Brunonianines D-F, three new C19-diterpenoid alkaloids from the Delphinium brunonianum, with therapeutic effect on ovarian cancer in vitro and in vivo.

The current standard treatment for ovarian cancer consists of surgery to reduce the size of the tumor, followed by treatment with chemotherapeutic drugs, which have major side effects. Therefore, finding a new natural product drug with fewer side effects is a strategy. Delphinium brunonianum (D. brunonianum) is a traditional Tibetan medicine, mainly from southern Tibet, China, whereas the chemical constituents in this plant remain elusive. The major metabolites in the dichloromethane fraction of D. brunonianum were analyzed and purified by HPLC and various column chromatography techniques. Nine diterpenoid alkaloids (1-9) and one amide alkaloid (10) were isolated from D. brunonianum, including three novel C19-type diterpenoid alkaloids (Brunonianines D-F) (1-3). Their structures were elucidated by 1D/2D NMR, HR-ESI-MS and single-crystal X-ray diffraction analyses. All compounds were evaluated for toxicity in four tumor cell lines. Most of the compounds exhibited potent inhibitory effects on Skov-3 cell lines, with IC50 values ranging from 2.57 to 8.05 µM. The western blotting experiment was used to further analyze the expression levels of molecules in the Bax/Bcl-2/Caspase-3 signaling pathway for compound 1. Molecular docking was performed to predict the binding modes of Brunonianine D with target proteins. In vivo experiments were also performed and evaluated in real time by monitoring the size of the Skov-3 tumor. Additionally, tumor H&E staining and the TUNEL assay used to evaluate anti-tumor effects.

Switching Over of the Chemoselectivity: I2-DMSO-Enabled α,α-Dichlorination of Functionalized Methyl Ketones.

Precise control of the chemoselectivity of the halogenation of a substrate equipped with multiple nucleophilic sites is highly demanding and challenging. Most reported chlorinations of methyl ketones show poor compatibility or even exclusive selectivity toward electron-rich arene, olefin, and alkyne residues. This is attributed to the direct or in situ employment of electrophilic Cl2/Cl+ species. Here, we reported that, even bearing those competitive residues, methyl ketones can still undergo dichlorination to afford α,α-dichloroketones in a chemo-specific manner. Enabled by the I2-dimethyl sulfoxide catalytic system, in which hydrochloric acid only acts as a nucleophilic Cl- donor, this straightforward dichlorination reaction is safe and operator-friendly and has high atomic economy, giving access to structurally diverse α,α-dichloroketones in good yields and with good functional-group tolerance.

Discovery of N-(2-benzyl-4-oxochroman-7-yl)-2-(5-(ethylsulfonyl) pyridin-2-yl) acetamide (b12) as a potent, selective, and orally available novel retinoic acid receptor-related orphan receptor γt inverse agonist.

The nuclear receptor retinoic acid receptor-related orphan receptor γ (RORγ, NR1F3, or RORc) exists in two isoforms, with one isoform (RORγ or RORc1) widely expressed in a variety of tissues, and the expression of the second isoform (RORγt or RORc2) restricted to the thymus and cells of the immune system. RORγt is a key regulator of the development and functions of T-helper 17 (Th17) cells. Clinical proof-of-concept (PoC) with small molecule inverse agonists of RORγt has been achieved with VTP-43742 (Phase II) for the treatment of psoriasis, and pre-clinical PoC for this mechanism has also been established for the treatment of autoimmune diseases. A series of aryl sulfonyl derivatives as novel RORγt inverse agonists were designed and synthesized based on VTP-43742. We conducted structural modifications that improved the activity profile. In pharmacodynamic (PD) studies, oral administration of compound b12 showed robust and dose-dependent inhibition of IL-6 and IL-17A cytokine expression. The ability of compound b12 to reduce the levels of IL-6 and IL-17A in vivo after oral dosing in mice, and a corresponding reduction in skin inflammation further supports the potential of small molecule RORγt modulation as a therapeutic target for the treatment of inflammatory diseases.

Discovery of antitumor ursolic acid long-chain diamine derivatives as potent inhibitors of NF-κB.

A series of inhibitors of NF-κB based on ursolic acid (UA) derivatives containing long-chain diamine moieties were designed and synthesized as well as evaluated the antitumor effects. These compounds exhibited significant inhibitory activity to the NF-κB with IC50 values at micromolar concentrations in A549 lung cancer cell line. Among them, compound 8c exerted potent activity against the test tumor cell lines including multidrug resistant human cancer lines, with the IC50 values ranged from 5.22 to 8.95 µM. Moreover, compound 8c successfully suppressed the migration of A549 cells. Related mechanism study indicated compound 8c caused cell cycle arrest at G1 phase and triggered apoptosis in A549 cells through blockage of NF-κB signalling pathway. Molecular docking study revealed that key interactions between 8c and the active site of NF-κB in which the bulky and strongly electrophilic group of long-chain diamine moieties were important for improving activity.

