Synthesis and antiproliferative activity of some novel triazole derivatives from dehydroabietic acid.

Dehydroabietic acid (DHA) is a naturally occurring diterpene with different and relevant biological activities. Previous studies have shown that some DHA derivatives display antiproliferative activity. However, the reported compounds did not include triazole derivatives. Starting from DHA (8,11,13-abietatrien-18-oic acid), and its alcohol dehydroabietinol (8,11,13-abietatrien-18-ol), four alkyl esters were prepared. The alkyl terpenes were treated with different aromatic azides to synthesize hybrid compounds using click chemistry. Some 16 new DHA hybrids were thus synthesized and their structures were confirmed by spectroscopic and spectrometric means. The antiproliferative activity of the new compounds was assessed towards human cell lines, namely normal lung fibroblasts (MRC-5), gastric epithelial adenocarcinoma (AGS), lung cancer (SK-MES-1) and bladder carcinoma (J82) cells. Better antiproliferative effect was found for compound 5, with an IC50 of 6.1 μM and selectivity on SK-MES-1 cells. Under the same experimental conditions, the IC50 of etoposide, was 1.83 µM.