Chemical Constituents from the Leaves of Litsea Acutivena

Continuous investigation of the CHCl₃‐soluble and n‐hexane fractions of the leaves of Litsea acutivena Hayata (Lauraceae) led to the isolation of one new butanolide, acutilactone ( 1 ), one new lactone, 4‐nonacosyl‐dihydrofuran‐2‐one ( 2 ), together with 15 known compounds. The known compounds included one butanolide, one norisoprenoid, one quinone, two steroids, one triterpenoid, one coumarin, two fatty acids, one amide, and five other compounds. The structures of these compounds were determined by means of spectral analyses.     

Synthesis and nuclear magnetic resonance analysis of starch‐g‐poly(1,4‐dioxan‐2‐one) copolymers

A new biodegradable starch graft copolymer, starch‐g‐poly(1,4‐dioxan‐2‐one), was synthesized through the ring‐opening graft polymerization of 1,4‐dioxan‐2‐one onto a starch backbone. The grafting reactions were conducted with various 1,4‐dioxan‐2‐one/starch feed ratios to obtain starch‐g‐poly(1,4‐dioxan‐2‐one) copolymers with various poly(1,4‐dioxan‐2‐one) graft structures. The microstructure of starch‐g‐poly(1,4‐dioxan‐2‐one) was characterized in detail with one‐ and two‐dimensional NMR spectroscopy. The effect of the feed composition on the resulting microstructure of starch‐g‐poly(1,4‐dioxan‐2‐one) was investigated. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3417–3422, 2004     

Chemical Constituents from the Root Bark of Formosan Zanthoxylum Ailanthoides

Two new N‐isobutylamides, hydroxy lanyuamide I ( 1 ) and hydroxy lanyuamide II ( 2 ), together with one hundred and ten known compounds, have been isolated from the root bark of Formosan Zanthoxylum ailanthoides. These known compounds include twenty coumarins, twenty‐one benzo[c]phenanthridines, ten quinoline derivatives, one aporphine, one purine, seven amides, twelve benzenoids, one lactone, four flavonoids, nine lignans, eight steroids, two chlorophylls, eleven terpenoids and three other compounds, which were determined by means of spectral analyses.     

Preparation of new C-alkyl-C-stannylimines

Treatment of (1,1,3,3-tetramethyl)butyl isocyanide with one equivalent of alkyllithium reagent followed by one equivalent of chlorotrialkylstannane afforded 1,1,3,3-tetramethyl-N-[1-(trialkylstannyl)alkylidene]butanamines in good yields. Similarly, the reaction of 2,6-dimethylphenyl isocyanide with one equivalent of diethylzinc then with one equivalent of chlorotrimethylstannane gave 2,6-dimethyl-N-[1-(trimethylstannyl)-propylidene]benzenamine.     

Chemical Constituents from Strychnos Cathayensis

Secostrychnosin ( 1 ), a new secoiridoid, as well as seven compounds never before isolated from nature: 4‐tert‐butyl‐2‐oxazolidinone ( 2 ), 3‐acetoxyindole ( 3 ), indole‐2‐carboxylic acid ( 4 ), benzocaine ( 5 ), 3‐acetylindole ( 6 ), butylparaben ( 7 ) and 2‐hydroxy‐3‐methoxybenzaldehyde ( 8 ), together with fifty other known compounds, have been isolated from the stem of Strychnos cathayensis. These compounds include twenty‐three alkaloids, twelve benzenoids, four steroids, three flavonoids, three iridoids, two triterpenoids, two secoiridoids, two fatty acids, one lignan, one acetophenone, one coumarin, one chromane, one tetraterpenoid, one tannin, and one organic acid. The structures of these compounds were determined by means of spectralanalyses.     

