The Diterpenoid Quinones from Coleus forskohlii

Two new diterpenoid quinones, colean S and T were isolated from the chloroform extract of the leaves of Coleus forskohlii, and based on spectroscopic data, their structures were identified as 1,4-phananthrenedione-4b,5,6,8a,9,10-hexahydro-3,9 beta ,10 alpha- tri-hydroxy-4b,7,8-trimethyl-2-propylene(2), respectively.

Two New Abietane Quinones from Isodon lophanthoides var. Micranthus

The structures of two new abietane quinones, named micranthins A and B, were determined to be 7a-methoxy-14, 16-epoxy-8, 13-abietadiene-11, 12-dione (1) and 16-acetoxy-6, 7-dehydroroyleanone (2) respectively, which were isolated from Isodon lophanthoides var. micranthus.

Theoretical insights on the hydration of quinones as catholytes in aqueous redox flow batteries

Quinones have been widely studied as a potential catholyte in water-based redox flow batteries(RFBs)due to their ability to carry both electrons and protons in aqueous solutions.The wide variety of quinones and derivatives offers exciting opportunities to optimize the device performance while poses theoretical challenges to quantify their electrochemical behavior as required for molecular design.Computational screening of target quinones with high performance is far from satisfactory.While solvation of quinones affects their potential application in RFBs in terms of both electrochemical windows,stability,and charge transport,experimental data for the solvation structure and solvation free energies are rarely available if not incomplete.Besides,conventional thermodynamic models are mostly unreliable to estimate the properties of direct interest for electrochemical applications.Here,we analyze the hydration free energies of more than 1,400 quinones by combining the first-principles calculations and the classical density functional theory.In order to attain chemical insights and possible trends,special attention is placed on the effects of"backbones"and functional groups on the solvation behavior.The theoretical results provide a thermodynamic basis for the design,synthesis,and screening of high-performance catholytes for electrical energy storage.

Abietane Quinones from Rabdosia serra

A new abietane quinone diterpenoid was isolated, together with horminone, 16-acetoxy-7-O-acetylhorminone, beta-sitosterol, stigmasterol. ursolic acid and palmitic acid from the leaves of Rabdosin Serra (MAXIM) Hara. The new compound was elucidated as 16-acetoxy-7 alpha-ethoxyroyleanone.

Two Quinones from the Aerial Parts of Sphallerocarpus gracillis

Two new quinones were isolated from the aerial parts of Sphallerocarpus gracillis. Their structure were determined by spectroscopic methods (HRMS.2D NMR) and finally confirmed by X-ray crystallography.

Studies on Antibacterial QSAR of Diterpene Quinones from Sclvic Przewalskii Maxim

The antibacierial (staphylococcus aureus) activities of 23 diterpene quinones from the Salvia przewalskii Maxim, the artificial synthesis ones and that of the metabolism in pigs were examined in an effort to study the quantitative structure activity relationship with the Free-Wilson method. With the application of the multipiy regression, the Free-Wilson pattern was established by the dummy (indicator) variable of the structural fragments or substituents. The results showed: (1) The diketone moiety played the fundamental role in antibacterial activities, ortho-quinones was higher active than para-quinones. (2) The single bond existed between the C15 and the C16 at D-ring led to higher activity. (3) The saturation at the A-ring led to higher activity. (4) The components adjacent to nitrogen substituents at C15 led to higher activity. (5)The hydroxylation or dehydrogenation at A-ring led to less activity. The research results can provide the theoretical basis for developing a new antibacterial drug from the Salvia diterpene quinones.

