黑荆树皮原花色素的精制、降解及清除DPPH自由基活性的研究

Purification,Degradation and Scavenging Activities on DPPH Free Radical of Proanthocyanidins from Black Wattle Bark

以黑荆树皮为原料,经过超声波提取,AB-8大孔吸附树脂精制,并用乙酸乙酯萃取出低聚物,再将水层高聚物以亚硫酸为降解剂进行降解,最终测定各组分清除二苯代苦酰肼自由基(DPPH·)能力。结果表明:用AB-8大孔吸附树脂精制后,粗提物原花色素质量分数由36.2%上升至50.4%,回收率为90.3%。亚硫酸降解原花色素高聚物效果明显,降解前平均聚合度为8.11,降解后平均聚合度为6.25,清除DPPH·能力明显提高,EC50值由2.25%降为1.88%。

Proanthocyanidins were extracted from black wattle bark by the ultrasonic technology and purified on AB-8 resin. The oligomers were extracted with ethyl acetate and polymers in water were degraded by H2 SO3. Finally, the scavenging activities on 2,2-diphenyl-l-picrylhydrazyl free radical （DPPH.） of each fraction were determined. The results showed that the mass fraction of proanthocyanidins in crude extraction increased from 36.2 % to 50.4 % by purification on AB-8 resin. The recovery was 90. 3 %. The proanthocyanidins were degraded by H2 SO3 significantly and the average degree of polymerization drop to 6.25 from 8.11 after degradation. It was found that the proanthocyanidins after degradation had higher DPPH scavenging activity and ECs0 reduced from 2.25 % to 1.88 %.