A Study on the Antioxidant and Active Compounds of Gardenia jasminoides Ellis (GJE) Leaves Extract

Purpose: The aim of this study was to isolate and identify the active compound antioxidant fractions from Gardenia jasminoides Ellis leaves.

Research Method: The antioxidant activity was determined using DPPH 0.1 mM (1:1), and was analyzed spectrophotometrically. In addition, separation was performed using column chromatography. The most active isolate was identified by UV-Vis, FT-IR, and LC-MS/MS. The quantitative analysis was done in three replicated.

Findings: It was discovered that the antioxidant activity in the semi-polar fraction (IC₅₀ = 62,50 ppm) was higher than both the polar and non-polar fractions. Combining 295 isolates via column chromatography, 11 combined isolates were obtained (fA-fK). The fK isolate had the highest antioxidant activity of 90.38% and IC₅₀ 15.74 ppm. It also obtained 2 maximum wavelengths (336 and 275 nm) and could be categorised as flavonoid (flavonol with 3-OH substituted). The FTIR analysis also showed that the fK isolate had functional groups found in flavonoid. Finally, the identification of the fK isolate by LC-MS/MS showed that the compound at retention times of 5,91 and 5,06 minutes were kaempferol 3-O-rutinoside and rutin, respectively.

Originality/ Value: Based on the obtained results, it was concluded that GJE leaves have the potential to be developed as a new and inexpensive source of flavonoids.