Sulphated Fucooligosaccharide from Sargassum Horneri: Structural Analysis and Anti-Alzheimer Activity.

In the present study, sulfated polysaccharides were obtained by digestion of Sargassum horneri and preparation with enzyme-assisted extraction using three food-grade enzymes, and their anti- Alzheimer's activities were investigated. The results demonstrated that the crude sulfated polysaccharides extracted using AMGSP, CSP and VSP dose-dependently (25-100 µg·mL- 1) raised the spontaneous alternating manner (%) in the Y maze experiment of mice and reduced the escape latency time in Morris maze test. AMGSP, CSP and VSP also exhibited good anti-AChE and moderate anti-BuChE activities. CSP displayed the best inhibitory efficacy against AChE. with IC50 values of 9.77 µM. And, CSP also exhibited good inhibitory selectivity of AChE over BuChE. Next, CSP of the best active crude extract was separated by the preparation type high performance liquid phase to obtain the sulphated fucooligosaccharide section: SFcup (→3-α-L-fucp(2-SO3-)-1→4-α-L-fucp(2,3-SO3-)-1→section), SFcup showed a best inhibitory efficacy against AChE with IC50 values of 4.03 µM. The kinetic research showed that SFcup inhibited AChE through dual binding sites. Moreover, the molecular docking of SFcup at the AChE active site was in accordance with the acquired pharmacological results.

(S)-N-Benzyl-1-phenyl-3,4-dihydroisoqunoline-2(1H)-carboxamide Derivatives, Multi-Target Inhibitors of Monoamine Oxidase and Cholinesterase: Design, Synthesis, and Biological Activity.

A series of (S)-1-phenyl-3,4-dihydroisoquinoline-2(1H)-carboxamide derivatives was synthesized and evaluated for inhibitory activity against monoamine oxidase (MAO)-A and-B, acetylcholine esterase (AChE), and butyrylcholine esterase (BChE). Four compounds (2i, 2p, 2t, and 2v) showed good inhibitory activity against both MAO-A and MAO-B, and two compounds (2d and 2j) showed selective inhibitory activity against MAO-A, with IC50 values of 1.38 and 2.48 µM, respectively. None of the compounds showed inhibitory activity against AChE; however, 12 compounds showed inhibitory activity against BChE. None of the active compounds showed cytotoxicity against L929cells. Molecular docking revealed several important interactions between the active analogs and amino acid residues of the protein receptors. This research paves the way for further study aimed at designing MAO and ChE inhibitors for the treatment of depression and neurodegenerative disorders.

Fast Capture and Efficient Removal of Bloom Algae Based on Improved Dielectrophoresis Process.

A dielectrophoresis (DEP) method for direct capture and fast removal of Anabaena was established in this work. The factors affecting the removal efficiency of Anabaena were investigated systematically, leading to optimized experimental conditions and improved DEP process equipment. The experimental results showed that our improved DEP method could directly capture Anabaena in eutrophic water with much enhanced removal efficiency of Anabaena from high-concentration algal bloom-eutrophication-simulated solution. The removal rate could increase by more than 20% after applying DEP at 15 V compared with a pure filtration process. Moreover, the removal rate could increase from 38.76% to 80.18% in optimized experimental conditions (the initial concentration of 615 µg/L, a flow rate of 0.168 L/h, an AC voltage of 15 V, and frequency of 100 kHz). Optical microscopic images showed that the structure of the captured algae cells was intact, indicating that the DEP method could avoid the secondary pollution caused by the addition of reagents and the release of phycotoxins, providing a new practical method for emergent treatment of water bloom outbreaks.

Antioxidative and Cytoprotective Effects of Ganoderma applanatum and Fomitopsis pinicola in PC12 Adrenal Phaeochromocytoma Cells.