[Chemical Constituents from Rubus stans].

Objective: To study the chemical constituents of Rubus stans. Methods: The chemical constituents were isolated and purified by silica gel and Sephadex LH-20 column chromatography. The structures were identified on the basis of spectroscopic analysis and physicochemical properties. Results: Eleven compounds were isolated and purified from the ethanol extract of Rubus stans. They were identified as ß-sitosterol( 1),betulinic acid( 2),euscaphic acid( 3),ursolic acid( 4),corosolic acid( 5),kaempferol( 6),quercetin( 7),2α,3ß,19α,23-tetrahydroxy-urs-12-en-28-oic acid( 8),ß-daucosterol( 9),quercetin-3-O-ß-D-glucoside( 10) and kaempferol-3-O-ß-D-6-O-( p-hydroxycinnamoyl)-glucopyranoside( 11). Conclusion: All the compounds are isolated from this plant for the first time.

[Study on Chemical Constituents of Delphinium caeruleum].

Objective: To study the chemical constituents from the whole plant of Delphinium caeruleum. Methods: The chemical constituents were isolated and purified by silica gel and Sephadex LH-20 column chromatography. The structures of the isolated compounds were elucidated by spectroscopic analysis and physicochemical properties. Results: Twelve compounds were isolated and purified from the ethanol extract of Delphinium caeruleum. They were identified as ß-sitosterol( 1),kaempferol( 2),quercetin( 3),isovanillic acid( 4),apigenin( 5),luteolin( 6),8-methoxy-5,7,3',4'-tetrahydroxy-flavone( 7),ß-daucosterol( 8),kaempferol-3-O-ß-D-glucoside( 9),3,5-dihydroxy-4'-methoxyflavone-7-yl-O-ß-D-glucopyranosyl-( 1→4)-α-L-rhamnopyranoside( 10),rutin( 11) and sucrose( 12). Conclusion: Compounds 1 ~ 12 are isolated from this plant for the first time.

Synthesis and antitumor activities of novel rhein α-aminophosphonates conjugates.

Several rhein α-aminophosphonates conjugates (5a-5q) were synthesized and evaluated for in vitro cytotoxicity against HepG-2, CNE, Spca-2, Hela and Hct-116 cell lines. Some compounds showed relatively high cytotoxicity. Especially, compound 5i exhibited the strongest cytotoxicity against Hct-116 cells (IC50 was 5.32 µM). All the synthesized compounds exhibited low cytotoxicity against HUVEC cells. The mechanism of compound 5i was preliminarily investigated by Hoechst 33258 staining, JC-1 mitochondrial membrane potential staining and flow cytometry, which indicated that the compound 5i induced apoptosis in Hct-116 cancer cells. Cell cycle analysis showed that these compound 5i mainly arrested Hct-116 cells in G1 stage. The effects of 5i on the activation of caspases expression indicated that 5i might induce apoptosis via the membrane death receptor pathways. In addition, the binding properties of a model analog 5i to DNA were investigated by methods (UV-vis, fluorescence, CD spectroscopy and FRET-melting) in compare with that of rhein. Results indicated that 5i showed moderate ability to interact ct-DNA.

Two new 2,3-seco-hopane triterpene derivatives from Megacodon stylophorus and their antiproliferative and antimicrobial activities.

Chemical investigation of the ethanol extract of the whole plant of Megacodon stylophorus led to the isolation and identification of two new seco-hopane triterpenoids, 2,3-seco-22(29)-hopene-2-carboxyl-3-aldehyde (1) and 2,3-seco-4(23),22(29)-hopene-2-carboxyl-3-aldehyde (2), along with 10 known compounds, 3-12. All the isolates were reported from this plant for the first time. The structures of compounds 1 and 2 were determined by detailed analysis of their spectral data including 1D and 2D NMR. In addition, compound 1 was further analyzed by X-ray crystallography. Compounds 1-3 were evaluated for their in vitro anti-proliferative activities on HeLa, MCF-7, and Hep-G2 tumor cell lines. Compound 2 was active against the three cell lines with IC50 values of 3.6, 7.5, and 13.6 µM, respectively, while compound 1 exhibited cytotoxicity on MCF-7 (IC50 14.0 µM) and HeLa (IC50 18.2 µM) cell lines. Antimicrobial activities of compounds 1-2 (minimum inhibitory concentration values in the range of 3.12-12.50 mg/mL) were also observed.

