Five new unusual citrinin-derived alkaloids with a tetracyclic core, citrinidines A–E (1–5), two new amide alkaloids, methyl (2S,8E)-1′-(2-methyl-3-oxodec-8-enamido) butanoate (6) and (2S,8E)-2-methyl-3-oxodec-8-enamide (7), a new unusual citrinin trimer, tricitrinol C (8), a new citrinin acetal-ketal derivative, citrininol (9), together with four known citrinin monomers (10–13), and three known citrinin dimers (14–16), were isolated from the fermentation of hydrothermal vent-associated fungus Penicillium citrinum TW132-59. Their structures were unambiguously determined by nuclear magnetic resonance (NMR), mass spectrometry, Mosher′s method, 13C NMR calculation in combination with DP4+, and ECD calculations. A plausible biosynthetic pathway of all new compounds (1–9) was proposed. Citrinin trimer (8) exhibited potent cytotoxicity activity with an IC50 value of 1.34 ± 0.11 μM, and compounds 1 and 15 showed moderate cytotoxicity with IC50 values of 17.50 ± 1.43 and 9.45 ± 0.55 μM, respectively, against A549 cell line.

Two new prenylated glycine derivatives N‐({4‐[(3‐methylbut‐2‐en‐1‐yl)oxy]phenyl}acetyl)glycine (1) and methyl N‐({4‐[(3‐methylbut‐2‐en‐1‐yl)oxy]phenyl}acetyl)glycinate (2), along with nine known compounds (3‐11) were purified from the marine‐derived fungus Fusarium sp. TW56‐10. Their chemical structures were determined by spectroscopic evidence, including extensive nuclear magnetic resonance (NMR), high‐resolution electrospray ionization mass spectroscopy (HR‐ESI‐MS) data, infrared radiation (IR) and Ultraviolet spectra (UV). Compound 4 (8‐O‐methylfusarubin) exhibited cytotoxic activity with IC50 value of 11.45 μM for A549 cells.

Chemical investigation of the leaves and stems of Rubus hirsutus Thunb has resulted in the isolation and characterization of a rare new tricyclic thienocyclopentapyran (1) and 2 known thiophenes, 5-(3-buten-1-ynul)−2,2’-bithiophene (2) and α-terthienyl (3). The structure of compound 1 was unambiguously determined by nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry and time-dependent density functional theory electronic circular dichroism calculations. The new compound 1 exhibited impressive antibiotic properties against methicillin resistant Staphylococcus aureus (MRSA), with an MIC value of around 1 µg/mL.