Anti-neuroinflammatory andrastin-type meroterpenoids from the marine-derived fungus Penicillium chrysogenum HNNU w0032.

A new andrastin-type meroterpenoid penimerodione A (1), and three known analogues (2-4), were isolated from the culture of a marine-derived fungus Penicillium chrysogenum HNNU w0032 by the guidance of MS/MS-based molecular networking. The planar structure of 1 was established by extensive NMR spectroscopic and HRESIMS analyses, and the absolute configuration was elucidated by a single-crystal X-ray diffraction. Compound 1 showed significant inhibitory effect on NO production in LPS-stimulated BV-2 macrophages with an IC50 value of 5.9 ± 0.3 µM. The Western blot result revealed that compound 1 exerted an anti-neuroinflammatory effect via the MAPK signalling pathway.

Structurally diverse isoquinoline alkaloids from the barks of Alangium salviifolium (L. f.) Wangerin and their cytotoxicity.

Eleven undescribed isoquinoline alkaloids (1-8, 14, 15, and 24), along with 19 analogues (9-13, 16-23, and 25-30) were isolated from the barks of Alangium salviifolium. The structures of the undescribed compounds were elucidated through the analysis of their HR-ESI-MS, 1D and 2D NMR, IR, UV, and X-ray diffraction. The absolute configuration of 8 was established via the ECD calculation. Notably, compounds 1/2 and 3/4 were two pairs of C-14 epimers. The isolated alkaloids were evaluated for their cytotoxicity against various cancer cell lines, including SGC-7901, HeLa, K562, A549, BEL-7402, HepG2, and B16, ß-carboline-benzoquinolizidine (14-22) and cepheline-type (24-28) alkaloids exhibited remarkable cytotoxicity, with IC50 values ranging from 0.01 to 48.12 µM. Remarkably, compounds 17 and 21 demonstrated greater cytotoxicity than the positive control doxorubicin hydrochloride. Furthermore, a significant proportion of these bioactive alkaloids possess a C-1' epimer configuration. The exploration of their structure-activity relationship holds promise for directing future investigations into alkaloids derived from Alangium, potentially leading to novel insights and therapeutic advancements.

Design, synthesis of combretastatin A-4 piperazine derivatives as potential antitumor agents by inhibiting tubulin polymerization and inducing autophagy in HCT116 cells.

A series of combretastatin A-4 (CA-4) derivatives were designed and synthesized, which contain stilbene core structure with different linker, predominantly piperazine derivatives. These compounds were evaluated for their cytotoxic activities against four cancer cell lines, HCT116, A549, AGS, and SK-MES-1. Among them, compound 13 displayed the best effectiveness with IC50 values of 0.227 µM and 0.253 µM against HCT116 and A549 cells, respectively, showing low toxicity to normal cells. Mechanistic studies showed that 13 inhibited HCT116 proliferation via arresting cell cycle at the G2/M phase through disrupting the microtubule network and inducing autophagy in HCT116 cells by regulating the expression levels of autophagy-related proteins. In addition, 13 displayed antiproliferative activities against A549 cells through blocking the cell cycle and inducing A549 cells apoptosis. Because of the poor water solubility of 13, four carbohydrate conjugates were synthesized which exhibited better water solubility. Further investigations revealed that 13 showed positive effects in vivo anticancer study with HCT116 xenograft models. These data suggest that 13 could be served as a promising lead compound for further development of anti-colon carcinoma agent.

Four new diterpenoids from the aerial parts of Leucas zeylanica (L.) R. Br.

Four new undescribed halimane- and labdane-type diterpenoids, named zeylleucapenoids E-H (1-4), along with four known analogues (5-8), were isolated from the aerial parts of Leucas zeylanica (L.) R. Br. Their structures were determined by comprehensive spectroscopic analysis and computational calculations. Compounds 1 and 2 are the highly modified halimane diterpenoids featuring a 6/6/6-fused tricyclic system with an unusual six-membered 6,11-ether ring. Compound 8 exhibits nontoxic effects for zebrafish embryo, while it displays efficient reduction against NO production in a dose-dependent manner and strongly suppresses the secretion of LPS-induced TNF-α and IL-6 cytokines in RAW264.7 macrophages. In addition, marked reductions of iNOS and COX-2 expression were observed. Molecular docking analysis indicated that 8 has high affinities with the target amino acid residues on protein-binding sites, which may be a possible mechanism contributing to the anti-inflammatory potential of this molecule.

