Optimized ultrasound-assisted recovery, HPLC/LC-MS identification and biological activities of Tetrapleura tetraptera L. dry fruit polyphenols

Abstract

Little information exists in literature about the optimization of ultrasound-assisted extraction (UAE) of Tetrapleura tetraptera (TT) fruit polyphenols (TTP). The use of conventional methods and lack of literature on the application of green extraction methods limit the study scope and application of TT. This study optimized UAE to maximize total phenol content (TPC) and antioxidant activity (AA) of TTP extract. TTP extract was characterized using HPLC/LC-MS. Cellular antioxidant activity (CAA), cytotoxicity and antimicrobial activity of TTP against E. coli, Staph. aureus and B. subtilis were investigated. TPC of 7.044 mg GAE g−1 dw−1 and AA of 66.558% were observed at optimum time, frequency, power and liquid-to-solid ratio of 20 min, 20 kHz, 150 W and 26 mL g−1, respectively. Twenty-four phenolic acids and flavonoids were identified. TTP exhibited high CAA and cytotoxicity in HepG2 liver cancer cells and also showed strong bactericidal activity even at low concentrations.

Keywords

• Ultrasound assisted extraction
• Antimicrobial activity
• Tetrapleura tetraptera
• Polyphenols
• Antioxidant activity
• Green extraction