Fourteen previously undescribed cassane diterpenoids, named caesalsins A-N (1-14), along with ten known related compounds (15-24), were isolated from the seeds of Caesalpinia sinensis. Their structures and absolute configurations were determined through comprehensive spectral analysis, single-crystal X-ray diffraction, NMR computational techniques, and electronic circular dichroism calculations. Notably, compound 1 represents an unprecedented 8,14-secocassane diterpenoid featuring an unreported carbon skeleton, while compound 2 is the first naturally occurring 11,12-secocassane diterpenoid. Compounds 3 and 4 are uncommon rearranged cassane diterpenoids characterized by a 6/6/5/5 spirocyclic ring system. Compounds 19-22 exhibited potent inhibitory activity against α-glucosidase, with IC50 values ranging from 9.02 ± 1.30 to 44.64 ± 0.91 μM; notably, compound 21 demonstrated remarkable inhibition with an IC50 value of 9.02 ± 1.30 μM. Additionally, compounds 6, 11, 17, and 21 displayed moderate inhibitory effects on lipopolysaccharide-induced nitric oxide production in RAW 264.7 macrophage cells, with IC50 values between 15.74 ± 0.27 and 36.14 ± 1.01 μM, among which 17 exerted superior anti-inflammatory potency. Molecular docking studies of 19-22 were conducted to clarify their interactions with α-glucosidase. Furthermore, plausible biosynthetic pathways for 1-4 were proposed. These findings expand the chemical diversity of cassane diterpenoids and provide promising bioactive compounds for the development of potential anti-diabetic and anti-inflammatory agents.

The genus Fusarium is a prolific producer of chemically diverse natural products that exhibit a broad spectrum of biological activities, including antibacterial, insecticidal, and anticancer effects. In this study, bioassay-guided isolation from an endophytic fungus Fusarium iranicum YH6 led to the discovery of four previously undescribed cyclodepsipeptides, fusaristatins I-L (1-4), along with a known analogue fusaristatin A (5). Their planar structures were elucidated on the basis of 1D and 2D NMR, and HR ESI-MS spectroscopic analyses. The relative and absolute configurations were rigorously assigned using advanced Marfey's method, J-based configuration analysis, and DP4+ probability assessments. The biological activities of all isolated cyclodepsipeptides were evaluated, including anti-inflammatory activity in LPS-induced RAW264.7 macrophage cells, anti-proliferative activity against A549 and HCC827 cell lines, and antibacterial activity against Staphylococcus aureus. Compounds 1-5 exhibited potent anti-inflammatory activities by inhibiting NO production in LPS-stimulated RAW264.7 macrophages, with IC50 values ranging from 5.7 to 20.5 μM. Fusaristatin K (3) (IC50: 5.7 μM) displayed the most significant inhibition and down-regulated the expression of the TLR4/NF-κB/NLRP3 signaling pathway to exert the anti-inflammatory activity.

The GNPS (Global Natural Products Social Molecular Networking) strategy enable the targeted isolation of eremophilane sesquiterpenoids from Penicillium roqueforti, a fungus isolated from the rhizosphere soil of Hypericum beanii N. Robson collected in the Shennongjia Forestry District, Hubei Province, China. The isolated metabolites comprised eleven previously undescribed lactam- or pyrrole-bearing eremophilane sesquiterpenoid derivatives (1-11), six undescribed highly oxidized analogues (12 and 14-18), and three known congeners (13 and 19-20). Their structures, including absolute configurations, were elucidated through comprehensive spectroscopic analyses, DP4+ probability analysis, ECD calculations, and single-crystal X-ray diffraction. The agrochemical potential of selected compounds (1-13) was evaluated using phytotoxic and antifungal assays. Compound 7 displayed moderate, dose-dependent inhibition of Medicago sativa seed germination, whereas the remaining tested compounds were inactive under the same conditions. By contrast, none of the tested compounds exhibited significant antifungal activity against a panel of nine fungal pathogens at 50 μM. Overall, this work broadens the structural diversity of fungal eremophilane sesquiterpenoids and highlights compound 7 as a moderate phytotoxin.

The LC-MS-guided phytochemical investigation of Pseudostellaria heterophylla, combined with the TLC analysis using ninhydrin as a detection reagent, led to the isolation of 21 cyclic peptides (1-21), including 10 undescribed ones (1-10). Their structures were elucidated via extensive spectroscopic analysis, LC-MS/MS, solid-phase synthesis, and Marfey's method. The obtained cyclic peptides were evaluated for their α-glucosidase inhibitory activities. Compounds 2, 10, 12, 15, and 17 exhibited α-glucosidase inhibitory effects comparable to those of the positive control acarbose. Among them, compound 2 exhibited the most potent activity, even superior to that of acarbose. Molecular docking of 2 with α-glucosidase was performed to explore its binding mode. In a zebrafish model, compound 2 effectively reduced glucose levels, regulated the expression of key metabolic genes (pepck, gck, and sdhdb), and exhibited no obvious toxicity toward human cell lines or zebrafish at the tested concentrations. These results identify 2 as a potential lead compound for the development of new natural antidiabetic agents.

