Four new secondary metabolites, chaetosemins G-J (1-4), along with 11 known ones (5-15) were isolated from the culture of C. seminudum C208 and Chaetomium sp. C521. Their structures were determined by extensive NMR spectroscopic analyses. These metabolites were evaluated in vitro for antifungal, antioxidant, toxicity, and α-glucosidase inhibitory activities. Chaetosemin J (4) and monaschromone (5) significantly inhibited the growth of four plant pathogenic fungi Botrytis cinerea, Alternaria solani, Magnaporthe oryzae, and Gibberella saubinettii with the minimum inhibitory concentrations (MIC) values ranging from 6.25 to 25.0 μM. Moreover, both epicoccone B (11) and flavipin (14) exhibited the DPPH free radical scavenging ability with IC₅₀ values of 10.8 and 7.2 μM, respectively, and had more potent α-glucosidase inhibition than the drug acarbose with IC₅₀ values of 27.3 and 33.8 μM, respectively. Monaschromone (5) might act as the lead compound of pesticide.

中文翻译：

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来自两个龟形目物种的聚酮化合物及其生物学功能。

从半裸念珠菌C208和Chaetomium sp。的培养物中分离出四种新的次生代谢物，chaetosemins GJ（1-4），以及11种已知的次生代谢物（5-15）。C521。通过广泛的NMR光谱分析确定它们的结构。在体外评估了这些代谢物的抗真菌，抗氧化剂，毒性和α-葡萄糖苷酶抑制活性。Chaetosemin J（4）和monaschromone（5）显着抑制四种植物病原性真菌灰葡萄孢，链格孢菌，稻瘟病菌和赤霉菌的生长，其最小抑菌浓度（MIC）值范围为6.25至25.0μM。此外，Epicoccone B（11）和flavipin（14）均具有IC ₅₀清除DPPH自由基的能力。值分别为10.8和7.2μM，并且比药物阿卡波糖具有更强的α-葡萄糖苷酶抑制作用，IC ₅₀值分别为27.3和33.8μM。Monaschromone（5）可能是农药的先导化合物。