Glycopentanolones A-D, four new geranylated quinolone alkaloids from Glycosmis pentaphylla

• Published in: Bioorganic chemistry 2019-06, Vol.87, p.714-719
• Main Authors: Choi, Yun-Hyeok, Seo, Changon, Jeong, Wonsik, Lee, Ji Eun, Lee, Jae Yeon, Ahn, Eun-Kyung, Kang, Jae-Shin, Lee, Jae-Ho, Choi, Chun Whan, Oh, Joa Sub, Lee, Dongho, Hong, Seong Su
• Format: Article
• Language: English
• Subjects: 2-Quinolone alkaloid; Glycopentanolone; Glycosmis pentaphylla; β-hexosaminidase
• ISSN: 0045-2068; 1090-2120
• DOI: 10.1016/j.bioorg.2019.03.069

[Display omitted] •Four new geranylated 2(1H)-quinolone alkaloids and 12 known compounds were isolated from the stem of Glycosmis pentaphylla.•The structures of the compounds were elucidated by NMR and MS data.•Four alkaloids (1, 5, 8, and 11) with N-methyl moiety exhibited potent inhibition activity β-hexosaminidase release. The ethanolic extract obtained from the stems of Glycosmis pentaphylla was found to suppress antigen-mediated degranulation of rat basophilic leukemia (RBL-2H3) cells. Four new geranylated 2-quinolone alkaloids, named glycopentanolones A–D (1–4), and 12 known metabolites (5–16) were isolated from the ethanolic extract from the stems of G. pentaphylla using bioassay-guided fractionation. Their structures were elucidated by a combination of 1D and 2D NMR, and HRESI-MS. The inhibitory effects of the isolated constituents on β-hexosaminidase release from RBL-2H3 cells were examined, and compounds 1, 5, 8 and 11 exhibited potent inhibitory activity with IC50 values between 0.05 and 4.28 μM.