National Engineering Research Center of Navel Orange, Gannan Normal University, Ganzhou, 341000, China.
Chem Biodivers. 2021 Dec;18(12):e2100679. doi: 10.1002/cbdv.202100679. Epub 2021 Oct 27.
Pomelo seeds (PS) are important by-product of pomelo fruits (Citrus grandis Osbeck). The value-added utilization of PS remains highly challenged. This study aimed to investigate the utilization potential of PS as natural antioxidant, antibacterial, herbicidal agents, and their functional components. The ethanolic extract (EE) of PS and its four fractions as PEE (petroleum ether extract), AcOEtE (ethyl acetate extract), BTE (butanol extract), and WE (water extract), were prepared and biologically evaluated. BTE exhibited the best antioxidant activity among all these extracts, in both ABTS (2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) and FRAP (ferric reducing antioxidant power) assays. AcOEtE was superior to other extracts in herbicidal assay against both Festuca elata Keng (IC of 0.48 mg mL ) and Amaranthus retroflexus L. (IC of 0.94 mg mL ). Meanwhile, both AcOEtE and BTE demonstrated inhibitory effects against Bacillus subtilis, Escherichia coli, and Xanthomonas citri subsp. citri, with MIC ranging 2.5-5.0 mg mL . Furthermore, the primary chemical components involving naringin, deacetylnomilin, limonin, nomilin, and obacunone, were quantified in all these extracts. PCA (principal component analysis) suggested that naringin might highly contribute to the antioxidant activity of PS, and the herbicidal activity should be ascribed to limonoids. This study successfully identified AcOEtE and BTE as naturally occurring antioxidant, antibacterial, and herbicidal agents, showing application potential in food and cosmetics industries, and organic farming agriculture.
柚籽（PS）是柚子（Citrus grandis Osbeck）的重要副产品。PS 的增值利用仍然极具挑战性。本研究旨在探讨 PS 作为天然抗氧化剂、抗菌剂和除草剂的利用潜力及其功能成分。柚籽的乙醇提取物（EE）及其四个馏分（PEE、AcOEtE、BTE 和 WE）被制备并进行了生物学评价。BTE 在 ABTS（2,2-偶氮-双（3-乙基苯并噻唑啉-6-磺酸）二铵盐）和 FRAP（铁还原抗氧化能力）测定中均表现出比所有其他提取物更好的抗氧化活性。AcOEtE 在除草测定中对高羊茅（IC 为 0.48mg/mL）和反枝苋（IC 为 0.94mg/mL）均优于其他提取物。同时，AcOEtE 和 BTE 对枯草芽孢杆菌、大肠杆菌和柑橘溃疡病菌均表现出抑制作用，MIC 范围为 2.5-5.0mg/mL。此外，所有提取物中的主要化学成分为柚皮苷、去乙酰诺米林、柠檬苦素、诺米林和obacunone。PCA（主成分分析）表明，柚皮苷可能对 PS 的抗氧化活性有很大贡献，而除草活性应归因于柠檬苦素。本研究成功鉴定出 AcOEtE 和 BTE 为天然抗氧化剂、抗菌剂和除草剂，在食品和化妆品行业以及有机农业中具有应用潜力。
