The marine derived fungus Alternaria alternata (Fr.) Keissl. was isolated from branch samples of Beibu Gulf, Qinzhou, Guangxi, China and identified by 16s rDNA. Chemical study of A. alternata led to the isolation of a new isomer compound named tricycloalternarene 18c and nine known compounds, including alternariol monomethyl ether, mannitol, cyclo(Gly-Ala), tenuazonic acid, allantoin, thymine, uracil, erythritol, and ergosterol. Their chemical structures were identified by extensive spectrum (IR, MS, 1D, and 2D NMR spectra) and compared with the reported literature data.

中文翻译：

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从 Alternaria alternata 中分离出的一种新异构体和其他代谢物

海洋来源的真菌 Alternaria alternata (Fr.) Keissl。分离自广西钦州北部湾支流样品，经16s rDNA鉴定。对 A. alternata 的化学研究导致分离出一种名为三环交替芳烃 18c 的新异构体化合物和九种已知化合物，包括交替醇单甲醚、甘露醇、环 (Gly-Ala)、tenuazonic 酸、尿囊素、胸腺嘧啶、尿嘧啶、赤藓糖醇和麦角甾醇. 它们的化学结构通过广泛的光谱（IR、MS、1D 和 2D NMR 光谱）进行鉴定，并与报道的文献数据进行比较。