The novel C-5 aryl, alkenyl, and alkynyl substituted uracil derivatives of L-ascorbic acid: Synthesis, cytostatic, and antiviral activity evaluations

The novel C-5 substituted uracil derivatives Of L-ascorbic acid were synthesized by coupling of 5-iodouracil-4,5-didehydro-5,6-dideoxy-L-ascorbic acid with unsaturated stannanes under Stille reaction conditions. The new compounds were evaluated for their antitumoral and antiviral activities. Among all compounds evaluated the 5-propynyl substituted uracil derivative of L-ascorbic acid (7) exhibited the most pronounced cytostatic activities against all examined tumor cell lines (IC50: 0.2-0.78 PM). However, this compound was also cytotoxic to human normal fibroblasts WI 38. The 5-(phenylethynyl)uracil-2,3-di-O-benzylated L-ascorbic acid derivative (4) exhibited an albeit slight (IC50: 55-108 mu M), but selective inhibitory effect toward all tumor cell lines except for cervical carcinoma (HeLa), pancreatic carcinoma (MiaPaCa-2), laryngeal carcinoma (Hep-2), and colon carcinoma (SW 620), and no cytotoxicity to normal human fibroblast (WI 38). Compound 7 showed some, not highly specific, inhibitory potential against vesicular stomatitis virus, Coxsackie 134 virus, and Sindbis viruses (EC50: 1.6 mu M). (c) 2006 Elsevier Ltd. All rights reserved.