Association between obstructive sleep apnea and low bone mass in adults: a systematic review and meta-analysis.

Introduction: This study aimed to synthesize existing evidence on the potential association between obstructive sleep apnea (OSA) and low bone mass in adults. Methods: Electronic searches of four main databases were performed. The inclusion criteria consisted of observational studies investigating the relationship between OSA and bone mass, osteoporosis, fractures, or bone metabolism markers in adult population. Bone mineral density (BMD) and T score of lumbar and femur neck, incidence of osteoporosis and fractures, bone metabolism marker levels were extracted as primary outcomes. Results: Among the 693 relevant publications, 10 studies consisting of 158,427 participants met with the inclusion and exclusion criteria. Meta-analysis showed a significant lower BMD of lumbar (mean difference (MD) = - 0.03; 95% CI - 0.05, - 0.01; I2 = 46%), femur neck (MD = - 0.06; 95% CI - 0.12, 0.00; I2 = 71%), and a significant lower T score of lumbar (MD = - 0.42; 95% CI - 0.79, - 0.05; I2 = 63%) in the OSA group. The results suggested that both male (odds ratio (OR) = 2.03; 95% CI 1.23, 3.35; I2 = 38%) and female (OR = 2.56; 95% CI 1.96, 3.34; I2 = 0%) had higher risk of osteoporosis in the OSA group. Besides, meta-analysis also showed that bone-specific alkaline phosphatase was significantly lower in OSA patients (MD = - 1.90; 95% CI - 3.48, - 0.32; I2 = 48%). Conclusions: A potential association between OSA and lower bone mass in adults is preliminarily proved. It also seems plausible that both male and female with OSA have a higher risk of osteoporosis. Supplementary Information: The online version contains supplementary material available at 10.1007/s41105-023-00481-1.

Chemical constituents of Rubia tibetica Hook. f. from Tibetan medicine and cytotoxic activity evaluation.

Two unprecedented quinone compounds Rubiaxylm A (1) and Rubiaxylm B (2), along with fifteen known anthraquinones (3-17) were isolated and characterized from the roots of Rubia tibetica in Tibetan medicine. Their structures were identified through comprehensive analyses of 1D/2D NMR as well as HR-ESIMS data. Furthermore, all separated compounds were evaluated for their cytotoxic activity on A549, Caco-2, MDA-MB-231 and Skov-3 cell lines. In particular, compound 2 effectively inhibited MDA-MB-231 cells with an IC50 value of 8.15 ± 0.20 µM. Subsequently, the anti-tumor mechanism of 2 was investigated by flow cytometry, JC-1 staining, cell scratching and cell colony. These results indicated that compound 2 could inhibit the proliferation of MDA-MB-231 cells by arresting cells in the G1 phase.

Brunonianines A-C, C20-diterpenoid alkaloids with cyano group from Delphinium brunonianum Royle.

Cyano tends to have better biological activity, but it is rarely reported in natural products, especially in the C20-diterpene alkaloids. Herein, three unprecedented C20-diterpenoid alkaloids, brunonianines A-C (1-3), possessing rare cyano functional group as well as an atisine backbone constructed from a phenethyl substituent and a tetrahydropyran ring, along with four C19-alkaloids (4-7) and one amide alkaloids (8), were isolated from the whole plant of Delphinium brunonianum Royle. Compounds 1-3 are also the first atisine type diterpenoid alkaloids with cyano group obtained from nature. The structures of the previously undescribed compounds were elucidated by HR-ESI-MS, 1D/2D NMR spectroscopic data and electronic circular dichroism calculations and single-crystal X-ray diffraction. Reasonable speculations have also been made regarding the biogenic synthetic pathways of compounds 1-3. In addition, the inhibitory activity of all compounds was also tested against four tumor lines: A549, Caco-2, H460 and Skov-3, where compound 2 (IC50 2.20 ± 0.21 µM) showed better inhibitory activity against Skov-3 cells than the hydroxycamptothecin. Using flow cytometry, cell staining, migration and invasion analysis, and Western blot, compound 2 was found to arrest cells in the G2/M phase and was able to effectively inhibit cell motility to achieve potent anti-tumor effects. In addition, compound 2 can effectively induce apoptosis by activating the Bax/Bcl-2/Caspase-3 signaling pathway.

