Soursop (Annona muricata L.) Fruit Peels as Source of Phenolic Constituents and Annonacin with Biological Activities

Aims: In this study, chemical constituents and biological activities of the Annona muricata L. fruit peels were evaluated using methanol extract (MEAM) and hexane (HFAM), dichloromethane (DFAM), ethyl acetate (EFAM), and butanol (BFAM) fractions. Place and Duration of Study: All the experiments were done in the Department of Pharmaceutical Sciences and Department of Biochemistry, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, 36026-900, Brazil, between January 2012 and July 2016. Methodology: Phytochemical screening (specific chemical reactions), total phenolic and flavonoid contents (Spectrophotometric methods) and chemical compounds were assessed (High performance liquid chromatography analysis). The antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), beta-carotene, and thiobarbituric acid assays. The inhibitory effect against digestive enzymes (lipase, ?-amylase and ?-glucosidase) was measured by spectrophotometric assays and and toxicity by the brine shrimp lethality bioassay. Results: Tannins, flavonoids, coumarins, terpenes and steroids, saponins, and alkaloids were detected. EFAM had the highest values of total phenolic and flavonoids, while a similar compound to annonacin was found in MEAM by HPLC. EFAM was also more active in DPPH and FRAP assays, and HFAM was effective in inhibiting the linoleic acid oxidation and the malondialdehyde. MEAM and fractions blocked lipase, ?-amylase and ?-glucosidase, while HFAM and DFAM were toxic against Artemia salina. Conclusion: The results showed that the A. muricata fruit peels have important biological effects, which can bring great benefits to human and animal health.