Content and Antioxidant Activity of Active Components in Different Parts of Gardenia jasminoides Ellis

To compare the active compounds in different parts of Gardenia jasminoides Ellis and evaluate their in vitro antioxidant activities, this study used the ultrasound-assisted method to extract the active compounds in different parts of Gardenia jasminoides Ellis and measured the yield. Their total iridoids, total crocins, total flavonoids and total polyphenols were measured by UV-visible spectrophotometer method. Their active compound monomers were measured by HPLC method. DPPH and ABTS⁺ radical scavenging methods were used to valuate their in vitro antioxidative activities then the correlation analysis was founded between the contents of active compounds and IC₅₀ of DPPH and ABTS⁺ radical. Gardenia jasminoides Ellis leaf had the highest total iridoids contents and total polyphenols contents, which were 244.87±5.89 mg·g⁻¹ and 16.71±0.55 mg·g⁻¹ respectively. Results showed that, theGardenia jasminoides Ellis fruit had the significantly highest total crocins contents (P<0.05), which was 16.18±1.40 mg·g⁻¹, Crocin-I was the main form of crocin, which occupied about 60% of the total crocin contents. Gardenia jasminoides Ellis flower had the highest total flavonoids contents and, which was 43.61±1.01 mg·g⁻¹. According to DPPH and ABTS⁺ radical scavenging experiments, the Gardenia jasminoides Ellis leaf had the best antioxidative activities, which IC₅₀ of DPPH and ABTS⁺ were 36.00±2.70 and 31.96±3.87 μg·mL⁻¹. The correlation analysis showed that iridoids compounds and polyphenols compounds had strong correlation with antioxidative activities. Among the different parts of Gardenia jasminoides Ellis extracted by ultrasound-assisted method, it was found that different parts had certain antioxidant capacity. Gardenia jasminoides Ellis leaf had antioxidative activities beyond the fruit, which provided theoretical sources for development of natural antioxidants.