Ferroelectrovalley in Two-Dimensional Multiferroic Lattices.

Engineering the valley index is essential and highly sought for valley physics, but currently, it is exclusively based on the paradigm of the challenging ferrovalley with spin-orientation reversal under a magnetic field. Here, an alternative strategy, i.e., the so-called ferroelectrovalley, is proposed to tackle the insurmountable spin-orientation reversal, which reverses the valley index with the feasible ferroelectricity. Using symmetry arguments and the tight-binding model, the C2z rotation is unveiled to be able to take the place of time reversal for operating the valley index in two-dimensional multiferroic kagome lattices, which enables a ferroelectricity-engineered valley index, thereby generating the concept of a ferroelectrovalley. Based on first-principles calculations, this concept is further demonstrated in the breathing kagome lattice of single-layer Ti3Br8, wherein ferroelectricity couples with the breathing process. These findings open a new direction for valleytronics and 2D materials research.

Chemical Composition of Artemisia Scoparia and Their Bioactivities.

Three undescribed sesquiterpenes (1-3), two enantiomeric pairs of monoterpenes (4a/4b-5a/5b), one alkyne (6), two known alkynes (7-8) and eight known coumarins (9-16) were isolated from the aerial parts extracts of Artemisia scoparia. The structures of these compounds were fully elucidated by their 1D and 2D NMR, HRESIMS spectral data analyses, and comparison with literature. The absolute configurations of compounds were determined by single-crystal X-ray crystallography (1), a comparison of experimental and calculated electronic circular dichroism (ECD) data (2-6). 15 showed moderate inhibitory activity with the NO release in LPS-induced RAW264.7 cells. 9-16 showed varying degrees of promoting melanogenesis and tyrosinase activity in B16 cells.

Exploring anti-inflammatory and antioxidant-related quality markers of Artemisia absinthium L. based on spectrum-effect relationship.

INTRODUCTION: Artemisia absinthium L. is a well-known medicinal, aromatic, and edible plant with important medicinal and economic properties and a long history of use in treating liver inflammation and other diseases; however, there has been insufficient progress in quality control. OBJECTIVE: This study aimed to investigate the quality markers for the anti-inflammatory and antioxidant activities of A. absinthium based on spectrum-effect relationship analysis. MATERIALS AND METHODS: Eighteen batches of A. absinthium from different origins were used. Chemical fingerprints were obtained by ultra-performance liquid chromatography (UPLC). The chemical compositions were identified by quadrupole-Orbitrap high-resolution mass spectrometry. Anti-inflammatory activity was assessed by inhibition of cyclooxygenase-2 and 15-lipoxygenase in vitro and inhibition of nitric oxide release in lipopolysaccharide-induced BV-2 cells. Antioxidant activity was assessed by DPPH and ABTS radical scavenging assays. The relationship between bioactivity and chemical fingerprints was then analyzed using chemometrics including gray relational analysis, bivariate correlation analysis, and orthogonal partial least squares analysis. RESULTS: Different batches of A. absinthium extracts possessed significant anti-inflammatory and antioxidant activities to varying degrees. Eighty compounds were identified from A. absinthium, and 12 main common peaks were obtained from the UPLC fingerprints. P3 (chlorogenic acid), P5 (isochlorogenic acid A), and P6 (isochlorogenic acid C) were screened as the most promising active compounds by correlation analysis and further validated for their remarkable anti-inflammatory effects. CONCLUSION: This is the first study to screen the quality markers of A. absinthium by establishing the spectrum-effect relationship, which can provide a reference for the development of quality standards and further research on A. absinthium.

Discovery of novel (E)-1-methyl-9-(3-methylbenzylidene)-6,7,8,9-tetrahydropyrazolo[3,4-d]pyrido[1,2-a]pyrimidin-4(1H)-one as DDR2 kinase inhibitor: Synthesis, molecular docking, and anticancer properties.

