AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The synthesis and crystal structures of bis(S-methylisothiouronium) (MSTUH)(+), N,N'-bis((3- guanidinopropyl)piperazinium (PipeC3GuaH4)(4+) and hexamidinium (HexaH2)(2+) tetrachloro platinate(ll) salts ( called hereafter PtMSTU, PtPipeC3Gua and PtHexa respectively ) were investigated. These compounds contain the "amidine" function ( - C(=NH)NH(2) ) in which the H atoms supplied by the acid have become attached to the imino group of each terminal amidino function. Moreover, in PtPipeC3Gua, the nitrogen atoms of the chair-piperazine moiety are also protonated. The influence of tetrachloroplatinate(ll) counteranion ( versus sulfate, nitrate and diisethionate ) in the in vivo nitrite inhibition by the (MSTUH)(+), (PipeC3GuaH4)(4+) and (HexaH2)(2+) cations was investigated. The three tetrachloroplatinate(ll) salts, unexpectedly, do not inhibit significantly the in vivo nitrite production in comparison with the other salts (sulfate, nitrate and diisethionate and their corresponding previous countercations) which exhibit NO synthase inhibition, especially bis(S-methylisothiouronium) sulfate, a selective and potent inducible NO synthase (iNOS) inhibitor commonly used as standard.

2-thiaisatoic anhydride 1 and 3-thiaisatoic anhydride 2 were synthesized in large scale under microwave heating conditions with 85% and 67% yields respectively. The reactivity of these two compounds was studied towards various nucleophiles and appeared to be generally different from that of isatoic anhydride: many new thiophene-2 and 3-carboxylic acids were isolated with good yields as potential new pharmacological scaffolds.

The design, synthesis, crystal structure and interaction with DNA of the N,N'-(butane-1,4-diyl)bis(guanidinium) tetrachloroplatinate(ll) are described. Crystal data: a = 8.152(1), b = 8.889(4), c = 10.700(3) A , alpha = 81.59(3), beta = 87.99(5), gamma = 78.48(6) degrees , V = 752(1) A(3), Z = 2 , space group P-1. The structure was refined to R = 0.039 and Rw = 0.046 from 1853 reflections (I > 3sigma(I)). This compound, named PtC(4)Gua, does not exhibit a center of symmetry and the center linker chain C(2) - C(3) - C(4) - C(5) is in gauche conformation. The cation is bisprotonated with the H(+) attached to the imine group of each terminal guanidinium function. The presence of the platinum moiety reinforces the binding of the butane(bis)guanidinium structure with double stranded DNA as judged from thermal denaturation studies and DNA unwinding experiments.

The DNA sequences targeted by a complete homologous series of aromatic diamidines have been determined at single-nucleotide resolution via protection from cutting by the endonucleases DNase I, DNase II and micrococcal nuclease. Propamidine, pentamidine and to a lesser extent hexamidine bind selectively to nucleotide sequences composed of at least four consecutive A-T base pairs. In contrast, the binding to DNA of butamidine, heptamidine, octamidine and nonamidine is poorly sequence-selective. Sequences composed of only three consecutive A-T base pairs do not afford a potential binding site for propamidine or the longer homologues, and none of the drugs tolerate the presence of a G-C base pair within the binding site. Experiments with DNA molecules containing inosine in place of guanosine and 2,6-diaminopurine in place of adenine reveal that the lack of binding of propamidine to GC-containing sites is attributable to an obstructive effect of the exocyclic 2-amino group of guanosine. The present data support the view that the local conformation of the double helix (in particular the width of the minor groove) plays a dominant role in the binding reaction and that the capacity of diamidines to recognize AT-rich sequences selectively varies considerably depending on the length of the alkyl chain. The evidence indicates that binding to AT-tracts in DNA must play a role in the biological activity of these diamidines, but there is no simple correlation between binding and pharmacological efficacy.

Thirty-seven new 5,11-dimethyl-6H-pyrido[3,2-b]carbazole derivatives have been synthesized. These compounds are structurally related to the 5,11-dimethyl-6H-pyrido[4,3-b]carbazole antitumor drug ellipticine. They bear either a fluorine, a bromine or a chlorine atom on position 9, and are variously substituted on the pyridine ring. Twenty-nine of these compounds (78%) were found active when tested in vitro for their cytotoxic activity in a clonogenic assay using murine leukemia L1210 cell line. Structure-activity relationships are described in detail.

A molecular modelling study was carried out in order to compare the structural and electronic properties of the pyridinone L-696,229 and the HEPT derivative EBPU. This comparison led to a hybrid structure, 3-(benzyloxymethyl)-5-ethyl-6-methylpyridin-2-one [18a], which revealed a good structural correlation with the models. A series of 2-[(arylmethyl)oxymethyl]pyridin-2-ones related to [18a] was synthesized and tested for antiviral activity against human immunodeficiency virus type 1 (HIV-1). Compound [18a] and four other derivatives showed anti-HIV-1 activity.