Considering the impact of oxidative stress on the development of many diseases, together with the role of natural antioxidants in maintaining physiological balance in humans, medicinal mushrooms are potential sources of bioactive compounds against many diseases. In the present work, in vitro evaluation of the biological activities of the alcoholic extracts of two wild tree mushrooms, namely, Ganoderma applanatum and Fomitopsis pinicola, has been performed. Extraction of G. applanatum (GAE) and F. pinicola (FPE) was conducted with 60% ethanol and 100% ethanol sequentially. UPLC-MS/MS identification was conducted on the two mushrooms extracts. A total of 15 substances were identified in GAE, including 3 spiro meroterpenoids and 12 triterpenoids; a total of 14 chemical constituents were iden¬tified in FPE, including 8 triterpenoids, 4 triterpene glycosides, 1 lanosterol, and 1 lanostanoid. The resulting extracts were examined for their in vitro antioxidative and cytoprotective effects against AAPH-induced oxidative damage. Our results demonstrated that both extracts have potent antioxidative activities, when GAE was 0.2 mg/mL, the clearance rates of DPPH and ABTS have reached 93.34% and 99.93%, respectively. When FPE was 1.4 mg/mL and 0.6 mg/mL, the scavenging rates of DPPH and ABTS have reached 91.76% and 100%, respectively. Both the alcoholic extracts of G. applanatum and F. pinicola were able to protect the AAPH-induced damage and could effectively inhibit cell aging via ß-galactosidase (SA ß-gal) staining activity test and scanning electron microscopy analysis.

Novel triterpenoids from Alisma plantago-aquatica with influence on LDL uptake in HepG2 cells by inhibiting PCSK9.

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 (PCSK9) has been regarded as an effective and exciting target in the treatment of atherosclerotic cardiovascular disease since 2003. Only two monoclonal antibodies have been approved in the market which, however, were also criticized for their high cost to $9000 per dose and delivery route. Exploration of natural new effective and cheaper small molecule alternatives with effective PCSK9 inhibition is feasible and desired. PURPOSE: The aim of the study was to explore natural small molecules with anti-hyperlipidemia activity through PCSK9 from Alisma plantago-aquatica. METHOD: A targeted isolation of triterpenoids from A. plantago-aquatica by LC-Orbitrap-QDa was conducted. The isolates were evaluated for their DiI-LDL uptake promoting activity with fluorescence intensity assayed in High-content Imaging System and PCSK9 inhibitory activity by Human PCSK9 Kit or western blot. The LDL uptake and PCSK9 level of target component in different concentrations and their mRNA level were further verified by corresponding kit, qPCR and western blot. RESULTS: Six novel triterpenoids, including three unusual nor-triterpenoids (1-3) and three protostane-type triterpenoids (4-6), along with thirty-four known ones, were isolated from A. plantago-aquatica. Compound 2 had the lowest number of carbon atoms than previous reported nor-PTs in this plant. The 17 triterpenoids showed relatively remarkable activities in promoting LDL uptake with relevant structure-activity relationships. And 6 triterpenoids may improve LDL uptake in HepG2 cells by inhibiting PCSK9, especially for alisol G (28) with PCSK9 inhibition reaching to 55.6%, which demonstrated to increase LDLR mRNA or protein, and simultaneously reduce PCSK9 mRNA or protein significantly. CONCLUSION: The protostane triterpenoids may serve as a new source for PCSK9 inhibitors.

Highly Efficient Removal of Nitrate and Phosphate to Control Eutrophication by the Dielectrophoresis-Assisted Adsorption Method.

The removal of excessive amounts of nitrate and phosphate from water sources, especially agricultural wastewater, has been of high significance to control eutrophication in aquatic systems. Here, a new method is reported for the removal of nitrate and phosphate simultaneously from wastewater based on the combination of the solution-phased adsorption (ADS) and dielectrophoresis (DEP) techniques. The plant ash was first selected as the adsorbent by screening tests, followed by a systematic investigation of using the adsorbent to remove nitrate and phosphate from wastewater under various experimental conditions, including the testing of adsorbent dosage, pretreatment time, water flow rate, and electrode voltage. The analysis of the adsorbent particles was also performed by scanning electron microscope (SEM) analysis, the energy dispersive X-ray spectroscopy (EDX) test, and the measurement of Zeta potentials. Compared with the ADS method alone, the introduction of DEP into the purification process has greatly increased the removal rate by 66.06% for nitrate and 43.04% for phosphate, respectively. In the meantime, it is observed that the processing time has been greatly reduced by 92% with the assistance of DEP.

