A depsidone and six triterpenoids from the bark of Garcinia celebica

• Published in: Tetrahedron letters 2016-06, Vol.57 (23), p.2524-2529
• Main Authors: Bui, Thai Q., Bui, An T., Nguyen, Kien T., Nguyen, Vy T., Trinh, Binh T.D., Nguyen, Lien-Hoa D.
• Format: Article
• Language: English
• Subjects: Cytotoxicity; Depsidone; Garcinia celebica; Lanostanes and friedolanostanes; Structural elucidation; Xanthones
• ISSN: 0040-4039; 1873-3581
• DOI: 10.1016/j.tetlet.2016.04.104

[Display omitted] •Nineteen compounds were isolated from the bark of Garcinia celebica.•A new depsidone and six triterpenoids were characterized using spectroscopic methods.•One of these was a rare rearranged lanostane, 13α,30-cyclo-17,13-friedolanostane.•Cytotoxicity of the compounds toward MCF-7 cells using an SRB assay was tested. A new depsidone, garcinisidone H (1), and six novel triterpenoids, were isolated from the bark of Garcinia celebica. The latter compounds consisted of two lanostanes, (E)-3β,9α-dihydroxylanosta-24-en-26-oic acid (2) and 3,23-dioxo-9,16-lanostadien-26-oic acid (3), and four friedolanostanes, (24E)-3-oxo-17,14-friedolanosta-8,14,24-trien-26-oic acid (4), (22Z,24E)-9α-hydroxy-3-oxo-17,13-friedolanosta-12,22,24-trien-26-oic acid (5), (22Z,24E)-3-oxo-17,14-friedolanosta-8,14,22,24-tetraen-26-oic acid (6) and (22Z,24E)-9α-hydroxy-3-oxo-13α,30-cyclo-17,13-friedolanosta-22,24-dien-26-oic acid (7). In addition, twelve known compounds were obtained. The structures of the new compounds were elucidated using spectroscopic methods, mainly 1D and 2D NMR. The cytotoxicity of the isolated compounds against the human breast cancer cell line MCF-7 was evaluated using the sulforhodamine B assay, in which macluraxanthone exhibited the strongest activity with an IC50 of 6.1μM.