We report the synthesis, molecular docking and anticancer properties of the novel compound (E)-1-methyl-9-(3-methylbenzylidene)-6,7,8,9-tetrahydropyrazolo[3,4-d]pyrido[1,2-a]pyrimidin-4(1H)-one (PP562). PP562 was screened against sixteen human cancer cell lines and exhibited excellent antiproliferative activity with IC50 values ranging from 0.016 to 5.667 µM. Experiments were carried out using the target PP562 at a single dose of 1.0 µM against a kinase panel comprising 100 different enzymes. A plausible binding mechanism for PP562 inhibition of DDR2 was determined using molecular dynamic analysis. The effect of PP562 on cell proliferation was also examined in cancer cell models with both high and low expression of the DDR2 gene; PP562 inhibition of high-expressing cells was more prominent than that for low expressing cells. PP562 also exhibits excellent anticancer potency toward the HGC-27 gastric cancer cell line. In addition, PP562 inhibits colony formation, cell migration, and adhesion, induces cell cycle arrest at the G2/M phase, and affects ROS generation and cell apoptosis. After DDR2 gene knockdown, the antitumor effects of PP562 on tumor cells were significantly impaired. These results suggested that PP562 might exert its inhibitory effect on HCG-27 proliferation through the DDR2 target.

Design, combinatorial synthesis and cytotoxic activity of 2-substituted furo[2,3-d]pyrimidinone and pyrrolo[2,3-d]pyrimidinone library.

A facile protocol was developed for the combinatorial synthesis of furo[2,3-d]pyrimidinone and pyrrolo[2,3-d]pyrimidinone library via a one-pot condensation, from 2-amino furans/pyrroles. Herein reported process required a similar reaction condition, providing mild access to two diverse series of natural product-like heterocycles. Both furo[2,3-d]pyrimidinones and pyrrolo[2,3-d]pyrimidinones were evaluated in vitro against a panel of human cancer cell lines including against human cancer HeLa (cervical), MCF-7 (breast) and HT-29 (colon) cell lines. Derivative 12n ((2-(4-chlorophenyl)-1-methyl-6,7,8,9-tetrahydropyrido[1,2-a]pyrrolo[2,3-d]pyrimidin-4(1H)-one)) showed high activity (IC50 = 6.55 ± 0.31 µM) against the HeLa cell line. These products could be subjected to a various modification and therefore represent important skeletons for the anticancer drug discovery.

Furo[2,3-d]pyrimidines as Mackinazolinone/Isaindigotone Analogs: Synthesis, Modification, Antitumor Activity, and Molecular Docking Study.

The chemical transformation of the tricyclic furo[2,3-d]pyrimidines was performed under isosteric and scaffold-hopping strategies focusing on the synthesis of its arylidene and imine-containing derivatives. Naturally-occurring alkaloids mackinazolinone and isaindigotone were as templates of target heterocycles. Synthesized compounds evaluated for their antitumor activity on human cancer cervical HeLa, breast MCF-7, and colon HT-29 cell lines. Four compounds: 8c, 8e, 10b, and 10c demonstrated potency against HeLa and HT-29 cell lines, and IC50 values were between 7.37-13.72 µM, respectively. The molecular docking results showed that compounds 8c and 10b had good binding and high matching with the target EGFR protein.

Two New C19 -Diterpenoid Alkaloids from Delphinium shawurense.

Shawurenine C (1a) and D (1b), a new pair of regioisomeric C19 -diterpenoid alkaloids, and five known C19 -diterpenoid alkaloids (2-6) were isolated from the aerial part of Delphinium shawurense W. T. Wang. The chemical structures of new compounds were established based on spectroscopic analyses: HR-ESI-MS, and 1D, 2D NMR spectroscopic data. The anti-inflammatory and cytotoxic activities of these diterpenoid alkaloids were also evaluated.

Enantioselective construction of substituted pyridine and a seven-membered carbocyclic skeleton: biomimetic synthesis of (-)-rupestine D, (-)-guaipyridine, (-)-epiguaipyridine, and (-)-cananodine and their stereoisomers.

Guaipyridine alkaloids (-)-rupestine D, (-)-guaipyridine, (-)-epiguaipyridine, and (-)-cananodine together with two stereoisomers 8-epi-rupestine D and 5-epi-cananodine were synthesized enantioselectively from readily available citronellol. The key steps in this synthesis are (i) intermolecular opening of a trisubstituted epoxide for the formation of a chiral center at C-8; (ii) ring-closing metathesis for the construction of a seven-membered carbocyclic ring; and (iii) biomimetic cyclization of a 1,5-dicarbonyl compound for the construction of a pyridine-fused bicyclic skeleton.

