5,12-Dimethyl-3,10-diphenyl-1,3,4,8,10,11-hexaazatetracyclo[6.6.1.0(2,6).0(9,13)]pentadeca-2(6),4,9,(13),11-tetraene,a new Tröger's base analogue.

The synthesis of the title Tröger's base analogue, C(23)H(22)N(6), was undertaken in order to study the influence of a methyl substituent on the structure. Minor differences were found in the bond lengths of the title structure in comparison with the values for free pyrazole and for the first pyrazolic Tröger's base reported in the literature. There are two molecules of opposite chirality in the asymmetric unit and the packing in the lattice is characterized by a non-crystallographic n-glide plane relating these molecules.

Two natural products from the algae Laurencia scoparia.

The structures and absolute stereochemistries of two chamigrene-type metabolites (spiro[5.5]undecane derivatives) isolated from the red algae Laurencia scoparia are described. One, a non-sesquiterpene named mailione (8-bromo-9-hydroxy-7,7-dimethyl-11-methylenespiro[5.5]undec-1-en-3-one), C(14)H(19)BrO(2), was detected previously in Laurencia cartilaginea, while the other, the sesquiterpene isorigidol (8-bromo-3,7,7-trimethyl-11-methylenespiro[5.5]-undec-1-ene-3,9-diol), C(15)H(23)BrO(2), is a new isomer of rigidol, first isolated from Laurencia rigida. The A rings of these spirocyclic compounds show the same carbon skeleton. However, the relative stereochemistry of the 8-Br and 9-OH substituents is different. While mailione displays the usual syn (or cis) relative stereochemistry of the bromohydroxy vicinal group, isorigidol shows an anti (or trans) arrangement. The 8-Br and 9-OH groups are both in equatorial positions in isorigidol, while the 9-OH group is axial in mailione, as in most chamigrenes. The absolute configurations of the chiral centers were determined as 6S, 8S and 9R in mailione, and 3R, 6S, 8S and 9S in isorigidol.

Marchantin M trimethyl ether.

The title macrocycle, C(31)H(30)O(5), is comprised of two bibenzyl ether moieties linked cyclically by spacers which each consist of two-carbon alkyl chains. The observed conformation of the macrocycle may be partly stabilized by intramolecular C-H.O close contacts. The packing appears to be directed by van der Waals forces. This work explains the occurrence of a signal found in the (1)H NMR spectra of both marchantinquinone and marchantin M trimethyl ether at delta = 5. 49 and 5.56 p.p.m., respectively. The shift in the position of the expected peak can be explained by the proximity of an H atom belonging to one of the aromatic rings to another ring in the same molecule.

Bis(1,10-phenanthroline-N,N')(thiosulfato-O, S)nickel(II)-water-methanol (1/0.92/1.4) and bis(2,2'-bipyridyl-N, N')(thiosulfato-O,S)nickel(II)-water-methanol (1/2/0.55)

The title compounds, [Ni(S(2)O(3))(C(12)H(8)N(2))(2)].0.92H(2)O.1. 4CH(4)O and [Ni(S(2)O(3))(C(10)H(8)N(2))(2)].2H(2)O.0.55CH(4)O, are monomeric, containing nickel(II) in a distorted octahedral coordination environment provided by the four N atoms of two bidentate bipy or phen groups and one S and one O atom from a chelating thiosulfate anion. The crystals are highly unstable outside their mother liquors and are stabilized in solution by a not fully determined number of water and methanol solvate molecules. The phenanthroline structure includes two independent moieties related by a non-crystallographic inversion center. The thiosulfate anions display the usual S-O lengthening found when the anion acts in a bidentate mode.

[1,3-Bis(diphenylphosphino)propane]trichlorooxorhenium(V).

Trichlorooxo[1,3-propanediylbis(diphenylphosphine)-P,P ']rhenium(V), [ReCl(3)O(C(27)H(26)P(2))], crystallizes with four formula units per unit cell. The crystal structure consists of neutral complexes of [ReOCl(3)(dppp)] [dppp is 1,3-bis(diphenylphosphino)propane] packed by H.pi-ring interactions. The Re atom is octahedrally coordinated to the oxo anion, three Cl atoms and two P atoms from the dppp ligand. The six-membered ring formed by the bidentate dppp ligand and the rhenium metal centre is in a chair conformation. The title compound is an intermediate in the synthesis of bis(dppp) complexes of rhenium.

Two absorption furosemide prodrugs.

The structures of two absorption furosemide prodrugs, hexanoyloxymethyl 4-chloro-N-furfuryl-5-sulfamoyl-anthranilate (C19H23CIN2O7S), (I), and benzoyloxymethyl 4-chloro-N-furfuryl-5-sulfamoylanthranilate (C20H17CIN2O7S), (II), are described in this paper and compared with furosemide and four other prodrugs. The molecular conformations of both compounds are similar to those of the other prodrugs; the packing and the crystal system are the primary differences. Compound (I) crystallizes in the trigonal space group R3 and compound (II) in the monoclinic space group P2(1)/n. The packing of both structures is stabilized by a three-dimensional hydrogen-bond network.

Synthesis and biological evaluation of 1,2,5-oxadiazole N-oxide derivatives as hypoxia-selective cytotoxins.

Synthesis and biological evaluation of new 1,2,5-oxadiazole N-oxide derivatives with potential cytotoxic effects are described. From the series of compounds tested, compounds 2 and 6 proved to be very active, although non-selective.

A new indole derivative from the red alga Chondria atropurpurea. Isolation, structure determination, and anthelmintic activity.

Chondriamide C (3), a new bis(indole) amide, was isolated from the red alga Chondria atropurpurea, and its structure was established from spectroscopic data and chemical transformations. A new natural product, 3-indoleacrylamide (4), and the previously described chondriamides A and B (1, 2) and 3-indoleacrylic acid (5) were also isolated. The anthelmintic activities of compounds 1, 3, 4, and 6 (the O,N1,N1'-trimethyl derivative of compound 2) against Nippostrongylus brasiliensis in vitro were evaluated.

Synthesis and in vitro anthelmintic activity against Nippostrongylus brasiliensis of new 2-amino-4-hydroxy-delta-valerolactam derivatives.

The synthesis of a series of 2-amino-4-hydroxy-delta-valerolactam derivatives is described (compounds 4 to 10). These compounds showed a high anthelmintic in vitro activity against the Nippostrongylus brasiliensis model.