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,...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.展开更多
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 ...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.展开更多
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 we...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.展开更多
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 propert...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.展开更多
Plants of the genus Cordia(Boraginaceae family)are widely distributed in the tropical regions of America,Africa,and Asia.They are extensively used in folk medicine due to their rich medicinal properties.This review pr...Plants of the genus Cordia(Boraginaceae family)are widely distributed in the tropical regions of America,Africa,and Asia.They are extensively used in folk medicine due to their rich medicinal properties.This review presents a comprehensive analysis of the isolation,structure,biogenesis,and biological properties of quinones from Cordia species reported from 1972 to 2023.Meroterpenoids were identified as the major quinones in most Cordia species and are reported as a chemotaxonomic markers of the Cordia.In addition to this property,quinones are reported to display a wider and broader spectrum of activities,are efficient scaffold in biological activity,compared to other classes of compounds reported in Cordia,hence our focus on the study of quinones reported from Cordia species.About 70 types of quinones have been isolated,while others have been identified by phytochemical screening or gas chromatography.Although the biosynthesis of quinones from Cordia species is not yet fully understood,previous reports suggest that they may be derived from geranyl pyrophosphate and an aromatic precursor unit,followed by oxidative cyclization of the allylic methyl group.Studies have demonstrated that quinones from this genus exhibit antifungal,larvicidal,antileishmanial,anti-inflammatory,antibiofilm,antimycobacterial,antioxidant,antimalarial,neuroinhibitory,and hemolytic activities.In addition,they have been shown to exhibit remarkable cytotoxic effects against several cancer cell lines which is likely related to their ability to inhibit electron transport as well as oxidative phosphorylation,and generate reactive oxygen species(ROS).Their biological activities indicate potential utility in the development of new drugs,especially as active components in drug-carrier systems,against a broad spectrum of pathogens and ailments.展开更多
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 deriva...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.展开更多
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. T...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.展开更多
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.
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 qu...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.展开更多
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 p...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.展开更多
Quinones,as highly redox active molecules in biology,are believed to react with hydroperoxides to produce highly reactive•OH,assuming that radical adducts are exclusively formed by the addition of free radicals to the...Quinones,as highly redox active molecules in biology,are believed to react with hydroperoxides to produce highly reactive•OH,assuming that radical adducts are exclusively formed by the addition of free radicals to the spin trap as detected by the electron paramagnetic resonance(EPR)methodology.Here,direct formation of the same DMPO adduct as that formed by genuine radical trapping of•OH is discovered,while quinones(i.e.,1,4-benzoquinone(BQ),methyl-BQ(2-Me-BQ,2,5-Me-BQ,2,6-Me-BQ),and chlorinated-BQ(2-Cl-BQ,2,5-Cl-BQ,2,6-Cl-BQ))meet with the spin trap 5,5-dimethyl-1-pyrroline N-oxide(DMPO),independent of peroxides.According to differences in alcohol-derived adducts(e.g.,DMPO-CH2OH or DMPO-OCH3)while alcohol is attacked by•OH or DMPO•+,a nonradical mechanism is proposed for the BQ/DMPO system.This is further evidenced by the mass spectrometry data in which DMPO-OCH3 has been identified in BQ(or chlorinated-BQ)/DMPO systems.17O incorporation experiments verify that hydroxyl oxygen in DMPO-OH originates from water.The DMPO-OH adduct might be formed via direct oxidation and water substitution or one-electron oxidation and nucleophilic addition.This study provides a peroxide-independent alternative route leading to DMPO-OH adduct in quinone-based systems,which has profound implications for assessing adverse health effects and even biogeochemical impacts of quinones if EPR is applied.展开更多
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 charac...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.展开更多
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 adenocarcin...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.展开更多
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 ben...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.展开更多
The first total synthesis of marine sesquiterpene(hydro)quinone meroterpenoids dysideanones A and E–G(1 and 4–6)has been accomplished in an enantioselective and divergent way.The sesquiterpene fragment and the aroma...The first total synthesis of marine sesquiterpene(hydro)quinone meroterpenoids dysideanones A and E–G(1 and 4–6)has been accomplished in an enantioselective and divergent way.The sesquiterpene fragment and the aromatic moiety were efficiently connected via a site-selective and diastereoselective intermolecular alkylation of Wieland–Miescher ketone derivative 9 and benzyl bromide 10.The core 6/6/6/6-fused backbone of dysideanones was efficiently constructed through an intramolecular radical cyclization reaction.Dysideanone G(6)was easily prepared on a gram-scale and dysideanones A,E,and F(1,4,and 5)were divergently transformed from dysideanone G(6)in one or two steps.展开更多
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 di...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.展开更多
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-t...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.展开更多
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.
