Cytotoxic Steroidal Saponins Containing a Rare Fructosyl from the Rhizomes of Paris polyphylla var. latifolia.

A phytochemical investigation of the steroidal saponins from the rhizomes of Paris polyohylla var. latifolia led to the discovery and characterization of three new spirostanol saponins, papolatiosides A-C (1-3), and nine known compounds (4-12). Their structures were established via extensive spectroscopic data analysis and chemical methods. Interestingly, compounds 1 and 2 possessed a fructosyl in their oligosaccharide moiety, which is rare in natural product and was firstly reported in family Melanthiaceae. The cytotoxicity of these saponins against several human cancer cell lines was evaluated by a CCK-8 experiment. As a result, compound 1 exhibited a significant cytotoxic effect on LN229, U251, Capan-2, HeLa, and HepG2 cancer cells with IC50 values of 4.18 ± 0.31, 3.85 ± 0.44, 3.26 ± 0.34, 3.30 ± 0.38 and 4.32 ± 0.51 µM, respectively. In addition, the result of flow cytometry analysis indicated that compound 1 could induce apoptosis of glioma cells LN229. The underlying mechanism was explored by network pharmacology and western bolt experiments, which indicated that compound 1 could induce glioma cells LN229 apoptosis by regulating the EGFR/PI3K/Akt/mTOR pathway.

Solubility Determination and Comprehensive Analysis of the New Heat-Resistant Energetic Material TNBP.

To improve the crystal quality of 4,8-bis(2,4,6-trinitrophenyl)difurazolo [3,4-b:3',4'-e] pyrazine (TNBP), the solubility of TNBP in organic solvents (six pure and four mixed solvents) was determined by the laser monitoring technique from 293.15 to 353.15 K. The results showed that the solubility was positively correlated with the increase in the experimental temperature and the main solvent content, except for the co-solvent phenomenon in the DMSO + ethyl acetate solvent mixture. To explain the dissolution behavior of TNBP, the KAT-SER model was analyzed for pure solvent systems, and it was found that hydrogen bonding alkalinity and self-cohesiveness were the main influencing factors. The free energy of solvation and radial distribution function of TNBP in mixed solvents were also obtained by molecular dynamics simulation, and the effect of solute-solvent and solvent-solvent interactions on the solubility trend was analyzed. The experimental data were correlated using three empirical equations (van't Hoff equation, modified Apelblat equation, and λh equation), and the deviation analysis showed the good applicability of the modified Apelblat model. Furthermore, the dissolution of TNBP was heat-absorbing and not spontaneous, according to the thermodynamic characteristics estimated by the van't Hoff equation.

Cytotoxic steroidal glycosides from the rhizomes of Paris polyphylla var. yunnanensis.

Paris polyphylla var. yunnanensis (Franch.) Hand.-Mazz. (Melanthiaceae), an important specie of the genus Paris, has long been in a traditional Chinese medicine (TCM) for a long time. This study aimed to isolate and identify the structures of bioactive saponins from the rhizomes of P. polyphylla var. yunnanensis and evaluate their cytotoxicity against BxPC-3, HepG2, U373 and SGC-7901 carcinoma cell lines. Seven previously undescribed and seven known saponins were identified, and Paris saponins VII (PSVII) showed significant cytotoxicity against the BxPC-3 cell line with IC50 values of 3.59 µM. Furthermore, flow cytometry, transmission electron microscopy and western-bolt analysis revealed that PSVII inhibited the proliferation of BxPC-3 cells and might be involved in inducing apoptosis and pyroptosis by activating caspase-3, -7 and caspase-1, respectively.

Hyperhubeins A-I, Bioactive Sesquiterpenes with Diverse Skeletons from Hypericum hubeiense.