Several ethyl 3-[(3-aryl-4-methyl)-2(1H)-pyrrolyl]-4-methyl-1H-pyrrole-2-carboxylates have been synthesized using two successive ethyl isocyanide addition-cyclizations to the appropriate nitropropene derivatives.

The anticonvulsant activity of a second series of pyrrolidin-2-ones (1-2a, 1-4b, 1-9c) was tested on pentylenetetrazole (PTZ) treated mice. The compounds were obtained by acylation of N-(3'-aminopropyl)-2-pyrrolidinone with the suitable acid chloride.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

In search of new biological active agents in the series of [1,5]benzothiazepines, some 2,3,4,5-tetrahydro-N-(5-morpholinopentanoyl)-[1,5]benzo[f] thiazepines were synthesized and examined in vitro for their calcium antagonist activity compared to the Diltiazem one.

The synthesis and crystal structures of the N,N′-(octane-1,8-diyl)bis(guanidinium)tetrachloroplatinate (II) or palladate (II) [C10H26N6]2+ [MCl4]2− with M = Pd(II) or Pt(II) were investigated. They are isostructural and crystallize in the monoclinic system, space group P21/c with Z = 2. For the platinum (II) compound, the cell dimensions are a = 7.599(2), b = 9.513(2), c = 14.200(4) Å and β = 98.57(2)°. The structure was refined to R = 0.025 and wR = 0.030. It consists of square-planar [PtCl4]2− anions and [OBG]2+ cations where [OBG]2+ is the bis-protonated form of the organic ligand ((octane-1,8-diyl)bis(guanidine)). The cation exhibits a center of symmetry and packs in an extended “all-trans” configuration. The Pt(II) and Pd(II) salts were screened for their antiamebic activity against an inoculum of 103 trophozoites of an Acanthameba strain implicated in an acanthamebic keratitis case. While the trophozoite inoculum was rapidly destroyed by the organic ligand, its Pt(II) salt was found exhibiting cytostatic effects. On the contrary, no effect was recorded for the Pd(II) salt.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Percoll-purified mature rat Leydig cells have been used to evaluate the testicular toxicity of two highly potent intercalating agents (Celiptium and MR 14505). Testosterone secretion in the absence and in the presence of human chorionic gonadotropin (hCG) was measured to assess Leydig cell function. Celiptium and MR 14504 induce time- and dose-related inhibitory effects on the production of testosterone by Leydig cells, both in the presence and in the absence of hCG, whatever the concentration of hCG used. We have observed that MR 14504 is about 5 times more potent as an inhibitor of rat Leydig cell steroidogenesis than Celiptium without inducing any cell toxicity. The present study indicates that the Leydig cell is an additional potential site for the primary toxic effects of these drugs in the adult rat testis.

A series of piperazinopyrrolo[1,2-a]thieno[3,2-e]- and -[2,3-e]pyrazine derivatives were prepared and evaluated in order to determine the necessary requirements for high affinity on the 5-HT3 receptors and high selectivity versus other 5-HT receptor subtypes. Various substitutions on the piperazine and the thiophene ring of the pyrrolothienopyrazine moieties were systematically explored as well as replacement of the piperazine by other cyclic amines. The best compounds are in the nanomolar range of affinity of 5-HT3 receptors with high to very high selectivity (up to 10,000 for 14b). These high-affinity compounds have in common a benzyl- or allylpiperazine substituent with no substitutions on the thiophene ring. Five of these compounds (1a, 4b, 13a,b, and 14b) have been evaluated on the Von Bezold-Jarisch reflex and were characterized as partial agonists. One of them, 13a, has shown in vivo at very low dose a potent anxiolytic-like activity in the light/dark test.

We report the practical synthesis of the first fused[a]triazolo, tetrazolo and oxadiazolothiazolo[4,3-c][1,4]benzodiazepine-5,11-diones via hydrazidines and oximes.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Reactivity of 1,2,3,10,11,11a-hexahydro-5H-thiazolo[4,3-c][1,4]benzodiazepin-5-one-11-thione, and 1,2,3,10,11,11a-hexahydro-5H-thiazolo[4,3-c][1,4]benzodiazepine-5,11-dithione was evaluated against various amines. The synthetic pathways involved in these reactions which led to new thiazolo[4,3-c][1,4]benzodiazepine amidines are described.

A series of methyl or ethyl 3-(N-arylpyrrol-3-yl)-1H-pyrrole-2-carboxylates and 2,4-dicarboxylates have been synthesized using an alkyl isocyanides addition-cyclization with N-arylpyrrole derivatives such as the carboxaldehydes and nitropropenes.

Propose. The interest of the present study was to test the activity against Microsporum canis of fifteen produces from the chemistry family of 6-amino-5,6-dihydro-4H-cyclopenta (C) thiophen-4-ones. Results. Only two produces present an interest. The minimal inhibitory concentrations (MIC) are evaluate fur each produce. The MLC of product MR 16844 is of 0.061 mu g.ml(-1) in liquid media and of 9.76 mu g.ml(-1) in solid media; whereas MIC's salt MR 19220 is identic in both media, 19.53 mu g.ml(-1). The results evaluated antifungal activity are compared with griseofulvin as reference molecule.