Di‐μ‐acetato‐bis­{[2,4‐dichloro‐6‐(2‐pyridylmethyl­imino­meth­yl)­phenol­ato]zinc(II)} and di‐μ‐thio­cyanato‐bis­{[2,4‐dichloro‐6‐(2‐pyridylmethyl­imino­meth­yl)phenolato]copper(II)}

The two title complexes, [Zn₂(C₁₃H₉Cl₂N₂O)₂(C₂H₃O₂)₂], (I), and [Cu₂(C₁₃H₉Cl₂N₂O)₂(NCS)₂], (II), are dinuclear Schiff base compounds. Both mol­ecules are located on crystallographic centres of inversion. In (I), the Zn^II atom is five‐coordinated in a trigonal–bipyramidal coordination, with one imine N atom of one Schiff base and two acetate O atoms defining the basal plane, and one O atom and one pyridine N atom of the Schiff base occupying the axial positions, while in (II), the Cu^II atom is five‐coordinated in a square‐pyramidal coordination, with one O and two N atoms of one Schiff base and one terminal N atom of a bridging thio­cyanate ligand defining the basal plane, and one terminal S atom of another bridging thio­cyanate ligand occupying the apical position. The different bridging ligands lead to the different coordinations of the complexes.     

Chemical Constituents from the Leaves of Zanthoxylum Schinifolium

cis‐Fagaramide ( 1 ), a new amide, together with fifty known compounds, have been isolated from the leaves of Zanthoxylum schinifolium. These known compounds include twenty‐one coumarins, eleven alkaloids, one furan, four benzenoids, three chlorophylls, four triterpenoids, one diterpenoid, one sesquiterpenoid, and four steroids. The structures of these compounds were determined by means of spectral analyses.     

Transition Metal Acetate Promoted Syntheses of Some New N‐Heterocycles by Multicomponent Reactions

The intermolecular cyclization reactions of N‐tosyl‐ethylenediamine with glyoxal promoted by transition metal acetate at different ratios gave three N‐heterocyclic compounds. The ligand in compound 1 contains one N‐heterocycle, which is formed by a one‐pot three‐component reaction. In compound 2 , two imidazolidine rings and one piperazine ring are fused together to form a tricyclic skeleton by a one‐pot five‐component reaction. Two 1,3,6‐triazabicyclo[3.3.0]octanes are connected by one C–C bond to form the skeleton of 3 , which is constructed from a one‐pot nine‐component reaction. It revealed that the key factor for the preparation of these compounds is the ratio of starting materials, as well as the presence of corresponding transition metal acetates.     

Syntheses,Crystal Structures,and Antibacterial Activities of Four Schiff Base Copper(II), Zinc(II), and Cadmium(II) Complexes Derived from 2‐[(2‐Dimethylaminoethylimino)methyl]phenol

Four Schiff base complexes, [Zn₂L₂(NCS)₂] ( 1 ), [Cd₂L₂(NCS)₂]_n ( 2 ), [Zn₄L₂(N₃)₂Cl₄(OH₂)(CH₃OH)] ( 3 ), and [Cu₄L₂(N₃)₂Cl₄(OH₂)(CH₃OH)] ( 4 ) (where L = 2‐[(2‐dimethylaminoethylimino)methyl]phenol), were synthesized and characterized by elemental analyses, infrared spectroscopy, and single crystal X‐ray determinations. Both 1 and 2 are structurally similar polynuclear complexes. In 1 , each Zn atom has a slightly distorted square‐pyramidal coordination configuration. In the basal plane, the Zn atom is coordinated by one O and two N atoms of one L, and by one O atom of another L. The apical position is occupied by one terminal N atom of a coordinated thiocyanate anion. The Zn···Zn separation is 3.179(3) Å. While in 2 , the Cd1 atom is six‐coordinated in an octahedral coordination. In the equatorial plane, the Cd1 atom is coordinated by one O and two N atoms of one L, and by one O atom of another L. The axial positions are occupied by the terminal N and S atoms from two bridging thiocyanate anions. The coordination of Cd2 atom in 2 is similar to those of the zinc atoms in 1 . The Cd···Cd separation is 3.425(2) Å. Both 3 and 4 are novel tetra‐nuclear complexes. Each metal atom in the complexes has a slightly distorted square‐pyramidal coordination. The arrangements of the terminal metal atoms are similar, involving one O and two N atoms of one L ligand and one bridging Cl atom defining the basal plane, and one O atom of a coordinated water molecule or MeOH molecule occupying the apical position. The coordinations of the central metal atoms are also similar. The basal plane of each metal atom involves one O atom of one L ligand, one terminal Cl atom, and two terminal N atoms from two bridging azide groups. The apical position is occupied by a bridging Cl atom which also acts as a basal donor atom of the terminal metal atom. The Schiff base ligand and the four complexes showed high selectivity and antibacterial activities against most of the bacteria.     