Nine new sesquiterpenes, hyperhubeins A-I (1-9), and 14 known analogues (10-23) were isolated from the aerial portions of Hypericum hubeiense. Their structures and absolute configurations were determined unambiguously via spectroscopic analysis, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Compounds 1-3 possess an unprecedented sesquiterpene carbon skeleton. Further, a plausible biosynthetic pathway from farnesyl diphosphate (FPP) is proposed. The isolated phytochemicals were evaluated for neuroprotective and anti-neuroinflammatory properties in vitro. Compounds 1, 2, 5-8, 14, and 21 displayed notable neuroprotective activity against hydrogen peroxide (H2O2)-induced lesions in PC-12 cells at 10 µM. Additionally, compounds 1, 2, 12, and 13 exhibited inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) production in BV-2 microglial cells, with their IC50 values ranging from 4.92 to 6.81 µM. Possible interactions between these bioactive compounds and inducible nitric oxide synthase (iNOS) were predicted via molecular docking. Moreover, Western blotting indicated that compound 12 exerted anti-neuroinflammatory activity by suppressing LPS-stimulated expression of toll-like receptor-4 (TLR-4) and inhibiting consequent activation of nuclear factor-kappa-B (NF-κB) signaling.

Further sesquiterpenoids from Pittosporum qinlingense and their anti-inflammatory activity.

Four new sesquiterpenoid glycoside esters, Pitqinlingoside N-Q (1-4), together with eleven known metabolites (5-15), were isolated from 95% EtOH extract of the twigs, fruits and leaves of P. qinlingense. The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses, including IR, UV, HRMS, NMR and electronic circular dichroism spectra. Unusal glycoside esters are characterized by the presence of polyacylated ß-D-fucopyranosyl and ß-d-glucopyranosyl units. Pitqinlingoside N (1), O (2), P (3), boscialin (5) and arvoside C (6) showed significant nitric oxide production inhibition in lipopolysaccharide (LPS)-induced BV-2 microglial cells with IC50 values ranging from 1.58 to 28.74 µM. Structure-activity relationships of the isolated compounds are discussed.

Simultaneous determination of the component ratio and moisture content in TEGDN/NG composites by the qNMR method.

A novel qNMR method was developed for the simultaneous determination of the component ratio and moisture content in triethyleneglycol dinitrate (TEGDN) and nitroglycerin (NG) composites. Using the ERETIC module technique of NMR spectrometry, moisture in the solvent and internal standard were eliminated by the integral value subtraction method, and the component ratio and moisture content in TEGDN/NG composites could be accurately calculated. Method validation was carried out in terms of the precision, stability, linearity, recovery, robustness, limit of quantification (LOQ) and limit of detection (LOD). The results of the qNMR method show good accuracy compared with the HPLC and Karl Fischer methods. Statistical Student's t-test and F-test at the 95% confidence level proved that there was no significant difference between the qNMR method and the other two methods. For TEGDN/NG composites of high-energy and high-sensitivity explosives, the low dose and high efficiency of the qNMR method could effectively avoid the danger of explosion and burning.

Noncovalent Interactions and Crystal Structure Prediction of Energetic Materials.

The crystal and molecular structures, intermolecular interactions, and energy of CL-20, HATO, and FOX-7 were comparatively predicted based on molecular dynamic (MD) simulations. By comparison, the 2D fingerprint plot, Hirshfeld surface, reduced density gradient isosurface, and electrostatic potential surface were studied to detect the intermolecular interactions. Meanwhile, the effects of vacuum and different solvents on the crystal habit of CL-20, HATO, and FOX-7 were studied by AE and MAE model, respectively. The energy calculation was also analysed based on the equilibrium structures of these crystal models by MD simulations. Our results would provide fundamental insights for the crystal engineering of energetic materials.

Synthetic Strategies Toward Nitrogen-Rich Energetic Compounds Via the Reaction Characteristics of Cyanofurazan/Furoxan.