Alkaloid-metabolites from the mangrove-derived fungus Penicillium robsamsonii HNNU0006.

Nine metabolites, including three undescribed alkaloids pyripyropenes VW (1-2), penicioxa A (4), two previously reported pyripyropene A (3), oxaline (5), three grisephenone-type xanthone derivatives (6-8), and a diphenyl ether derivative 4-chloro-7,4'-dihydroxy-5,2'-dimethoxy-2-methylformate-6'-methybenzophone (9), were isolated from cultures of the mangrove-derived fungus Penicillium robsamsonii HNNU0006. Their structures were determined by spectroscopic analysis, ECD calculations, together with DP4+ probability analysis. Furthermore, all the isolated compounds were tested for cytotoxicity and anti-phytopathogenic fungal activities. Compounds 6-8 showed moderate cytotoxicity against tumor cell lines A549, with IC50 values ranging from 5.68 ± 0.21 to 9.71 ± 0.34 µg/mL, respectively.

Trilobolide-6-O-isobutyrate exerts anti-tumor effects on cholangiocarcinoma cells through inhibiting JAK/STAT3 signaling pathway.

Trilobolide-6-O-isobutyrate exhibits significant antitumor effects on cholangiocarcinoma (CCA) cells by effectively inhibiting the JAK/STAT3 signaling pathway. This study aims to investigate the mechanisms underlying the antitumor properties of trilobolide-6-O-isobutyrate, and to explore its potential as a therapeutic agent for CCA. This study illustrates that trilobolide-6-O-isobutyrate efficiently suppresses CCA cell proliferation in a dose- and time-dependent manner. Furthermore, trilobolide-6-O-isobutyrate stimulates the production of reactive oxygen species, leading to oxidative stress and initiation of apoptosis via the activation of the mitochondrial pathway. Data from xenograft tumor assays in nude mice confirms that TBB inhibits tumor growth, and that there are no obvious toxic effects or side effects in vivo. Mechanistically, trilobolide-6-O-isobutyrate exerts antitumor effects by inhibiting STAT3 transcriptional activation, reducing PCNA and Bcl-2 expression, and increasing P21 expression. These findings emphasizes the potential of trilobolide-6-O-isobutyrate as a promising therapeutic candidate for the treatment of CCA.

Bioactive polyketides and meroterpenoids from the mangrove-derived fungus Talaromyces flavus TGGP35.

Six new polyketides, which includes three new lactones (talarotones A-C) (1-3), one new polyketide (talarotide A) (4), two new polyenes (talaroyenes A, B) (5, 6), together with one new meroterpenoid (talaropenoid A) (7) and 13 known compounds (8-20) were isolated from the mangrove-derived fungus Talaromyces flavus TGGP35. The structure and configuration of the compounds 1-7 were elucidated from the data obtained from HR-ESI-MS, IR, 1D/2D NMR spectroscopy, Mo2 (OAc)4-induced electronic circular dichroism (ECD), CD spectroscopy, and modified Mosher's method. Compounds 5 and 20 displayed antioxidant activity with IC50 values of 0.40 and 1.36 mM, respectively. Compounds 3, 6, 11, 16, and 17 displayed cytotoxic activity against human cancer cells Hela, A549, and had IC50 values ranging from 28.89 to 62.23 µM. Compounds 7, 10-12, and 14-18 exhibited moderate or potent anti-insect activity against newly hatched larvae of Helicoverpa armigera Hubner, with IC50 values in the range 50-200 µg/mL. Compound 18 showed antibacterial activity against Ralstonia solanacearum with the MIC value of 50 µg/mL.

Design, Synthesis, and Anti-Hepatocellular Carcinoma Evaluation of Sesquiterpene Lactone Epimers Trilobolide-6-O-isobutyrate Analogs.