Two new benzophenone glycosides from the aerial parts of Hypericum przewalskii.

Plants of the genus Hypericum contain various types of secondary metabolites that exhibited extensive biological activities. In the ongoing efforts to discover natural neuroinflammatory inhibitors with the potential to develop into therapeutic agents for neurodegenerative diseases, two new benzophenone glycosides, hyperewalones A and B (1 and 2), along with eight known compounds (3-10), were isolated from the aerial parts of Hypericum przewalskii. Their structures were elucidated by comprehensive analysis of IR, HRESIMS, 1D and 2D NMR spectra, and chemical derivatization. The anti-neuroinflammatory activity of compounds 1-10 was evaluated by determining their ability to inhibit the production of nitric oxide (NO) in lipopolysaccharide (LPS)-activated BV-2 microglial cells. Compounds 2, 4, 6-8 exhibited significant anti-neuroinflammatory activity with IC50 values of 0.61-4.90 µM. These findings suggest that the benzophenone, ionone, and flavonoid glycosides isolated from H. przewalskii are promising anti-neuroinflammatory compounds worthy of further investigations.

"Force iteration molecular designing" strategy for the systematic characterization and discovery of new protostane triterpenoids from Alisma Rhizoma by UHPLC/LTQ-Orbitrap-MS.

Comprehensive analysis and identification of chemical components are of great significance for evaluating the efficacy and safety of herbal medicines, as well as for drug exploitation and development. Here we developed a "force iteration molecular designing" strategy, by combing a database-based in-house software for a precursor ion list (PIL) and PIL-triggered collision-induced dissociation-MS2 and high-energy C-trap dissociation-MS2 (PIL-CID/MS2-HCD/MS2) on an LTQ-Orbitrap mass spectrometer, aiming for the systematic characterization and discovery of new protostane triterpenoids (PTs) from Alisma Rhizoma (AR). AR was a well-known herbal remedy widely used for diarrhea, but its systematic characterization and comparison between two botanical origins have not been reported. Firstly, in-house software was developed based on force iteration, to generate a PIL that contains 483 accurate precursor ions. Secondly, to facilitate the acquisition of rich fragments and diagnostic ions sufficient for the structural elucidation of different types of PTs, a hybrid data acquisition method, namely PIL-CID/MS2-HCD/MS2, was generated. Thirdly, a total of 473 PTs were rapidly characterized from two botanical origins of AR according to an established four-step interpretation method, and the common constituents were 277 with ratio 70% (277/395) and 78% (277/355) in the rhizome of Alisma plantago-aquatica and A. orientale, respectively. Finally, two new PTs were isolated and unambiguously identified by NMR verifying the feasibility of this combined data acquisition strategy. This integrated strategy could improve the efficiency in the detection of new compounds in a single run and is practical to comprehensively characterize the complex components in herbal medicines.

Biological evaluation of 2,3-dioxoindolin-N-phenylacetamide derivatives as potent CDC25B and PTP1B phosphatase inhibitors