The structural units of amino-/cyano-substituted furazans and furoxans played significant roles in the synthesis of nitrogen-rich energetic compounds. This account focused on the synthetic strategies toward nitrogen-rich energetic compounds through the transformations based on cyanofurazan/furoxan structures, including 3-amino-4-cyanofurazan, 4-amino-3-cyano furoxan, 3,4-dicyanofurazan, and 3,4-dicyanofuroxan. The synthetic strategies toward seven kinds of nitrogen-rich energetic compounds, such as azo (azoxy)-bridged, ether-bridged, methylene-bridged, hybrid furazan/furoxan-tetrazole-based, tandem furoxan-based, hybrid furazan-isofurazan-based, hybrid furoxan-isoxazole-based and fused framework-based energetic compounds were fully reviewed, with the corresponding reaction mechanisms toward the nitrogen-rich aromatic frameworks and examples of using the frameworks to create high energetic substances highlighted and discussed. The energetic properties of typical nitrogen-rich energetic compounds had also been compared and summarized.

Two new polyhydroxylated steroidal glycosides from the starfish Culcita novaeguineae.

The chemical constituent investigation on the starfish Culcita novaeguineae resulted in the isolation of two new polyhydroxylated steroidal glycosides and two known ones. The new compounds were identified as (25S)-3-O-(2-O-methyl-ß-D-xylopyranosyl)-26-O-(ß-D-xylopyranosyl)-cholest-4-ene-3ß,6ß,7α,8,15α,16ß,26-heptaol (1) and (25S)-3-O-(2-O-methyl-ß-D-xylopyranosyl)-26-O-(ß-D-xylopyranosyl)-cholest-4,24(28)-diene-3ß,6ß,7α,8,15α,16ß,26-heptaol (2) and the known compounds were determined as linckosides I and H (3-4). The structures of the isolated compounds were elucidated on the basis of extensive spectroscopic studies and chemical evidence. In addition, the cytotoxicity of the two new compounds against human glioblastoma cell lines U87, U251 and SHG44 was evaluated by MTT method.

New Steroidal Saponins Isolated from the Rhizomes of Paris mairei.

The genus Paris is an excellent source of steroidal saponins that exhibit various bioactivities. Paris mairei is a unique species and has been widely used as folk medicine in Southwest China for a long time. With the help of chemical methods and modern spectra analysis, five new steroidal saponins, pamaiosides A-E (1-5), along with five known steroidal saponins 6-10, were isolated from the rhizomes of Paris mairei. The cytotoxicity of all the new saponins was evaluated against human pancreatic adenocarcinoma PANC-1 and BxPC3 cell lines.

Recent advances in polysaccharides from Lentinus edodes (Berk.): Isolation, structures and bioactivities.

Lentinus edodes, an important edible mushroom cultivated in East Asia for thousands of years, has been widely used as food and medicinal ingredient worldwide. Modern phytochemistry studies have demonstrated that L. edodes is very rich in bioactive polysaccharides, especially the ß-glucans. Over the past two decades, the isolation, chemical properties, and bioactivities of polysaccharides from fruiting bodies, mycelium and fermentation broth of L. edodes have been drawing much attention from scholars around the world. It has been demonstrated that L. edodes polysaccharides possess various remarkable biological activities, including anti-oxidant, anti-tumor, anti-aging, anti-inflammation, immunomodulatory, antiviral, and hepatoprotection effects. This review summarizes the recent development of polysaccharides from L. edodes including the isolation methods, structural features, bioactivities and mechanisms, and their structure-activity relationship, which can provide useful research underpinnings and update information for their further application as therapeutic agents and functional foods.

Redox signaling and Alzheimer's disease: from pathomechanism insights to biomarker discovery and therapy strategy.

