Laboratory of Nutritional Physiology and Feeding, Department of Animal Science, School of Animal Biosciences, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece.
Division of Pharmacognosy and Chemistry of Natural Products, Faculty of Pharmacy, University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece.
Molecules. 2021 Dec 12;26(24):7527. doi: 10.3390/molecules26247527.
Cold pressed essential oil (CPEO) of mandarin ( Blanco), a by-product of the juice-making industrial process known to contain large amounts of polymethoxyflavones, was exploited for its content in high added value natural coumarins. The study herein afforded a method referring to the evaporation of CPEO volatile fraction under mild conditions (reduced pressure and temperature below 35 °C) as azeotrope with isopropanol. This allowed the isolation of high added value coumarins from the non-volatile fragment using preparative High Performance Liquid Chromatography (HPLC). Pilot-scale application of this procedure afforded for each kg of CPEO processed the following natural bioactive coumarins in chemically pure forms: heraclenol (38-55 mg), 8-gerayloxypsoralen (35-51 mg), auraptene (22-33 mg), and bergamottin (14-19 mg). The structures of coumarins were verified by Nuclear Magnetic Resonance (NMR) spectroscopy and HPLC co-injection with authentic standards. Thus, the low market value mandarin CPEO with current value of 17 to 22 EUR/kg can be valorized through the production of four highly bioactive natural compounds worth 3479 to 5057 EUR/kg, indicating the great potentials of this methodology in the terms of the circular economy.
从鲜橙（Blanco）冷榨精油（CPEO）中提取高附加值天然香豆素，这种精油是橙汁生产过程中的副产品，已知其中含有大量的多甲氧基黄酮。本文提供了一种方法，即在温和条件下（减压和温度低于 35°C）将 CPEO 挥发性馏分与异丙醇共沸，从而可以从非挥发性馏分中分离出高附加值的香豆素。使用制备高效液相色谱（HPLC）对该方法进行了中试放大，从每公斤加工的 CPEO 中获得以下化学纯形式的天然生物活性香豆素：heraclenol（38-55mg）、8-gerayloxypsoralen（35-51mg）、auraptene（22-33mg）和bergamottin（14-19mg）。通过核磁共振（NMR）光谱和与真实标准品的 HPLC 共注射验证了香豆素的结构。因此，目前市场价值为 17 至 22 欧元/公斤的低价值 mandarin CPEO 可以通过生产四种高生物活性天然化合物来增值，这些化合物的价值为 3479 至 5057 欧元/公斤，这表明该方法在循环经济方面具有巨大的潜力。
