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Rhein, a component derived from rhubarb, has been proven to possess anti-inflammatory properties. Here, we show that rhein mitigates obesity by promoting adipose tissue thermogenesis in diet-induced obese mice. We construct a macrophage-adipocyte co-culture system and demonstrate that rhein promotes adipocyte thermogenesis through inhibiting NLRP3 inflammasome activation in macrophages. Moreover, clues from acetylome analysis identify SIRT2 as a potential drug target of rhein. We further verify that rhein directly interacts with SIRT2 and inhibits NLRP3 inflammasome activation in a SIRT2-dependent way. Myeloid knockdown of SIRT2 abrogates adipose tissue thermogenesis and metabolic benefits in obese mice induced by rhein. Together, our findings elucidate that rhein inhibits NLRP3 inflammasome activation in macrophages by regulating SIRT2, and thus promotes white adipose tissue thermogenesis during obesity. These findings uncover the molecular mechanism underlying the anti-inflammatory and anti-obesity effects of rhein, and suggest that rhein may become a potential drug for treating obesity.

Lithium‐sulfur batteries, despite being a promising solution for next‐generation secondary batteries, require substantial efforts to overcome the challenges of sluggish sulfur redox kinetics, polysulfides shuttling, and Li metal instability before achieving practical viability. Conventional strategies that utilize metal catalysts or soluble redox mediators (RMs) are limited by either impractical producing processes or unsatisfactory service life. Herein, an electrochemically active organic material, phloroglucinol – 2,6‐diaminoanthraquinone (PG‐DAAQ) is synthesized through a green and facile polymerization process to better resolve these issues. Serving as an RM at the cathode, PG‐DAAQ exhibits enduring redox activity within the sulfur operating potential window, leading to enhanced redox kinetics and sulfur utilization. Remarkably, even without any metal elements, PG‐DAAQ exhibits an excellent affinity to polysulfides, thereby suppressing the shuttling and facilitating the formation of a more favorable solid‐electrolyte interface to stabilize Li deposition at the anode. As a result, Li‐S cells employing PG‐DAAQ show significantly enhanced cycling and rate performances than the control cells. Even with a low electrolyte‐to‐sulfur ratio of 6, pouch cells with PG‐DAAQ deliver a reversible discharge capacity of 821 mA h g−1 after 100 cycles at a C/10 rate. [ABSTRACT FROM AUTHOR]

Reynoutria multiflora is a widely used medicinal plant in China. Its medicinal compounds are mainly stilbenes and anthraquinones which possess important pharmacological activities in anti‐aging, anti‐inflammatory and anti‐oxidation, but their biosynthetic pathways are still largely unresolved. Here, we reported a near‐complete genome assembly of R. multiflora consisting of 1.39 Gb with a contig N50 of 122.91 Mb and only one gap left. Genome evolution analysis revealed that two recent bursts of long terminal repeats (LTRs) contributed significantly to the increased genome size of R. multiflora, and numerous large chromosome rearrangements were observed between R. multiflora and Fagopyrum tataricum genomes. Comparative genomics analysis revealed that a recent whole‐genome duplication specific to Polygonaceae led to a significant expansion of gene families associated with disease tolerance and the biosynthesis of stilbenes and anthraquinones in R. multiflora. Combining transcriptomic and metabolomic analyses, we elucidated the molecular mechanisms underlying the dynamic changes in content of medicinal ingredients in R. multiflora roots across different growth years. Additionally, we identified several putative key genes responsible for anthraquinone and stilbene biosynthesis. We identified a stilbene synthase gene PM0G05131 highly expressed in roost, which may exhibit an important role in the accumulation of stilbenes in R. multiflora. These genomic data will expedite the discovery of anthraquinone and stilbenes biosynthesis pathways in medicinal plants. [ABSTRACT FROM AUTHOR]

Emodin (EMO) is an anthraquinone compound derived from Rheum palmatum L., which has rich pharmacological activity. However, studies have shown that EMO may cause hepatotoxicity. In this study, EMO was combined with tetrandrine and prepared as lipid nanoparticles (E-T/LNPs). The anti-liver fibrosis activity of EMO before and after formulation was evaluated by zebrafish and mice. In addition, the toxicity of EMO and E-T/LNPs was compared and the toxicity–efficacy concentrations of E-T/LNPs in zebrafish were verified. E-T/LNPs are morphologically stable (particle size within 100 nm), have high encapsulation efficiency and good stability, and are capable of long-lasting slow release in vitro. The combination and preparation can reduce the toxicity and enhance the effect of EMO, and increase the toxicity and effect concentration of E-T/LNPs in vivo. In a short period, low doses of E-T/LNPs can be used for the treatment of liver fibrosis; high doses of E-T/LNPs cause toxicity in vivo. Immunohistochemistry showed that E-T/LNPs inhibited hepatic fibrosis by downregulating the levels of IL-1β and TGF-β. Based on the advantages of combination therapy and nanotechnology, it can play a role in reducing the toxicity and increasing the efficacy of EMO in the treatment of liver fibrosis. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) serve as an excellent foundation for heterogeneous photocatalysis. Herein, we synthesized an anthraquinone‐based COF (TpAQ) on a gram scale via a mechanochemical grinding pathway. This COF was employed as a visible‐light‐harvesting photocatalyst for selective fluorination of benzylic C─H bonds and perfluoroalkylation of arenes. The carbonyl core in the anthraquinone linker facilitated benzylic fluorination through a hydrogen atom transfer (HAT) pathway. Control experiments and photophysical analysis were conducted to gain deeper insight into the reaction mechanism. The recyclability up to the fifth cycle without significant loss of yield (>90%) highlighted the robustness of the catalyst. This reaction strategy was also executed on a gram scale to validate the scalability of the protocol. [ABSTRACT FROM AUTHOR]

