecular isomerism in the hydrogen-bonded network of (5<Emphasis Type="Italic">R</Emphasis>,10<Emphasis Type="Italic">R</Emphasis>)-3,8-dihydroxy-5,10-diethoxy-5,10-dihydrochromeno[5,4,3-<Emphasis Type="Italic">cde</Emphasis>]chromene monohydrate

A new compound (5R, 10R)-3,8-dihydroxy-5,10-diethoxy-5,10-dihydrochromeno[5,4,3-cde]chromene monohydrate was obtained from 3,4-dihydroxybenzaldehyde in aerobic basic aqueous ethanol solution in the presence of manganese chloride and triethylamine and crystallized in orthorhombic P2₁2₁2₁ space group (denoted as 1). When 1 was recrystallized from aqueous methanol, it was transformed to another crystal (2) with the same composition but in P2₁/n space group. The drastic difference in the extensive hydrogen bond network makes 1 a 3D and 2 a 2D infinite supramolecular structure, respectively.     

Two new eunicellin diterpenoids from the South China Sea gorgonian Muricella sibogae and their bioactivities

A systematic re-study on gorgonian Muricella sibogae from South China Sea yielded 10 eunicellin-based diterpenoids including two new ones, sibogins C and D (1 and 2). Their structures were elucidated by extensive spectroscopic analyses (1D and 2D NMR, IR and MS) and by comparison with data reported in literatures. All the isolates were tested for cytotoxic and antifouling activities. Compounds 3 and 5 showed significant antifouling activity against the green mussel Perna viridis, and especially 3 was suggested as a potent low-toxic antifouling agent with a large LC₅₀/EC₅₀ value of 18.6. This was the first report on the antifouling activity of the eunicellin-type diterpenoids against the green mussel.     

New naphthopyrones from marine-derived fungus Aspergillus niger 2HL-M-8 and their in vitro antiproliferative activity

A new cytotoxic dimeric naphthopyrone, aurasperone H (1), together with eight related known polyketides (2–9) was isolated from a marine-derived fungus Aspergillus niger 2HL-M-8. The structure of new compound 1 was elucidated on the basis of its spectroscopic data (1D, 2D NMR and CD). Compound 1 exhibited moderate inhibitory activity against the human lung adenocarcinoma A549 and the human leukaemia HL-60 cell lines. Compound 5 displayed significant in vitro antiproliferative activity against HL-60 cell line with an IC₅₀ value of 0.8 μM.     

Paenibacillin A,a new 2(1H)-pyrazinone ring-containing natural product from the endophytic bacterium Paenibacillus sp. Xy-2

A new 2(1H)-pyrazinone ring-containing natural product, paenibacillin A (1), together with five known diketopiperazine derivatives 2–6 and two known isoflavones 7–8, was isolated from the culture of an endophytic bacterium Paenibacillus sp. Xy-2. The structure of compound 1 was elucidated by extensive spectral methods, including UV, IR, HR-ESI-MS, 1D and 2D NMR and ECD experiments. Compound 1 exhibited moderate cytotoxicity against HL-60 cell line with IC₅₀ value of 50.48 μM.     

Colletotrichine A,a new sesquiterpenoid from Colletotrichum gloeosporioides GT-7, a fungal endophyte of Uncaria rhynchophylla

One new compound, Colletotrichine A (1), was produced by the fungal Colletotrichum gloeosporioides GT-7. The structure was established by 1D and 2D NMR spectra. Monoamine oxidase (MAO) and acetylcholinesterase (AChE) inhibitory activity of 1 was also evaluated. Compound 1 showed AChE-inhibiting activity with IC₅₀ value of 28 μg/mL.     

Penicindopene A,a new indole diterpene from the deep-sea fungus Penicillium sp. YPCMAC1

A new indole diterpene, named penicindopene A (1), together with seven known compounds (2?–?8), was isolated from the deep-sea fungus Penicillium sp. YPCMAC1. The structure of penicindopene A was elucidated by extensive spectroscopic analyses (1?D and 2?D NMR, and HRESIMS data), in addition to the ECD calculations for the assignments of its absolute configuration. Penicindopene A represented the first example of indole diterpenes possessing a 3-hydroxyl-2-indolone moiety, and it exhibited moderate cytotoxicities against A549 and HeLa cell lines with IC₅₀ values of 15.2 and 20.5?µM, respectively.     

