Gan Dong, Li Chenzhe, Shu Yan, Wang Jiapeng, Wang Chengyao, Zhu Li, Yang Yujun, Liu Jiaqi, He Bijian, Cai Le, Ding Zhongtao
Functional Molecules Analysis and Biotransformation Key Laboratory of Universities in Yunnan Province, Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091, China.
Functional Molecules Analysis and Biotransformation Key Laboratory of Universities in Yunnan Province, Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091, China.
Chin J Nat Med. 2023 Feb;21(2):154-160. doi: 10.1016/S1875-5364(23)60394-2.
The fungus Xylaria sp. KYJ-15 was isolated from Illigera celebica. Based on the one strain many compounds (OSMAC) strategy, the strain was fermented on potato and rice solid media, respectively. As a result, two novel steroids, xylarsteroids A (1) and B (2), which are the first examples of C-steroid with an unusual β- and γ-lactone ring, respectively, along with two new dihydroisocoumarin glycosides, xylarglycosides A (3) and B (4), were identified. Their structures were elucidated by spectroscopic methods, X-ray diffraction and electronic circular dichroism (ECD) experiments. All isolated compounds were evaluated for cytotoxicity, DPPH radical scavenging activity, acetylcholinesterase inhibitory and antimicrobial effect. Compound 1 exhibited potent AChE inhibitory activity with an IC value of 2.61 ± 0.05 μmol·L. The β-lactone ring unit of 1 is critical for its AChE inhibitory activity. The finding was further confirmed through exploring the interaction of 1 with AChE by molecular docking. In addition, both compounds 1 and 2 exhibited obvious antibacterial activity against Bacillus subtilis with a minimum inhibitory concentration (MIC) of 2 μg·mL. Compounds 3 and 4 exhibited antibacterial activities against Staphylococcus aureus with MICs of 4 and 2 μg·mL, respectively, which also exhibited DPPH radical scavenging activity comparable to the positive control with IC values of 9.2 ± 0.03 and 13.3 ± 0.01 μmol·L, respectively.
真菌木层孔菌属KYJ - 15是从翼叶山壳骨中分离得到的。基于“一株多化合物”（OSMAC）策略，该菌株分别在马铃薯和大米固体培养基上进行发酵。结果，鉴定出两种新型甾体化合物，即木层孔甾体A（1）和B（2），它们分别是具有不寻常β - 和γ - 内酯环的C - 甾体的首个实例，同时还鉴定出两种新的二氢异香豆素糖苷，即木层孔糖苷A（3）和B（4）。通过光谱方法、X射线衍射和电子圆二色性（ECD）实验阐明了它们的结构。对所有分离得到的化合物进行了细胞毒性、DPPH自由基清除活性、乙酰胆碱酯酶抑制和抗菌效果评估。化合物1表现出较强的乙酰胆碱酯酶抑制活性，IC值为2.61±0.05 μmol·L。1的β - 内酯环单元对其乙酰胆碱酯酶抑制活性至关重要。通过分子对接探索1与乙酰胆碱酯酶的相互作用进一步证实了这一发现。此外，化合物1和2对枯草芽孢杆菌均表现出明显的抗菌活性，最低抑菌浓度（MIC）为2 μg·mL。化合物3和4对金黄色葡萄球菌表现出抗菌活性，MIC分别为4和2 μg·mL，它们还表现出与阳性对照相当的DPPH自由基清除活性，IC值分别为9.2±0.03和13.3±0.01 μmol·L。
