Pierre Demerseman

Synthesis and some CNS activities of new benzofuranylacryloylpiperazines

Summary A series of novel benzofuranylacryloylpiperazines, which are structurally related to both cinnamamide derivatives and befuraline, have been prepared as their hydrochlorides. Their anticonvulsant and antidepressant activities against seizures induced by electroshock and against tetrabenazine-induced palpebral ptosis have been evaluated in mice. Some of them revealed interesting potencies since, although they are less active than the reference drugs, they exhibited a higher protective index.

(2-chloro-2-nitroethenyl)benzenes as synthons: a general method for the preparation of 2,3-dihydro- 2-nitro-3-phenyl-4H-furo [3,2-c] [1]benzopyran-4-ones and 3-phenyl-4H-furo[3,2-c][1]benzopyran-4-ones

Abstract we describe a convenient and general method for the preparation of 2,3-dihydro-2-nitro-3-phenyl-4 H -furo[3,2-c] [1]benzopyran-4-ones from 4-hydroxy-coumarin and (2-chloro-2-nitroethenyl)benzenes in the presence of potassium fluoride. Using the same starting materials and by replacing potassium fluoride with triethylamine the hitherto unknown 3-phenyl-4 H -furo[3,2-c] [1]benzopyran-4-ones are obtained in a one-pot procedure.

Sur la transformation du β-nitrostyrène sous l'action du chlorure d'acétyle en présence d'un chlorure métallique

Abstract While β-nitrostyrene yields only hydroxymic or hydroxamic acid derivatives by treatment with acetyl chloride in the presence of zinc, tin, titanium or aluminium chloride, it also gives 3-chloro 2-indolinone and a 5-acetyl derivative of the latter, when the reaction is carried out with ferric chloride. The procedures of this reaction are examined, and a mechanism is suggested.

Photobiological activities of 1,6-dioxapyrene in pro- and eukaryotic cells

The photobiological effect of a new pyrene derivative, 1,6-dioxapyrene (1,6-DP), was studied in Salmonella typhimurium (strain TA100) and in the diploid strain D7 of the yeast Saccharomyces cerevisiae. In Salmonella, 1,6-DP shows little mutagenicity in the dark in comparison to benzo[a]pyrene (B[a]P). This mutagenic activity decreases in the presence of liver S9 homogenates from Aroclor induced XVIInc/Z mice. However, in combination with 365 nm (UVA) radiation and in the absence of S9 mix, 1,6-DP behaves as an effective photodynamic compound inducing lethal and mutagenic effects in both organisms. In yeast, its activity, like that of B[a]P, is highly dependent on the presence of oxygen. For the same incident dose of UVA, 1,6-DP is, however, at least 6 times more effective than B[a]P in inducing cytotoxic and mutagenic effects. At equitoxic doses, 1,6-DP is as photomutagenic as B[a]P, suggesting that in both cases mutagenicity is due to similar mechanisms. Spectrophotometric measurements indicate physical interaction of 1,6-DP with DNA in the dark. Laser flash photolysis experiments show that 1,6-DP generates singlet oxygen with a quantum yield of 0.17. In vitro 1,6-DP produces oxidative damage to guanine bases specific for singlet oxygen mediated reactions. Alkaline step elution analysis of 1,6-DP plus UVA treated yeast cells indicates a decrease in average molecular weights in DNA and an induction of single strand breaks (ssb) originating from alkali labile sites. This effect is enhanced by D2O and is thus likely to be due to the production of singlet oxygen. The strand breaks appear to differ from those induced by gamma-rays because little, if any, repair of these ssb occurs during 30 min of post-treatment incubation in complete growth medium. These results suggest that the photobiological effects of 1,6-DP are due to oxidative damage in DNA mostly induced by singlet oxygen.

Polymethylenedioxy bis(2-hydroxyiminomethylpyridinium) as in vitro reactivators of organophosphorous inhibited eeL acetylcholinesterase

The synthesis and in vitro AChE reactivating potency of 5 new bridged pyridinium-2 carbaldoximes are described. Tested as reactivators and protectors in vitro against 5 organophosphorous inhibitors, they show a particularly interesting activity against paraoxon and tabun. These oximes themselves are reversible AChE inhibitors.

Sur une transformation inhabituelle de nitro-2 benzofurannes dans les conditions de la reaction de friedel et crafts

Abstract On treatment with acetyl chloride or acetic anhydride in presence of aluminium chloride in methylene chloride. 2-nitro and 5-chloro 2-nitro benzofurans yield 2,3-dichloro benzofurans, 3-chloro 2-coumaranones and 2-acetoximino 3-chloro coumarans. By the action of acetyl chloride, in presence of titanium (IV) chloride in methylene chloride, on 2-nitro benzofuran, 2,3-dichloro benzofuran can be obtained with a fairly good yield beside a relatively restricted quantity of 3-chloro 2-coumaranone. In the same conditions, 5-chloro-2-nitro benzofuran yields not only 2,3,5-trichloro benzofuran but also 2,2,3,3,5-pentachloro coumaran and, occasionally. 3,5-dichloro 2-coumaranone.