Hepatocellular carcinoma (HCC), one of the most common malignant cancers with a low 5-year survival rate, is the third leading cause of cancer-related deaths worldwide. The finding of novel agents and strategies for the treatment of HCC is an urgent need. Sesquiterpene lactones (SLs) have attracted extensive attention because of their potent antitumor activity. In this study, a new series of SL derivatives (3-18) were synthesized using epimers 1 and 2 as parent molecules, isolated from Sphagneticola trilobata, and evaluated for their anti-HCC activity. Furthermore, the structures of 4, 6, and 14 were confirmed by X-ray single-crystal diffraction analyses. The cytotoxic activities of 3-18 on two HCC cell lines, including HepG2 and Huh7, were evaluated using the CCK-8 assay. Among them, compound 10 exhibited the best activity against the HepG2 and Huh7 cell lines. Further studies showed that 10 induced cell apoptosis, arrested the cell cycle at the S phase, and induced the inhibition of cell proliferation and migration in HepG2 and Huh7. In addition, absorption, distribution, metabolism, and excretion (ADME) properties prediction showed that 10 may possess the properties to be a drug candidate. Thus, 10 may be a promising lead compound for the treatment of HCC.

Drimane-type sesquiterpenoids and their anti-inflammatory evaluation from Pyrrhoderma noxium HNNU0524.

Chemical investigation of a culture broth from the marine-derived fungus Pyrrhoderma noxium HNNU0524 yielded two new compounds including a drimane-type sesquiterpenoid named pyrrnoxin A (1) and a benzoic acid derivative, pyrrnoxin B (5), together with three related known analogues (2-4). The chemical structures of 1 and 5 were determined by detailed analysis of spectroscopic data, single-crystal X-ray crystallography, quantum mechanics-based DP4+ and ECD calculations. Compounds 2 and 3 moderately inhibited NO production of lipopolysaccharide-induced microglia cells BV2 with IC50 values of 26.6 and 60.5 µM, respectively.

Design, synthesis and anti-rheumatoid arthritis activity of target TLR4 inhibitors.

A series of 1-(2-oxocyclohexyl)butane-1, 3-dione derivatives were designed and synthesized as TLR4 inhibitors by modifying the core structure of the lead compound ((6, 8-dioxo-1, 2, 3, 4, 6, 7, 8, 8a-octahydronaphthalen-2-yl) carbamate)). In vitro, compound 3p significantly inhibited the proliferation of rat synovial cells, inhibited the proliferation of LPS-induced RAW264.7 cells, and inhibited TLR4 activity, with IC50 values of 1.21 ± 0.09 µM, 0.73 ± 0.05 µM and 0.43 ± 0.03 µM, respectively, which was superior to the positive control methotrexate. In vivo anti-rheumatoid arthritis evaluation, compound 3p can significantly inhibit the inflammatory factors TNF-α, IL-1ß and IL-6, so as to achieve the therapeutic purpose. In the preliminary mechanism study, compound 3p has obvious regulatory effects on the abnormal increase of TLR4, JAK2 and STAT3 protein and gene expression related to inflammatory signaling pathway in RAW264.7 cells. In summary, this study aims to develop more effective candidates for rheumatoid arthritis.

Rhizoaspergillin A and Rhizoaspergillinol A, including a Unique Orsellinic Acid-Ribose-Pyridazinone-N-Oxide Hybrid, from the Mangrove Endophytic Fungus Aspergillus sp. A1E3.

Two new compounds, named rhizoaspergillin A (1) and rhizoaspergillinol A (2), were isolated from the mangrove endophytic fungus Aspergillus sp. A1E3, associated with the fruit of Rhizophora mucronata, together with averufanin (3). The planar structures and absolute configurations of rhizoaspergillinol A (2) and averufanin (3) were established by extensive NMR investigations and quantum-chemical electronic circular dichroism (ECD) calculations. Most notably, the constitution and absolute configuration of rhizoaspergillin A (1) were unambiguously determined by single-crystal X-ray diffraction analysis of its tri-pivaloyl derivative 4, conducted with Cu Kα radiation, whereas those of averufanin (3) were first clarified by quantum-chemical ECD calculations. Rhizoaspergillin A is the first orsellinic acid-ribose-pyridazinone-N-oxide hybrid containing a unique ß-oxo-2,3-dihydropyridazine 1-oxide moiety, whereas rhizoaspergillinol A (2) and averufanin (3) are sterigmatocystin and anthraquinone derivatives, respectively. From the perspective of biosynthesis, rhizoaspergillin A (1) could be originated from the combined assembly of three building blocks, viz., orsellinic acid, ß-D-ribofuranose, and L-glutamine. It is an unprecedented alkaloid-N-oxide involving biosynthetic pathways of polyketides, pentose, and amino acids. In addition, rhizoaspergillinol A (2) exhibited potent antiproliferative activity against four cancer cell lines. It could dose-dependently induce G2/M phase arrest in HepG2 cells.