Photocatalytic splitting of water was carried out in a two-phase system. Nanocrystalline titanium dioxide was used as photocatalyst and potassium hexacyanoferrate(III)/(II) as electron transporter. Generated hydrogen ...Photocatalytic splitting of water was carried out in a two-phase system. Nanocrystalline titanium dioxide was used as photocatalyst and potassium hexacyanoferrate(III)/(II) as electron transporter. Generated hydrogen was chemically stored by use of a 1,4-benzoquinone/1,4-hydroquinone system, which was used as a recyclable fuel in a commercialised direct methanol fuel cell (DMFC). The electrical output of the cell was about half compared to methanol. The conversion process for water splitting and recombination in a fuel cell was monitored by UV-Vis spectroscopy and compared to a simulated spectrum. Products of side reactions, which lead to a decrease of the overall efficiency, were identified based on UV-Vis investigations. A proof of principle for the use of quinoide systems as a recyclable hydrogen storage system in a photocatalytic water splitting and fuel cell cyclic process was given.展开更多
基金Project supported by the Applied Basic Research Foundation of Yunnan Province (1999C0081M). Authors would like to thank the staf
文摘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.
基金supported by the National Key Research and Development Program of China(No.2018YFC 0310900)the National Natural Science Foundation of China(Nos.U1605221,82022068,81773866,41906075,and 41576130)。
文摘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.
文摘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.
文摘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.
基金XS-N kindly acknowledges a National Research Foundation(NRF)Competitive Support for Unrated Researchers(CSUR)grant,Reference Number:SRUG2203291031.
文摘Plants of the genus Cordia(Boraginaceae family)are widely distributed in the tropical regions of America,Africa,and Asia.They are extensively used in folk medicine due to their rich medicinal properties.This review presents a comprehensive analysis of the isolation,structure,biogenesis,and biological properties of quinones from Cordia species reported from 1972 to 2023.Meroterpenoids were identified as the major quinones in most Cordia species and are reported as a chemotaxonomic markers of the Cordia.In addition to this property,quinones are reported to display a wider and broader spectrum of activities,are efficient scaffold in biological activity,compared to other classes of compounds reported in Cordia,hence our focus on the study of quinones reported from Cordia species.About 70 types of quinones have been isolated,while others have been identified by phytochemical screening or gas chromatography.Although the biosynthesis of quinones from Cordia species is not yet fully understood,previous reports suggest that they may be derived from geranyl pyrophosphate and an aromatic precursor unit,followed by oxidative cyclization of the allylic methyl group.Studies have demonstrated that quinones from this genus exhibit antifungal,larvicidal,antileishmanial,anti-inflammatory,antibiofilm,antimycobacterial,antioxidant,antimalarial,neuroinhibitory,and hemolytic activities.In addition,they have been shown to exhibit remarkable cytotoxic effects against several cancer cell lines which is likely related to their ability to inhibit electron transport as well as oxidative phosphorylation,and generate reactive oxygen species(ROS).Their biological activities indicate potential utility in the development of new drugs,especially as active components in drug-carrier systems,against a broad spectrum of pathogens and ailments.
基金supported by the National Natural Science Foundation of China(U1862204)the U.S.National Science Foundation(NSF-1940118)。
文摘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.
文摘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.
文摘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.
基金This work was supported by a grant from the National Tackle Key Projects of Chinathe project of sciences and techniques of CAAS.
文摘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.
文摘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.
基金supported by Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration(SHUES2023C02)the National Natural Science Foundation of China(Nos.21677031,41977313)+1 种基金the Fundamental Research Funds for the Central UniversitiesZ.W.thanks the support from the Science&Technology Innovation Action Plan of Shanghai under the Belt and Road Initiative(No.19230742800).
