A New Rare Halogenated Depside from Lichen and Study of its Anti-Proliferative Activity.

Lichens are a symbiotic association of algae and fungus, belonging to the family Parmeliaceae. Some lichen species are edible and used as an active ingredient for preparation of exotic spices as well as folklore medicine to cure different kinds of ailments. A specimen of lichen was collected from Munner in the Kerala State of South India for chemical profiling. Chemical analyses of the diethyl ether extract of the defatted lichen led to the isolation of six phenols 1-6 with variation of relative abundance. Amongst them, the relative abundance of compound 3 was the greatest (1 % of crude extract) and it was identified as atranorin. The structures of known compounds were confirmed by comparison of their 1H-NMR, 13C NMR, and mass data with published values available in the literature. In vitro bioassay for anti-proliferative activity of these compounds has been conducted against various human cancer cell lines in comparison with paclitaxel as control using SRB assay. Interestingly, a new compound 5 was found along with previously reported compounds from this lichen. This new compound was designated as fluoroatranorin 5 which was reported for the first time herein. The structural characterization of a new depside was determined by spectral methods such as 1H-NMR, 13C NMR, 19F NMR, IR, LC-HRESI-MS, and LC-MS/MS study. Its structure was confirmed by single crystal X-ray diffraction study. This new compound was designated as fluoroatranorin 5 which was reported first time herein. Anti-proliferative activity of all these compounds was evaluated against six different cancer cell lines. The inhibitory activity, IC50 value of compounds 1-3 and 5 exhibited at 99.64, 102.04, 109.20, 53.0 and 2.4 µM on cancer cell lines HT-29 (colon), Hela (cervical), HT-29, HPAC (pancreas) and A2780 (ovarian cancer cell line) respectively in comparison with paclitaxel as control. The new compound 5 exhibited significant activity with IC50 value 2.4 µM on A2780 ovarian cancer cell line.

Anti-Proliferative Acyl Phenols and Arylnonanoids from the Fruit Rind of Myristica malabarica Lam.

Phytochemical investigation of the methanol extract of the fruit rind of Myristica malabarica led to the isolation of eight known compounds that were identified as malabaricones A-D, promalabaricones B and C, 1-(2,6-dihydroxyphenyl)tetradecan-1-one, and ericanone by comparison with literature spectroscopic data. The structures of malabaricones A-D, promalabaricone B, and 1-(2,6-dihydroxyphenyl)tetradecan-1-one were confirmed by X-ray crystallography. In vitro assay of the isolated phenols indicated that they exhibited moderate anti-proliferative activity against the A2780 human ovarian cancer cell. Compounds (1, 3, 5, 6 and 7) had the most potent activities, whereas the anti-proliferative activities of compounds 2 and 4 were less potent.

Triptycene-Based Chiral and meso-N-Heterocyclic Carbene Ligands and Metal Complexes.

Based on 1-amino-4-hydroxy-triptycene, new saturated and unsaturated triptycene-NHC (N-heterocyclic carbene) ligands were synthesized from glyoxal-derived diimines. The respective carbenes were converted into metal complexes [(NHC)MX] (M=Cu, Ag, Au; X=Cl, Br) and [(NHC)MCl(cod)] (M=Rh, Ir; cod=1,5-cyclooctadiene) in good yields. The new azolium salts and metal complexes suffer from limited solubility in common organic solvents. Consequently, the introduction of solubilizing groups (such as 2-ethylhexyl or 1-hexyl by O-alkylation) is essential to render the complexes soluble. The triptycene unit infers special steric properties onto the metal complexes that enable the steric shielding of selected areas close to the metal center. Next, chiral and meso-triptycene based N-heterocyclic carbene ligands were prepared. The key step in the synthesis of the chiral ligand is the Buchwald-Hartwig amination of 1-bromo-4-butoxy-triptycene with (1S,2S)-1,2-diphenyl-1,2-diaminoethane, followed by cyclization to the azolinium salt with HC(OEt)3 . The analogous reaction with meso-1,2-diphenyl-1,2-diaminoethane provides the respective meso-azolinium salt. Both the chiral and meso-azolinium salts were converted into metal complexes including [(NHC)AuCl], [(NHC)RhCl(cod)], [(NHC)IrCl(cod)], and [(NHC)PdCl(allyl)]. An in situ prepared chiral copper complex was tested in the enantioselective borylation of α,ß-unsaturated esters and found to give an excellent enantiomeric ratio (er close to 90:10).

Structural Polymorphism and Thin Film Transistor Behavior in the Fullerene Framework Molecule 5,6;11,12-di-o-Phenylenetetracene.