Synthesis and anticancer activity of ethyl 5-amino-1-N-substituted-imidazole-4-carboxylate building blocks.

A series of 5-amino-1-N-substituted-imidazole-4-carboxylate building blocks was synthesized and assayed for their antiproliferative potential against human cancer cell lines, including HeLa (cervical), HT-29, HCT-15 (colon), A549 (lung), and MDA-MB-231 (breast) cells. The preliminary screening results revealed that several derivatives containing alkyl chains at the N-1 position of the imidazole core demonstrate a certain inhibitory effect on growth and proliferation. A significant effect was observed following ethyl 5-amino-1-dodecyl-1H-imidazole-4-carboxylate (5e) treatment for 72 h. The IC50 value for HeLa cells was 0.737 ± 0.05 µM, whereas that for HT-29 cells was 1.194 ± 0.02 µM. Further investigations revealed that 5e significantly inhibited tumor cell colony formation and migration, and it exhibited antiadhesive effects on HeLa cells as well as antitubulin activity along with the induction of early apoptosis of HeLa and HT-29 cells. In addition, derivative 5e significantly reduced the cell mitochondrial membrane potential in a dose-dependent manner and induced early apoptosis of HeLa and HT-29 cells, indicating that 5e may serve as a lead compound for further drug discovery and development.

Novel amides modified rupestonic acid derivatives as anti-influenza virus reagents.

In spired by the important role of amide groups of anti-influenza drugs oseltamivir, zanamivir and peramivir in bioactivity, a series of novel amides modified rupestonic acid derivatives were designed and synthesized. The absolute configuration of critical intermediate bearing chloride with newly formed stereocenter was confirmed by X-ray crystallographic analysis. And all new compounds were evaluated for their in vitro inhibitory activities against influenza A (H1N1 and H3N2) and influenza B viruses. The bioassay results showed that 5h with 4-fluorbenzylsulfonyl modified to 2 position of methyl rupestonate displayed the highest activity against influenza A (H1N1 and H3N2) viruses, even stronger than reference drugs oseltamivir and ribavirin (RVB), and might be recommended as a lead compound to further develop the new anti-influenza reagent.

1,2,3-Triazole-containing hybrids as leads in medicinal chemistry: A recent overview.

The 1,2,3-triazole ring is a major pharmacophore system among nitrogen-containing heterocycles. These five-membered heterocyclic motifs with three nitrogen heteroatoms can be prepared easily using 'click' chemistry with copper- or ruthenium-catalysed azide-alkyne cycloaddition reactions. Recently, the 'linker' property of 1,2,3-triazoles was demonstrated, and a novel class of 1,2,3-triazole-containing hybrids and conjugates was synthesised and evaluated as lead compounds for diverse biological targets. These lead compounds have been demonstrated as anticancer, antimicrobial, anti-tubercular, antiviral, antidiabetic, antimalarial, anti-leishmanial, and neuroprotective agents. The present review summarises advances in lead compounds of 1,2,3-triazole-containing hybrids, conjugates, and their related heterocycles in medicinal chemistry published in 2018. This review will be useful to scientists in research fields of organic synthesis, medicinal chemistry, phytochemistry, and pharmacology.

Structural modification on rupestonic acid leads to highly potent inhibitors against influenza virus.

Influenza viruses are responsible for seasonal epidemics and occasional pandemics, which cause significant morbidity and mortality. Although several drugs (adamantanes and neuraminidase inhibitors) are available in the market, the worldwide spread of drug-resistant influenza strains poses an urgent need for novel antiviral drugs. Artemisia rupestris L. is a folk medicine used to treat cold. In this paper, we structurally modified rupestonic acid, a bioactive component of A. rupestris, to synthesize a series of 2-substituted rupestonic acid methyl esters (3a-3o). Their structures were fully characterized by 1H NMR, 13C NMR, HRMS spectra. Among them, compounds 3b and 3c exhibited potent activities against influenza H1N1 with micromolar IC50 values and might serve as new lead compounds for the treatment of influenza.

Structure-activity relationship studies of 1-(1'-hydroxyalkyl)rupestonic acid methyl esters against influenza viruses.

