np500302e_si_002.cif (22.36 kB)

Cytotoxic Cleistanthane and Cassane Diterpenoids from the Entomogenous Fungus Paraconiothyrium hawaiiense

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posted on 27.06.2014, 00:00 by Shenxi Chen, Yang Zhang, Shubin Niu, Xingzhong Liu, Yongsheng Che
Hawaiinolides A–D (14), four new secondary metabolites including three cleistanthane (1, 3, and 4) and one cassane (2) type of diterpene lactones, were isolated from the crude extract of Paraconiothyrium hawaiiense, a fungus entomogenous to the Septobasidium-infected insect Diaspidiotus sp. The structures of 14 were elucidated by nuclear magnetic resonance experiments, and 1 and 3 were further confirmed by X-ray crystallography. The absolute configuration of 1 was assigned via single-crystal X-ray diffraction analysis using Cu Kα radiation, whereas that of 24 was deduced via the circular dichroism data. Compound 1 showed significant cytotoxicity against a small panel of five human tumor cell lines, A549, T24, HeLa, HCT116, and MCF-7.