Dentatacid A: An Unprecedented 2, 3-Seco-arbor-2, 3-dioic Triterpenoid from the Invasive Plant Euphorbia dentata, with Cytotoxicity Effect on Colon Cancer.

Euphorbia dentata Michx. is an invasive plant species in China, known for its toxicity and potential to reduce crop yields, posing numerous threats. To gain a deeper understanding of this invasive plant, phytochemical methods were employed to isolate 13 terpenoids (1-11, 19, 20) and 7 sterols (12-18) from the ethanol extract of E. dentata, identifying one new compound and 19 known compounds. Within spectroscopic methods such as NMR, HR-ESI-MS, and ECD, the structures and absolute configurations of these compounds were established. Among them, dentatacid A (11) possesses an unprecedented 2, 3-seco-arbor-2, 3-dioic skeleton within the potential biosynthetic pathway proposed. Dentatacid A also exhibited excellent anti-proliferative activity against the HT-29 (human colorectal adenocarcinoma) cell line, with an IC50 value of 2.64 ± 0.78 µM, which was further confirmed through network pharmacology and molecular docking. This study significantly expands the chemical diversity of E. dentata and offers new insights into the resource utilization and management of this invasive plant from the perspective of natural product discovery.

Synthesis and antitumor activity evaluation of maleopimaric acid N-aryl imide atropisomers.

Maleopimaric acid N-aryl imides (2) and methyl maleopimaric acid N-aryl imides (3) were designed and synthesized. Their atropisomers (A and B) were separated into their enantiomeric pure forms and the anti-proliferative activity was tested against NCI, A549, Hep G-2, MGC-803 and Hct-116 cell lines, respectively. A significant difference in the level of cytotoxicity was observed between R and S conformers. Atropisomers A with an R configuration exhibited significant toxicity (the IC50 values ranging from 7.51 to 32.1 µM). Further experiments proved that antitumor activity of 2A was achieved through the induction of cell apoptosis by G1 cell-cycle arrest.

Norlathyrane diterpenes from the root of Euphorbia kansuensis.

Phytochemical investigation of the EtOH extract obtained from the root of the Euphorbia kansuensis Proch. grown in China resulted in the isolation of two novel norlathyrane diterpenes, named ekanpenoids A and B (1 and 2, resp.). Their structures were established by extensive 1D- and 2D-NMR spectroscopy, as well as other spectra. The isolated diterpenes exhibited potent cytotoxic activities against the HeLa and Hep-G2 cell lines with the IC50 values ranging from 3.6 to 9.7 µg/ml.

Synthesis, cytotoxicity, DNA binding and apoptosis of rhein-phosphonate derivatives as antitumor agents.

Several rhein-phosphonate derivatives (5a-c) were synthesized and evaluated for in vitro cytotoxicity against HepG-2, CNE, Spca-2, Hela and Hct-116 cell lines. Some compounds showed relatively high cytotoxicity. Especially compounds 5b exhibited the strongest cytotoxicity against HepG-2 and Spca-2 cells (IC50 was 8.82 and 9.01 µM), respectively. All the synthesized compounds exhibited low cytotoxicity against HUVEC cells. Further experiments proved that 5b could disturb the cell cycle in HepG-2 cells and induce apoptosis. In addition, the binding properties of a model conjugate 5b to DNA were investigated by methods (UV-Vis, fluorescence, CD spectroscopy). Results indicated that 5b showed moderate ability to interact ct-DNA.

A geniposide-phospholipid complex ameliorates posthyperuricemia chronic kidney disease induced by inflammatory reactions and oxidative stress.

Hyperuricemia is a common metabolic disease and is one of the factors that could induce chronic kidney disease (CKD). Geniposide (GEN) is a typical natural iridoid glucoside compound with a series of biological activities, but the poor bioavailability of GEN limits its clinical application. In this context, the pharmacological activity of the geniposide-phospholipid complex (GEN-PLC) in ameliorating posthyperuricemia CKD was evaluated by in vitro and in vivo experiments in this study. In vitro cell experiments showed that GEN-PLC treatment markedly decreased inflammatory cytokine levels and reactive oxygen species levels compared with those of GEN in uric acid-treated HKC cells. In vivo research results confirmed that a high concentration of uric acid could cause CKD by increasing inflammatory cytokines and reactive oxygen species in hyperuricemic mice. At the same time, GEN-PLC could regulate the PI3K/AKT/NF-κB and Keap1/Nrf2/HO-1 signaling pathways to effectively inhibit the inflammatory response and oxidative stress, thereby ameliorating posthyperuricemia CKD, and the therapeutic effect was better than that of GEN. In addition, the preparation technology of GEN-PLC was optimized, and the physiochemical analysis explained the intermolecular interactions of the two components. Based on the research results, GEN-PLC could enhance the bioavailability of GEN and become a promising candidate for clinical drug development.