A series of 1-(1'-hydroxyalkyl)rupestonic acid methyl esters were synthesized via the condensation of methyl rupestonate with various aldehydes in the presence of LDA. This mixed aldol reaction was highly stereoselective and all the new compounds were elucidated by detailed NMR and MS analyses. The absolute configurations of the newly formed stereocenters were further confirmed by X-ray crystallographic analysis of 3d, the results of which were found to be opposite to the prediction based on Zimmerman-Traxler's and Houk's models. All the compounds synthesized were then evaluated for their in vitro inhibitory activities against influenza A (H1N1 and H3N2) and B viruses. The data showed that 3p displayed the highest activity against influenza A H1N1 (IC50=0.69µg/mL) and H3N2 (IC50=0.69µg/mL) viruses, which were even better than Ribavirin and Oseltmivir. On the other hand, both 3c and 3o were found to show comparable activities with the reference drugs in inhibiting both influenza A and B viruses. Further studies will focus on reducing the cytotoxicity of the hits reported in this work.

Identification of metabolites of rupestonic acid in rat urine by liquid chromatography combined with electrospray ionization quadrupole time-of-flight tandem mass spectrometry.

Rupestonic acid, a potential anti-influenza agent, is an important and characteristic compound in Artemisia rupestris L., a well-known traditional Uighur medicine for the treatment of colds. In the present study, high-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight tandem mass spectrometry was used to detect and identify the metabolites in rat urine after oral administration of rupestonic acid. A total of 10 metabolites were identified or partially characterized. The structure elucidations of the metabolites were performed by comparing the changes in accurate molecular masses and fragment ions with those of the parent compound. The results showed that the main metabolites of rupestonic acid in rat urine were formed by oxidation, hydrogenation and glucuronidation. A metabolism pathway was proposed for the first time based on the characterized structures. This metabolism study can provide essential information for drug discovery, design and clinical application of rupestonic acid.

Diprenylated phenolic enantiomers from Artemisia scoparia.

Investigation on the chemical constituents of Artemisia scoparia resulted in the isolation of sixteen compounds, including undescribed six pairs of diprenylated phenolic enantiomers (±)-scopacoumaricin A-F, and two pairs of cis-trans isomers cis/trans-scopacoumaricin G and cis/trans-artepillin A. Trans-artepillin A was obtained from this plant for the first time. The structures of the isolates were proposed by analysis of their 1D, 2D-NMR and HRESIMS spectroscopic data. Their absolute configurations were determined by comparison of their experimental and calculated electronic circular dichroism spectra. Evaluations of the anti-inflammatory activity revealed that (-)-scopacoumaricin D, (+)-scopacoumaricin F and cis-scopacoumaricin G showed moderate anti-inflammatory activity on lipopolysaccharide-induced nitric oxide production in RAW264.7 cell.

Phytochemical study on ethyl acetate fraction of Lepidium obtusum Basin.

Three undescribed compounds (1-3), including two butenolides and one indol alkaloids. Together with twenty-one known compounds (4-24) were isolated and identified from Lepidium obtusum Basin. Their structures were elucidated by spectroscopic analysis and ECD calculations. The isolated compounds were tested for their antimicrobial, antioxidant, and anti-inflammatory activities. Among them, compounds 11, 12, 14, 21 and 23 showed moderated antimicrobial activities against (Candida albicans, E. coli, Staphylococcus aureus). Compounds 11, 12, 14, 15, 17 and 18 exhibited potent antioxidant activities against ABTS and DPPH. Compound 1 exhibited moderated anti-inflammatory activities. Compounds 4-24 were isolated from this plant for the first time.

seco-iridoid glycosides and flavonoid glycosides from the Gentiana olivieri Griseb and their anti-inflammatory activities.

Three undescribed seco-iridoid glycosides, one undescribed flavonoid glycoside, and three known glycosides were isolated and identified from Gentiana olivieri Griseb. The structures of these compounds were determined through spectroscopic analysis and ECD calculations. Olivierisecosides NP (1-3) were identified as aromatic conjugated seco-iridoid glucosides, among them olivierisecoside N was representing a particularly rare subtype known as the morroniside seco-iridoids. The compounds 2, 3, 5, and 6 exhibited significant inhibition of COX-2 expression, particularly compound 5 which demonstrated the most pronounced inhibitory activity with IC50 value of 23.33 ± 0.51 µM. This study provides evidence for the potential development and utilization of G. olivieri as a source of anti-inflammatory components.

