Synthesis and D₂-like binding affinity of new derivatives of N3-[(1- ethyltetrahydro-1H-2-pyrrolyl)methyl]-4,5-dihydrobenzo[g]indole-3- carboxamide and related compounds

In previous papers 4a,b we have reported the syntheses and structure-activity relationships of a series of 5-phenyl-3-pyrrole carboxamide and related 4,5-dihydrobenzo[g]indole-3-carboxamide analogues whose most representative terms were 1a and 2a respectively. Encouraged by these results we carried out several modifications of 2a

Synthesis and cytotoxicity evaluation of thiophene analogues of 1-methyl-2,3-bis(hydroxymethyl)benzo[<i>g</i>]indole bis[<i>N</i>-(2-propyl)carbamate]

The cytotoxicity of the bis[N-(2-propyl)carbamates] 2 and 3 which are linked to thieno[i,j-g]indole scaffolds through methylene bridges were studied as thiophene analogues of prototype 1. Compounds 2 and 3 were evaluated in vitro against 60 human–tumor cell lines derived from nine cancer-cell types and demonstrated, for compound 3 not only strong growth-inhibitory activities against leukemia cancer cells, but also fairly good activities against the growth of certain renal and ovarian cancer cell lines. Compound 2, the thieno[2,3-g]indole bis-carbamate, possessed only significant (MG-MID log10 GI50=−4.89) and selective cytoxicity against NCI–HOP92 (non-small cell lung), MALME 3M (melanoma) and IGROV 1 (ovarian) cancer cell with log10 GI50 values of −5.66, −5.48 and −5.47, respectively

N-3(9)-arylpropenyl-N-9(3)-propionyl-3,9-diazabicyclo[3.3.1]nonanes as µ-opioid receptor agonists. Effects on µ-affinity of arylalkenyl chain modifications

Two series of N-3-arylpropenyl-N-9-propionyl-3,9-diazabicyclo[3.3.1]nonanes (1b-j) and of the reverted N-3-propionyl-N-9-arylpropenyl isomers (2b-j) as analogues of the previously reported analgesic N-3(9)-cinnamyl-N-9(3)-propionyl-3,9-diazabicyclo[3.3.1]nonanes (DBN) (1a, 2a) were synthesised and their affinity and selectivity towards opioid µ-, δ- and k-receptors were evaluated. Several compounds (1e,i,j-2d,e,f,g,j) exhibited a µ-affinity in the low nanomolar range with moderate or negligible affinity towards δ- and k-receptors. The representative term N-9-(3,3-diphenylprop-2-enyl)-N-3-propionyl-DBN (2d) displayed in vivo (mouse) a potent analgesic effect (ED50 3.88 mg/kg ip) which favourably compared with that of morphine (ED50 5 mg/kg ip). In addition, 2d produced in mice tolerance after a period twice as long with morphine

Chromophore-modified bis-benzo[<i>g</i>]indole carboxamides: synthesis and antiproliferative activity of bis-benzo[<i>g</i>]indazole-3-carboxamides and related dimers

Tricyclic pyrazole dimers that comprise two kinds of CONH---(CH2)n---N(CH3)---(CH2)n---NHCO bridges to which are linked potential DNA-intercalating groups such as 1H-benzo[g]indazole, 2H-benzo[g]indazole and 1,4-dihydroindeno[1,2-c]pyrazole were designed, synthesized and some of them evaluated in vitro by NCI (Bethesda, USA) against nine types of cancer cells. Compounds 2a, 2f&#x2013;i and 2o&#x2013;r demonstrated significant antiproliferative activity, all with GI50 values in the low micromolar range. Preliminary analysis of the structure&#x2013;activity relationship for dimers 2 indicated that: (i) in the ground terms (2a and 2k) antitumor activities were strongly related to the type of chromophore, (ii) in contrast, either 1H-benzo[g]indazole- or 1,4-dihydroindeno[1,2-c]pyrazole-dimers when bore a N1-aryl group (2g, 2h, 2i, 2o, 2p, 2q and 2r) generally showed a good level of antitumor potency and (iii) for the most representative compounds (pairs of compounds: 2g,2h; 2o,2p and 2q,2r) the length of the bridges did not significantly contribute to the variations in cytotoxicity. Two members of this series, 2f and 2q, were selected and tested in the hollow fiber cell assay to evaluate in a preliminary fashion their in vivo antitumor activity. Finally, viscosity measurement of 2f with poly(dA-dT)2, confirmed that these promising compounds behaved as typical DNA-intercalating agents