Betaine lipids are non-phosphorus glycerolipids found across diverse organisms, including bacteria, algae, ferns, and certain fungi, and are capable of substituting phospholipids under phosphate deficiency. Their distribution in the Basidiomycota division of fungi remains enigmatic. This study presents the first comprehensive survey of diacylglyceryl-N,N,N-trimethylhomoserine (DGTS) distribution in both natural fruiting bodies and pure cultures of over 150 fungal species. Comparative lipid analysis of fungal mycelium grown on complete versus phosphorus-depleted media revealed that DGTS biosynthesis is predominantly a non-constitutive process that depends on the availability of phosphorus. HPLC-MS/MS lipidomics enabled the identification of 55 molecular species of DGTS and demonstrated that the molecular profile of DGTS markedly differs from other membrane glycerolipids by pronounced enrichment in odd-chain fatty acids, particularly 15:0 and 17:0. DGTS primarily comprises fatty acid combinations of 16- and 18-carbon chains, in contrast to phosphatidylcholine (PC), which is predominantly esterified with two 18-carbon moieties. Notably, neither phylogenetic relationships nor ecological traits of the fungal species correlate strongly with DGTS presence or molecular profile, suggesting that its distribution is governed primarily by lineage-specific evolutionary events rather than adaptive pressures.

Seeds of Swietenia macrophylla are recognized as a beneficial dietary supplement due to their pronounced hypoglycemic and hypotensive properties. To explore the pharmaceutical potential of this plant, eight previously undescribed mexicanolide- and phragmalin-type limonoids (1-8), together with twenty known analogues (9-28), were isolated from the seeds. Their planar structures and absolute configurations were elucidated through extensive spectroscopic investigations, electronic circular dichroism (ECD) calculations, and X-ray diffraction analyses. Among them, swimacrolin A (1) was identified as a rare trinor-limonoid possessing a 16,20-dicarboxylic acid mexicanolide skeleton. In an in vitro anti-inflammatory assay, compounds 1-8 did not inhibit nitric oxide (NO) production in lipopolysaccharide (LPS)- stimulated RAW 264.7 macrophages. However, compounds 1-8, 11, 12, 14-18, 20, 21, 23, and 25-28 significantly suppressed interleukin-1β (IL-1β) release in LPS/nigericin (NIG)-induced THP-1 cells, with IC50 values ranging from 0.64 to 23.05 μM. Notably, compound 2 demonstrated marked anti-inflammatory activity (IC50 = 0.64 ± 0.19 μM). Further mechanistic investigation revealed that compound 2 directly binds to the NOD-like receptor family pyrin domain containing 3 (NLRP3) protein, thereby interfering with apoptosis-associated speck-like protein containing a CARD (ASC) oligomerization and inhibiting NLRP3 inflammasome activation.

Cytosolic detoxification through vacuolar sequestration is essential for plant growth and stress tolerance. A key driver of this process is the vacuolar ABC transporter, ABCC1, which sequesters diverse amphiphilic anions including glutathione (GS)-conjugates, glucuronic acid-conjugates, and thiol-coordinated metal complexes. However, mechanistic studies of plant ABCC1 have largely relied on Arabidopsis genetics and crude membrane transport assays. Here, phylogenetic and sequence-guided analysis of ABCC1 orthologs from multiple plant species was combined with in vitro functional assays with purified protein to investigate plant ABCC1 transporter activity. Compared to mammalian ABCC1, all plant ABCC1 orthologs contain a conserved bipartite binding pocket with a cationic pocket for anion recognition and a hydrophobic pocket. Key differences between mammalian and plant ABCC1 include a substitution in the cation coordinating histidine residue that is compensated by a peripheral arginine mutation to preserve the cationic electrostatic environment. Furthermore, the plant ABCC1 hydrophobic pocket is enlarged relative to its mammalian counterpart due to several substitutions with smaller side-chain residues. To investigate the in vitro activity of plant ABCC1, several orthologs were screened for expression, and those from maize, date palm, and rice exhibited high biochemical stability and comparable substrate-stimulated ATPase activity. ZmABCC1 was further characterized through a series of assay optimization experiments, which found that its ATPase activity is strongly stimulated by E217βG and GS-conjugates, and inhibited by orthovanadate. This study verifies that ABCC1 is widely conserved across plant species with a consistent substrate binding pocket and activity, supporting its role in cytosolic detoxification in plants.

