Four 10-membered ring resorcylic acid lactones (RALs) including a new compound hispidulactone F (1) and three known analogs hispidulactone B (2), 2 R, 4R-sonnerlactone (3), and 2 R, 4S-sonnerlactone (4) were isolated from the special bioenvironmental desert plant endophytic fungus Chaetosphaeronema hispidulum. The structure of the new compound hispidulactone F (1) was determined by extensive spectra analysis including HR-ESI-MS, NMR (¹H, ¹³C, ¹H-¹H COSY, HSQC, and HMBC). Hispidulactone F (1) and hispidulactone B (2) were a pair of stereoisomers at C-3, whereas 2 R, 4R-sonnerlactone (3) and 2 R, 4S-sonnerlactone (4) were another pair of stereoisomers at C-4. The stereochemistries of the hydroxyl groups at C-3 in 1 and 2, and at C-4 in 3 and 4 were first determined by modified Mosher’s reactions. Thus, the absolute configuration C-3 in hispidulactone B (2) was not right in our previous report, and was rectified to be R. Compounds 1 and 4 were evaluated for their cytotoxic effects on the proliferation of HepG2. The possible biosynthetic pathway of compounds 1–4 was also presented.

四个10元环间苯二酸内酯（RAL），包括新的化合物组氨酸内酯F（1）和三个已知的类似物组氨酸内酯B（2），2 R，4 R-松内酯（3）和2 R，4 S-松内酯（4）从特殊的生物沙漠植物内生真菌组脂壳象球藻中分离到。通过包括HR-ESI-MS，NMR（¹ H，¹³ C，¹ H- ¹在内）的广泛光谱分析确定了新化合物组氨酸内酯F（1）的结构H COSY，HSQC和HMBC）。组氨酸内酯F（1）和组脂内酯B（2）是C-3处的一对立体异构体，而2 R，4 R -sonnerlactone（3）和2 R，4 S -sonnerlactone（4）是C处的另一对立体异构体。 -4。首先通过修饰的Mosher's反应确定1和2中C- 3以及3和4中C-4处的羟基的立体化学。因此，组氨酸内酯B（2）中的绝对构型C-3在我们先前的报告中是不正确的，并且被纠正为R。评价化合物1和4对HepG2增殖的细胞毒性作用。化合物的可能的生物合成途径1 - 4还介绍。