Suchada Chantrapromma

Synthesis, structure and in vitro antibacterial activities of new hybrid disinfectants quaternary ammonium compounds: pyridinium and quinolinium stilbene benzenesulfonates.

The series of pyridinium (1-10) and quinolinium (11-20) stilbene benzenesulfonates have been synthesized and their structures were investigated by UV-vis, FT-IR and (1)H NMR spectroscopy. In addition, compound 5 was also determined by single crystal X-ray diffraction technique. The antibacterial activity of the synthesized compounds against both gram-positive and gram-negative bacteria has been determined. The quinolinium derivatives exhibited two very potent characteristic activities, namely, (i) specific activity to Methicillin-Resistant Staphylococcus aureus and (ii) with broad band spectrum activity. Compounds 11, 13 and 14 are the most active showing broad spectrum antibacterial activity against gram-positive (Methicillin-Resistant S. aureus, S. aureus, Bacillus subtilis, Vancomycin-Resistant Enterococcus faecalis and E. faecalis) and gram-negative bacterium (Shigella sonnei). The MICs of these compounds were found to be better than that of Benzalkonium chloride (BZK), the commercially used disinfectant.

Copper(I)–azoimidazoles: a comparative account on the structure and electronic properties of copper(I) complexes of 1-methyl-2-(phenylazo)imidazole and 1-alkyl-2-(naphthyl-(α/β)-azo)imidazoles

Abstract Bis-[1-alkyl-2-(naphthyl-(α/β)azo)imidazole]copper(I) perchlorate derivatives, [Cu(α-NaiR)2(ClO4)] and Cu(β-NaiR)2](ClO4), have been characterised by spectral and electrochemical studies. The single crystal X-ray structure of bis-[1-ethyl-2-(naphthyl-α-azo)imidazole]copper(I) perchlorate shows strong bonding with two imidazole-N atoms, two azo-N donors interact weakly and the structure is described as having a [2+2] distorted linear geometry. A structural comparison has been done with the X-ray structure of bis-[1-methyl-2-(phenylazo)imidazole]copper(I) perchlorate which is Td symmetric. Solution electronic spectra and redox properties are compared and have been correlated with EHMO calculation.

Cytotoxic and antibacterial sesquiterpenes from Thespesia populnea.

Eight new sesquiterpenoids, named populene A-H (1-8), were isolated from dichloromethane extracts of the wood and dark heartwood of Thespesia populnea, together with 11 known compounds (9-19). Their structures were determined on the basis of spectroscopic analyses. The cytotoxic activity of isolated compounds was evaluated against four cancer cell lines: MCF-7, HeLa, HT-29, and KB. Mansonone E (11) and (+)-gossypol (18) showed significant activities. Their antibacterial properties against Bacillus subtilis, Staphylococcus aureus, and Enterococcus faecalis are also presented.

Phanginin A-K, diterpenoids from the seeds of Caesalpinia sappan Linn.

The first chemical study on the seeds of Caesalpinia sappan Linn. led to isolation of 11 cassane-type diterpenes, named phanginin A-K (1-11). The skeleton present in compounds 1-8 is rather unusual, consisting of a cassane-type diterpene with an ether bridge between C-19/C-20 in compounds 1-6 and C-11/C-20 in compounds 7 and 8. Their structures were elucidated on the basis of spectroscopic techniques. In addition, the X-ray structure of phanginin A (1) is reported. Only phanginin I (9) exhibited cytotoxic effect against KB cell line with IC50 value of 4.4 microg/ml.

4-Chloro-N′-[(Z)-4-nitro­benzyl­idene]benzohydrazide monohydrate

In the title compound, C14H10ClN3O3·H2O, the benzohydrazide group is not planar and the molecule exists in a cis configuration with respect to the methylidene unit. The dihedral angle between the two substituted benzene rings is 38.7 (3)°. In the crystal structure, molecules are linked by O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds into a two-dimensional network parallel to the (100) plane. The crystal structure is further stabilized by weak C—H⋯O interactions.

