New Steroids and a New Alkaloid from the Gorgonian Isis minorbrachyblasta: Structures, Cytotoxicity, and Antilarval Activity

Authors

  • Shu-Hua Qi,

    1. Key Laboratory of Marine Bio-resources Sustainable Utilization/Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, P. R. China, (phone: +86-20-89023105; fax: +86-20-84458964)
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  • Li Miao,

    1. Hong Kong University of Science and Technology/Department of Biology – CML/Clearwater Bay, KLN, Hong Kong, P. R. China
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  • Cheng-Hai Gao,

    1. Key Laboratory of Marine Bio-resources Sustainable Utilization/Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, P. R. China, (phone: +86-20-89023105; fax: +86-20-84458964)
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  • Ying Xu,

    1. Hong Kong University of Science and Technology/Department of Biology – CML/Clearwater Bay, KLN, Hong Kong, P. R. China
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  • Si Zhang,

    1. Key Laboratory of Marine Bio-resources Sustainable Utilization/Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, P. R. China, (phone: +86-20-89023105; fax: +86-20-84458964)
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  • Pei-Yuan Qian

    1. Hong Kong University of Science and Technology/Department of Biology – CML/Clearwater Bay, KLN, Hong Kong, P. R. China
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Abstract

Two new polyoxygenated steroids, (1α,3β,7α,11α,12β)-gorgost-5-ene-1,3,7,11,12-pentol 12-acetate (1) and 11-O-acetyl-22-epihippuristanol (2), and a new alkaloid, 2,3,5,6,11,11b-hexahydro-2-hydroxy-1H-indolizino[8,7-b]indole-2-carboxylic acid (3), together with three known compounds, 22-epihippuristanol (4), hippuristanol (5), and tryptamine (6), were isolated from the EtOH/CH2Cl2 extracts of the South China Sea gorgonian Isis minorbrachyblasta. The structures of the new compounds were determined by spectroscopic methods. Compound 1 showed weak cytotoxicity against A549, HONE1, and HeLa cancer cell lines and strong antilarval activity towards Bugula neritina larvae with an EC50 value of 5.8 μg/ml. Compound 5 showed moderate cytotoxicity against A549, HONE1, and HeLa cell lines, and the epimer mixture 4/5 (weight ratio 3 : 2) exhibited potent cytotoxicity against A549 and HONE1 cell lines with IC50 values of 4.2 and 4.8 μg/ml, which indicated that epimers 4 and 5 might have a synergistic effect on their cytotoxicity against A549 and HONE1 cell lines.

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