An antibacterial activity-guided phytochemical investigation of the fungus Sanghuangporus sp. resulted in the isolation of two new cyclofarnesane sesquiterpenoids, (4S,6S)-4-hydroxy-γ-ionylideneacetic acid (1) and (4R,5R,6S)-5,14-dihydro-4-hydroxy-γ-ionylideneacetic acid (2), together with three known compounds, γ-ionylideneacetic acid (3), 1S-(2E)-5-[(1R)-2,2-dimethyl-6-methylidenecyclohexyl]-3-methylpent-2-enoic acid (4), and d-mannitol (5). Their structures were elucidated using extensive spectroscopic data (IR, 1D and 2D NMR) and mass spectrometry. The absolute configurations of compounds 1 and 2 were identified by NOESY and comparisons of their experimental and calculated electronic circular dichroism spectral data. Compounds 1, 3, and 4 were evaluated for antibacterial activity against five bacterial strains (Staphylococcus aureus MSSA 2933, S. aureus MRSA 20651, Bacillus cereus ATCC 11778, Escherichia coli 25922, and Shigella dysenteriae 15110).

真菌Sanghuangporus sp。的抗菌活性指导植物化学研究。导致分离出两个新的环法呢烷倍半萜类化合物（4 S，6 S）-4-羟基-γ-亚苯基乙酸（1）和（4 R，5 R，6 S）-5,14-二氢-4-羟基-γ-亚苯基乙酸（2）和三种已知化合物γ-亚苯基乙酸（3），1 S-（2 E）-5-[（1 R）-2,2-二甲基-6-亚甲基亚环己基]- 3-甲基戊-2-烯酸（4）和d-甘露醇（5）。使用大量的光谱数据（IR，1D和2D NMR）和质谱法阐明了它们的结构。化合物1和2的绝对构型通过NOESY进行了鉴定，并对它们的实验和计算出的电子圆二色性光谱数据进行了比较。化合物1，3，和4对抗菌活性进行了评价对五种细菌菌株（金黄色葡萄球菌MSSA 2933，金黄色葡萄球菌MRSA 20651，蜡状芽孢杆菌ATCC 11778，大肠杆菌中25922，和志贺氏痢疾杆菌15110）。