ABSTRACT: Aging and average life expectancy have been increasing at a rapid rate, while there is an exponential risk to suffer from brain-related frailties and neurodegenerative diseases as the population ages. Alzheimer's disease (AD) is the most common neurodegenerative disease worldwide with a projected expectation to blossom into the major challenge in elders and the cases are forecasted to increase about 3-fold in the next 40 years. Considering the etiological factors of AD are too complex to be completely understood, there is almost no effective cure to date, suggesting deeper pathomechanism insights are urgently needed. Metabolites are able to reflect the dynamic processes that are in progress or have happened, and metabolomic may therefore provide a more cost-effective and productive route to disease intervention, especially in the arena for pathomechanism exploration and new biomarker identification. In this review, we primarily focused on how redox signaling was involved in AD-related pathologies and the association between redox signaling and altered metabolic pathways. Moreover, we also expatiated the main redox signaling-associated mechanisms and their cross-talk that may be amenable to mechanism-based therapies. Five natural products with promising efficacy on AD inhibition and the benefit of AD intervention on its complications were highlighted as well.

Alisol B 23-acetate attenuates CKD progression by regulating the renin-angiotensin system and gut-kidney axis.

BACKGROUND: Increasing evidence suggests a link between the gut microbiome and various diseases including hypertension and chronic kidney disease (CKD). However, studies examining the efficacy of controlling blood pressure and inhibiting the renin-angiotensin system (RAS) in preventing CKD progression are limited. METHODS: In the present study, we used 5/6 nephrectomised (NX) and unilateral ureteral obstructed (UUO) rat models and cultured renal tubular epithelial cells and fibroblasts to test whether alisol B 23-acetate (ABA) can attenuate renal fibrogenesis by regulating blood pressure and inhibiting RAS. RESULTS: ABA treatment re-established dysbiosis of the gut microbiome, lowered blood pressure, reduced serum creatinine and proteinuria, suppressed expression of RAS constituents and inhibited the epithelial-to-mesenchymal transition in NX rats. Similarly, ABA treatment inhibited expression of collagen I, fibronectin, vimentin, α-smooth muscle actin and fibroblast-specific protein 1 at both mRNA and protein levels in UUO rats. ABA was also effective in suppressing activation of the transforming growth factor-ß (TGF-ß)/Smad3 and preserving Smad7 expression in both NX and UUO rats. In vitro experiments demonstrated that ABA treatment inhibited the Wnt/ß-catenin and mitochondrial-associated caspase pathways. CONCLUSION: These data suggest that ABA attenuated renal fibrosis through a mechanism associated with re-establishing dysbiosis of the gut microbiome and regulating blood pressure, and Smad7-mediated inhibition of Smad3 phosphorylation. Thus, we demonstrate ABA as a promising candidate for treatment of CKD by improving the gut microbiome and regulating blood pressure.

Novel RAS inhibitor 25-O-methylalisol F attenuates epithelial-to-mesenchymal transition and tubulo-interstitial fibrosis by selectively inhibiting TGF-ß-mediated Smad3 phosphorylation.