Synthesis, spectral studies and structure of 2-hydroxyacetophenone nicotinic acid hydrazone

Abstract 2-Hydroxyacetophenone nicotinic acid hydrazone (H2ApNH) was synthesized as a part of our work, in search for non-linear optical crystal based on hydrazones, and studied spectroscopically. Complete NMR assignments for the hydrazone was made using COSY homonuclear and HMQC heteronuclear correlation techniques. Solid state reflectance was also studied in order to understand the electronic structure of the synthesized compound. The crystal and molecular structures of H2ApNH were determined. The compound crystallizes into an orthorhombic lattice with a non-centrosymmetric space group Pca21 with two crystallographically unique molecules of in an asymmetric unit. The geometry reveals quasi co planarity in the whole molecular skeleton with localization of the double bonds in the CN–N–CO with an E-configuration.

Potential anti-inflammatory diterpenoids from the roots of Caesalpinia mimosoides Lamk.

Anti-inflammatory assay-guided separation of extracts from the roots of Caesalpinia mimosoides Lamk. led to isolation of seven compounds: four diterpenes (1-4), a dimer (9), and two dibenzo[b,d]furans (10, 11) together with eleven known compounds. Their structures were elucidated by 1D- and 2D-NMR techniques as well as UV, IR, mass spectral data and comparison with literature values. The anti-inflammatory activities of all compounds were evaluated for inhibitory activities against lipopolysaccharide (LPS) induced nitric oxide (NO) production in RAW264.7 cell lines. Compounds 4, 6, 8, and 12-14 were also tested for the inhibitory effect on LPS-induced tumor necrosis factor-alpha (TNF-alpha) release in RAW264.7 cells. The results indicated that 4 possessed potent inhibitory activity for both tests with IC(50) values of 3.0 and 6.5 microM, respectively.

Zn(II) and Cd(II) N-carbazolylacetates with strong fluorescence

N-carbazolylacetic acid was synthesized using a new method in a high yield and two carbazolylacetato complexes [Zn(Cabo)-(phen)2ClO4]·0.5C2H5OH and [Cd(Cabo)(phen)2-ClO4] (Cabo=N-carbazolylacetate, phen=1,10-phenanthroline) were synthesized and characterized by elemental analysis, IR, UV–Vis spectra, thermal analyses, photoluminescence measurement and X-ray diffraction studies. Both of the complexes exhibit strong blue emission in solid state as well as high thermal stability and solvent-resistant properties.

Synthesis of dinuclear metal complexes of a macrocyclic ligand with multi-ligating pendant-arms. Crystal structures of its manganese(II) and cadmium(II) complexes

Abstract A series of dinuclear metal complexes, [M 2 L](ClO 4 ) 2 (M=Mn 2+ , Ni 2+ , Zn 2+ and Cd 2+ ), of a pendant-arm macrocyclic ligand (H 2 L) have been prepared via the cyclocondensation between sodium 2,6-diformyl-4-chlorophenolate and N -(2-methylenepyridinyl)tris(2-aminoethyl)amine and the subsequent transmetallation with metal perchlorates, and characterized spectroscopically. Among these, the crystal and molecular structures of [Mn 2 L](ClO 4 ) 2 and [Cd 2 L](ClO 4 ) 2 have been determined by X-ray diffraction. The structure of the manganese complex indicates that each pendant-arm is bonded bidentately to the adjacent metal atom and both arms are on the same side of the resulting tetra-imine macrocycle. The six-coordinated manganese ion has a distorted octahedral configuration in which an uncommon eight-membered chelating ring has been formed due to the non-bonding tertiary nitrogen. In the structure of the cadmium complex, the pendent arm binds in the same manner to the metal as in the manganese complex. Each metal atom is coordinated by all the donor atoms including the tertiary nitrogen atom in one chamber of the macrocycle, and the cadmium ion is seven-coordinated with a geometry of a highly distorted pentagonal bipyramid. The manganese(II) ions in the macrocycle are both essential high spin, with only a very weak antiferromagnetic interaction. The manganese compound showed only a moderate activity in the catalytic decomposition of hydrogen peroxide.

Cadinane sesquiterpenes from the leaves of Eupatorium adenophorum.

Four new cadinane sesquiterpenes (1- 4), including a dimeric cadinane derivative (2) and a peroxide cadinane analogue (3), have been isolated from the leaves of Eupatorium adenophorum. Their structures including absolute configurations were determined on the basis of spectroscopic data interpretation and single-crystal X-ray crystallography. Compound 4 showed in vitro cytotoxicity against the HCT-8, Bel-7402, and A2780 cancer cell lines.