The molecular structure of the hydrocarbon 5,6;11,12-di-o-phenylenetetracene (DOPT), its material characterization and evaluation of electronic properties is reported for the first time. A single-crystal X-ray study reveals two different motifs of intramolecular overlap with herringbone-type arrangement displaying either face-to-edge or co-facial face-to-face packing depicting intensive π-π interactions. Density functional theory (DFT) calculations underpin that a favorable electronic transport mechanism occurs by a charge hopping process due to a π-bond overlap in the DOPT polymorph with co-facial arene orientation. The performance of polycrystalline DOPT films as active organic semiconducting layer in a state-of-the-art organic field effect transistor (OFET) device was evaluated and proves to be film thickness dependent. For 40 nm layer thickness it displays a saturation hole mobility (µhole ) of up to 0.01 cm(2) V(-1) s(-1) and an on/off-ratio (Ion /Ioff ) of 1.5×10(3) .

Oxidation-triggered ring-opening metathesis polymerization.

Eight new N-Hoveyda-type complexes were synthesized in yields of 67-92 % through reaction of [RuCl2 (NHC)(Ind)(py)] (NHC=1,3-bis(2,4,6-trimethylphenylimidazolin)-2-ylidene (SIMes) or 1,3-bis(2,6-diisopropylphenylimidazolin)-2-ylidene (SIPr), Ind=3-phenylindenylid-1-ene, py=pyridine) with various 1- or 1,2-substituted ferrocene compounds with vinyl and amine or imine substituents. The redox potentials of the respective complexes were determined; in all complexes an iron-centered oxidation reaction occurs at potentials close to E=+0.5 V. The crystal structures of the reduced and of the respective oxidized Hoveyda-type complexes were determined and show that the oxidation of the ferrocene unit has little effect on the ruthenium environment. Two of the eight new complexes were found to be switchable catalysts, in that the reduced form is inactive in the ring-opening metathesis polymerization of cis-cyclooctene (COE), whereas the oxidized complexes produce polyCOE. The other complexes are not switchable catalysts and are either inactive or active in both reduced and oxidized states.

N-(4-Chloro-phen-yl)-4-nitro-benzene-sulfonamide.

In the title compound, C12H9ClN2O4S, the dihedral angle between the benzene rings is 31.4 (2)°. In the crystal, N-H⋯O hydrogen bonds link the mol-ecules into C(4) chains running along the a-axis direction.

N-(2,3-Dichloro-phen-yl)-2-nitro-benzene-sulfonamide.

In the title compound, C12H8Cl2N2O4S, the N-C bond in the C-SO2-NH-C segment has gauche torsions with respect to the S=O bonds. Further, the N-H bond is syn to the ortho-nitro group in the sulfonyl benzene ring and also syn to both the ortho- and meta-Cl atoms in the aniline ring. The mol-ecule is twisted at the S-N bond with a torsion angle of 61.15 (18)°. The dihedral angle between the planes of the benzene rings is 68.00 (6)°. The amide H atom exhibits an intra-molecular bifurcated N-H⋯(O,O) hydrogen bond. In the crystal, pairs of N-H⋯O(S) hydrogen bonds link the mol-ecules into inversion dimers with R2(2)(8) motifs.

Poly[µ-aqua-µ-(N,4-di-chloro-2-methyl-benzene-sulfonamidato)-potassium].

In the title compound, [K(C7H6Cl2NO2S)(H2O)] n , the K(+) cation is hepta-coordinated by two water O atoms, a sulfonyl O atom from each of four different N,4-dichloro-2-methyl-benzene-sulfonamidate anions and a Cl atom of one of the anions. Further, K-O-K bridges form extensive polymeric chains along the b axis. In the crystal structure, the anions are linked into layers parallel to (100) by O-H⋯Cl and O-H⋯N hydrogen bonds.

Potassium N-bromo-4-chloro-2-methyl-benzene-sulfonamidate monohydrate.

In the title compound, K(+)·C7H6BrClNO2S(-)·H2O, the K(+) cation is hepta-coordinated by two water O atoms, four sulfonyl O atoms of four different N-bromo-4-chloro-2-methyl-benzene-sulfonamidate anions, and one Br atom of one of the anions. The S-N distance of 1.584 (3) Šis consistent with an S=N double bond. In the crystal, the anions are linked into layers by O-H⋯Br and O-H⋯N hydrogen bonds.

Syntheses, crystal structures and Hirshfeld surface analysis of 4-(4-nitro-phen-yl)piperazin-1-ium tri-fluoro-acetate and 4-(4-nitro-phen-yl)piperazin-1-ium tri-chloro-acetate.

