One pair of new cyclopentaisochromenone enantiomer from Alternaria sp TNXY-P-1 and their cytotoxic activity

• Published in: Journal of asian natural products research Vol. 20; no. 4; pp. 328 - 336
• Main Authors: Lu, Xiao-Jie, Chen, Shao-Fei, Xu, Xiang-Wei, Zhao, Dan, Wang, Hai-Feng, Bai, Jiao, Hua, Hui-Ming, Chen, Gang, Pei, Yue-Hu
• Format: Journal Article
• Language: English
• Published: ABINGDON Taylor & Francis 01.04.2018; Taylor & Francis Ltd
• Subjects: Anticancer properties; Cell culture; Cell lines; Chemistry; Chemistry, Applied; Chemistry, Medicinal; Cytotoxicity; Enantiomers; Endophytes; Fungi; High-performance liquid chromatography; Life Sciences & Biomedicine; Liquid chromatography; NMR; Nuclear magnetic resonance; Pharmacology & Pharmacy; Physical Sciences; Plant Sciences; Quantum chemistry; Science & Technology; Two dimensional analysis; FUNGAL ENDOPHYTE; ALTENUSIN; Alternaria sp; endophytic fungus; cytotoxic activity; Cyclopentaisochromenone; DERIVATIVES
• ISSN: 1028-6020; 1477-2213
• DOI: 10.1080/10286020.2017.1336164

One pair of new cyclopentaisochromenone derivatives, (+)-(S)-6-hydroxy-1,8-dimethoxy-3a-methyl-3,3a-dihydrocyclopenta[c]isochromene-2,5-dione (1a) and (-)-(R)-6-hydroxy-1,8-dimethoxy-3a-methyl-3,3a-dihydrocyclopenta[c]-isochromene-2,5-dione (1b), together with seven known analog 2-8, were isolated from a rice solid culture of the endophytic fungus Alternaria sp. TNXY-P-1, obtained from fresh leaf of Arisaema heterophyllum. Their structures were elucidated on the basis of detailed 1D, 2D NMR, and HRESIMS analysis. Among them, compounds 1a and 1b were enantiomers separated from 1 by chiral HPLC. The absolute configurations of 1a and 1b were assigned by quantum chemical calculations of the electronic circular dichroic spectra. All isolated compounds were evaluated for cytotoxic activities. Interestingly, enantiomers (+)-1a and (-)-1b showed distinct selective antitumor activities against HL-60 cell lines with IC50 values of >200, 75.3 mu M, respectively. [GRAPHICS] .