Three new azaphilone alkaloids containing glutamine residues, namely N-glutarylchaetoviridins A–C (1–3), together with two related compounds (4 and 5) were isolated from the extract of Chaetomium globosum HDN151398, a fungus isolated from a deep-sea sediment sample collected in South China Sea. Their structures were elucidated on the basis of extensive 1D and 2D NMR as well as HRESIMS spectroscopic data and chemical analysis. N-glutarylchaetoviridins A–C (1–3) represent the first class of chaetoviridins characterized by embedded glutamate residues. Amino acids incubation experiments produced five azaphilone laden different amino acids residues (6–10) which indicated that this method can enhanced the structural diversity of this strain by culturing with amino acids. Cytotoxicity of the isolated compounds were evaluated against a panel of human cancer cell lines.

Four new anthraquinone derivatives, namely saliniquinones G−I (1–3) and heraclemycin E (4), were obtained from the Antarctic marine-derived actinomycete Nocardiopsis aegyptia HDN19-252, guided by the Global Natural Products Social (GNPS) molecular networking platform. Their structures, including absolute configurations, were elucidated by extensive NMR, MS, and ECD analyses. Compounds 1 and 2 showed promising inhibitory activity against six tested bacterial strains, including methicillin-resistant coagulase-negative staphylococci (MRCNS), with MIC values ranging from 3.1 to 12.5 μM.

Six angucyclines including three unreported compounds (1–3) were isolated from Streptomyces sp. XS-16 by overexpressing the native global regulator of SCrp (cyclic AMP receptor). The structures were characterized based on nuclear magnetic resonance (NMR) and spectrometry analysis and assisted by electronic circular dichroism (ECD) calculations. All compounds were tested for their antitumor and antimicrobial activities, and compound 1 showed different inhibitory activities against various tumor cell lines with IC₅₀ values ranging from 0.32 to 5.33 μM.

Four new polyketides, namely furantides A–B (1–2), talamin E (3) and arugosinacid A (4), and two known polyketides were obtained from the mangrove-derived fungus Penicillium sp. HDN15-312 using the One Strain Many Compounds (OSMAC) strategy. Their chemical structures, including configurations, were elucidated by detailed analysis of extensive NMR spectra, HRESIMS and ECD. The DPPH radicals scavenging activity of 3, with an IC₅₀ value of 6.79 µM, was better than vitamin C.

To better assess the practical value and avoid potential risks of the traditionally medicinal and edible basidiomycete Schizophyllum commune, which may arise from undescribed metabolites, a combination of elicitors was introduced for the first time to discover products from cryptic and low-expressed gene clusters under laboratory cultivation. Treating S. commune NJFU21 with the combination of five elicitors led to the upregulated production of a class of unusual linear diterpene-derived variants, including eleven new ones (1–11), along with three known ones (12–14). The structures and stereochemistry were determined by 1D and 2D NMR, HRESIMS, ECD, OR and VCD calculations. Notably, the elongation terminus of all the diterpenes was decorated by an unusual butenedioic acid moiety. Compound 1 was a rare monocyclic diterpene, while 2–6 possessed a tetrahydrofuran moiety. The truncated metabolites 4, 5 and 13 belong to the trinorditerpenes. All the diterpenes displayed approximately 70% scavenging of hydroxyl radicals at 50 μM and null cytotoxic activity at 10 μM. In addition, compound 1 exhibited potent antifungal activity against the plant pathogenic fungi Colletotrichum camelliae, with MIC values of 8 μg/mL. Our findings indicated that this class of diterpenes could provide valuable protectants for cosmetic ingredients and the lead compounds for agricultural fungicide development.

Six new alkaloid compounds, including two rare aromatic nitrile compounds talaronitriles A–B (1–2), a novel oxime-functionalized azadiphilone analogue talarooxime A (3), a new phenylhydrazone alkaloid talarohydrazone E (4), and two new dipeptide compounds talarodipeptides A–B (5–6), were isolated from the deep-sea cold-seep-derived fungus Talaromyces amestolkiae HDN21-0307 via OSMAC approach. Compound 1 is the first natural naphthalene compound with cyano groups. Compound 3 represents the first natural product containing an oxime-functionalized azadiphilone scaffold. Their structures and absolute configurations were elucidated through spectroscopic data analysis and quantum chemical calculations. Notably, compound 3 demonstrated moderate DPPH free-radical-scavenging activity, with an IC₅₀ value of 29.41 μM.