Synthesis and biological evaluation of thiazolidine-2-thione derivatives as novel xanthine oxidase inhibitors.

Xanthine oxidase (XO) is a key enzyme in the generation and development of hyperuricemia. Thiazolidine-2-thione, a typical heterocyclic compound, have been widely used in the field of drug synthesis. In this study, a series of novel thiazolidine-2-thione derivatives were synthesized as XO inhibitors, and the XO inhibitory potencies of obtained compounds were evaluated by in vitro enzyme catalysis. The result shown that compound 6k behaved the strongest XO inhibitory activity with an IC50 value of 3.56 µmol/L, which was approximately 2.5-fold more potent than allopurinol. The structure-activity relationship revealed that the phenyl-sulfonamide group was indispensable for thiazolidine-2-thione derivatives to produce XO inhibitory activity. The enzyme inhibition kinetics analyses confirmed that compound 6k exerted a mixed-type XO inhibition. Additionally, the molecular docking results suggested that the 4-fluorophenyl-sulfonyl moiety could interact with Gly260 and Ile264 in the innermost part of the active pocket through 2 hydrogen bonds, while the thiazolidinethione moiety could form two hydrogen bonds with Glu263 and Ser347 in hydrophobic pockets. In summary, the results described above suggested that compound 6k could be a valuable lead compound for the treatment of hyperuricemia as a novel XO inhibitor.

Two new alkaloids from Tibetan medicine of Hypecoum leptocarpum.

Two new alkaloids, leptocarpinine B (1) and corydamine acid (2), with thirteen known alkaloid compounds (3-15), were isolated from Hypecoum leptocarpum. The structures of the isolated compounds were determined based on spectroscopic data analyses, including IR, ESI-MS, 1 D, and 2 D NMR. In addition, all the isolates were evaluated for cytotoxic activities. Compound 6 showed moderate cytotoxicity against human ovarian cancer cell lines (A2780), human cervical cancer cell lines (HeLa), and human hepatocellular carcinomas cell lines (HepG2).[Formula: see text].

Discovery of 2H-chromone-4-one based sulfonamide derivatives as potent retinoic acid receptor-related orphan receptor γt inverse agonists.

Retinoic acid receptor related orphan receptor γt (RORγt), identified as the essential functional regulator of IL-17 producing Th17 cells, is an attractive drug target for treating autoimmune diseases. Starting from the reported GSK2981278 (Phase II), we structurally modified and synthesized a series of 2H-chromone-4-one based sulfonamide derivatives as novel RORγt inverse agonists, which significantly improved their human metabolic stabilities while maintaining a potent RORγt inverse agonist profile. Efforts in reducing the lipophilicity and improving the LLE values led to the discovery of c9, which demonstrated potent RORγt inverse agonistic activity and consistent metabolic stability. During in vivo studies, oral administration of compound c9 exhibited a robust and dose-dependent inhibition of IL-17A cytokine expression and significantly lessened the skin inflammatory symptoms in the mouse imiquimod-induced skin inflammation model. Docking analysis of the binding mode revealed that c9 can suitably occupy the active pocket, and the introduction of the morpholine pyridine group can interact with Leu396, His479, and Cys393. Thus, compound c9 was selected as a preclinical compound for treating Th17-driven autoimmune diseases.

Discovery of Chromane-6-Sulfonamide Derivative as a Potent, Selective, and Orally Available Novel Retinoic Acid Receptor-Related Orphan Receptor γt Inverse Agonist.

Interleukin-17 (IL-17) is a proinflammatory cytokine that plays a dominant role in inflammation, autoimmunity, and host defense. RORγt is a key transcription factor mediating T helper 17 (Th17) cell differentiation and IL-17 production, which is able to activate CD8+ T cells and elicit antitumor efficacy. A series of sulfonamide derivatives as novel RORγt inverse agonists were designed and synthesized. Using GSK2981278 (phase II) as a starting point, we engineered structural modifications that significantly improved the activity and pharmacokinetic profile. In animal studies, oral administration of compound d3 showed a robust and dose-dependent inhibition of the IL-17A cytokine expression in a mouse imiquimod-induced skin inflammation model. Docking analysis of the binding mode revealed that the compound d3 occupied the active pocket suitably. Thus, compound d3 was selected as a clinical compound for the treatment of Th17-driven autoimmune diseases.