Cytotoxic Indole Diterpenoids from a Sphagneticola trilobata-Derived Fungus Aspergillus sp. PQJ-1.

Two new indole diterpene derivatives, 5S-hydroxy-ß-aflatrem (1) and 14R-hydroxy-ß-aflatrem (2), along with one known analogue, 14-(N,N-dimethl-L-valyloxy)paspalinine (3), were isolated from the fermentation broth of the fungus Aspergillus sp. PQJ-1 derived from Sphagneticola trilobata. The structures of the new compounds were elucidated from spectroscopic data and ECD spectroscopic analyses. All the compounds (1-3) were evaluated for their cytotoxicity against A549, Hela, Hep G2, and MCF-7 cell lines. Compounds 1 and 2 exhibited selective inhibition against Hela cells. Further studies showed that 1 significantly induced apoptosis and suppressed migration and invasion in Hela cells. Moreover, 1 could up-regulate pro-apoptotic genes BAX and Caspase-3 and down-regulate anti-apoptotic genes Bcl-xL and XIXP.

Four Undescribed Pyranones from the Scutellaria formosana-Derived Endophytic Fungi Ascomycota sp. FAE17.

Four undescribed pyranone derivatives, named ascomycopyrones A-D (1-4), as well as one known analogue simplicilopyrone (5) (this is the first study to report the absolute configuration), were isolated from the endophytic fungus Ascomycota sp. FAE17 derived from the flowers of Scutellaria formosa. The structures of these pyranones were identified by comprehensive spectroscopic and MS analyses, and the absolute configurations were determined by their experimental and quantum chemical electronic circular dichroism (ECD) calculations. All isolated compounds were tested for various bioactivities, including antibacterial, cytotoxic activity, and NO inhibitory activity. Unfortunately, none of the compounds showed significant bioactivities.

Zeylleucapenoids A-D, Highly Oxygenated Diterpenoids with Anti-Inflammatory Activity from Leucas zeylanica (L.) R. Br.

Four previously undescribed highly oxygenated diterpenoids (1-4), zeylleucapenoids A-D, characterized by halimane and labdane skeletons, were isolated from the aerial parts of Leucas zeylanica. Their structures were elucidated primarily via NMR experiments. The absolute configuration of 1 was established using theoretical ECD calculations and X-ray crystallographic analysis, whereas those for 2-4 were assigned using theoretical ORD calculations. Zeylleucapenoids A-D were tested for anti-inflammatory activity against nitric oxide (NO) production in RAW264.7 macrophages, of which only 4 showed significant efficacy with an IC50 value of 38.45 µM. Further, active compound 4 was also evaluated for the inhibition of the release of pro-inflammatory cytokines TNF-α and IL-6 and was found to have a dose-dependent inhibitory effect, while it showed nontoxic activity for zebrafish embryos. A subsequent Western blotting experiment revealed that 4 inhibited the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Furthermore, molecular docking analysis indicated that the possible mechanism of action for 4 may be bind to targets via hydrogen and hydrophobic bond interactions.

Copper-catalyzed umpolung Sonogashira-type coupling of arene boronic acids under visible light.

We report herein that a copper catalyst catalyzed efficient cross-coupling of aryl and alkenyl boronic acids with alkynyl-1,2-benziodoxol-3(1H)-ones to afford diaryl alkynes and enynes under mild visible light irradiation conditions using a catalytic amount of base or even in the absence of base. The reaction applies copper as the catalyst and tolerates a variety of functional moieties including aryl bromide and iodide.

Four New Polyhydroxy Cyclohexanes from the Stems of Fissistigma tientangense.

Four undescribed polyhydroxy cyclohexanes, fissoxhydrylenes A-D (1-4), together with two known biogenetically related polyhydroxy cyclohexanes (5 and 6) were isolated from the stems of Fissistigma tientangense Tsiang et P. T. Li. Their structures were elucidated by detailed analysis of NMR, HR-ESI-MS, IR, UV and Optical rotations data. The absolute configuration of 1 was confirmed by X-ray crystallographic. The absolute configurations of 2-4 were confirmed by chemical reaction and optical rotations. Compound 4 represent the first example of a no substituent polyhydroxy cyclohexanes from natural products. All isolated compounds were evaluated for their anti-inflammatory activities against the lipopolysaccharide-induced nitric oxide (NO) production in mouse macrophage RAW 264.7 cells in vitro. Compounds 3 and 4 showed inhibitory activities with the IC50 values of 16.63±0.06 µM and 14.38±0.08 µM, respectively.