Potentiometric Measurement of State-of-Charge of Lead-Acid Batteries Using Polymeric Ferrocene and Quinones Derivatives

Measurement of state-of-charge of lead-acid batteries using potentiometric sensors would be convenient;however, most of the electrochemical couples are either soluble or are unstable in the battery electrolyte. This paper describes the results of an investigation of poly (divinylferrocene) (PDVF) and Poly(diethynylanthraquinone) (PAQ) couples in sulfuric acid with the view to developing a potentiometric sensor for lead-acid batteries. These compounds were both found to be quite stable and undergo reversible reduction/oxidation in sulfuric acid media. Their redox potential difference varied linearly with sulfuric acid concentration in the range of 1 M - 5 M (i.e. simulated lead-acid electrolyte during battery charge/discharge cycles). A sensor based on these compounds has been investigated.

Proliferation Inhibitory Activity of Quinones from Blaps rynchopetera Defense Secretion on Colorectal Tumor Cells

Objective: To explore the proliferation inhibitory effect of quinones from Blaps rynchopetera defense secretion on colorectal tumor cell lines. Methods: Human colorectal cancer cell HT-29, human colorectal adenocarcinoma cell Caco-2 and normal human colon epithelial cell CCD841 were chosen for the evaluation of inhibitory activity of the main quinones of B. rynchopetera defense secretion, including methyl p-benzoquinone(MBQ), ethyl p-benzoquinone(EBQ), and methyl hydroquinone(MHQ), through methyl thiazolyl tetrazolium assay. The tumor-related factors, cell cycles, related gene expressions and protein levels were detected by enzyme-linked immunosorbent assy, flow cytometry, RT-polymerase chain reaction and Western blot, respectively. Results: MBQ, EBQ, and MHQ could significantly inhibit the proliferation of Caco-2, with half maximal inhibitory concentration(IC50) values of 7.04±0.88, 10.92±0.32, 9.35±0.83, HT-29, with IC50values of 14.90±2.71, 20.50±6.37, 13.90±1.30, and CCD841, with IC50values of 11.40±0.68, 7.02±0.44 and 7.83±0.05 μg/mL, respectively. Tested quinones can reduce the expression of tumor-related factors tumor necrosis factor α, interleukin(IL)-10, and IL-6 in HT-29 cells, selectively promote apoptosis, and regulate the cell cycle which can reduce the proportion of cells in the G1phase and increase the proportion of the S phase.Meanwhile, tested quinones could up-regulate mRNA and protein expression of GSK-3β and APC, while down-regulate that of β-catenin, Frizzled1, c-Myc, and CyclinD1 in the Wnt/β-catenin pathway of HT-29 cells.Conclusion: Quinones from B. rynchopetera defense secretion could inhibit the proliferation of colorectal tumor cells and reduce the expression of related factors, which would be functioned by regulating cell cycle, selectively promoting apoptosis, and affecting Wnt/β-catenin pathway-related mRNA and protein expressions.

Terahertz time-domain spectroscopic investigation on quinones

Well resolved far-infrared spectra of 1,4-benzoquinone, 1,4-naphthoquinone, and 9, 10-anthraquinonme in polycrystalline form have been measured with terahertz time domain spectroscopy at room tem- perature. The characterizations of power absorption and index of refraction in the frequency range 0.3 -2.0 THz are presented. Theoretical calculation is applied to assist the analysis and assignment of individual THz absorption spectra of the p-quinones with semiempirical AM1, Hartree-Fock (HF), and density functional theory (DFT) method. Observed THz responses are assigned to the translational and torsional vibrations of p-quinone dimer held together by weak hydrogen bonds.

Pyrroloquinoline quinone:a potential neuroprotective compound for neurodegenerative diseases targeting metabolism

