Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, Hainan Normal University, Haikou, Hainan 571158, People's Republic of China.
State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China.
J Agric Food Chem. 2020 Nov 4;68(44):12326-12335. doi: 10.1021/acs.jafc.0c06352. Epub 2020 Oct 27.
, popularly known as Chinese toon or Chinese mahogany, is a perennial deciduous arbor belonging to the genus in the Meliaceae family, which is widely distributed and cultivated in eastern and southeastern Asia. Its fresh young leaves and buds have been consumed as a very popular nutritious vegetable in China and confirmed to display a wide variety of biological activities. To investigate the chemical constituents and their potential health benefits from the fresh young leaves and buds of , a phytochemical study on its fresh young leaves and buds was therefore undertaken. In our current investigation, 16 limonoids (-), including four new limonoids, toonasinenoids A-D (-), and a new naturally occurring limonoid, toonasinenoid E (), were isolated and characterized from the fresh young leaves and buds of . The chemical structures and absolute configurations of limonoids - were elucidated by comprehensive spectroscopic data analyses. All known limonoids (-) were identified via comparing their experimental spectral data containing mass spectrometry data, H and C nuclear magnetic resonance data, and optical rotation values to the data reported in the literature. All known limonoids (-) were isolated from for the first time. Furthermore, the neuroprotective effects of all isolated limonoids - against 6-hydroxydopamine-induced cell death in human neuroblastoma SH-SY5Y cells were assessed . Limonoids - exhibited notable neuroprotective activities, with EC values in the range from 0.27 ± 0.03 to 17.28 ± 0.16 μM. These results suggest that regular consumption of the fresh young leaves and buds of might prevent the occurrence and development of Parkinson's disease (PD). Moreover, the isolation and characterization of these limonoids that exhibit notable neuroprotective activities from the fresh young leaves and buds of could be very significant for researching and developing new neuroprotective drugs used for the prevention and treatment of PD.
香椿，俗称中国香椿或中国桃花心木，是一种属于楝科香椿属的多年生落叶乔木，广泛分布和栽培于东亚和东南亚。其新鲜的嫩叶和芽已被中国作为一种非常受欢迎的营养蔬菜食用，并被证实具有广泛的生物活性。为了研究香椿新鲜嫩叶和芽的化学成分及其潜在的健康益处，我们对其新鲜嫩叶和芽进行了植物化学研究。在我们目前的研究中，从香椿的新鲜嫩叶和芽中分离并鉴定了 16 种柠檬苦素（-），包括 4 种新的柠檬苦素，香椿宁 A-D（-），和一种新的天然存在的柠檬苦素，香椿宁 E（）。柠檬苦素 - 的化学结构和绝对构型通过综合光谱数据分析得到阐明。通过比较包含质谱数据、氢核磁共振数据和旋光值的实验光谱数据与文献中报道的数据，鉴定了所有已知的柠檬苦素（-）。所有已知的柠檬苦素（-）均首次从香椿中分离得到。此外，还评估了所有分离得到的柠檬苦素 - 对人神经母细胞瘤 SH-SY5Y 细胞中 6-羟多巴胺诱导的细胞死亡的神经保护作用。柠檬苦素 - 表现出显著的神经保护活性，EC 值范围为 0.27 ± 0.03 至 17.28 ± 0.16 μM。这些结果表明，经常食用香椿的新鲜嫩叶和芽可能有助于预防和发展帕金森病（PD）。此外，从香椿新鲜嫩叶和芽中分离并鉴定出具有显著神经保护活性的这些柠檬苦素，对于研究和开发用于预防和治疗 PD 的新型神经保护药物具有重要意义。