Addition of Nucleophiles to Fragment Ions in Mass Spectrometers under Electrospray-Ionization Conditions

Mass spectra of several aromatic compounds containing an amino or thiol group were recorded under electrospray conditions with a Finnigan TSQ 700, as well as on a Bruker Esquire-LC spectrometer. The MS/MS spectra displayed two main peaks: the first one arising from the cleavage of the amino or thiol group; the second one appeared at 18 Da higher than the first one. It could be shown that the second peak resulted from a nucleophilic addition of one water molecule to the fragment ion.     

A novel three‐dimensional AgI coordination polymer based on mixed naphthalene‐1,5‐disulfonate and aminoacetate ligands

The three‐dimensional coordination polymer poly[[bis(μ₃‐2‐aminoacetato)di‐μ‐aqua‐μ₃‐(naphthalene‐1,5‐disulfonato)‐hexasilver(I)] dihydrate], {[Ag₆(C₁₀H₆O₆S₂)(C₂H₄NO₂)₄(H₂O)₂]·2H₂O}_n, based on mixed naphthalene‐1,5‐disulfonate (L1) and 2‐aminoacetate (L2) ligands, contains two Ag^I centres (Ag1 and Ag4) in general positions, and another two (Ag2 and Ag3) on inversion centres. Ag1 is five‐coordinated by three O atoms from one L1 anion, one L2 anion and one water molecule, one N atom from one L2 anion and one Ag^I cation in a distorted trigonal–bipyramidal coordination geometry. Ag2 is surrounded by four O atoms from two L2 anions and two water molecules, and two Ag^I cations in a slightly octahedral coordination geometry. Ag3 is four‐coordinated by two O atoms from two L2 anions and two Ag^I cations in a slightly distorted square geometry, while Ag4 is also four‐coordinated by two O atoms from one L1 and one L2 ligand, one N atom from another L2 anion, and one Ag^I cation, exhibiting a distorted tetrahedral coordination geometry. In the crystal structure, there are two one‐dimensional chains nearly perpendicular to one another (interchain angle = 87.0°). The chains are connected by water molecules to give a two‐dimensional layer, and the layers are further bridged by L1 anions to generate a novel three‐dimensional framework. Moreover, hydrogen‐bonding interactions consolidate the network.     

钾(Ⅰ)(苯并－15－冠－5)新型配合物的合成及性质

在非水溶剂中合成并－１５－冠－５与碘化钾,硫氰化钾及苦味酸钾形成的三种新型固体配合物,并进行了有关物理,化学性质表征,结果表明,钾（Ⅰ）离子不仅易苯并－１５－冠－５天成常见的１：２夹心式配合物,而且还能生成稳定的１：１型固体配合物。     

Polymeric aqua(nitrilotriacetato)erbium(III)

In the structure of the title compound, [Er(C₆H₆NO₆)(H₂O)]_n, the Er atoms are eight‐coordinated by one N atom and six O atoms from three symmetry‐related nitrilo­tri­acetate (NTA) ligands, and by one O atom of a water mol­ecule, adopting a distorted square‐antiprismatic geometry. The Er atoms are linked by the NTA ligands into layers, which are interconnected via O—H?O hydrogen bonds between the water mol­ecules and the carboxyl­ate O atoms. The asymmetric unit contains one Er atom, one NTA ligand and one water mol­ecule, all of which are located in general positions.     

Microbial Transformation of Isolongifolen‐4‐one

The microbial transformation of (+)‐isolongifolen‐4‐one ( 4 ) by a number of fungi by means of a standard two‐stage fermentation technique afforded (7R)‐12‐hydroxyisolongifolen‐4‐one ( 5 ), (7S)‐13‐hydroxyisolongifolen‐4‐one ( 6 ), (11R)‐11‐hydroxyisolongifolen‐4‐one ( 7 ), (10R)‐10‐hydroxyisolongifolen‐4‐one ( 8 ), and (9R)‐9‐hydroxyisolongifolen‐4‐one ( 9 ) (Scheme). All five metabolites were found to be new, and metabolites 6 and 9 showed potent tyrosinase inhibitory activity (Table 1). The metabolites and their derivatives were characterized on the basis of spectroscopic and single‐crystal X‐ray‐diffraction techniques.     