BACKGROUND: Tubulo-interstitial fibrosis (TIF) is the common pathway in the chronic kidney disease (CKD). Epithelial-to-mesenchymal transition (EMT) is a major contributor to the TIF by the increased myofibroblasts. Renin-angiotensin system (RAS) is critical mediator on EMT in progressive CKD. Angiotensin II (ANG) mediates EMT and causes TIF by stimulating transforming growth factor-ß1 (TGF-ß1). RAS activation could further activate TGF-ß1. Inhibition of the RAS is one of the most powerful therapies for progressive CKD. 25-O-methylalisol F (MAF) is a new tetracyclic triterpenoid compound isolated from the Alismatis rhizoma, which is extensively used for anti-hypertensive, diuretic and anti-hyperlipidemic effects. METHODS: Inhibitory effect of MAF on EMT is investigated in both TGF-ß1- and ANG-induced tubular epithelial cells (NRK-52E) and fibroblasts (NRK-49F). Western blot analysis, qRT-PCR, siRNA, immunofluorescence staining and co-immunoprecipitation techniques were used to evaluate the inhibition of MAF on EMT and further revealed the intervention effects on RAS, TGF-ß/Smad and Wnt/ß-catenin pathways. RESULTS: MAF treatment significantly inhibited TGF-ß1 and ANG-induced expressions of collagen I, fibronectin, α-SMA, vimentin and E-cadherin at both mRNA and protein levels in the NRK-52E and NRK-49F cells. The action mechanism revealed that MAF significantly ameliorated upregulation of angiotensinogen, renin, ACE and AT1R expressions. Further, MAF attenuated upregulation of Smad3 phosphorylation and downregulation of Smad7, but did not affect the phosphorylation of Smad2, PI3K, ERK1/2 and p38 expressions and Smad4 expression in NRK-52E cells. Co-immunoprecipitation analysis indicated that MAF selectively blocked the combination of Smad3 with TGFßRI and Smad3 with SARA without interfering with the Smad2, TGFßRI and SARA interaction. Additionally, MAF suppressed the expressions of Wnt1 and ß-catenin as well as its downstream target Snail1, Twist, MMP-7, PAI-1 and FSP1 expressions in NRK-52E cells. CONCLUSIONS: MAF simultaneously targeted multiple RAS components and it was a novel RAS inhibitor. MAF inhibited EMT by Smad3-specific signaling in the TGF-ß/Smad-dependent pathway and Wnt/ß-catenin pathway. MAF has an important effect on crosstalk between the TGF-ß/Smad and Wnt/ß-catenin pathway in EMT process by activation of RAS.

Cytotoxic Polyhydroxysteroidal Glycosides from Starfish Culcita novaeguineae.

Four new polyhydroxysteroidal glycosides-culcinosides A-D (1, 2, 4, and 7)-along with three known compounds-echinasteroside C (3), linckoside F (5), and linckoside L3 (6)-were isolated from the ethanol extract of starfish Culcita novaeguineae collected from the Xisha Islands of the South China Sea. The structures of new compounds were elucidated through extensive spectroscopic studies and chemical evidence, especially two-dimensional (2D) NMR techniques. The cytotoxicity of the new compounds against human glioblastoma cell lines U87, U251, and SHG44 were evaluated.

New Steroidal Saponins from the Rhizomes of Paris vietnamensis and Their Cytotoxicity.

Four new spirostanol saponins, named pavitnosides A-D (1-4), with six known steroidal saponins 5-10 were isolated from the rhizomes of Paris vietnamensis. Their chemical structures were determined based on extensive spectroscopic studies and chemical methods. The aglycones of pavitnoside B and pavitnoside C were not reported in previous work. The cytotoxicity of all saponins was evaluated against human glioblastoma U87MG and U251 cell lines. The new spirostanol saponin 1 displayed weak anti-proliferative activity against U87MG cell line and the known saponins 8 and 9 exhibited significant cytotoxicity against the two tumor cell lines, with IC50 values of 2.16 to 3.14 µM, but did not affect the growth of primary cultures of human astrocytes.

Poricoic acid ZA, a novel RAS inhibitor, attenuates tubulo-interstitial fibrosis and podocyte injury by inhibiting TGF-ß/Smad signaling pathway.

