One new neogrifolin derivative, mortfurafolin (1), together with four known analogues, (S)-18,19-dihydroxyneogrifolin (2), cylindrocarpol (3), methyl 2,4-dihydroxy-3,5,6-trimethylbenzoate (4), and 5-methylbenzene-1,3-diol (5), was isolated from the rhizosphere soil fungus Mortierella sp. ZS-10 associated with Gastrodia elata. The structure and absolute configuration of compound 1 were unambiguously elucidated via comprehensive spectroscopic analyses, electronic circular dichroism (ECD) calculations, and DP4 + probability calculations. Compound 1 features a rare tetrahydrofuran ring system in the neogrifolin skeleton. In addition, compound 1 was subjected to bioactivity assessments, including its inhibitory effect on nitric oxide (NO) production and cytotoxic activity against multiple tumor cell lines.
Marine macroalgae are an important source of bioactive compounds with potential applications in food, nutraceutical and pharmaceutical industries. Among them, brown algae are particularly rich in polysaccharides, phlorotannins, lipids, pigments, sterols and mineral elements which contribute to a wide range of biological activities. This review summarizes the major phytochemical classes reported in brown algae and discusses their documented antioxidant, antimicrobial, anti-inflammatory, antiviral and other health-related properties. It also highlights the value of molecular docking and other in silico approaches for linking chemical composition with possible mechanisms of action. Overall, brown algae represent a promising sustainable source for the development of functional foods and bioactive products, although further work is needed to standardize extraction, characterization of bioactive compounds and validate biological activities in vivo.
In our ongoing research to discover bioactive compounds from mangrove endophytic fungi, three metabolites have been isolated from Alternaria sp. HN-17, including one new isocoumarin derivative (2) and one new fatty acid derivative (3), together with one known analog (1). Their structures were determined by extensive analysis of Nuclear Magnetic Resonance (NMR) and High-Resolution Electrospray Ionization Mass Spectrometry (HRESIMS) data, and hydrolysis reaction experiments. In vitro, compounds 1 and 2 showed moderate inhibitory effects on lipopolysaccharide (LPS)‑stimulated nitric oxide (NO) production in RAW 264.7 cells, with IC50 values of 25.8 and 36.5 µM, respectively. The positive control Nω-methyl-L-arginine (L-NMMA) showed an IC50 of 17.7 µM.
Biochemical systems occupy restricted regions of admissible state space defined by coupled metabolic, enzymatic, regulatory, and ecological constraints. Behaviour in these regions is controlled by mechanisms, but at the boundaries, where admissibility changes, systems reorganise suddenly. Here I develop a boundary-centred formalism for natural product biosynthesis in which biosynthetic gene clusters (BGCs) are treated as bounded subsystems whose reachable transformations form a finite region Ω generated by a constraint field C. This framework, referred to here as Boundary Theory (BT), treats biosynthetic systems as occupying bounded admissible regions whose geometry governs reachability and transition behaviour. The boundary (∂Ω) separates trivially reachable interior transformations from those requiring external justification, and perturbations deform ∂Ω to make new regions Ω′ accessible. Boundary curvature governs transition difficulty: steep regions require strong justification, whereas shallow regions permit easier traversal. This framework provides a geometric explanation for biosynthetic silence, conditional activation, and the failure of purely mechanistic interventions, offering a structural basis for predicting when and how BGCs reorganise under altered constraint regimes. This geometric framework is illustrated across major biosynthetic classes including polyketides, terpenoids, alkaloids, and NRPS/RiPP pathways, showing how class-specific constraint regimes shape Ω, ∂Ω, and the conditions under which new regions Ω′ become reachable.
Nine tremulane sesquiterpenoids, including two undescribed compounds (1 and 2) were isolated from Irpex lacteus, an endophytic fungus of Dendrobium officinale, and their structures were unambiguously identified by spectroscopic analyses and ECD calculations. All isolates were evaluated for anti‑inflammatory activity using LPS‑stimulated RAW264.7 macrophages. Compounds 1 and 4 exhibited potent inhibition against nitric oxide production with IC50 values of 9.88 ± 0.35 μM and 14.32 ± 0.80 μM, respectively, comparable to the positive control dexamethasone (6.55 ± 0.42 μM). Both compounds also markedly decreased the secretion of pro‑inflammatory TNF‑α, IL‑6 and IL‑1β in a dose‑dependent manner. Molecular docking results indicated that the compound 1 stably bound to the active sites of iNOS and COX‑2 with binding energies of −6.8 kcal/mol and −6.2 kcal/mol through hydrogen‑bond interactions. This study demonstrates the anti‑inflammatory potential of tremulane sesquiterpenoids from I. lacteus, supporting the further development of fungal metabolites as natural anti‑inflammatory candidates.
