Terretonin P and additional new compounds from mesophilic Aspergillus terreus MSM18

We present terretonin P (1), a novel oxygenated tetracyclic meroterpenoid derived from the mesophilic Aspergillus terreus MSM18, alongside a tetra-hydrofurano-acrylic acid derivative (2a), its 5'-epimer (3a), the respective 5'-methylethers (2b, 3b), the new microbial 3-prenyl-4-hydroxy-benzaldehyde (4a), and our previously reported terretonins M-O (5-7). Structurally, the new compounds (1-4a) have been clarified through comprehensive analyses of NMR (1D, 2D) spectroscopy and HR-ESIM spectrometry. The relative configuration of compounds 1-3a,b was established through NOESY experiment. The separation and taxonomical characterisation of A. terreus MSM18, along with the antimicrobic properties of the newly identified compounds (1-4a) as well as the corresponding fungal extract were investigated as well.