Hydrothermal synthesis,crystal structure,and properties of a novel magnesium phosphonate with a 1D chain structure

A novel 1D chain magnesium phosphonate with a 1D channel system along the c-axis, [Mg(H₄L)(H₂O)₃]_n (1) (H₄L^2-=HN(CH₂PO₃H)₃)^2-, has been synthesized under hydrothermal condition using triphosphonate ligand. The MgO₆ polyhedra and NC₃ planes are connected by phosphonate groups to form a 1D chain. The chains are interlinked by hydrogen bonds into 2D layers. Adjacent layers are further linked via hydrogen bonds to build a 3D network structure. The luminescent property of complex 1 has been also studied. For the complex 1, a blue fluorescent emission band with a maximum peak at 460 nm was observed.     

Dendrobeaniamine A,a new alkaloid from the Arctic marine bryozoan Dendrobeania murrayana

Abstract

The new guanidine alkaloid Dendrobeaniamine A (1) was isolated from the organic extract of the Arctic marine bryozoan Dendrobeania murrayana. The chemical structure of 1 was elucidated by spectroscopic experiments, including 1D and 2D NMR and HRESIMS analysis. Compound 1 is a lipoamino acid, consisting of a C₁₂ fatty acid anchored to the amino acid arginine. The bioactivity of 1 was evaluated using cellular and biochemical assays, but the compound did not show cytotoxic, antimicrobial, anti-inflammatory or antioxidant activities     

Globrauneine A–F: six new triterpenoid esters from the leaves of Globimetula braunii

Abstract

Phytochemical study was conducted on the leaves of Globimetula braunii which is a hemi parasitic plant belonging to the family Loranthaceae. Extraction was carried out using cold extraction method with increasing polarity of solvents i.e n-hexane, CH₂Cl₂ and MeOH. The components were separated by chromatographic technique and the structures of the compounds were elucidated by extensive spectroscopic analyses including MS, FTIR, 1D and 2D NMR, HRMS and chemical methods. Six new pentacyclic triterpenoid esters named as globrauneine A (1), globrauneine B (2), globrauneine C (3), globrauneine D (4), globrauneine E (5), and globrauneine F (6), together with six known compounds (7 – 12) were successfully isolated from the leaves of G. braunii growing on Piliostigma thonningii. These results depict a substantial support to the chemotaxonomy of the genus Globimetula.     

Conformational effects on mesophase stability: numerical comparison of carborane diester homologous series with their bicyclo[2.2.2]octane,cyclohexane and benzene analogues

Three series of diesters of 4‐alkoxyphenols containing 12‐vertex p‐carborane (1A[n], n = 1–22), 10‐vertex p‐carborane (1B[n], n = 1–12) or bicyclo[2.2.2]octane (1C[n], n = 1–12) as the central structural element were prepared and investigated by optical and calorimetric methods. All carborane diesters exhibited exclusively nematic behaviour, whereas the carbocyclic analogues 1C[n] and also cyclohexane (1D[n]) and benzene (1E[n]) derivatives, showed early onset of SmA phase and complete disappearance of nematic behaviour. The isotropic transition temperatures, T _MI, for the five series of mesogens were analysed numerically using a three‐parameter exponential function. The resulting limiting values, T _MI(∞), provided a quantitative assessment of the central element ability to support the mesogenic state. They demonstrated that, whereas the T _MI(∞) values for the carbocycles, C, D, and E, are around 125°C, for carboranes A and B this value is 70±2°C and 49±19°C, respectively. Two types of comparative analysis of trends in T _MI relative to those of the terephthalate series 1E[n] demonstrated abnormal behaviour of both carborane series (1A[n] and 1B[n]) and also the cyclohexane series (1D[n]). The former showed progressive destabilisation of the mesophase, whereas the series 1D[n] exhibited increasing mesophase stability relative to 1E[n] with increasing chain length. Both of these effects were explained using conformational analysis of theoretical models and experimental molecular structures for 1A[3], 1B[4] and 1C[4]. The increasing relative destabilisation of the mesophase in the carborane derivatives was rationalised by the high order rotational axes in A and B and D _4d symmetry for B. The trend of the ΔT _MI values for series 1D[n] was explained with the existence of the equatorial‐axial conformational equilibrium for the cyclohexane derivatives. The clearing temperatures for the hypothetical pure diequatorial conformers 1D[n]‐ee were estimated.     

Structure elucidation and NMR assignments of a new dihydrochalcone from Empetrum nigrum subsp. asiaticum (Nakai ex H.Ito) Kuvaev

Abstract

A new dihydrochalcone, namely 2',5'-dimethyl-3'-methoxy-4',6'-dihydroxyl-dihydrochalcone (1) together with five known compounds were isolated from the CHCl₃ extract from Empetrum nigrum L. var. japonicum K. Koch (E. nigrum). The structures of 1 was elucidated by spectroscopic methods, including UV, IR, HR-ESI-MS and extensive 1D and 2D NMR techniques.     

