Synthesis and biological evaluation of novel angular fused Pyrrolocoumarins

Abstract

Angular pyrrolocoumarins were synthesized from the reaction of 4-hydroxyindole or 5-hydroxyindole with DMAD and PPh 3 and were tested for anti-inflammatory and antioxidant activity. These compounds significantly inhibited the carrageenininduced paw edema (60.5% -73.4%) and have important scavenging activity. Although their interaction with the free stable radical DPPH is not high, compound 9 is the most potent (73.4%) in the in vivo experiment. Compound 7 seems to be a potent LOX inhibitor. An attempt was made to correlate the biological results with their structural characteristics and physicochemical parameters.

Convenient synthesis of fused pyrano[3,2-h]- and furo[3,2-h]benzo[f]coumarins from naphthalene-2,3-diol

“…24 As we can see in the above procedures, BF 3 $Et 2 O is not yet in use in the Claisen rearrangement of the propargyloxycoumarins. In the course of our interest on the synthesis 3,14,30-34 of fused coumarin derivatives and the study of their biological activity 3,14,33,34 we wish to report here the application of BF 3 $Et 2 O on the synthesis of title compounds from 8-propargyloxy-benzo[f]coumarins. The reactions studied and the products received are depicted in Schemes 1 and 2.…”

Synthesis of 3-iodopyrrolocoumarins via iodine-induced 5-endo-dig electrophilic cyclization

“…In particular, pyrrolocoumarin derivatives exhibit photobiological activity [8], photophysical properties [9], and antiproliferative [10], anti-inflammatory, and antioxidant activities [11]. Pyrrolocoumarins can act as monofunctional DNAphotobinding agents [12].…”

“…Several methods [11,20,21] including our methodologies [22][23][24][25] have been employed for their synthesis, but most of them require harsh conditions, expensive catalytic systems, complicated work-up and purification procedures, etc. Moreover, functionalization at the 3-position of the pyrrole unit may be useful for some target syntheses [21].…”

Synthesis of purine homo-N-nucleosides modified with coumarins as free radicals scavengers*

“…Interaction-reducing activity with DPPH (RA%); competition with DMSO for hydroxyl radical (HO˙ %); inhibition of lipid peroxidation (AAPH%); in vitro inhibition of soybean lipoxygenase (LOX); in vitro inhibition of thrombin (% Thr). Competition of the tested compounds with DMSO for hydroxyl radicals 28 The hydroxyl radicals generated by the Fe 3+ /ascorbic acid system, were detected according to Nash, by the determination of formaldehyde produced from the oxidation of DMSO. The reaction mixture contained EDTA (0.1 mM), Fe 3+ (167 μM), DMSO (33 mM) in phosphate buffer (50 mM, pH 7.4), the tested compounds at 0.1 mM and ascorbic acid (10 mM).…”