Guaiane-Type Sesquiterpenes from the Stems of Fissistigma oldhamii.

Two new guaiane-type sesquiterpenes dysodensiols J and L, one new natural product dysodensiol K together with four known biogenetically related guaiane-type sesquiterpenes were isolated from the stems of Fissistigma oldhamii. Their structures were elucidated by detailed analysis of NMR, HR-ESI-MS, IR and Optical rotations data. Compound 1 contains an uncommon five-membered ether ring. The inhibitory effect of all compounds on the proliferation of primary synovial cells was evaluated. Compound 3 showed inhibitory activity with an IC50 value of 6.8 µM. Compounds 5-7 exhibited moderate inhibitory activity with IC50 values of 23.8, 26.6, and 27.1 µM, respectively.

Flavonoidal alkaloids from the flowers of Chromolaena odorata (L.) R.M.King & H.Rob.

A pair of epimers of flavonoid alkaloids, with a pyrrolidone moiety, 2S,5''R-eupodoratin A (1), 2S,5''S-eupodoratin A (2), together with two known analogues, drahebephin A (3), drahebephin B (4), were isolated from the flowers of Chromolaena odorata (L.) R.M.King & H.Rob. Their structures were elucidated on the basis of HR-ESI-MS, 1D/2D NMR spectral analyses. The absolute configuration of compounds (1) and (2) was determined by its experimental and calculated electronic circular dichroism (ECD) spectra. All compounds were isolated from the Asteraceae family for the first time. The ABTS·+ scavenging activity of compound (4) reached 93.56% at a concentration of 0.5 mM, while the scavenging capacity of positive control Trolox was 55.94%. In addition, all compounds show moderate antimicrobial activity against Escherichia coli (ATCC, 337304), Staphylococcus aureus (ATCC, 337371) and Candida albicans (ATCC, 186382) with a MIC value of more than 50 µg/mL.

Analogues of natural products yaequinolones as potential inflammatory inhibitors: Design, synthesis and biological evaluation.

Inflammation is connected with a variety of diseases and there is still a need to develop more effective and safer anti-inflammatory drugs. Herein, we synthesized, resolved, and characterized eight enantiopure isomers of yaequinolone J1 (1), yaequinolone J2 (2), 4'-desmethoxyyaequinolone J1 (3), and 4'-desmethoxyyaequinolone J2 (4). The key synthetic steps were extended and 34 racemic analogues modified at the 4-aryl, the N-position, and the pyran ring were designed and synthesized. All the synthesized compounds were evaluated for their anti-inflammatory activities in RAW 264.7 cells of which 13 compounds showed significant inhibition of nitric oxide (NO) production at a concentration of 0.1 µM, which was more potent than that of indomethacin. Furthermore, compounds (-)-3, (-)-4, 5h, and 6g reduced the production of IL-6 in LPS-stimulated RAW 264.7 cells at a concentration of 50 nM. A preliminary SAR indicated that 3'-Br (5h), 4'-NO2 (6g) on 4-phenyl and 3-bromobenzyl (7f) on the N-position were the most effective substituents. This is the first report of the anti-inflammatory yaequinolone alkaloids and the present study provided evidence for exploiting this series of highly efficacious derivatives for new anti-inflammatory agents.

Anthraquinones with potential antiproliferative activities from the fruits of Morinda citrifolia.

The phytochemical investigation on the fruits of Morinda citrifolia led to the isolation and characterization of a new anthraquinone, moricitrifone (1), along with seven known anthraquinones (2-8). The chemical structure of 1 was elucidated by extensive spectral analyses. The known compounds (2-8) were identified by comparing their spectral data with those reported in the literature. The antiproliferative activities of all isolated anthraquinones (1-8) against five human cancer cell lines: HL-60, SMMC-7721, A-549, MCF-7 and SW480 were evaluated in vitro. Compounds 1-8 exhibited remarkable antiproliferative activities with IC50 values ranging from 0.26 ± 0.05 to 16.58 ± 0.18 µM, which were comparable to those of doxorubicin.