含苯并咪唑基配体Zn(Ⅱ)、Cd(Ⅱ)配位聚合物的合成、结构以及荧光性质研究

以3,5-二(苯并咪唑基)吡啶(L)、间苯二甲酸(m-H₂BDC)、4-羧基肉桂酸(H₂CCA)、ZnSO₄·7H₂O和Cd(NO₃)₂·4H₂O为原料,使用溶剂热方法合成了两个配位聚合物[Zn(L)(m-BDC)] (1)和[Cd(L)(CCA)]·2H₂O (2),利用红外、元素分析、热重分析和X-射线粉末衍射对其进行了表征,利用X-射线单晶衍射对结构进行了测定,并研究了配合物的荧光性质。在配合物1中,L与金属离子连接形成了一维(1D)链结构,而间苯二甲根离子与金属离子构成了一个M₂(m-BDC)₂(M=金属离子)的单元。一维链之间通过M₂(m-BDC)₂单元连接形成二维网状(2D)结构。在配合物2中,和配合物1类似,L与金属离子连接形成一维链,但与1不同的是羧酸配体与金属离子配位也构成了一维链结构,两种一维链通过配位作用连接构成二维结构。     

含1，3，5-三-((4-吡啶)-1，2-乙烯基)苯的配位聚合物的合成、结构及性质

用三烯烃三吡啶配体1,3,5三-((4-吡啶)-1,2-乙烯基)苯(tpeb)和M(NO_3)_2(M=Co,Ni,Zn,Cd)以及4种不同的有机羧酸(3,5-二溴苯甲酸(3,5-HDBB)、2,5-噻吩二羧酸(2,5-H_2TDC)、2,5-呋喃二羧酸(2,5-H_2FDC)、2,5-二溴对苯二甲酸(2,5-H_2DBTP))进行溶剂热反应,得到了[Zn(tpeb)(3,5-DBB)_2]_n(1)、[Co_2(tpeb)_2(2,5-TDC)_2]_n(2)、[Co_2(tpeb)_2(2,5-FDC)_2]_n(3)、[Co(tpeb)(2,5-DBTP)]_n(4)、[Ni(tpeb)(2,5-DBTP)]_n(5)、[Cd(tpeb)_(0.5)(2,5-DBTP)]_n(6)六个配位聚合物。对配合物1～6分别进行了单晶X射线衍射、粉末X射线衍射、红外、元素分析、热重、荧光等结构表征。配合物1～6结构独特且多样。配合物1是由[Zn(3,5-DBB)_2]单元通过配体tpeb桥联构筑的一维zigzag链状结构;配合物2和3是由一维梯状[Co(tpeb)]_n链分别与2种不同的五元杂环二取代羧酸桥联构筑而成的二维双层结构;配合物4和5均是由一维[M(2,5-DBTP)]_n(M=Co,Ni)链通过tpeb交叉连接而成的三维网络结构;配合物6则是由二维的[Cd(2,5-DBTP)]_n层状结构通过tpeb连接而成的三维互穿拓扑网络结构。配合物1～6的热稳定性较好,它们在固态时表现出不同的荧光性质。     

Oligoamide,a new lactam from the leaves of Angylocalyx oligophyllus

A new lactam, oligoamide (1), along with three known compounds (2–4), stigmasterol-3-O-β-D-glucopyranoside (2), formononetin (3) and (-)-pinitol (4) were isolated from the CH₂Cl₂/CH₃OH (1:1) extract of the leaves of Angylocalyx oligophyllus by chromatographic separation. Their structures were elucidated on the basis of spectroscopic analysis (UV, IR, MS, 1D, and 2D NMR). Compound 1 was found to have weak antioxidant and urease inhibitory potential.     

Synthesis and Crystal Structures of Tetraazamacrocycle NickelII Complexes Containing O-Phenylenedioxydithiophosphate Anion

Abstract

A tetraazamacrocycle nickel^II complex of O,O′-diaryldithiophosphate, [Ni(hmtade)] [S₂P(O₂C₆H₄-o)]₂ (1), and its unexpected complex methanolysis product, [Ni(hmtade)] [S₂P(OMe)(OC₆H₄(OH-o)]₂ (2) (the ligand hmtade is 5,7,7,12,14,14-hexamethyl-1,4,8,11- tetraazacyclotetradeca-1,11-diene), have been synthesized and characterized by elemental analysis, IR, ¹H(¹³C, ³¹P) NMR spectroscopies, thermogravimetric analysis, and single-crystal X-ray diffraction methods. The results show that the difference in O,O′-diaryldithiophosphate anions hardly brings about any influence on the structure of complex cation [Ni(hmtade)]²⁺. In the packing of 1, the molecules self-assemble into a folded two-dimensional (2D) network and which further links into a complicated 3D supramolecular framework. Two different kinds of 2D networks form independently via intermolecular hydrogen bonds and alternatively arrange into a novel 3D lamellar sandwich-layer structure in the packing of 2.     