The synthesis and crystal structures of the mol-ecular salts of 4-(4-nitro-phen-yl)piperazine with tri-fluoro-acetate, namely, 4-(4-nitro-phen-yl)piperazin-1-ium tri-fluoro-acetate, C10H14N3O2 +·C2F3O2 - (I), and with tri-chloro-acetate, namely, 4-(4-nitro-phen-yl)piperazin-1-ium tri-chloro-acetate, C10H14N3O2 +·C2Cl3O2 -, (II), are reported and compared. A partial positional disorder of the anions was found. In both structures, the piperazine rings adopt a chair conformation, whereas the positions of the nitro-phenyl group on the piperazine ring differ from bis-ectional in (I) to equatorial in (II). In both structures, the supra-molecular assemblies are mono-periodic on the basis of the chain-of-rings motifs supported by aromatic π-π inter-actions. Hirshfeld surface analysis was used to explore the inter-molecular close contacts in both crystals. The most dominant contacts of the Hirshfeld surface of the cation-anion pairs of the asymmetric units are O⋯H/H⋯O, and those with a contribution of halogen atoms: F⋯H/H⋯F in (I) and Cl⋯H/H⋯Cl in (II), respectively.

Syntheses and crystal structures of three salts of 1-(4-nitro-phenyl)-piperazine.

The crystal structures and Hirshfeld surface analyses of three salts of 1-(4-nitro-phenyl)-piperazine with 2-chloro-benzoic acid, 2-bromo-benzoic acid and 2-iodo-benzoic acid are reported. The chloro-benzoate salt, C10H14N3O2 +·C7H4ClO2 -, contains whole-ion-disordered cations and anions, which were modeled with two equivalent conformations with occupancies of 0.745 (10)/0.255 (10) and 0.563 (13)/0.437 (13), respectively. The bromo-benzoate and iodo-benzoate derivatives are isomorphous and crystallize as hemihydrates, viz. C10H14N3O2 +·C7H4BrO2 -·0.5H2O and C10H14N3O2 +·C7H4IO2 -·0.5H2O, respectively [the water mol-ecule is disordered over two locations with occupancies of 0.276 (3)/0.223 (3) for the iodo-benzoate derivative]. In the extended structures, all three salts feature an R 4 4(12) loop of two anions and two cations linked by N-H⋯O hydrogen bonds.

Syntheses, crystal structures and Hirshfeld surface analysis of three salts of 1-(4-nitro-phenyl)-piperazine.

The structures and Hirshfeld surface analysis of three salts of 1-(4-nitro-phenyl)-piperazine are discussed. In 4-(4-nitro-phen-yl)piperazin-1-ium salicylate (C10H14N3O2 +·C7H5O3 -), there are strong hydrogen bonds between cation and anion and the 4-nitro-phenyl substituent occupies an equatorial position in the piperazinium ring. The cation and anion are linked together by supra-molecular inter-actions [graph-set notation of hydrogen bonding (6) propagating in the a-axis direction]. Additionally, there is π-π stacking involving the salicylate anion and the piperazinium cation in adjacent asymmetric units as well as a C-H⋯π inter-action between a hydrogen atom on the piperazine ring and the phenyl ring within the salicyclate anion. In bis-[4-(4-nitro-phen-yl)piperazin-1-ium] bis-(4-fluoro-benzoate) trihydrate (2C10H14N3O2 +·2C7H4FO2 -·3H2O), there are two cations, two anions, and three water mol-ecules of solvation in the asymmetric unit, all linked by hydrogen bonds [graph-set notation of hydrogen bonding R 2 2(20) between adjacent cations and R 3 3(9) between a cation and its adjacent anion]. In the anion, the 4-nitro-phenyl ring occupies an axial substitution position in the piperazinium ring, which is relatively rare. Within the asymmetric unit, the phenyl groups in the cations show an offset π-π inter-action. Additionally, there is a C-H⋯π inter-action between a hydrogen atom on the phenyl ring within a cation and the phenyl ring within an anion. In 4-(4-nitro-phen-yl)piperazin-1-ium 3,5-di-nitro-benzoate (C10H14N3O2 +·C7H4N2O6 -), there is a strong N-H⋯O hydrogen bond linking the cation and anion and the 4-nitro-phenyl ring occupies an axial substitution position in the piperazinium ring, as seen in the previous structure. In the crystal, the cation and the anion form a complex three-dimensional hydrogen-bonded array involving R 2 2(8), R 4 4(12) and R 4 4(20) rings propogating in the a-axis direction. The nitro-phenyl group is disordered with occupancies of 0.806 (10) and 0.194 (10).

