Chemical Constituents of Papulaspora immersa, an Endophyte from Smallanthus sonchifolius (Asteraceae), and Their Cytotoxic Activity
✍ Scribed by Margareth Borges Coutinho Gallo; Bruno Coêlho Cavalcanti; Francisco Washington Araújo Barros; Manoel Odorico de Moraes; Letícia Veras Costa-Lotufo; Cláudia Pessoa; Jairo Kenupp Bastos; Mônica Tallarico Pupo
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 222 KB
- Volume
- 7
- Category
- Article
- ISSN
- 1612-1872
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✦ Synopsis
Abstract
Papulaspora immersa H. H. Hotson was isolated from roots and leaves of Smallanthus sonchifolius (Poepp. and Endl.) H. Rob. (Asteraceae), traditionally known as Yacon. The fungus was cultured in rice, and, from the AcOEt fraction, 14 compounds were isolated. Among them, (22__E__,24__R__)‐8,14‐epoxyergosta‐4,22‐diene‐3,6‐dione (4), 2,3‐epoxy‐1,2,3,4‐tetrahydronaphthalene‐c‐1,c‐4,8‐triol (10), and the chromone papulasporin (13) were new secondary metabolites. The spectral data of the known natural products were compared with the literature data, and their structures were established as the (24__R__)‐stigmast‐4‐en‐3‐one (1), 24‐methylenecycloartan‐3__β__‐ol (2), (22__E__,24__R__)‐ergosta‐4,6,8(14),22‐tetraen‐3‐one (3), (−)‐(3__R__,4__R__)‐4‐hydroxymellein (5), (−)‐(3__R__)‐5‐hydroxymellein (6), 6,8‐dihydroxy‐3‐methylisocoumarin (7), (−)‐(4__S__)‐4,8‐dihydroxy‐α‐tetralone (8), naphthalene‐1,8‐diol (9), 6,7,8‐trihydroxy‐3‐methylisocoumarin (11), 7‐hydroxy‐2,5‐dimethylchromone (12), and tyrosol (14). Compound 4 showed the highest cytotoxic activity against the human tumor cell lines MDA‐MB435 (melanoma), HCT‐8 (colon), SF295 (glioblastoma), and HL‐60 (promyelocytic leukemia), with IC~50~ values of 3.3, 14.7, 5.0 and 1.6 μM, respectively. Strong synergistic effects were also observed with compound 5 and some of the isolated steroidal compounds.