Isolation and antimicrobial susceptibility testing of Helicobacter pylori strains from gastric biopsies from Pakistani patients.

Helicobacter pylori is the etiological agent of gastritis and peptic ulcer. This importance had proposed antibiotics as a principle treatment of gastrointestinal pathologies. The focus of this research was to investigate the occurrence of H. pylori in patients having gastritis or gastric ulcer and also draw the susceptibility profile of isolates to several antibiotics. Blood and biopsy specimen from 96 acid peptic disease patients from both sexes were collected. Each sample was used for culture, gram staining, catalase, oxidase, urease and nitrate reduction test by conventional method. Serology using anti Helicobacter pylori IgG was done. The susceptibility profile to six common antibiotics was checked by E- test method. H. pylori was obtained from 40 patients (41.67%) with greater frequency in male (25%) than females (16.67%). With regards to age, H. pylori was recovered highest from the patients between 51-55 (75.86%) years of age. Tetracycline and rifampin were the most effective antibiotics in vitro, while metronidazole was less effective. Nine (22.5%) strains displayed resistance to at least one antimicrobial drug. Whereas, resistance to amoxicillin, ciprofloxacin, clarithromycin, metronidazole and combination of antibiotics like ciprofloxacin, clarithromycin and metronidazole, and ciprofloxin and metronidazole were 11.11, 55.56, 22.22, 33.33, 11.11 and 44.44% respectively. Lower susceptibility profile of H. pylori to antibiotics is because of frequent use of antibiotics to treat other infections.

3-Methyl-1-{(E)-[1-(4-methyl-pyridin-2-yl)ethyl-idene]amino}-thio-urea: crystal structure and Hirshfeld surface analysis.

The title disubstituted thio-urea derivative, C10H14N4S, features an almost planar imine (E configuration, C3N) core flanked by thio-urea (CN2S) and methyl-pyridyl (C5N) residues (each plane has a r.m.s. deviation of the respective fitted atoms of 0.0066 Å). The dihedral angles between the core and the thio-urea and pyridyl residues are 20.25 (8) and 7.60 (9)°, respectively, indicating twists in the mol-ecule; the dihedral angle between the outer planes is 13.62 (7)°. There is an anti-disposition of the amine-N-H atoms which allows for the formation of an intra-molecular amine-N-H⋯N(imine) hydrogen bond that closes an S(5) loop. In the crystal, amine-N-H⋯N(pyrid-yl) hydrogen bonds lead to zigzag (glide symmetry) supra-molecular chains along the c-axis direction. These are connected into a supra-molecular layer propagating in the bc plane by thio-amide-N-H⋯S(thione) hydrogen bonds via eight-membered thio-amide {⋯HNCS}2 synthons.

Crystal structure of benzyl (E)-2-(3,4-di-meth-oxy-benzyl-idene)hydrazine-1-carbodi-thio-ate.

The title compound, C17H18N2O2S2, synthesized via a condensation reaction between S-benzyl di-thio-carbazate and 3,4-di-meth-oxy-benzaldehyde, crystallized with two independent mol-ecules (A and B) in the asymmetric unit. Both mol-ecules have an L-shape but differ in the orientation of the benzyl ring with respect to the 3,4-di-meth-oxy-benzyl-idine ring, this dihedral angle is 65.59 (8)° in mol-ecule A and 73.10 (8)° in mol-ecule B. In the crystal, the A and B mol-ecules are linked via pairs of N-H⋯S hydrogen bonds, forming dimers with an R 2 (2)(8) ring motif. The dimers are linked via pairs of C-H⋯O hydrogen bonds, giving inversion dimers of dimers. These units are linked by C-H⋯π inter-actions, forming ribbons propagating in the [100] direction.

Synthesis, Characterization, and Bioactivity of Schiff Bases and Their Cd(2+), Zn(2+), Cu(2+), and Ni(2+) Complexes Derived from Chloroacetophenone Isomers with S-Benzyldithiocarbazate and the X-Ray Crystal Structure of S-Benzyl- ß -N-(4-chlorophenyl)methylenedithiocarbazate.

Two bidentate Schiff base ligands having nitrogen sulphur donor sequence were derived from the condensation of S-benzyldithiocarbazate (SBDTC) with 2-chloroacetophenone and 4-chloroacetophenone to give S-benzyl- ß -N-(2-chlorophenyl)methylenedithiocarbazate (NS2) and S-benzyl- ß -N-(4-chlorophenyl)methylenedithiocarbazate (NS4) isomers. Each of the ligands was then chelated with Cd(2+), Zn(2+), Cu(2+), and Ni(2+). The compounds were characterized via IR spectroscopy and melting point while the structure of NS4 was revealed via X-ray crystallography. Finally, the compounds were screened for antimicrobial activity to investigate the effect that is brought by the introduction of the chlorine atom to the benzene ring. X-ray crystallographic analysis showed that the structure of NS4 is planar with a phenyl ring that is nearly perpendicular to the rest of the molecules. The qualitative antimicrobial assay results showed that NS4 and its complexes lacked antifungal activity while Gram-positive bacteria were generally inhibited more strongly than Gram-negative bacteria. Furthermore, NS4 metal complexes were inhibited more strongly than the ligand while the opposite was seen with NS2 ligand and its complexes due to the partial solubility in dimethyl sulfoxide (DMSO). It was concluded that generally NS2 derivatives have higher bioactivity than that of NS4 derivatives and that the Cd complexes of both ligands have pronounced activity specifically on K. rhizophila.

