CONICET | Buscador de Institutos y Recursos Humanos

Santi M D, Peralta M A, Ovejero M, Mendoza C, Cabrera J L and Ortega M G Journal of Pharmaceutical Care & Health Systems, Vol 4, Issue 2 (2015).ISSN 2376-0419.Tyrosinase enzyme (Tyr) participates in the biosynthesis of melanin, responsible for the color formation in the skin of mammals,catalyzing two reactions: L-Tyrosine?s hydroxylation (monophenolase activity) and L-Dopa´s oxidation (diphenolase activity).Tyr inhibitory compounds are important in the treatment with abnormal pigmentation diseases and as whitening agents in cosmetics,but they showed toxicity, so research for new inhibitors of Tyr becomes primary. Chemical and pharmacological studies of argentinianspecies from the Dalea genus have been performed by our group informing new flavonoids with important activity as Tyr inhibitors.The promising results motivate us to study other species in the genus. Previously, we inform that different extracts of pazensis,Bolivian specie, showed significant inhibition of monophenolase activity. In the present study, the inhibitory activity of diphenolaseby its extracts is presented. Also, the isolation, identification and diphenolase inhibitory activity of 5,7,2 ?, 4?-tretrahydroxy-5?-(1???,1?? ?-dimethylallyl)-8-prenylflavanone (8PP), isolated from the benzene extract and informed in other species of the genus, arereported. The results show a benzene extract as the most active (82.6 ± 1.0) % at 1μg/mL. 8PP showed an IC50 (80.7 ± 0.4) mM,compared with reference inhibitor Kojic Acid (IC50 =129.6 ± 0.3) mM, showing two times more active than this. Previously, 8PP hadshown a significant inhibition on monophenolase activity. Thus, 8PP could be a new candidate with potential applications in thepharmaceutical and cosmetic industries, motivating us to search other components that could contribute to the significant activityobserved for the benzene extract as Tyr inhibitors.