Application of flow injection—chemiluminescence to the study of radical scavenging activity in plants

✍ Scribed by Hong Yeob Choi; Eun Ja Jhun; Beong Ou Lim; Ill Min Chung; Suk Hun Kyung; Dong Ki Park

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 78 KB
• Volume: 14
• Category: Article
• ISSN: 0951-418X
• DOI: 10.1002/1099-1573(200006)14:4<250::aid-ptr587>3.0.co;2-j

✦ Synopsis

Chemiluminescence (CL) was observed during the oxidation of luminol (2 mg/L). mediated by 0.06% hydrogen peroxide (H 2 O 2 ) and cytochrome c (10 mg/L). CL intensity was decreased by the presence of radical scavengers and the reduction was linearly proportional to the concentration and ability of scavengers; butylated hydroxytoluene (BHT), caffeic acid and gallic acid. The order of effectiveness as radical scavengers was gallic acid b caffeic acid b BHT, which shows that the number of hydroxyl groups (OH) in the B-ring of flavonoids plays a key role in a good radical scavenging activity. Of eight catechins obtained from green tea extracts, (À)-catechin was the least effective and (À)-epigallocatechin gallate (EGCg) showed the strongest activity. This result indicates that the stereoscopic structure between the C-3 group and the B ring of flavonoids as well as substituents at the C-3 position make a contribution to radical scavenging activity. Of the tested Chinese herbal ingredients, five species of ingredients represented more than 90% of the radical scavenging activity.