Tricyclic pyrazoles. Part 1: synthesis and biological evaluation of novel 1,4-dihydroindeno[1,2-<i>c</i>]pyrazol-based ligands for CB₁ and CB₂ cannabinoid receptors

Cannabinoids receptors, cellular elements of the endocannabinoid system, have been the focus of extensive studies because of their potential functional role in several important physiological and pathological processes. To further evaluate the properties of CB receptors, especially CB1 and CB2 subtypes, we have designed, using SR141716A as a benchmark, a new series of rigid 1-aryl-1,4-dihydroindeno[1,2-c]pyrazole-3-carboxamides. Compounds 1 were synthesized from substituted 1-aryl-1,4-dihydroindeno[1,2-c]pyrazole-3-carboxylic acids and requisite amines. The various analogues were assayed for binding both to the brain and peripheral cannabinoid receptors (CB1 and CB2). Seven of the new compounds displayed very high in vitro CB2 binding affinities, especially 1a, 1b, 1c, 1e, 1g, 1h and 1j which showed Ki values of 0.34, 0.225, 0.27, 0.23, 0.385, 0.037 and 0.9 nM, respectively. Compounds 1a, 1b, 1c and 1h showed the highest selectivity for CB2 receptor with Ki(CB1) to Ki(CB2) ratios of 6029, 5635, 5814 and 9810, respectively. Noticeably, 1h exhibited the highest affinity and selectivity for CB2 receptors

Synthesis and characterization of NESS 0327: a novel putative antagonist of the CB₁ cannabinoid receptor

The compound N-piperidinyl-[8-chloro-1-(2,4-dichlorophenyl)- 1,4,5,6-tetrahydrobenzo [6,7]cyclohepta[1,2-c]pyrazole-3-carboxamide] (NESS 0327) was synthesized and evaluated for binding affinity toward cannabinoid CB1 and CB2 receptor. NESS 0327 exhibited a stronger selectivity for CB1 receptor compared with N-piperidinyl-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl- 1H-pyrazole-3-carboxamide (SR 141716A), showing a much higher affinity for CB1 receptor (Ki = 350 ± 5 fM and 1.8 ± 0.075 nM, respectively) and a higher affinity for the CB2 receptor (Ki = 21 ± 0.5 nM and 514 ± 30 nM, respectively). Affinity ratios demonstrated that NESS 0327 was more than 60,000-fold selective for the CB1 receptor, whereas SR 141716A only 285-fold. NESS 0327 alone did not produce concentration-dependent stimulation of guanosine 5'-O-(3-[35S]thio)-triphosphate ([35S]GTPγS) binding in rat cerebella membranes. Conversely, NESS 0327 antagonized [R(+)-[2,3-dihydro-5-methyl-3-[(morpholinyl)methyl]pyrolol [1,2,3-de]-1,4-benzoxazin-yl]-(1-naphthalenyl)methanone mesylate] (WIN 55,212-2)-stimulated [35S]GTPγS binding. In functional assay, NESS 0327 antagonized the inhibitory effects of WIN 55,212-2 on electrically evoked contractions in mouse isolated vas deferens preparations with pA2 value of 12.46 ± 0.23. In vivo studies indicated that NESS 0327 antagonized the antinociceptive effect produced by WIN 55,212-2 (2 mg/kg s.c.) in both tail-flick (ID50 = 0.0420 ± 01 mg/kg i.p.) and hot-plate test (ID50 = 0.018 ± 0.006 mg/kg i.p.). These results indicated that NESS 0327 is a novel cannabinoid antagonist with high selectivity for the cannabinoid CB1 receptor

Tricyclic pyrazoles: Part 2: Synthesis and biological evaluation of novel 4,5-dihydro-1<i>H</i>-benzo[<i>g</i>]indazole-based ligands for cannabinoid receptors

A series of 4,5-dihydro-1H-benzo[g]indazole-3-carboxamides (2a–k) as analogues of the previously reported CB2 ligands 6-chloro- and 6-methyl-1-(2′,4′-dichlorophenyl)-N-piperidin-1-yl-1,4-dihydroindeno[1,2-c]pyrazole-3-carboxamides (1a,b) was synthesized and their affinity and selectivity towards CB1 and CB2 receptors were evaluated. Several of the new compounds (2a,b,c,d and i) exhibited CB1 affinity in the nanomolar range with moderate or negligible affinity towards CB2 receptors. Compounds 2a and c increased intestinal propulsion in mouse. Their pro-kinetic effects were reversed by the reference CB agonist CP-55,940. Consequently, in vivo CB1 antagonistic activity was highlighted for these compounds