The crystals of a mannose-specific jacalin-related lectin from Morus nigra are merohedrally twinned.

MornigaM, a lectin from Morus nigra, belongs to the mannose-binding subgroup of the family of jacalin-related plant lectins. It was crystallized in the P6(5) space group, with unit-cell parameters a = b = 110.74, c = 159.28 A. The partially merohedrally twinned crystals could be detwinned and a subsequent molecular-replacement solution could be found using the coordinates of jacalin. Preliminary analysis clearly shows the tetrameric assembly of this protein. Furthermore, data from MornigaM crystals soaked in a mannose solution were collected.

Ethyl methyl 1,4-dihydro-4-(3-nitrophenyl)-2, 6-bis(1-piperidylmethyl)pyridine-3,5-dicarboxylate.

In the title compound, C(28)H(38)N(4)O(6), the 4-aryl substituent occupies a pseudo-axial position approximately orthogonal to the plane of the dihydropyridine ring [88.1 (3) degrees ]. The dihydropyridine ring adopts a flattened boat conformation. The H atom on the pyridine N atom is involved in a bifurcated intramolecular hydrogen bond, the acceptors being the N atoms of the two piperidylmethyl groups [N.N 2.629 (4) and 2.695 (4) A].

O-Isopropyl N-(2-furoyl)thiocarbamate

The title compound, C(9)H(11)NO(3)S, has crystallographic mirror symmetry, occurs in the thiocarbamate form and is stabilized in an s-cisoid,s-transoid conformation with respect to the C-N-C group. There are two intramolecular hydrogen bonds, one between the H atom of the N-H group and the O atom of the furan ring, and the other between the H atom of the secondary carbon of the isopropyl group and the S atom. The packing of the molecules is assumed to be dictated by van der Waals interactions.

Physico-chemical and solid-state characterization of secnidazole.

Secnidazole (hydroxy-2-propyl)-l-methyl-2-nitro-5-imidazole) is an antimicrobic agent. This drug has pharmacological activity against intestinal and hepatic amebiasis, giardiasis and vaginal trichomoniasis. This paper shows the physicochemical parameters of secnidazole determined during a preformulation study. The determination of the apparent partition coefficient and the profile of solubility in dependence of pH demonstrate the basic characteristic of the drug. The dissolution assay was performed to evaluate its behavior in water. For this purpose, a new spectrophotometric method, which was linear from 5 to 15 microg/ml, sensitive, precise, accurate and selective, was validated to assay the bulk drug. The evaluation of higroscopicity revealed that the drug is unstable above 54% of relative humidity. Rheological properties, such as porosity, tapped and bulk densities and percentage of compressibility were calculated. Results show a bad rheological characteristic for this drug. DSC curves do not show any physical interaction between the drug and the excipients in the compatibility studies.

Tribenzylphosphine oxide.

The title compound, (C(6)H(5)CH(2))(3)PO, is an organic tertiary phosphine oxide. The molecule has threefold symmetry, with the P-O bond along the threefold axis. Main dimensions include P-O 1.488 (4), P-C 1.823 (3) A and O-P-C 114.7 (1) degrees. The crystals were accidentally obtained when preparing complexes of nickel(II) with dibenzylphosphine.

Synthesis, structural studies and pharmacological activity of novel bicyclic compounds derived from 3,4-dihydropyridones: 4-aryl-7,7-dimethyl-2,5-dioxo-1,2,3,4,5,6,7,8-octahydroquinolines.

The purpose of this research is to characterize the possible vascular selectivity of a series of novel bicyclic compounds derived from 3,4-dihydropyridones. We describe the synthesis, structural study by X-ray analysis and quantum chemical calculations at semiempirical (AMI) and ab initio (HF/321G) levels and pharmacological activity of these 4-aryl-7,7-dimethyl-2,5-dioxo-1,2,3,4,5,6,7,8-octahydroquinolines. In addition, the more favoured conformation for compounds 4a-c in solution was determined from the calculated and experimental proton coupling constants. We report the first computational study on the structure of octahydroquinolines. The results of ab initio (HF/3-21G) and semiempirical molecular orbital calculations (AMI) are compared with the data obtained by X-ray crystallographic study for 4a.