Pyrroloquinoline quinone is a quinone described as a cofactor for many bacterial dehydrogenases and is reported to exert an effect on metabolism in mammalian cells/tissues.Pyrroloquinoline quinone is present in the diet being available in foodstuffs,conferring the potential of this compound to be supplemented by dietary administration.Pyrroloquinoline quinone’s nutritional role in mammalian health is supported by the extensive deficits in reproduction,growth,and immunity resulting from the dietary absence of pyrroloquinoline quinone,and as such,pyrroloquinoline quinone has been considered as a“new vitamin.”Although the classification of pyrroloquinoline quinone as a vitamin needs to be properly established,the wide range of benefits for health provided has been reported in many studies.In this respect,pyrroloquinoline quinone seems to be particularly involved in regulating cell signaling pathways that promote metabolic and mitochondrial processes in many experimental contexts,thus dictating the rationale to consider pyrroloquinoline quinone as a vital compound for mammalian life.Through the regulation of different metabolic mechanisms,pyrroloquinoline quinone may improve clinical deficits where dysfunctional metabolism and mitochondrial activity contribute to induce cell damage and death.Pyrroloquinoline quinone has been demonstrated to have neuroprotective properties in different experimental models of neurodegeneration,although the link between pyrroloquinoline quinone-promoted metabolism and improved neuronal viability in some of such contexts is still to be fully elucidated.Here,we review the general properties of pyrroloquinoline quinone and its capacity to modulate metabolic and mitochondrial mechanisms in physiological contexts.In addition,we analyze the neuroprotective properties of pyrroloquinoline quinone in different neurodegenerative conditions and consider future perspectives for pyrroloquinoline quinone’s potential in health and disease.

NQO1 Mediates Lenvatinib Resistance by Regulating ROS-induced Apoptosis in Hepatocellular Carcinoma

Objective Hepatocellular carcinoma(HCC)is the third leading cause of cancer-associated death worldwide.As a first-line drug for advanced HCC treatment,lenvatinib faces a significant hurdle due to the development of both intrinsic and acquired resistance among patients,and the underlying mechanism remains largely unknown.The present study aims to identify the pivotal gene responsible for lenvatinib resistance in HCC,explore the potential molecular mechanism,and propose combinatorial therapeutic targets for HCC management.Methods Cell viability and colony formation assays were conducted to evaluate the sensitivity of cells to lenvatinib and dicoumarol.RNA-Seq was used to determine the differences in transcriptome between parental cells and lenvatinib-resistant(LR)cells.The upregulated genes were analyzed by GO and KEGG analyses.Then,qPCR and Western blotting were employed to determine the relative gene expression levels.Afterwards,the intracellular reactive oxygen species(ROS)and apoptosis were detected by flow cytometry.Results PLC-LR and Hep3B-LR were established.There was a total of 116 significantly upregulated genes common to both LR cell lines.The GO and KEGG analyses indicated that these genes were involved in oxidoreductase and dehydrogenase activities,and reactive oxygen species pathways.Notably,NAD(P)H:quinone oxidoreductase 1(NQO1)was highly expressed in LR cells,and was involved in the lenvatinib resistance.The high expression of NQO1 decreased the production of ROS induced by lenvatinib,and subsequently suppressed the apoptosis.The combination of lenvatinib and NQO1 inhibitor,dicoumarol,reversed the resistance of LR cells.Conclusion The high NQO1 expression in HCC cells impedes the lenvatinib-induced apoptosis by regulating the ROS levels,thereby promoting lenvatinib resistance in HCC cells.

Steroids, Tri- and Meroterpenoids with a Quinone Structure—A Review

Terpenoids with quinoid structures are found as natural products. This includes steroidal quinones, quinones with a secosteroid structure and meroterpenoid quinones. Importantly, catechol estrogens as endogenous metabolites of estradiol and estrone are precursors of reactive quinones and semiquinones, which are thought to contribute to estrogen-induced carcinogenesis. On the other hand, a number of quinones that include substituted naphthoquinones and anthraquinones are highly cytotoxic and have been used in cancer treatment. This makes the structures interesting synthetic targets. The following is a review of important natural and synthetic terpenoid and steroid quinone hybrids.

