Synthesis and biological evaluation of α-methylidene-δ-lactones with 3,4-dihydrocoumarin skeleton.

Jakub Modranka, Anna Albrecht, Rafał Jakubowski, Henryk Krawczyk, Marek Różalski, Urszula Krajewska, Anna Janecka, Anna Wyrębska, Barbara Różalska, Tomasz Janecki

Index: Bioorg. Med. Chem. 20(16) , 5017-26, (2012)

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Abstract

A series of new 3-methylidenechroman-2-ones bearing various aromatic moieties and various substituents at position 4 were synthesized in a three step reaction sequence. Friedel-Crafts alkylation of phenols or naphthols using ethyl 3-methoxy-2-diethoxyphosphorylacrylate in the presence of trifluoromethanesulphonic acid gave 3-diethoxyphosphorylchromen-2-ones. These compounds were employed as Michael acceptors in the reaction with Grignard reagents to give adducts which were finally used as Horner-Wadsworth-Emmons reagents for the olefination of formaldehyde. All obtained 3-methylidenechroman-2-ones were tested against two human leukemia cell lines NALM-6 and HL-60 as well as MCF-7 breast cancer and HT-29 colon cancer adenocarcinomas. Several obtained methylidenechromanones displayed high cytotoxic activity with IC(50) values below 1 μM, mainly against leukemia and MCF-7 cell lines. Investigation of structure-activity relationships revealed that the presence of additional, ortho-fused benzene ring and n-butyl or i-propyl group in position 4 enhances the activity. Selected methylidenechromanones were also tested on normal human umbilical vein endothelial cells (HUVEC) and chromanone 14o was found to be eightfold more toxic against MCF-7 than normal cells. Furthermore, antimicrobial assays revealed that chromanone 14n is highly active and bactericidal at concentration equal to MIC or 2MIC against nosocomial and community-associated staphylococci (MRSA) which are resistant to most or all available therapeutic classes of antimicrobial drugs.Copyright © 2012 Elsevier Ltd. All rights reserved.