Abstract
6-[(8Z)-8-pentadecenyl] salicylic acid [1] was isolated from the shell oil of Indonesian cashew nuts and used to synthesize two derivatives via epoxidation and hydrolysis of the C15 side chain. The antimicrobial activity of the derivatives toward Bacillus subtilis (Bs), Brevibacterium ammonigenes (Ba), Bacillus thuringienis israelenis (Bt), Propionibacterium acnes (Pac), Staphylococcus aurenus (Sa) and Streptococcus mutans (Sm) was examined. The two derivatives, 6-[8, 9-epoxy pentadecanyl] salicylic acid [2] and 6-[8, 9-dihydroxy pentadecanyl] salicylic acid [3] (at 0.39-3.13 μg/mL) derived from compound [1], were found to inhibit completely the growth of Pac and Sm. These derivatives were tested for their ability to inhibit the enzyme tyrosinase. Compound [3] was found to inhibit tyrosinase (using tyrosine as a substrate) activity by 77.9%. The inhibitory rates exceeded that of Arbutin, a compound used in commercial cosmetics. We also examined their toxicity and whitening effect through the inhibition of melangenesis in B-16 melanoma cells, and confirmed their safety for use in cosmetics.