Syntheses,structures and fluorescent properties of three copper cyanide coordination polymers based on N-heterocyclic ligands

Hydrothermal reactions of CuCN, K₃[Fe(CN)₆] with 2,2′-bipyridine, 1,10-phenanthroline or 2,6-bis(1,2,4-triazolyl)pyridine (btp) afford three coordination polymers, [Cu₇(CN)₇(bipy)₂] _n (1), [Cu₂(CN)₂(phen)] _n (2) and [Cu₃(CN)₃(btp)] _n (3). Complex 1 displays 1D polymeric ribbons which are assembled through Cu ··· Cu and π–π stacking interactions into a 3D framework. Complex 2 shows a 1D zigzag chain structure in which phen is a side ligand. In 3, the copper cyanide 2D polymeric networks are connected by tridentate btp to form a 3D metal-organic framework. These coordination polymers exhibit strong fluorescent emissions in the solid state.     

One ligand capable of in situ reaction in a mixed-ligand system with two new different frameworks

The in situ ligand 2,3-pyrazinedicarboxylic acid (2,3-H₂pzdc) mixed with 1,1′-(1,4-butanediyl)bis(benzimidazole) (bbbi) is used to form two coordination polymers ([Cd(2,3-pzdc)(bbbi)] (1) and [Cd₂Cl₃(2-pzc)(bbbi)₂] (2)) under hydrothermal conditions. Complex 1 was obtained in the absence of in situ reaction and 2 was synthesized with 2,3-H₂pzdc in situ generating 2-pyrazinecarboxylate (2-pzc^?). The structural details reveal that 1 has a 3D framework with dia topology, and 2 is a 2D layer structure and develops a 3D supramolecular structure via strong π?π stacking interactions. The ligand effects were compared for the two frameworks. In addition, fluorescence properties and thermal stabilities of 1 and 2 in the solid were studied.     

A novel dicyanamide-bridged zinc(II) complex incorporating the 4,4′-azopyridine ligand

A novel complex {[Zn(azpy)₂(dca)(H₂O)₂]·ClO₄·azpy·2H₂O}_n (1) has been synthesized and structurally and spectroscopically characterized, where azpy is the 4,4′-azopyridine and dca the dicyanamide. The crystal structure analysis of 1 shows that in 1 the dca ligands act as μ _1,5-bridges linking the zinc(II) ions into 1D covalent bonding chains. The zinc(II) ion lies in a distorted octahedral environment completed by two nitrogen atoms from two terminal azpy groups, two nitrogen atoms from two dca bridges, and two water molecules. The most striking feature of 1 is that the 1D covalent bonding chains are linked through O–H·N hydrogen bonds and π–π stacking interactions into a 3D supramolecular structure.     

基于半刚性双(噻唑基苯并咪唑)和不同羧酸的五个一维配合物的合成和表征

通过水热或溶剂热合成的方法制备了5个一维配合物{[Zn(btbb)_(0.5)(m-phda)]·0.5H_2O}_n(1),{[Cd_2(btbb)(adtda)_2(H_2O)]·H_2O}_n(2),[Mn_2(btbb)(tbi)_2]_n(3),{[Cd(btbb)_(0.5)(3-Nitro-o-bdc)(H_2O)]·H_2O}_n(4)和[Cd_2(btbb)(tbi)_2]_n(5)(btbb=1,4-双(2-(4-噻唑基)苯并咪唑-1-基甲基)苯,m-H_2phda=间苯二甲酸,H_2adtda=1,3-金刚烷二羧酸,H_2tbi=5-叔丁基间苯二甲酸,3-Nitro-o-H_2bdc=3-硝基-1,2-苯二甲酸)。配合物1是一个包含22元环的一维链。配合物2是一个包含8元环的一维链,并且氮配体在这个一维链中仅仅起到装饰作用。配合物3是一个一维双链结构。配合物4是一个包含14元环的一维链。配合物5是一个阶梯状的一维双链结构。     

Eudesmane and aromadendrane sesquiterpenoids from the Vietnamese soft coral Sinularia erecta

Using various chromatographic separations, eight sesquiterpenoids (1–8), including one new compound 3β,5α-dihydroxyeudesma-4(15),11-diene (1), were isolated from the MeOH extract of the Vietnamese soft coral Sinularia erecta. The structure elucidation was confirmed by spectroscopic experiments including 1D and 2D NMR and HR-ESI-MS. The cytotoxic activities against three human cancer cell lines (A-549, HeLa and PANC-1) of all isolated compounds were evaluated by MTT-based colorimetric assays. Compound 1 exhibited selective cytotoxicity against the A549 cell line with IC₅₀ of 14.79 ± 0.91 μM.