Emodin and shikonin(quinones): an overview of their chemistry, plant sources, pharmacology and cytotoxic activities against lung cancer

Emodin and shikonin are quinones that are commonly found in the roots of plant species of the families Polygonaceae and Boraginceae,respectively.They have a wide spectrum of bioactivities,including anti-cancer properties.This overview on the cytotoxic properties of emodin and shikonin is focused on lung cancer,the leading cause of cancer death in the world.In emodin,the-OH groups at C1 and C3 positions,while in shikonin,the-OH groups of the naphthazarin moiety and chiral side-chain,are important for their anti-tumour functions.Studies have shown that emodin and shikonin inhibit the growth of lung cancer cells by inducing apoptosis,autophagy,necrosis and early senescence,and by inhibiting proliferation,invasion,migration and metastasis.The cytotoxic activities are involved multiple molecular targets and signalling pathways.A clinical trial using shikonin to treat patients with late-stage lung cancer has been presented.Some future perspectives and research needs are suggested.Sources of information are from Google Scholar,Pub Med,Science Direct,J-Stage,Pub Chem and CNKI.

Dysideanones F—G and dysiherbols D—E,unusual sesquiterpene quinones with rearranged skeletons from the marine sponge Dysidea avara

Four new sesquiterpene quinone meroterpenoids,dysideanones F—G(1—2)and dysiherbols D—E(3—4),were isolated from the marine sponge Dysidea avara collected from the South China Sea.The new structures were elucidated by extensive analysis of spectroscopic data including HR-MS and 1D and 2D NMR spectra,and their absolute configurations were assigned by single-crystal X-ray diffraction and ECD calculations.Anti-inflammatory evaluation showed that dysiherbols D—E(3—4)exhibited moderate inhibitory activity on TNF-α-induced NF-κB activation in human HEK-293T cells with IC_(50)values of 10.2 and 8.6μmol·L^(-1),respectively.

Visible-Light-Promoted[3+2]Cycloaddition of 2H-Azirines with Quinones:Access to Substituted Benzo[f]isoindole-4,9-diones

A visible-light-promoteded[3+2]cycloaddition reaction of 2H-azirines with quinones has been developed under mild reaction con-ditions.The reaction provides a general and efficient strategy for the synthesis of the benzo[f]isoindole-4,9-diones scaffold via a tandem[3+2]cyclization/oxidative aromatization with molecular oxygen.Furthermore,preliminary studies for photocatalytic prop-erties show that the benzo[f]isoindole-4,9-diones 3 can be used as photocatalysts in several organic transformations.

Detection and Identification of a Novel Quinone Ketoxy Radical Produced by Metal-independent Decomposition of Hydroperoxides by Halogenated Quinones

We have shown recently that halogenated quinones could enhance the decomposition of hydroperoxides and formation of alkoxyl/hydroxyl radicals independent of transition

Molecular Engineering Design for High-Performance Aqueous Zinc-Organic Battery

Novel small sulfur heterocyclic quinones(6a,16adihydrobenzo[b]naphtho[2′,3′:5,6][1,4]dithiino[2,3-i]thianthrene-5,7,9,14,16,18-hexaone(4S6Q)and benzo[b]naphtho[2′,3′:5,6][1,4]dithiino[2,3-i]thianthrene-5,9,14,18-tetraone(4S4Q))are developed by molecule structural design method and as cathode for aqueous zincorganic batteries.The conjugated thioether(–S–)bonds as connected units not only improve the conductivity of compounds but also inhibit their dissolution by both extendedπ-conjugated plane and constructed flexible molecular skeleton.Hence,the Zn//4S6Q and Zn//4S4Q batteries exhibit satisfactory electrochemical performance based on 3.5 mol L-1(M)Zn(ClO4)2electrolyte.For instance,the Zn//4S6Q battery obtains 240 and 208.6 mAh g^(-1)of discharge capacity at 150 mA g^(-1)and 30 A g^(-1),respectively.The excellent rate capability is ascribed to the fast reaction kinetics.This system displays a superlong life of 20,000 cycles with no capacity fading at 3 A g^(-1).Additionally,the H+-storage mechanism of the 4S6Q compound is demonstrated by ex situ analyses and density functional theory calculations.Impressively,the battery can normally work at-60℃benefiting from the anti-freezing electrolyte and maintain a high discharge capacity of 201.7 mAh g^(-1),which is 86.2%of discharge capacity at 25℃.The cutting-edge electrochemical performances of these novel compounds make them alternative electrode materials for Zn-organic batteries.

