Antioxidant Activity of Three Constituents Identified in Feces from Zophobas atratus (Order: Tenebrionidae)

Abstract

Reactive oxygen species (ROS) are generated as by-products of cellular metabolism. An imbalance between ROS such as singlet oxygen, superoxide radical, hydrogen peroxide, and hydroxyl radical, causes oxidative stress leading to cellular and DNA damage as well as oxidation of low-density lipoproteins. Oxidative stress disorders caused by the actions of ROS are associated with many acute and chronic diseases such as inflammation and neurodegenerative conditions including Alzheimers disease (AD). Antioxidants stabilize or deactivate free radicals, often before they attack targets in biological cells. Thus, taking dietary antioxidants will also reduce the risks of numerous diseases. In this study, an assessment was made of the antioxidant activity of constituents isolated from super mealworm feces using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The antioxidant activities of these materials were compared with those of ascorbic acid, broad-spectrum antioxidant agent. The biologically active constituents were determined to be the simple 3-ethyl-5-methoxyanaphthalen-1(2H)-one, Methyl (9Z,12E)-15-methoxypentadeca-9,12-dienoate and Isopropyl(Z)-3-Anilino-3-phenyl-2-propenoate by spectroscopic analysis, including EI-MS and NMR. 3-ethyl-5-methoxyanaphthalen-1(2H)-one, methyl (9Z,12E)-15-methoxypentadeca-9,12-dienoate and isopropyl(Z)-3-anilino-3-phenyl-2-propenoate were isolated from the super mealworm feces as a new antioxidant activity principle. Based on fifty percent inhibition concentration (IC50), isopropyl(Z)-3-anilino-3-phenyl-2-propenoate (96.21 µM) was the most antioxidant constituent. The IC50 of 3-ethyl-5-methoxyanaphthalen-1(2H)-one, methyl (9Z,12E)-15-methoxypentadeca-9,12-dienoate were 191.29 µM and 146.12 µM, respectively. In conclusion, global efforts to reduce the level of antioxidant agents justify further studies on the feces of Super mealworm derived materials containing 3-ethyl-5-methoxyanaphthalen-1(2H)-one, methyl (9Z,12E)-15-methoxypentadeca-9,12-dienoate and isopropyl(Z)-3-anilino-3-phenyl-2-propenoate as potential antioxidant products of lead molecule for the eradication from oxidative stress.