Corybungines A−K: Isoquinoline alkaloids from Corydalis bungeana with dopamine D2 receptor activity

• Published in: Phytochemistry (Oxford) 2022-07, Vol.199, p.113209-113209, Article 113209
• Main Authors: Han, Yang, Hou, Tao, Zhang, Zi-Hui, Zhu, Yun-Hui, Cheng, Jun-Xiang, Zhou, Han, Wang, Ji-Xia, Feng, Jia-Tao, Liu, Yan-Fang, Guo, Zhi-Mou, Liang, Xin-Miao
• Format: Article
• Language: English
• Subjects: Corybungines A−K; Corydalis bungeana Turcz; D2 antagonistic activity; Isoquinoline alkaloids; Papaveraceae
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2022.113209

Eleven undescribed isoquinoline alkaloids corybungines A−K including a protoberberine-type alkaloid, an isoquinoline alkaloid with a unique 6-norprotoberberine skeleton, one 13,14-seco-protoberberine-type alkaloid, two 1a,14-seco-protoberberine-type alkaloids with a 4-(hydroxymethyl)phenoxy moiety and six aporphine alkaloids, together with seven known alkaloids, have been isolated from the whole herb extract of Corydalis bungeana Turcz. Their structures and absolute configurations were elucidated based on an analysis of spectroscopic data and electronic circular dichroism (ECD) spectra. (R)-stephanine displayed high antagonistic activity against the dopamine D2 receptor with an IC50 value of 0.85 ± 0.09 μM in CHO-D2 cells. Additionally, corybungines D, F, H, (R)-roemerine, (R)-vireakine and (R)-tuduranine showed moderate D2 antagonism (IC50 5.20–26.07 μM). The preliminary structure-activity relationships (SARs) of aporphine alkaloids were discussed. [Display omitted] •Eleven undescribed isoquinoline alkaloids were obtained from Corydalis bungeana.•Spectroscopic data and ECD calculation were used to determine their structures.•Stephanine exhibited high antagonistism on dopamine D2 receptor in CHO-D2 cells.