Artemisiverins A1-A32 (1‒32), undescribed guaiane-type sesquiterpenoid dimers, and 23 known analogues (33‒55) were obtained from Artemisia sieversiana Ehrhart ex Willd. (Asteraceae). The structures of compounds 1‒32 were identified through comprehensive spectroscopic analysis, ECD calculations, and X-ray diffraction. These diverse scaffolds were biosynthetically derived from Diels-Alder reactions involving six different connection patterns and the formation of ester bonds, leading to construction of a previously reported linkage type of C-2‒C-3'/C-3‒C-1' for compound 8, the second example of an architecture featuring the linkage of C-2‒C-1'/C-3‒C-3' for compounds 1‒7, and the presence of unique hemiacetal moiety for compounds 15 and 16. The antihepatoma assay revealed that compound 6 significantly inhibited both HepG2 and Huh7 cells with ratios of 91.8% and 92.3% at 200 μM, respectively.

Camellia fascicularis is a golden camellia species endemic to the Dawei Mountain National Nature Reserve in Yunnan Province, China. In this study, we identified a stable, heritable natural mutant of this species and systematically characterized metabolic differentiation between wild-type and mutant floral and foliar tissues by integrating morphological phenotyping, widely targeted metabolomics, physiological and biochemical quantification, and transcriptional validation of key genes. Phenotypic observation revealed that the mutant exhibited markedly enhanced petal glossiness and characteristic yellowish-green leaves. Metabolomic analysis identified 136 and 166 differentially accumulated metabolites (DAMs) in flowers and leaves, respectively; these DAMs were significantly enriched in amino acid metabolism, flavonoid biosynthesis, and ascorbate and aldarate metabolism pathways. Amino acids displayed an inverse tissue-specific accumulation pattern between flowers and leaves, suggesting a potential source-sink allocation mode. In petals, the coordinated upregulation of key flavonoid genes drove the enrichment of flavonol glycosides, which constitute the material basis for the bright coloration. In leaves, the downregulation of amino acids, together with flavonoid accumulation and reduced chlorophyll content, jointly contributed to chlorosis, while ascorbate and flavonoids synergistically enhanced antioxidant capacity. Mineral cofactors such as Fe, Zn, and Mg synergistically remodeled the whole-plant metabolic network, with concurrent increases in soluble sugar and total flavonoid contents. This study presents a novel golden camellia germplasm, reveals the regulatory mechanism underlying flavonoid biosynthesis, and proposes an integrated metabolic framework centered on amino acid source-sink allocation, providing a scientific basis for the conservation and utilization of this resource and for understanding the metabolic diversity of golden camellia.

Five undescribed sesquiterpene lactones, named minimolides M-Q (1-5), along with twelve known analogues (6-17), were isolated from the whole plants of Centipeda minima. The structures of these previously undescribed compounds were elucidated using extensive spectroscopic methods (IR, UV, HRESIMS, and NMR), and the complete structures of 1 and 2 were further confirmed by single-crystal X-ray diffraction analysis. Among the isolates, compounds 5, 10, 13, 14, 16, and 17 exhibited STING inhibitory activity in DMXAA-stimulated RAW264.7-Lucia-ISG cells. Subsequent western blotting and RT-qPCR assays revealed that compound 5 suppressed DMXAA- and cyclic GMP-AMP (cGAMP)-induced phosphorylation of the STING-TBK1-IRF3/p65 signaling cascade, thereby inhibiting STING-dependent gene expression in murine RAW264.7 macrophages and human THP1-derived macrophages, respectively. These findings provide preliminary evidence supporting the potential of sesquiterpene lactones from C. minima as lead compounds for the developing anti-inflammatory ingredients.

Four previously unreported 5/7/6 diterpenoids (1-4), four undescribed sphenolobane diterpenoids (7-10), and three reported derivatives (5, 6, 11) were purified from Strophioblachia glandulosa (Euphorbiaceae) and identified through various spectroscopic methods, ECD calculation, [13]C NMR calculation with DP4+ analysis, and X-ray diffraction. The obtained diterpenoids were evaluated for the inhibitory activity against Candida albicans, and all the compounds demonstrated potent antifungal activity in combination with fluconazole (FLC) against drug-resistant C. albicans. Preliminary mechanism investigations revealed that the most abundant compound 6 when combined with FLC inhibited the formation of C. albicans hyphal and biofilm, disrupting the cell membrane integrity and mitochondrial function. These findings highlight the therapeutic potential of the combined optimization of the 5/7/6 diterpenoids with FLC for combating azole-resistant C. albicans infections.