Jasmonates, including jasmonic acid (JA) and its derivatives such as methyl jasmonate (MeJA) or jasmonly isoleucine (JA-Ile), regulate plant responses to various biotic and abiotic stresses. In this study, we applied exogenous MeJA onto Senna tora leaves subjected to wounding and conducted a transcriptome deep sequencing analysis at 1 (T1), 3 (T3), 6 (T6), and 24 (T24) h after MeJA induction, along with the pretreatment control at 0 h (T0). Out of 18,883 mapped genes, we identified 10,048 differentially expressed genes (DEGs) between the T0 time point and at least one of the four treatment times. We detected the most DEGs at T3, followed by T6, T1, and T24. We observed the upregulation of genes related to JA biosynthesis upon exogenous MeJA application. Similarly, transcript levels of genes related to flavonoid biosynthesis increased after MeJA application and tended to reach their maximum at T6. In agreement, the flavonols kaempferol and quercetin reached their highest accumulation at T24, whereas the levels of the anthraquinones aloe-emodin, emodin, and citreorosein remained constant until T24. This study highlights an increase in flavonoid biosynthesis following both MeJA application and mechanical wounding, whereas no significant influence is observed on anthraquinone biosynthesis. These results provide insights into the distinct regulatory pathways of flavonoid and anthraquinone biosynthesis in response to MeJA and mechanical wounding. [ABSTRACT FROM AUTHOR]

AbstractMedium/long-chain fatty acids/alcohols as hydrogen bond donors coupled with methyltrioctylammonium chloride were used to prepare hydrophobic deep eutectic solvents (DESs) that were employed for the extraction of the anthraquinones (rhein, emodin, and chrysophanol) from fetal bovine serum. Hydrophobic DES-based liquid-phase microextraction and high-performance liquid chromatography were developed. The most suitable combination was optimized for liquid-phase microextraction. Spiked fetal bovine serum was analyzed with satisfactory extraction recoveries. [ABSTRACT FROM AUTHOR]

Sodium sulfite (Na2SO3) is known as a selective chemical agent for wood delignification. In this work, Scots pine (Pinus sylvestris) wood was pulped using alkaline sulfite (AS) with the addition of 1,4-dihydro-9,10-dihydroxy anthracene (DDA) [called also soluble anthraquinone (SAQ)] and ethylene glycol (G). The studies showed the possibility of obtaining Kappa number (KN) 24 to 26 alkaline sulphite-DDA pine pulps with total and screened yields higher by 3.4 to 3.9% and 1.4 to 2.6%, respectively, than in the case of kraft pulping. The AS-SAQ pulping process was also characterized by much higher brightness of pulps but worse defibreability of wood than the kraft process. Increasing the amount of Na2SO3 dosed to the wood from 25% to 30-35% (based on wood) and adding G to the cooking liquor increased the delignification of pine wood in the AS-SAQ method to Kappa number of 17 to 20 units (without G) and approximately 14.5 units (with G). Such a modification had a positive effect on the defibreability of wood after pulping and the brightness of pulps but a negative effect on the screened yield of AS-SAQ and AS-SAQG pulps. [ABSTRACT FROM AUTHOR]

Anthraquinones are polycyclic compounds with an unsaturated diketone structure (quinoid moiety). As important secondary metabolites of plants, anthraquinones play an important role in the response of many biological processes and environmental factors. Anthraquinones are common in the human diet and have a variety of biological activities including anticancer, antibacterial, and antioxidant activities that reduce disease risk. The biological activity of anthraquinones depends on the substitution pattern of their hydroxyl groups on the anthraquinone ring structure. However, there is still a lack of systematic summary on the distribution, classification, and biosynthesis of plant anthraquinones. Therefore, this paper systematically reviews the research progress of the distribution, classification, biosynthesis, and regulation of plant anthraquinones. Additionally, we discuss future opportunities in anthraquinone research, including biotechnology, therapeutic products, and dietary anthraquinones. [ABSTRACT FROM AUTHOR]