Poly­[[(pyridazine-κN)copper(I)]-μ3-thio­cyanato-κ3N:S:S]

In the crystal structure of the title compound, [Cu(NCS)(C₄H₄N₂)]_n, each Cu atom is coordinated by one N atom of one pyridazine ligand and by one N and two S atoms of three symmetry-related thio­cyanate anions within a distorted tetrahedron. Only one N atom of the pyridazine ligand is involved in Cu coordination. The Cu atoms are connected via the thio­cyanate anions, forming layers parallel to the ab plane.     

Investigation of the Reaction between 3‐Benzisothiazolones,an Isoindole Isoster and Activated Acetylenes: Synthesis of Heterocyclic Backbones for Building Bioactive Molecules

Investigation of the reaction between benzo[d]isothiazol‐3‐one, 2‐aminobenzo[d]isothiazol‐3‐one, its isoster 2‐aminoisoindolin‐1‐one, and activated acetylenes, in the presence of triphenylphosphine, led us to synthesize novel heterocyclic compounds that could be attractive for the building of biologically active molecules. A one‐pot PPh₃‐promoted tandem reaction, with acetylene dicarboxylates and dibenzoylacetylene, afforded new tricyclic pyrazolo‐fused benzisothiazoles. The PPh₃‐promoted reaction between benzisothiazolones and methyl propiolate afforded 1,4‐benzothiazepine‐5‐one derivatives, via an isothiazole ring expansion. These studies are providing additional insights in benzisothiazolone chemistry and describe simple and original synthetic accesses to novel derivatives.     

Investigations on the luminescence of titanium-activated stannates and zirconates

The luminescence of several titanium-activated stannates and zirconates with spinel, perovskite, K₂NiF₄, pyrochlore, and fluorite structure is reported. For most compounds two emissions are observed, one blue and one yellow. Some compounds show only yellow emission and there is one compound with only blue emission. These results can be explained by one model, based on the occurrence of two different titanate centres, viz., a regular center and a defect center.     

[Bis(3,5‐dimethylpyrazol‐1‐yl‐κN2)dithioacetato‐κS](triphenylphosphine‐κP)copper(I)

In the title compound, [Cu(C₁₂H₁₅N₄S₂)(C₁₈H₁₅P)], the copper(I) center is tetrahedrally coordinated by one S atom and two N atoms from one bis(3,5‐dimethylpyrazol‐1‐yl)dithioacetate ligand and one P atom from a triphenylphosphine ligand. In the crystal structure, adjacent pyrazole rings are involved in weak π–π interactions, thereby forming a one‐dimensional zigzag chain running along the b axis.     

Constituents of the Bark of Ficus microcarpa Lf.

The isolation and identification of twenty-eight crystalline components from the bark of Ficus microcarpa L.f. are described. Their structures were determined on the basis of spectral data and values taken from the literature. These compounds include fourteen triterpenoids, one fatty alcohol, eight steroids, one coumarin, one flavane, two 4-hydroxybenzoates, and one carotenoid-like compound.     

Thermal cyclization of 3‐azido‐2‐phenyl‐indan‐l‐one to 5h‐indeno[1,2‐b]indol‐10‐one

3‐Azido‐2‐phenylindan‐1‐one ( 4 ), which was obtained from 3‐chloro‐2‐phenylindan‐1‐one ( 3 ), cyclizes on thermolysis to 5H‐indeno[1,2‐b]indol‐10‐one ( 5 ). Reaction of 3‐azido‐2‐phenylindan‐1‐one ( 4 ) with triphenylphosphane gives 2‐phenyl‐3‐(triphenylphosphoranylideneamino)‐indan‐1‐one ( 6 ), which can be hydrolyzed to 3‐amino‐2‐phenylindan‐1‐one ( 7 ). Attempts to perform a similar cyclization sequence with 3‐chloro‐2‐pyridylindan‐1‐ones failed.