BACKGROUND: The pathogenesis of tubulo-interstitial fibrosis and glomerulosclerosisis was characterized by cellular hypertrophy, extracellular matrix accumulation and podocyte detachment. Poricoic acid ZA (PZA) is a tetracyclic triterpenoid compound extracted from the surface layer of Poria cocos (LPC), which have been used extensively for diuretic and renoprotective effects. METHODS: The anti-fibrotic effect of PZA is investigated in HK-2 cells and podocytes induced by TGF-ß1 and angiotensin II (ANGII). qRT-PCR, siRNA, immunofluorescence staining, co-immunoprecipitation and Western blot analyses are used to evaluate the expression of RAS signaling, TGF-ß/Smad pathway, epithelial-to-mesenchymal transition (EMT) and podocyte markers. RESULTS: PZA restores the mRNA and protein expression of EMT in HK-2 cells. Specific TGF-ß1-siRNA efficiently blocks ANGII-induced protein expression of TGF-ß1 and further inhibits activated Smad signaling. PZA significantly attenuates up-regulation of angiotensinogen, renin, ACE and AT1. Further, PZA reverses up-regulation of TGFßRII and suppresses Smad proteins. Simultaneously, PZA inhibits the protein interaction of TGF-ß receptor and Smads and PZA also inhibits activated RAS and TGF-ß/Smad signaling cascade and up-regulates protein expression of podocyte markers and mitigates podocyte injury. CONCLUSIONS: This study demonstrated the beneficial role of PZA in renal fibrosis and podocyte injury. Our study highlighted that PZA inhibits RAS and further suppresses TGF-ß/Smad pathway through inhibiting Smad2/3 phosphorylation via blocking Smad2/3-TGFßRI protein interaction. PZA is implicated in activation of RAS/TGF-ß/Smad axis in HK-2 cells and podocytes. PZA could be considered as a novel RAS inhibitor for treating CKD.

New steroidal saponins from the rhizomes of Paris delavayi and their cytotoxicity.

Four new furostanol saponins, named padelaosides C-F (1-4), together with four known spirostanol saponins 5-8 were isolated from the rhizomes of Paris delavayi Franchet. Their structures were elucidated on the basis of extensive spectroscopic analysis and chemical evidences. The discovery of the new compounds 1-4 extended the diversity and complexity of this furostanol saponin family. The cytotoxicity of all the saponins was evaluated for their cytotoxicity against human glioblastoma U87MG and human hepatocellular carcinoma Hep-G2 cell lines. The known spirostanol saponins 7 and 8 exhibited notable cytotoxicity against the two tumor cell lines with IC50 values of 1.13 and 3.42µM, respectively, while the new furostanol saponins 3 and 4 showed moderate cytotoxicity with IC50 values of 15.28 to 16.98µM.

Three new cytotoxic isomalabaricane triterpenes from the marine sponge Stelletta tenuis.

Three new isomalabaricane-type triterpenes named stellettins N (1), O (2) and P (3), together with four known compounds (4­7),were isolated from the CCl4 extract of the marine sponge Stelletta tenuis Lindgren. Compound 4 was reported as a natural α-pyrone for the first time, which had been synthesized from gibepyrone B, while 5 was found in the genus Stelletta for the first time. The structures of the new compounds were established on the basis of extensive spectroscopic data analysis including IR, MS, 1D and 2D NMR. The inhibitory activities of compounds 1­3 against three human cancer cell lines (A549, AGS and U-251MG) were evaluated and all the tested compounds exhibited significant cytotoxicity to AGS cells, with IC50 values of 4.52, 9.61 and 7.44 µM, respectively.

Cytotoxic oleanane-type triterpenoid saponins from the Rhizomes of Anemone rivularis var. flore-minore.

Phytochemical investigation of the n-BuOH extract of the rhizomes of Anemone rivularis var. flore-minore led to the isolation of five new oleanane-type triterpenoid saponins 1-5, together with five known saponins 6-10. Their structures were determined by the extensive use of 1D and 2D NMR experiments, along with ESIMS analyses and acid hydrolysis. The aglycone of 4 and 5 was determined as 21α-hydroxyoleanolic acid, which was reported in this genus for the first time. The cytotoxicity of these compounds was evaluated against four human cancer cell line, including HL-60 (promyelocytic leukemia), HepG2 (hepatocellular carcinoma), A549 (lung carcinoma) and HeLa (cervical carcinoma). The monodesmosidic saponins 6-8 exhibited cytotoxic activity toward all tested cancer cell lines, with IC50 values in the 7.25-22.38 µM range.