A series of 2,3-dioxoindolin-N-phenylacetamide derivatives was evaluated for inhibitory activity against CDC25B and PTP1B enzymes. Most of the derivatives showed inhibitory activity against CDC25B (IC50 = 3.2-23.2 µg/mL) and PTP1B (IC50 = 2.9-21.4 µg/mL). Compound 2h showed the most inhibitory activity in vitro with IC50 values of 3.2 and 2.9 µg/mL against CDC25B and PTP1B, respectively, compared with the reference drugs Na3VO4 (IC50 = 2.7 µg/mL) and oleanolic acid (IC50 = 2.3 µg/mL). The results of selectivity experiments showed that the 2,3-dioxoindolin-N-phenylacetamide derivatives were selective inhibitors against CDC25B and PTP1B. Enzyme kinetic experiments demonstrated that compound 2h was a specific inhibitor with the typical characteristics of a mixed inhibitor. In cytotoxic activity assays compound 2h had potent activity against A549, HeLa, and HCT116 cell lines. In addition, compound 2h showed potent tumor inhibitory activity in a colo205 xenograft model in vivo.

Synthesis and antibacterial activity of a series novel 5,7-diisoprenyloxyflavone derivatives

In the present study, a series of novel 5,7-diisoprenyloxyflavone derivatives were designed, synthesized, and evaluated for their antibacterial activity. Most of these compounds displayed significant antibacterial effects against Gram-positive bacteria, especially against strains of multidrug-resistant clinical isolates. Compounds 4c, 4g, 4i, 4j, 4k, 4l, 4n, 4q and 4t showed high levels of antimicrobial activity against Staphylococcus aureus RN4220 with minimum inhibitory concentrations of 4.0-20 µM. Compound 4k showed the most potent activity among these compounds against all multidrug-resistant clinical isolates tested. Unfortunately, none of the compounds were active against Gram-negative bacteria at the doses of 24-164 µM.

Lignans from Saururus chinensis with Inhibitory Effects on Nitric Oxide Production.

Three biogenetically related ent-sauchinone-type lignans (1-3), four 8-O-4'-type neolignans (4-7), a diaryldimethylbutane lignan (8), and a cyclic carbonate (9), along with 12 known compounds, have been isolated from a methanol extract of the aerial parts of Saururus chinensis. The structures of the new compounds (1-9) were determined by analysis of their 1D and 2D NMR spectra, HRESIMS, and ECD data. A putative biosynthetic pathway for the three ent-sauchinone-type lignans (1-3) was postulated. Compounds 1, 7, and 10 showed inhibitory effects on LPS-induced NO production in RAW 264.7 cells with IC50 values of 5.6, 8.6, and 9.2 µM, respectively.

Novel C-17 spirost protostane-type triterpenoids from Alisma plantago-aquatica with anti-inflammatory activity in Caco-2 cells.

Twenty-one protostane-type triterpenoids with diverse structures, including nine new compounds (1-9), were isolated from the of Alisma plantago-aquatica Linn. Structurally, alisolides A‒F (1-6), composed of an oxole group coupled to a five-membered ring, represent unusual C-17 spirost protostane-type triterpenoids. Alisolide H (8) is a novel triterpenoid with an unreported endoperoxide bridge. Alisolide I (9) represents the first example of 23,24-acetal triterpenoid. Their structures were elucidated based on spectroscopic analysis, wherein the absolute configurations of 4‒6, 8 were further confirmed by the Mo2(OAc)4-induced ECD method. Furthermore, all isolates were evaluated for their inhibitory effects on LPS-induced NO production in Caco-2 cells, and all the compounds showed remarkable inhibitory activities, with IC50 values in the range of 0.76-38.20 µmol/L.

Syntheses of Benzo[d]Thiazol-2(3H)-One Derivatives and Their Antidepressant and Anticonvulsant Effects.

Thirty-four new benzo[d]thiazol derivatives 2a-2i, 3a-3r, and 4a-4g were synthesized and investigated for their potential antidepressant and anticonvulsant effects. In a forced swimming test, 2c and 2d showed the highest antidepressant and anticonvulsant effects. 2c and 2d displayed a higher percentage decrease in immobility duration (89.96% and 89.62%, respectively) than that of fluoxetine (83.62%). In the maximal electroshock seizure test, 3n and 3q showed the highest anticonvulsant effect, with ED50 values of 46.1 and 64.3 mg kg-1, and protective indices of 6.34 and 4.11, respectively, which were similar to those of phenobarbital or valproate. We also found that the mechanism for the antidepressant activity of 2c and 2d may be via increasing the concentrations of serotonin and norepinephrine.

