Abstract

Introduction: Oxidative stress is a major contributing factor to the onset and progression of chronic illnesses, including cancer, cardiovascular disease, and neurodegenerative disorders, as a result from an imbalance between reactive oxygen species and antioxidants in the body. In response, there is growing interest in natural antioxidants from fruits and plants as safer, health-supportive alternatives to synthetic compounds. Actinidia chinensis (commonly known as Chinese gooseberry or kiwi fruit) is widely valued for its high vitamin C content and nutritional value. However, there remains a lack of detailed research into specific phytochemicals responsible for their antioxidant activity, particularly compounds such as quercetin and catechin. This research focuses on analyzing the phytochemical composition and antioxidant potential of A. chinensis, with a particular focus on detecting and understanding key flavonoids like quercetin and catechin. Objectives: The primary objective of this study was to determine the phytochemical constituents, evaluate the antioxidant potential, and characterize the presence of quercetin and catechin in Actinidia chinensis using Fourier Transform Infrared (FTIR) spectroscopy. Method: Fresh A. chinensis was subjected to maceration extraction using 95% ethanol. The resulting extract was evaluated using three primary approaches, which includes phytochemical screening to detect the presence of bioactive classes of compounds, antioxidant activity evaluation using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay, and Fourier Transform Infrared (FTIR) spectroscopy for chemical characterization of quercetin and catechin. Result: The phytochemical screening revealed the presence of flavonoids, phenolics, tannins, saponins, terpenoids, alkaloids, and carbohydrates. In the DPPH assay, the extract showed a strong dose-dependent increase in radical scavenging activity, ranging from 28.67% at 50μg/mL to 90.93% at 1000μg/mL. The ethanolic extract had an IC₅₀ value of 178.33 μg/mL, while the reference standard BHT showed a lower IC₅₀ of 133.08μg/mL. This demonstrated that A. chinensis extract is less potent than the standard antioxidant under the same conditions. Furthermore, key absorption peaks observed in FTIR analysis correspond to functional groups found in the known FTIR spectra of quercetin and catechin, strongly suggesting the presence of these flavonoids in the extract. These results indicate that A. chinensis possesses a diverse phytochemical profile, predominantly rich in antioxidant-related compounds. Conclusion: To conclude, this study successfully demonstrated that Actinidia chinensis is a promising natural source of antioxidant rich phytochemicals and possesses strong antioxidant properties. The findings from phytochemical screening, DPPH antioxidant testing, and FTIR spectral evidence collectively indicate that compounds such as quercetin and catechin are likely present in the extract. These findings fulfill the research objectives that not only support future research in investigating traditional health benefits associated with A. chinensis but also act as a cornerstone for further exploration into its therapeutic potential.

Keywords

Actinidia chinensis, phytochemicals, flavonoids, antioxidant activity, FTIR spectroscopy