Bis{(Z)-[(E)-2-(pyridin-2-yl-methyl-idene)hydrazin-1-yl-idene][(pyridin-2-yl)methyl-sulfan-yl]methane-thiol-ato}nickel(II).

The title compound, [Ni(C13H11N4S2)2], was obtained by the reaction of S-2-picolyldi-thio-carbazate and pyridine-2-carbaldehyde with nickel(II) acetate. The Ni(II) atom is located on a twofold rotation axis and is bonded to four N atoms at distances of 2.037 (8) and 2.109 (9) Å, and to two S atoms at a distance of 2.406 (3) Å, leading to a distorted octa-hedral coordination. The angle between the mean planes of the coordinating moieties of the two symmetry-related tridentate ligands is 83.3 (2)°. In the crystal, complex mol-ecules are linked by weak C-H⋯S hydrogen bonds, π-π inter-actions between the pyridine rings [centroid-centroid distance = 3.775 (9) Å] and C-H⋯π inter-actions. The hydrogen-bonding inter-actions lead to the formation of layers parallel to (010); π-π inter-actions link these layers into a three-dimensional network.

Benzyl N-[(Z)-(1-methyl-2-sulfanyl-propyl-idene)amino]-carbamodithio-ate.

The title compound, C(12)H(16)N(2)S(3), was obtained by the condensation reaction of S-benzyl dithio-carbazate and 3-mercaptobutan-2-one. The phenyl ring and thiol (SH) group are approximately perpendicular [S-C-C-C and N-C-C-S torsion angles = 67.8 (3) and 116.9 (2)°, respectively] to the rest of the mol-ecule. In the crystal, mol-ecules are linked by weak S-H⋯S and N-H⋯S hydrogen bonds, π-π inter-actions between the benzene rings [centroid-centroid distance = 3.823 (2) Å] and C-H⋯π inter-actions.

A P212121 polymorph of (+)-clusianone.

The title compound, C33H42O4 [systematic name: (1S,5S,7R)-3-benzoyl-4-hy-droxy-8,8-dimethyl-1,5,7-tris-(3-methyl-but-2--enyl)bi-cyclo-[3.3.1]nona-3-ene-2,9-dione], has a central bi-cyclo-[3.3.1]nonane-2,4,9-trione surrounded by tetra-prenyl-ated and benzoyl groups. The compound was recrystallized several times in methanol using both a slow evaporation method and with a crystal-seeding technique. This subsequently produced diffraction-quality crystals which crystallize in the ortho-rhom-bic space group P212121, in contrast to a previous report of a structure determination in the Pna21 space group [McCandlish et al. (1976 ▶). Acta Cryst. B32, 1793-1801]. The title compound has a melting point of 365-366 K, and a specific rotation [α](20) value of +51.94°. A strong intra-molecular O-H⋯O hydrogen bond is noted. In the crystal, mol-ecules are assembled in the ab plane by weak C-H⋯O inter-actions.

N-(4-Chloro-benzo-yl)-N'-(3-fluoro-phen-yl)thio-urea.

In the title compound, C(14)H(10)ClFN(2)OS, the mol-ecule adopts a trans-cis geometry of the thio-urea unit. The dihedral angles between the benzene rings is 34.47 (7)°. The crystal packing features inter-molecular N-H⋯S and C-H⋯O hydrogen bonds, forming a chain along the b axis. A short C-H⋯S intramolecular contact is also observed.

Dichlorido{4-cyclo-hexyl-1-[1-(2-pyridyl-κN)ethyl-idene]thio-semicarbazidato-κN,S}phenyl-tin(IV).

The Sn(IV) atom in the title compound, [Sn(C(6)H(5))(C(14)H(19)N(4)S)Cl(2)], exists within a distorted octa-hedral geometry defined by the N,N',S-tridentate monodeprotonated Schiff base ligand, two mutually trans Cl atoms, and the ipso-C atom of the Sn-bound phenyl group; the latter is trans to the azo-N atom. The greatest distortion from the ideal geometry is found in the nominally trans angle formed by the S and pyridyl-N atoms at Sn [151.03 (4)°]. With the exception of the cyclo-hexyl group (chair form), the Schiff base ligand is almost planar (r.m.s. deviation of non-H and Sn atoms = 0.053 Å). The nearly orthogonal orientation of the Sn-bound phenyl group [N-Sn-C-C torsion angle = 70.8 (5)°] to the planar portion of the Schiff base allows for the formation of significant intra-molecular C-H⋯Cl inter-actions which preclude the Cl atoms from participating in N-H⋯Cl hydrogen bonds. Instead, C-H⋯π contacts, involving methyl-ene H and the Sn-bound phenyl group, lead to the formation of supra-molecular chains that pack in the bc plane. Connections between these layers are of the type C-H⋯Cl.