Overexpression of the global regulator LaeA in a marine-derived fungal strain of Penicillium dipodomyis YJ-11 induced obvious morphological changes and metabolic variations. Further chemical investigation of the mutant strain afforded a series of sorbicillinoids including two new ones named 10,11-dihydrobislongiquinolide (1) and 10,11,16,17-tetrahydrobislongiquinolide (2), as well as four known analogues, bislongiquinolide (3), 16,17-dihydrobislongiquinolide (4), sohirnone A (5), and 2′,3′-dihydrosorbicillin (6). The results support that the global regulator LaeA is a useful tool in activating silent gene clusters in Penicillium strains to obtain previously undiscovered compounds.

Heterologous biosynthesis has become an effective means to activate fungal silent biosynthetic gene clusters (BGCs) and efficiently utilize fungal genetic resources. Herein, thirteen labdane diterpene derivatives, including five undescribed ones named talarobicins A–E (3–7), were discovered via heterologous expression of a silent BGC (labd) in Aspergillus nidulans. Their structures with absolute configurations were elucidated using extensive MS and NMR spectroscopic methods, as well as electronic circular dichroism (ECD) calculations. These labdanes belong to four skeleton types, and talarobicin B (4) is the first 3,18-dinor-2,3:4,18-diseco-labdane diterpene with the cleavage of the C2–C3 bond in ring A and the decarboxylation at C-3 and C-18. Talarobicin B (4) represents the key intermediate in the biosynthesis of penioxalicin and compound 13. The combinatorial heterologous expression and feeding experiments revealed that the cytochrome P450 enzymes LabdC, LabdE, and LabdF were responsible for catalyzing various chemical reactions, such as oxidation, decarboxylation, and methylation. All of the compounds are noncytotoxic, and compounds 2 and 8 displayed inhibitory effects against methicillin-resistant coagulase-negative staphylococci (MRCNS) and Bacillus cereus.

Penicilactam A (1), a fungal alkaloid featuring a rare 5-oxaindolizidine scaffold, has long eluded biosynthetic characterization despite recent advances in microbial genomics. Through retro-biosynthetic analysis of Penicillium citrinum HDN11-186, we identified the pnlt gene cluster governing its production. This pathway ultilizes a hybrid polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS) system to assemble the prolinol-containing precursor scalusamide A (2). The multifunctional cytochrome P450 enzyme PnltC then orchestrates two mechanistically distinct reactions: radical-mediated C–C bond cleavage followed by iminium-driven cyclization. Combined structural and computational analyses unveil PnltC's unprecedented catalytic logic, merging radical oxidation with non-radical cyclization within a single active site, which challenges existing paradigms of P450 enzymology. Our findings expand the functional repertoire of oxygenases in natural products (NPs) biosynthesis, revealing nature's sophisticated strategies for constructing complex nitrogen heterocycles.

α-Amylases, catalyzing starch degradation, serve as vital biocatalysts in industrial and pharmaceutical applications. This study identified a new α-amylase, Alphaz, from Nocardiopsis aegyptia HDN19-252 of Antarctic animal origin, achieving heterologous expression in Escherichia coli. Phylogenetic analysis confirmed its classification into the GH13_5 subfamily of glycoside hydrolases. Recombinant Alphaz exhibited optimal activity at 40 °C/pH 8.0 while maintaining stability across 0–30 °C and pH 6.6–9.6. Its distinctive halotolerant properties included full activity retention in 0.6 M NaCl and >60% efficiency in salt-free conditions. The enzyme exhibits tolerance to K⁺, Ca²⁺, and Fe³⁺ while demonstrating specific inhibition by Cu²⁺/Zn²⁺. With its heterologously validated functional properties, Alphaz emerges as a programmable enzymatic tool offering advantages in sustained-release formulation quality control, targeted prodrug modification, and precision medicine applications, thereby enabling sustainable biomanufacturing solutions that harmonize process reliability with environmental compatibility.