Muhammad Akmal Khan

Phenyl N-phenyl­carbamate

In the title compound, C13H11NO2, the aromatic rings are oriented at a dihedral angle of 42.52 (12)°. The crystal structure is stabilized by intermolecular N—H⋯O hydrogen bonds, which form infinite one-dimensional polymeric chains extending along the a axis. C—H⋯π interactions between the aromatic rings are also present.

Bioactive constituents from Croton sparsiflorus Morong.

Whole plant extracts of Croton sparsiflorus in methanol have shown significant enzyme inhibition and antioxidant activities. Bioassay-guided isolation of chloroform fraction at pH 3 resulted in the identification of crotsparinine (1) and crotsparine (2), while sparsiflorine (3) was purified from the chloroform fraction at pH 9. The structures of the compounds were confirmed through spectral analyses (EI-MS, 1H and 13C NMR). The isolated compounds 1–3 exhibited remarkable enzyme inhibition activity with IC50 values 27.01 ± 1.1, 22.26 ± 1.0 and 18.02 ± 1.3 μM in xanthine oxidase and 48.42 ± 1.5, 48.05 ± 1.4 and 7.42 ± 1.0 μM in acetylcholine esterase assays, respectively. These compounds also showed potent radical scavenging and reducing properties in DPPH and FRAP assays, respectively. The present results suggest the validity of the traditional uses of C. sparsiflorus in rheumatism and gout. Furthermore, the isolated noraporphine alkaloids can be useful in the treatment of neurodegenerative diseases.

1,3-Bis(3-methyl-phen-yl)thio-urea: triclinic polymorph.

The title compound, C15H16N2S, crystallizes with two molecules in the asymmetric unit. The crystallographic behaviour of the two isomers is different. The molecules are dimerized, forming an R 2 2(8) ring motif due to intermolecular N—H⋯S hydrogen bonds. C—H⋯S hydrogen bonds form R 2 2(12) ring motifs. In one molecule, the dihedral angle between the benzene rings is 62.54 (6)°, whereas in the other it is 79.54 (6)°. The H atoms of one of the methyl groups in each molecule are disordered over two sites, with occupancy ratios of 0.52 (3):0.48 (3) and 0.60 (3):0.40 (3).

Phenyl piperidine-1-carboxyl-ate.

In the title compound, C12H15NO2, the dihedral angle between the benzene ring and the basal plane of the piperidine ring (which is in a chair conformation) is 49.55 (8)°. In the crystal, molecules are linked by C—H⋯O hydrogen bonds and very weak C–H⋯π interactions.

Phenyl-methanaminium chloro-acetate.

In the title compound, C7H10N+·C2H2ClO2 −, the planar chloracetate ion [with a maximum deviation of 0.025 (3) Å] is oriented at a dihedral angle of 31.07 (4)° with respect to the planar [maximum deviation of 0.022 (3) Å] phenylmethanaminium cation. In the crystal structure, intermolecular N—H⋯O hydrogen bonds link the molecules into a network. A weak C—H⋯π interaction is also present.

Cyclo­hexa­naminium trichloro­acetate

In the crystal of the title compound, C6H14N+·C2Cl3O2 −, centrosymmetric assemblies of two cyclohexanaminium cations and two trichloroacetate ions are linked by N—H⋯O hydrogen bonds, thereby forming R 4 4(12) ring motifs. Further N—H⋯O interactions link the tetramers into chains propagating along the a axis.

2-Benzoyl-2H-1,4-benzothia-zin-3(4H)-one.

In the title compound, C15H11NO2S, the dihedral angle between the aromatic rings is 80.35 (7)°. The heterocyclic six-membered ring is not planar: the puckering parameters of this ring are Q = 0.5308 (15) Å, θ = 63.11 (18) and ϕ = 23.5 (2)°. The molecules are linked into inversion dimers with R 2 2(8) ring motifs by pairs of N—H⋯O hydrogen bonds. The dimers are interlinked into polymeric sheets extending parallel to the bc plane by C—H⋯O hydrogen bonds, generating R 2 1(7) ring motifs. π–π interactions occur between the benzoyl phenyl rings with centroid–centroid separations of 3.9187 (15) Å.

3-Ammonio-4-hydroxy­benzoate monohydrate

The title compound, C7H7NO3·H2O, which crystallized as a hydrate, was obtained from an extraction of the plant species Saussurea atkinsonii of the asteraceae family collected from the hilly area (Ayubia) of Pakistan during the flowering season. The dihedral angle between the benzene ring and the carboxylate group is 25.64 (5)°. In the crystal, the packing is consolidated by N—H⋯O and O—H⋯O hydrogen bonds, as well as weak aromatic π–π stacking [centroid–centroid separation = 3.9365 (9) Å] and C=O⋯π interactions.

3-Cyclo-hexyl-2-thioxo-1,3-thia-zolidin-4-one.

In the title compound, C9H13NOS2, the complete molecule is generated by crystallographic mirror symmetry, with all the non-H atoms of the rhodanine (2-thioxo-1,3-thiazolidin-4-one) system and two C atoms of the cyclohexyl ring lying on the reflecting plane. The conformation is stabilized by intramolecular C—H⋯O and C—H⋯S interactions. In the crystal, weak π–π interactions at a distance of 3.8140 (5) Å between the centroids of the heterocyclic rings occur.

Methyl 2-(N-methoxy-carbonyl-meth-yl-N-methylsulfamo-yl)benzoate.

In the title compound, C12H15NO6S, the aromatic ring is oriented at dihedral angles of 64.76 (11) and 56.42 (13)° with respect to the planar methyl ester unit and the SO2 group, respectively. The dihedral angle between the SO2 group and the planar methoxycarbonylmethyl group is 50.42 (14)°. Intramolecular C—H⋯O hydrogen bonding results in the formation of an eight-membered ring. In the crystal structure, intermolecular C—H⋯O hydrogen bonds link the molecules.