荔枝生理落果中A型原花青素提取纯化鉴定及抗氧化活性研究

谢翀; 林琳; 吴戈仪; 王凯; 胡卓炎; 赵雷

doi:10.13386/j.issn1002-0306.2021050048

荔枝生理落果中A型原花青素提取纯化鉴定及抗氧化活性研究

Extraction, Purification, Identification of A-type Procyanidine from Litchi Fruitlet and Its Antioxidant Activity

摘要

摘要: 本文以荔枝生理落果为原料，采用乙醇提取、AB-8大孔树脂纯化和Sephadex LH-20葡聚糖凝胶分离得到多酚组分，采用DPPH·、ABTS⁺·清除法及FRAP法测定各多酚组分体外抗氧化活性后，使用电喷雾液质联用四级杆飞行时间质谱（LC-ESI-Q-TOF）对多酚进行鉴定。结果表明，荔枝生理落果总酚及总原花青素含量分别为（49.96±2.66）mg GAE/g DW和（27.25±0.44）mg EPE/g DW；而体外抗氧化活性结果表明，第4个多酚组分（P4）具有较强ABTS⁺·和DPPH·清除能力，当100 μg/mL时，清除率分别为92.52%和46.98%，总抗氧化能力显著高于抗坏血酸（P<0.05）；经LC-ESI-Q-TOF分析发现，荔枝生理落果多酚纯化物含有10种A型原花青素，其中P4组分由纯A型原花青素组成，分别为原花青素A₄、原花青素A₂及A型原花青素二聚体和四聚体。从荔枝生理落果中分离纯化的A型原花青素具有优秀的抗氧化活性，可作为新的A型原花青素来源。

Abstract: In this study, polyphenol fractions were extracted from litchi fruitlet which drop naturally, then purified by AB-8 macroporous resin and separated by Sephadex LH-20. After comparing the antioxidant activities of each sample in vitro, the polyphenol components were identified by LC-ESI-Q-TOF. The results showed that the content of total phenols and total procyanidines in litchi fruitlet were (49.96±2.66) mg GAE/g DW and (27.25±0.44) mg EPE/g DW, respectively. In vitro antioxidant activity text indicated that the fourth polyphenol component (P4) had strong ABTS⁺· and DPPH· scavenging ability, and its free radical scavenging rate could reach 92.52% and 46.98% in 100 μg/mL respectively. According to LC-ESI-Q-TOF analysis, PLFE contained 10 types of A procyanidines, which were much more than B procyanidines. P4 was composed of pure A-type procyanidine, which were procyanidine A₄, procyanidine A₂, A-type procyanidine dimer and tetramer. Therefore, A-type procyanidine isolated and purified from litchi fruitlet have remarkable antioxidant activity, which can be used as an excellent source of new A-type procyanidine.