N-(4-Methyl-benzo-yl)-2-nitro-benzene-sulfonamide.

The asymmetric unit of the title compound, C(14)H(12)N(2)O(5)S, contains two independent mol-ecules. The dihedral angles between the aromatic rings are 82.03 (9) and 79.47 (8)° in the two independent mol-ecules. In the crystal, the two mol-ecules in the asymmetric unit are linked into dimers via pairs of N-H⋯O(S) hydrogen bonds to generate C(4) chains.

N-(2-Chloro-4-methyl-phen-yl)succinamic acid.

In the title compound, C(11)H(12)ClNO(3), the N-C=O fragment is twisted from the plane of the attached benzene ring by 48.39 (12)°. The carb-oxy-lic acid group is involved in O-H⋯O hydrogen bonding, which links pairs of mol-ecules into centrosymmetric dimers. N-H⋯O hydrogen bonds link these dimers, related by translation along the a axis, into ribbons.

N-(4-Methyl-2-nitro-phen-yl)succinamic acid.

In the title compound, C(11)H(12)N(2)O(5), the conformation of the N-H bond in the amide segment is syn to the ortho-nitro group in the benzene ring. The amide C=O and the carboxyl C=O of the acid segment are syn to each other and both are anti to the H atoms on the adjacent -CH(2) groups. Furthermore, the C=O and O-H bonds of the acid group are in syn positions with respect to each other. The dihedral angle between the benzene ring and the amide group is 36.1 (1)°. The amide H atom shows bifurcated intra-molecular hydrogen bonding with an O atom of the ortho-nitro group and an inter-molecular hydrogen bond with the carbonyl O atom of another mol-ecule. In the crystal, the N-H⋯O(C) hydrogen bonds generate a chain running along the [100] direction. Inversion dimers are formed via a pair of O-H⋯O(C) interactions, that form an eight-membered hydrogen-bonded ring involving the carboxyl group.

N-(3-Chloro-4-methyl-phen-yl)succinamic acid.

In the crystal structure of the title compound, C(11)H(12)ClNO(3), the asymmetric unit contains two independent mol-ecules. The N-H bond in the amide segment is anti to the meta-Cl atom in the benzene ring, in both molecules. The amide and carboxyl C=O bonds are also anti to each other and anti to the H atoms on the adjacent -CH(2) groups. Furthermore, the C=O and O-H bonds of the acid group are in syn positions with respect to each other. The dihedral angles between the benzene ring and the amide group are 40.6 (2) and 44.9 (3)° in the two independent molecules. In the crystal, mol-ecules are packed into sheets parallel to the (11-3) plane through O-H⋯O and N-H⋯O hydrogen bonds.

N-(4-Chloro-3-nitro-phen-yl)maleamic acid.

In the mol-ecule of the title compound, C(10)H(7)ClN(2)O(5), the acyclic C=C double bond is cis configured. The C=O and O-H bonds of the acid group are in a relatively rare anti position to each other, due to the donation of intramolecular hydrogen bond to the amide by the carboxyl group. The nitro group is significantly twisted [dihedral angle = 66.9 (3)°] out of the plane of the remaining atoms, which are almost coplanar (r.m.s. deviation for non-H atoms except the nitro group = 0.202 Å). In the crystal, N-H⋯O hydrogen bonds link the mol-ecules into zigzag chains running along the b axis.

N-(4-Methyl-benzo-yl)-4-nitro-benzene-sulfonamide.

In the title compound, C(14)H(12)N(2)O(5)S, the dihedral angle between the nitro-phenyl group and the -S-NH-C-O fragment is 80.74 (17)° and that between the nitro-phenyl and methyl-phenyl groups is 87.66 (14)°. The C-S-N-C torsion angle at the S-N bond is -67.0 (3)°. In the crystal, mol-ecules are linked into C(4) chains via N-H⋯O hydrogen bonds.

N-(3-Chloro-4-methyl-phen-yl)maleamic acid.

In the title compound, C(11)H(10)ClNO(3), the dihedral angle between the benzene ring and the amide group is 6.6 (10)° and an intramolecular O-H⋯O hydrogen bond occurs. In the crystal, molecules are linked by N-H⋯O hydrogen bonds, generating C(7) zigzag chains.

N-(3-Chloro-phen-yl)-4-nitro-benzene-sulfonamide.

There are two independent mol-ecules in the asymmetric unit of the title compound, C12H9ClN2O4S, in which the dihedral angles between the planes of the benzene rings are 46.90 (14) and 44.50 (14)°. In the crystal, N-H⋯O hydrogen bonds link the mol-ecules into zigzag chains parallel to the a axis.