A high-efficiency strategy integrating offline two-dimensional separation and data post-processing with dereplication: Characterization of bufadienolides in Venenum Bufonis as a case study.

Comprehensive analysis and identification of chemical components are very important to evaluate the efficacy and safety of traditional Chinese medicine (TCM). Meanwhile, the discovery of new natural compounds is of great significance for drug exploitation and development. Although two-dimensional liquid chromatography (2D LC) systems expand the peak capacity and improve selectivity and resolution, interpreting the post-processing data is tedious and time-consuming. In this study, an off-line two-dimensional liquid chromatography/ultra-high performance supercritical fluid chromatography tandem quadrupole time-of-flight mass spectrometry (2D LC/UHPSFC-Q-TOF/MS) system was established for systematic chromatographic separation and identification of bufadienolides. Subsequently, the Global Natural Product Social Molecular Networking (GNPS) was applied for dereplication of chemical components of adjacent fractions with high efficiency and accuracy. The key parameters which affected separation and detection with respect to chromatographic conditions and mass spectrometry conditions were optimized. The extract of Venenum Bufonis was fractionated into forty fractions by first-dimensional reversed phase high-performance liquid chromatography (HPLC), which were further analyzed by the second-dimensional UHPSFC-Q-TOF/MS in positive ion mode. The data of forty fractions was imported into GNPS and processed automatically within about five hours. Furthermore, the chemical components with similar featured fragments were classified into the same cluster, which was helpful for components identification. A total of 229 bufadienolides were characterized and two subclasses of compounds (bufogenins conjugated with carboxylic acid and N-heterocyclic bufogenins) were found in Venenum Bufonis for the first time. In addition, UHPSFC exhibited powerful separation ability of isomers in Venenum Bufonis. In this analysis, two new compounds were isolated and fully characterized by NMR verifying the feasibility of this combined analytical strategy. This integrated strategy can improve the efficiency in the detection of new compounds and offer greater observation of isomers from medicinal herbs and other natural sources.

Chalcone derivatives bearing chromen or benzo[f]chromen moieties: Design, synthesis, and evaluations of anti-inflammatory, analgesic, selective COX-2 inhibitory activities.

Thirty-eight chalconederivatives bearing a chromen or benzo[f]chromen moiety were synthesized and evaluated for their anti-inflammatory and analgesic activities. Using an ear edema model, anti-inflammatory activities were observed for compounds 3a-3s (ear inflammation: 1.75-3.71 mg) and 4a-4s (ear inflammation: 1.71-4.94 mg). All compounds also displayed analgesic effects with inhibition values of 66.7-100% (3a-3s) and 96.2-100% (4a-4s). The 12 compounds that displayed excellent anti-inflammatory and analgesic effects were tested for their inhibitory activity against ovine COX-1 and COX-2. Six compounds bearing a chromen moiety were weak inhibitors of the COX-1 isozyme but showed moderate COX-2 isozyme inhibitory effects (IC50s from 0.37 µM to 0.83 µM) and COX-2 selectivity indexes (SI: 22.49-9.34). Those bearing a benzo[f]chromen moiety were more selective toward COX-2 than those bearing a chromen moiety with IC50s from 0.25 µM to 0.43 µM and COX-2 selectivity indexes from SI: 31.08 to 20.67.

Four New Depsides Isolated from Salvia miltiorrhiza and Their Significant Nerve-Protective Activities.