Effect of miR-27b-3p and Nrf2 in human retinal pigment epithelial cell induced by high-glucose

AIM:To determine whether the microRNA-27b-3p(miR-27b-3p)/NF-E2-related factor 2(Nrf2)pathway plays a role in human retinal pigment epithelial(hRPE)cell response to high glucose,how miR-27b-3p and Nrf2 expression are regulated,and whether this pathway could be specifically targeted.METHODS:hRPE cells were cultured in normal glucose or high glucose for 1,3,or 6d before measuring cellular proliferation rates using cell counting kit-8 and reactive oxygen species(ROS)levels using a dihydroethidium kit.miR-27b-3p,Nrf2,NAD(P)H quinone oxidoreductase 1(NQO1)and heme oxygenase-1(HO-1)mRNA and protein levels were analyzed using reverse transcription quantitative polymerase chain reaction(RT-qPCR)and immunocytofluorescence(ICF),respectively.Western blot analyses were performed to determine nuclear and total Nrf2 protein levels.Nrf2,NQO1,and HO-1 expression levels by RT-qPCR,ICF,or Western blot were further tested after miR-27b-3p overexpression or inhibitor lentiviral transfection.Finally,the expression level of those target genes was analyzed after treating hRPE cells with pyridoxamine.RESULTS:Persistent exposure to high glucose gradually suppressed hRPE Nrf2,NQO1,and HO-1 mRNA and protein levels and increased miR-27b-3p mRNA levels.High glucose also promoted ROS release and inhibited cellular proliferation.Nrf2,NQO1,and HO-1 mRNA levels decreased after miR-27b-3p overexpression and,conversely,both mRNA and protein levels increased after expressing a miR-27b-3p inhibitor.After treating hRPE cells exposed to high glucose with pyridoxamine,ROS levels tended to decreased,proliferation rate increased,Nrf2,NQO1,and HO-1 mRNA and protein levels were upregulated,and miR-27b-3p mRNA levels were suppressed.CONCLUSION:Nrf2 is a downstream target of miR-27b-3p.Furthermore,the miR-27b-3p inhibitor pyridoxamine can alleviate high glucose injury by regulating the miR-27b-3p/Nrf2 axis.

醌类电极材料Calix[4]quinone在二次电池中的应用

随着社会对大型储能设备的环保、充放电性能以及可持续发展的要求越来越高,基于金属氧化物的传统锂/钠离子电极材料受限于比容量,已难以满足未来储能系统的要求。有机材料、锂-硫/氧、液态流体等电池的研发与应用已成为未来能源系统研究的重要内容。其中,有机正极材料中的羰基类化合物Calix[4]quinone(C4Q)是一种很有前途的正极材料。该分子的空间位阻小,8个羰基结构都能发生可逆电极反应,其理论比容量高达446mA·h/g,远超传统无机电极材料。C4Q不仅可以作为储锂材料,也可作为钠、锌、镁等二次电池的电极材料。本文分别介绍了C4Q在锂、钠二次电池和锌水系电池中的应用成果,并对C4Q今后进一步的开发利用做了展望。

CIDNP Study of Photoinduced [2+2] Cycloadditions (the Paterno- Büchi Coupling) of Arylacetylenes and Quinone

CIDNP techniques were applied to study the mechanism of photocycloadditions of 2-chloro-5-methoxybenzoquinone 1 with arylacetylenes 2-5 in benzene-d6 and acetonitrile-d6 respectively.