Mutagenic activity of dichloroethylamino derivatives of nitronaphthofuran and some nitrobenzofurans in the Salmonella/microsome assay

The mutagenic activity of five dichloroethylamino 2-nitrobenzofuran derivatives and one dichloroethylamino 2-nitronaphthofuran derivative was analysed in the Salmonella/microsome assay. We investigated the influence of the position of the dichloroethylamino and/or the methoxy groups on the mutagenic activity of these nitro arenofurans in S. typhimurium strain TA100 and its variant TA100NR, deficient in nitroreductase. Without metabolic activation 7-[bis(2-chloroethyl)amino]-2-nitronaphtho[2,1-b]furan (1), 4-[bis(2-chloroethyl)amino]-7-methoxy-2-nitrobenzofuran (2), 7-[bis(2-chloroethyl)amino]-4-methoxy-2-nitrobenzofuran (5) and 6-[bis(2-chloroethyl)amino]-2-nitrobenzofuran (6) are mutagenic in TA100, while 4-[bis(2-chloroethyl)amino]-5-methoxy-2-nitrobenzofuran (4) is weakly mutagenic and 5-[bis(2-chloroethyl)-amino]-2-nitrobenzofuran (3) toxic. In the NR deficient strain compounds 1, 3 and 6 are strong mutagens and 4 is weakly positive. The two isomers 2 and 5 are negative in that strain. The naphthofuran derivative 1 is highly mutagenic in the absence of S9 mix in both strains considered, but less than R7000 (7). A decrease in the electronic polarity of compound 1 versus compound 7 according to the hypothesis developed by Royer et al. is a possible explanation. After exogenous metabolic activation by S9 mix all the compounds tested are highly mutagenic in both Salmonella strains. The position of the dichloroethylamino group and/or the presence of a methoxyl on the alpha-nitroarenofuran derivatives seem to modify the activity of bacterial as well as exogenous nitroreductases or other activating enzymes.

Spectroscopic Properties of Polycyclic Aromatic Compounds. Part III: Fluorescence Emission and Quenching Behavior of Periodic Table Group 16 Hetero-Atom Derivatives

Fluorescence emission spectra are reported for benzo[b]naphtho[2,3d]furan, dinaphtho[l,2b:l′,2′d]furan, dinaphtho[2,lb:l′,2′d]furan, dibenzo[2,3:10,11]perylo[l,12bcd]furan, dibenzo[2,3:10,ll]perylo-(l,12bcd]thiophene, naphtho[l,8bc:5,4b′c′]dipyran (also called 1,6-dioxapyrene), and naphtha[l,8bc:4,5b′c′]dipyran (also called 1,8-dioxapyrene) in organic nonelectrolyte solvents of varying polarity. Results of these measurements indicate that dinaphtho[l,2b:l′,2′d]furan exhibits slight signs of probe character as evidenced by changing emission intensity ratios; however, the dynamic range was much too small to classify this molecule as a polycyclic aromatic compound probe. The effect of nitromethane and 1,2,4-trimethoxybenzene as selective quenching agents was also examined. Nitromethane was found to quench fluorescence emission of all the aforementioned compounds except benzo[b]naphtho[2,3d]furan.

Molecular and electronic structures of some mutagenic nitronaphthofurans: structure—activity relationships

The study of the relationships between the mutagenic activities and the molecular and electronic structures of a series of 2-nitronaphthofurans by X-ray crystallography and theoretical calculation reveals: 1) the tendency of these molecules to superpose with important π orbitals overlapping; the formation of CH …O intermolecular bonds; 2) the high sensitivity of the electron distribution, and of the resulting molecular electrostatic potential (MEP), to the presence of substituents, particularly those β-positioned on the furan ring; 3) the existence of a good correlation between MEP and mutagenic activity, as demonstrated by statistical analysis of experimental and theoretical data.

Comparison of the carcinogenic effects of two 2-nitro-naphthofurans injected sub-cutaneously in rats.

7-Methoxy-2-nitro-naphtho[2,1-b]furan (R 7000) and its methylated homolog in position 1 (R 7372) are among the most mutagenic agents presently known, as shown by the results obtained both in the Ames test and in the SOS Chromotest. Their carcinogenic effects were tested in rats. We were able to confirm the carcinogenic effects of these nitro-naphthofurans, the presence of a methyl group--while increasing the mutagenic effect of R 7000 10 times--induces a significant decrease of the carcinogenic effects in R 7372. The discrepancy between the mutagenic effects in bacterial assays and the carcinogenic effects of these two 2-nitro-naphthofurans remains to be explained.