Phytochemical investigation of Mitragyna speciosa Korth. leaves yielded five previously undescribed indole alkaloids, kratomines A-E (1-5), together with four known analogs (6-9). Their structures and absolute configurations were established using 1D and 2D NMR, single-crystal X-ray diffraction, and chemical derivatization. The isolated compounds exhibited moderate α-glucosidase inhibitory activity with IC50 values of 0.172-0.351 mM. To further elucidate the structure-activity relationship, the main alkaloid named mitragynine (6), was chemically modified to produce some derivatives. Although these derivatives did not enhance the inhibitory potency, kinetic study revealed distinct inhibitory mechanism, suggesting that subtle structural changes may modulate the enzyme-inhibitor interaction. Kinetic analyses revealed that kratomine D (4), mitragynine (6), and 7-hydroxymitragynine (6c) inhibited α-glucosidase through noncompetitive, uncompetitive, and mixed mechanisms, respectively.

Thirty-three menthane-type monoterpenes, including fifteen pairs of enantiomers, were isolated and identified from the aerial parts of Achillea biebersteinii Afan. collected in Tashkent, Uzbekistan. These compounds comprised seventeen undescribed compounds named (±)-biebersteinins A-H and biebersteinins I, eleven previously unreported natural products, and five known analogues. Their structures were comprehensively elucidated by extensive spectroscopic analyses, including HRESIMS and NMR, single-crystal X-ray diffraction, [13]C NMR calculations combined with DP4+ probability analysis, ECD calculations, and comparison to literature. The stereochemical assignment of a previously reported monoterpene was revised on the basis of X-ray crystallographic evidence, highlighting the limited diagnostic value of certain NOESY correlations in 4-isopropyl-substituted menthane-type monoterpenes. In addition, the absolute configurations of nine previously unreported natural products and two known compounds were determined by experimental and calculated ECD data for the first time. Fourteen compounds exhibited weak to moderate inhibitory effects on NO production in LPS-stimulated BV2 cells.

Twenty-five sesquiterpene coumarins, including twelve previously undescribed ones, were isolated from the roots of Ferula kuhistanica Korovin. Their structures were established through comprehensive spectroscopic analysis, NMR, HRESIMS, quantum [13]C NMR DP4+ analysis, ECD calculations, and single-crystal X-ray diffraction analysis. This study systematically evaluated the melanogenesis, tyrosinase, anti-inflammatory, and cytotoxic activities of isolates. Kuhistanin B (1) significantly, promoted melanin synthesis (157.8% ± 1.8%) and increased tyrosinase activity (147.9% ± 10.5%) at 50 μM in B16F10 cells. An MTT assay confirmed no significant cytotoxicity at this concentration (cell viability = 100.0% ± 1.6%). In the anti-inflammatory assay, ethyl galbanate (17) and kopeolin (19) showed good activity with IC50 values of 7.1 ± 0.9 and 9.4 ± 3.1 μM. Isosamarcandin (14) and kopeolin (19) exhibited good cytotoxicity against HT-29 cells with IC50 values of 9.82 ± 0.51 and 7.64 ± 0.41 μM, respectively.

Triterpenoid ellagitannins serve as characteristic chemotaxonomic markers for Castanopsis species and exhibit potent α-glucosidase inhibitory activity. However, systematic phytochemical investigations targeting these compounds have not yet been performed on Castanopsis megaphylla Hu, an endemic subtropical tree native to Southwest China. An HSQC-DeepSAT prediction workflow was utilized for targeted isolation of fifteen triterpenoid ellagitannin derivatives (megaphyllanins A-O, 1-15) from this plant. This collection comprises five unreported galloyl triterpenoid esters (1-4, 12), nine unreported triterpenoid ellagitannins (5-11, 13, 15), and one known triterpenoid ellagitannin (14) obtained from natural sources for the first time. All isolated compounds exhibited significant inhibitory activity against α-glucosidase. Compounds 10, 14 and 15 exhibited superior activity (IC50: 7.41-11.32 μM) compared with acarbose (IC50 = 1698.67 μM). Enzymatic kinetics confirmed compound 15 as a mixed-type inhibitor, and molecular docking binding energies (-6.19, -7.15, -7.35 kcal/mol) matched their activity order. The three highly active compounds are promising acarbose alternatives. This study provides material and theoretical support for developing natural hypoglycemic agents and medicinal exploitation of C. megaphylla.