文摘Quinones,as highly redox active molecules in biology,are believed to react with hydroperoxides to produce highly reactive•OH,assuming that radical adducts are exclusively formed by the addition of free radicals to the spin trap as detected by the electron paramagnetic resonance(EPR)methodology.Here,direct formation of the same DMPO adduct as that formed by genuine radical trapping of•OH is discovered,while quinones(i.e.,1,4-benzoquinone(BQ),methyl-BQ(2-Me-BQ,2,5-Me-BQ,2,6-Me-BQ),and chlorinated-BQ(2-Cl-BQ,2,5-Cl-BQ,2,6-Cl-BQ))meet with the spin trap 5,5-dimethyl-1-pyrroline N-oxide(DMPO),independent of peroxides.According to differences in alcohol-derived adducts(e.g.,DMPO-CH2OH or DMPO-OCH3)while alcohol is attacked by•OH or DMPO•+,a nonradical mechanism is proposed for the BQ/DMPO system.This is further evidenced by the mass spectrometry data in which DMPO-OCH3 has been identified in BQ(or chlorinated-BQ)/DMPO systems.17O incorporation experiments verify that hydroxyl oxygen in DMPO-OH originates from water.The DMPO-OH adduct might be formed via direct oxidation and water substitution or one-electron oxidation and nucleophilic addition.This study provides a peroxide-independent alternative route leading to DMPO-OH adduct in quinone-based systems,which has profound implications for assessing adverse health effects and even biogeochemical impacts of quinones if EPR is applied.
基金Supported by the National Natural Science Foundation of China (Grant No. 10675158)the major project of the Shanghai Municipal Commission of Science and Technology (Grant No. 06dj14008)
文摘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.
基金National Natural Science Foundation of China(No.81960755)Bio-pharmaceutical Major Project of Yunnan Province(No.202002AA100007)+1 种基金Yunnan Fundamental Research Project(No.202001AU070022)Program for Innovative Research Team of Yunnan Province(No.202305AS350001)。
文摘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.
基金Financial support from the National Natural Science Foundation of China(Nos.21702087 and 21801105)the Liaoning Revitalization Talents Program(XLYC1907010 and XLYC1902085)+1 种基金the Research Project Fund of Liaoning Provincial Department of Education(L2020033 and UKZ0375)the Talent Scientific Research Fund of Liaoning Petrochemical University(2016XJJ-078 and 2016XJJ-079)is gratefully acknowledged.
文摘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.
基金Financial support for this work was provided by the National Natural Science Foundation of China(Nos.22171146,21971121,and 22188101)the Fundamental Research Funds for the Central Universities,Nankai University(No.63231199)the State Key Laboratory of Medicinal Chemical Biology。
文摘The first total synthesis of marine sesquiterpene(hydro)quinone meroterpenoids dysideanones A and E–G(1 and 4–6)has been accomplished in an enantioselective and divergent way.The sesquiterpene fragment and the aromatic moiety were efficiently connected via a site-selective and diastereoselective intermolecular alkylation of Wieland–Miescher ketone derivative 9 and benzyl bromide 10.The core 6/6/6/6-fused backbone of dysideanones was efficiently constructed through an intramolecular radical cyclization reaction.Dysideanone G(6)was easily prepared on a gram-scale and dysideanones A,E,and F(1,4,and 5)were divergently transformed from dysideanone G(6)in one or two steps.
基金supported by Karolinska Institutet in the form of a Board of Research Faculty Funded Career Positionby St.Erik Eye Hospital philanthropic donationsVetenskapsrådet 2022-00799.
文摘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.
基金the National Natural Science Foundation of China(22279063 and 21835004)the National Key R&D Program of China(2016YFB0901500)+1 种基金Ministry of Education of China(B12015 and IRT13R30)the Haihe Laboratory of Sustainable Chemical Transformations for financial support。
文摘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.
基金Financial support from the National Natural Science Foundation of China (No: 29975002) is gratefully acknowledged.
文摘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.
文摘Photocatalytic splitting of water was carried out in a two-phase system. Nanocrystalline titanium dioxide was used as photocatalyst and potassium hexacyanoferrate(III)/(II) as electron transporter. Generated hydrogen was chemically stored by use of a 1,4-benzoquinone/1,4-hydroquinone system, which was used as a recyclable fuel in a commercialised direct methanol fuel cell (DMFC). The electrical output of the cell was about half compared to methanol. The conversion process for water splitting and recombination in a fuel cell was monitored by UV-Vis spectroscopy and compared to a simulated spectrum. Products of side reactions, which lead to a decrease of the overall efficiency, were identified based on UV-Vis investigations. A proof of principle for the use of quinoide systems as a recyclable hydrogen storage system in a photocatalytic water splitting and fuel cell cyclic process was given.
