Solar Synthesis of Acyl hydroquinones and their Bioactivity.

Abstract

Without the Sun, we would not enjoy the benefits of life here on the Earth. This energy is essential and crucial for sustaining life: playing important roles in circadian rhythms and photosynthesis in plants. In our research, this endlessly renewable clean energy source is utilized for photo-Friedel-Crafts acylation of 1,4 - benzoquinones and 1,4 - naphthoquinones. Photo-Friedel-Crafts acylation was first discovered in 1891 and although there have been reported examples of acylated products, the substrates are still limited. In this project a variety of aldehydes having different substituents are examined, and bioassays were performed. While conventional methods for photochemistry use artificial UV light, replacement with solar radiation would yield no energy expense. Exposing a reaction mixture of 1,4-benzo or naphtho quinone with an aldehyde to direct sunlight gave acylated hydroquinones, compounds which serve as important intermediates for pharmaceuticals. Two products were evaluated for their anticancer activities against MCF-7 and MDA-MB-231 human breast cancer cells by MTS assay. CC50 values indicate that one of these compounds displays strong inhibitory activities against both tumor cell lines. These two compounds were also examined in a Luciferase assay using a parasitic protozoan, Giardia lamblia, the results demonstrated that one of them possesses anti-giardial activity. This is interesting because the difference between the two compounds is with/without one oxygen atom. These results encouraged us to elaborate the structure–activity relationship and find drug–receptor interactions. We will also synthesize more compounds with different substituents to study biological activity