By investigating of the roots of Salvia miltiorrhiza, which is one of the most widely used Chinese herbs, we used phytochemical methods successfully to obtain twelve depsides: four depsides (1⁻4) that were previously undescribed, along with eight known ones (5⁻12). Their structure characteristics were assessed by HR-ESIMS, CD, NMR (¹H, 13C, HSQC, HMBC) data analyses. These four newly isolated compounds (1⁻4), as well as the other eight compounds (5⁻12), show extraordinary protective effects on hydrogen peroxide-induced apoptosis in HS-SY5Y cells. Among them, depside 4 and depside 6 displayed more obviously protective effects than others.

Lathyrane-Type Diterpenoids from the Seeds of Euphorbia lathyris L. with Inhibitory Effects on NO Production in RAW 264.7 Cells.

Bioactivity-guided fractionation of the methanolic extract from the seeds of Euphorbia lathyris led to the isolation of 18 lathyrane-type diterpenoids including a new one, Euphorbia factor L29 (1). Their chemical structures were elucidated by extensive NMR spectroscopic data including 2D-NMR and HR-ESI-MS as well as CD data. All isolates (1 - 18) were found to inhibit the nitric oxide production in LPS-induced RAW 264.7 macrophages, with their IC50 values in the range of 11.2 - 52.2 µm.

Dimeric- and trimeric sesquiterpenes from the flower of Inula japonica.

An undescribed unusual sesquiterpene trimer and three sesquiterpene dimers were isolated from the flowers of Inula japonica. Their structures were elucidated by extensive analysis of 1D and 2D NMR spectroscopic data as well as HRESIMS data. Inulajaponicolide A has an undescribed carbon skeleton comprising of one xanthanolide and two guaianolide units with the linkage mode of C-11/C-3' and C-11'/C-1'' via a Diels-Alder cycloaddition reaction. Inulajaponicolides C and D exhibited moderate cytotoxic activity against A 549 and NCI-H460 human cancer cell lines with IC50 values ranging from 8.5 to 17.8 µM. Inulajaponicolides A-D and lineariifolianoid A possessed significant inhibitory potency against nitric oxide production in LPS-induced RAW264.7 cells with IC50 values ranging from 1.0 to 4.1 µM.

Cell Cycle Arrest and Apoptosis in HT-29 Cells Induced by Dichloromethane Fraction From Toddalia asiatica (L.) Lam.

The roots of Toddalia asiatica (L.) Lam. (TA) has been often used in Chinese folk medicine to treat different diseases, including but not limited to arthritis, injuries, stomachache, and even tumors. However, the anti-cancer effects and the action mechanisms of TA remain elusive. Therefore, we firstly evaluated the effects of different extracts of TA on the growth of human colon cancer cells, and then tried to further elucidate their underlying molecular mechanisms. As a result, the dichloromethane fraction (DF) was found to possess the highest anti-proliferative activity with IC50 value at 18 µg/mL among all of the four extracts from TA, and strongly inhibited HT-29 cell growth and halted cell cycle progression in G2/M phase. DF also induced phosphatidylserine externalization and activated caspases -8, -9, and -3, suggesting DF induced apoptosis through intrinsic and extrinsic pathways. Furthermore, we found that HT-29 cell cycle arrest induced by DF could be the result of reactive oxygen species (ROS), as the ROS scavenger N-acetyl cysteine (NAC) attenuating it. Taken together, these results indicated that DF induced cell cycle arrest at G2/M phase and apoptosis in HT-29 cells, and could be a promising source for developing natural therapeutics for colon cancer.

Melanogenesis inhibitory pregnane glycosides from Cynanchum atratum.

Bioassay-guided fractionation of the methanolic extract from the roots of Cynanchum atratum has resulted in the isolation of three new pregnane glycosides (1-3) along with four known compounds (4-7). Their structures were identified by analysis of the spectroscopic data including extensive 2D NMR. All of the isolates were evaluated for their potential to inhibit the melanin production in α-melanocyte stimulating hormone (α-MSH)-activated B16 melanoma cells. Of these, compounds 4-7 dose-dependently inhibited the melanin production with the IC50 values ranging from 4 µM to 33 µM.