*Article* **Hemiacetalmeroterpenoids A–C and Astellolide Q with Antimicrobial Activity from the Marine-Derived Fungus** *Penicillium* **sp. N-5**

**Tao Chen, Wencong Yang, Taobo Li, Yihao Yin, Yufeng Liu, Bo Wang \* and Zhigang She \***

School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China

**\*** Correspondence: ceswb@mail.sysu.edu.cn (B.W.); cesshzhg@mail.sysu.edu.cn (Z.S.)

**Abstract:** Four new compounds including three andrastin-type meroterpenoids hemiacetalmeroterpenoids A-C (**1**–**3**), and a drimane sesquiterpenoid astellolide Q (**15**), together with eleven known compounds (**4**–**14**) were isolated from the cultures of the marine-derived fungus *Penicillium* sp. N-5, while compound **14** was first isolated from a natural source. The structures of the new compounds were determined by analysis of detailed spectroscopic data, and the absolute configurations were further decided by a comparison of the experimental and calculated ECD spectra. Hemiacetalmeroterpenoid A (**1**) possesses a unique and highly congested 6,6,6,6,5,5-hexa-cyclic skeleton. Moreover, the absolute configuration of compound **14** was also reported for the first time. Compounds **1**, **5** and **10** exhibited significant antimicrobial activities against *Penicillium italicum* and *Colletrichum gloeosporioides* with MIC values ranging from 1.56 to 6.25 μg/mL.

**Keywords:** andrastin-type meroterpenoids; drimane sesquiterpenoid; marine-derived fungus; antimicrobials activities