New coumarin from the roots of Prangos pabularia growing wild in Tajikistan.

Dichloromethane and butanol extracts of the roots of Prangos pabularia were analyzed to determine chemical constituents and biological activity. The new coumarin 1, yuganin B ((5-(((2S,3R,4S,5S,6R)-4,5-dihydroxy-6-(hydroxymethyl)-2-((2-oxo-2H-chromen-7-yl)oxy)tetrahydro-2H-pyran-3-yl)oxy)-3,4-dihydroxytetrahydrofuran-3-yl)methyl 4-hydroxy-3-methoxybenzoate) along with three phenolic and twenty-four known coumarins were isolated from the roots of Prangos pabularia, and the structures of these isolated compounds were elucidated by UV, HR-ESIMS, and 1 D and 2 D NMR spectroscopy. In addition, the anti-melanogenic effect of several of the isolated individual compounds and their inhibitory effect on B16 cells were evaluated. Isolating and testing compounds may proof to be useful in the treatment of hyperpigmentation and as a skin-whitening agent in the cosmetics industry.

Seco-iridoid glycosides from the Gentiana olivieri Griseb and their bioactivities.

The ethanol extract of the Gentiana olivieri Griseb plant was subjected to an investigation to ascertain the presence of its iridoid constituents. By means of HPLC and TLC monitoring, a total of thirteen previously unreported seco-iridoid glucosides olivierisecoside A-M, as well as seven known seco-iridoid glycosides and one known iridoid glycoside were isolated. Their structures were elucidated by a comprehensive spectroscopic data analysis and ECD calculations. The absolute configuration of olivierisecoside D was further confirmed through single-crystal X-ray diffraction analysis. All the identified compounds were characterized as aromatic conjugated seco-iridoid glucosides, with olivierisecoside F-I representing a particularly rare subtype known as the morroniside type seco-iridoids. In vitro testing of the isolated compounds revealed their potential anti-inflammatory and hepatoprotective effects. The results showed olivieroside B and 6'-gentisoyl-8-epi-kingiside have good anti-inflammatory activities in LPS induced RAW264.7 cells. Additionally, olivierisecoside M exhibited some improvements in PA-induced L02 and HepG2 cells damage, known compound loganin showed slight hepatoprotective effect in PA-induced HepG2 cells damage.

Pharmacokinetic Study and Metabolite Identification of CAM106 in Rats by Validated UHPLC-MS/MS.

Given the limitations of existing antiviral drugs and vaccines, there is still an urgent need for new anti-influenza drugs. CAM106, a rupestonic acid derivative, was studied for its potent antiviral activity and showed a favorable inhibitory effect on influenza virus replication. However, many gaps exist in preclinical studies of CAM106. This study focused on the pharmacokinetic profile and metabolites of CAM106 in vivo. An efficient and fast bioanalytical method was successfully developed and validated for the quantitation of CAM106 in rat plasma. A mobile phase aqueous solution (A, containing 0.1% formic acid) and acetonitrile (B) worked within 0-3.5 min, with 60% B. The mass spectrum scanning mode was the parallel reaction monitoring (PRM) with a resolution of 17,500. The linear range of the method was 2.13-1063.83 ng/mL. The validated method was applied to a pharmacokinetic study in rats. The matrix effects ranged from 93.99% to 100.08% and the recovery ranged from 86.72% to 92.87%. The intra- and inter-day precisions were less than 10.24% and the relative error (RE) ranged from -8.92% to 7.1%. The oral bioavailability of CAM106 was 1.6%. Thereafter, its metabolites in rats were characterized using high-resolution mass spectrometry. The isomers M7-A, M7-B, M7-C, and M7-D were well separated. As a result, a total of 11 metabolites were identified in the feces, urine, and plasma of rats. The main metabolic pathways of CAM106 were oxidation, reduction, desaturation, and methylation. The assay was reliable and provided useful information for further clinical studies of CAM106.