The endophytic fungus Cladosporium sphaerospermum WBS017 was obtained from healthy bulbs of Fritillaria unibracteata var. wabuensis. Fermentation of C. sphaerospermum on solid rice medium yielded three new hybrid polyketides, cladosins L-N (1-3), and a known derivative cladodionen (4). Further cultivation of this fungus on white bean medium afforded an additional new hybrid polyketide, cladosin O (5) along with three known analogues (6-8). The structures of the new compounds were elucidated using a combination of NMR and HRESIMS data. The absolute configurations of compounds 2 and 3 were determined by Mosher's method and TDDFT-ECD calculations. All isolated compounds were evaluated for their cytotoxic and antimicrobial activities. Cladodionen (4) exhibited cytotoxicity against the mouse lymphoma cell line L5178Y with an IC50 value of 3.7 μM, and also exhibited antifungal activity against Ustilago maydis and Saccharomyces cerevisiae, while cladosin L (1) displayed week antibacterial activity against Staphylococcus aureus ATCC 29213 and S. aureus ATCC 700699 with MIC values of 50 and 25 μM, respectively.

中文翻译：

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Cladosins LO，来自内生真菌球孢子菌WBS017的新型杂合聚酮化合物。

内生真菌球形芽孢杆菌WBS017获自贝母的健康鳞茎。wabuensis。在固体大米培养基上发酵球形芽孢杆菌产生了三种新的杂合聚酮化合物，cladosins LN（1-3）和一种已知的衍生物cladodionen（4）。在白豆培养基上进一步培养这种真菌，得到了另外一种新的杂合聚酮化合物，cladosin O（5）以及三种已知的类似物（6-8）。结合使用NMR和HRESIMS数据阐明了新化合物的结构。化合物2和3的绝对构型通过Mosher法和TDDFT-ECD计算确定。评价所有分离的化合物的细胞毒性和抗微生物活性。Cladodionen（4）对小鼠淋巴瘤细胞L5178Y表现出细胞毒性，IC50值为3.7μM，