SARS-CoV-2 continues to mutate and circulate at alarming levels around the world and is exemplified by the emergence of the new variant JN.1. The emergence of novel SARS-CoV variants underscores the urgency for the development of new drugs. Phytochemicals, known for their safety and efficacy, have been widely used to address various ailments. This study aims at identifying the anti-SARS-CoV potential of emodin, a bioactive anthraquinone, and its derivatives. Key proteins, including hemagglutinin-esterase (HE), papain-like protease (PLpro), major protease (3CLpro), non-structural protein (nsp3) and spike protein(S) of SARS-CoV, were used as protein targets for the virtual screening of 110 emodin derivatives (ED) and remdesivir a proven antiviral drug. Among the 110 derivatives, ED21, ED25, ED5 inhibited HE, 3CLpro and S protein, respectively. ED29 inhibited both PLpro and nsp3 with high binding affinity. Similar receptor binding sites were occupied by remdesivir and emodin derivatives. These emodin derivatives are bound to similar amino acids in receptors as compared to remdesivir. Further dynamic simulations studies with ED21-HE, ED25-3CLpro, ED5-S, ED29-PLpro and ED29-nsp3 complexes showed all of them are stable with minimum root mean square deviation (RMSD), root mean square fluctuation (RMSF), solvent-accessible surface area (SASA) and radius of gyration (Rg) and are comparable to APO protein. All the ligands accepted Lipinski’s rule of five. Absorption, distribution, metabolism, excretion, and toxicity (ADMET) analysis revealed only ED21 and ED5 as promising druglike candidates that can have high therapeutic value and no side effects. These in-silico findings contribute to the development of potent SARS-CoV-2 inhibitors, potentially advancing the quest for effective antiviral drugs. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A water‐soluble anthraquinone derived from alizarin, 3HAAQ, is introduced as the redox‐active material in a negative potential electrolyte (anolyte) for aqueous redox flow batteries operating at pH 14. The synthesis of 3HAAQ is carried out using the Mannich reaction, which significantly improves the solubility of the new compound, an important factor for its use in RFB. Pairing with potassium ferri/ferrocyanide positive electrolyte, this flow battery exhibits an open‐circuit voltage of 1.24 V and maintains nearly 80% of the theoretical capacity at 40 mA cm−2 current density. [ABSTRACT FROM AUTHOR]

Copyright of China Synthetic Fiber Industry is the property of Sinopec Baling Petrochemical Company and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

AbstractPleuropterus multiflorus root (PMR, Polygoni Multiflori Radix) is an herbal medicine widely used in East Asia, particularly China. However, the potential hepatotoxicity has hindered its rational and safe application of PMR in clinical practice. Recently, the hepatotoxic study of PMR have made great progress, especially drug metabolism and transport-mediated liver injury. In this review, we summarized the advancement of drug metabolism and transport regluated hepatic injury of PMR, pointed out the key role of drug metabolizing enzymes and transporters in regulating hepatic injury of PMR, and emphasized the main hepatotoxic substances, toxicity promoter, and hepatic toxic substance-toxicity promoter interactions in PMR. On this basis, the clinical prospect of preventing and treating hepatic injury of PMR from the perspective of metabolism and transporter was discussed, to provide a useful reference and theoretical basis for the prevention and treatment of hepatic injury of PMR. [ABSTRACT FROM AUTHOR]

Photocatalytic synthesis of H2O2 is an advantageous and ecologically sustainable alternative to the conventional anthraquinone process. However, achieving high conversion efficiency without sacrificial agents remains a challenge. In this study, two covalent organic frameworks (COF−O and COF−C) were prepared with identical skeletal structures but with their pore walls anchored to different alkyl chains. They were used to investigate the effect of the chemical microenvironment of pores on photocatalytic H2O2 production. Experimental results reveal a change of hydrophilicity in COF−O, leading to suppressed charge recombination, diminished charge transfer resistance, and accelerated interfacial electron transfer. An apparent quantum yield as high as 10.3 % (λ=420 nm) can be achieved with H2O and O2 through oxygen reduction reaction. This is among the highest ever reported for polymer photocatalysts. This study may provide a novel avenue for optimizing photocatalytic activity and selectivity in H2O2 generation. [ABSTRACT FROM AUTHOR]

Photocatalytic synthesis of H2O2 is an advantageous and ecologically sustainable alternative to the conventional anthraquinone process. However, achieving high conversion efficiency without sacrificial agents remains a challenge. In this study, two covalent organic frameworks (COF−O and COF−C) were prepared with identical skeletal structures but with their pore walls anchored to different alkyl chains. They were used to investigate the effect of the chemical microenvironment of pores on photocatalytic H2O2 production. Experimental results reveal a change of hydrophilicity in COF−O, leading to suppressed charge recombination, diminished charge transfer resistance, and accelerated interfacial electron transfer. An apparent quantum yield as high as 10.3 % (λ=420 nm) can be achieved with H2O and O2 through oxygen reduction reaction. This is among the highest ever reported for polymer photocatalysts. This study may provide a novel avenue for optimizing photocatalytic activity and selectivity in H2O2 generation. [ABSTRACT FROM AUTHOR]

Photocatalytic synthesis of H2O2 is an advantageous and ecologically sustainable alternative to the conventional anthraquinone process. However, achieving high conversion efficiency without sacrificial agents remains a challenge. In this study, two covalent organic frameworks (COF−O and COF−C) were prepared with identical skeletal structures but with their pore walls anchored to different alkyl chains. They were used to investigate the effect of the chemical microenvironment of pores on photocatalytic H2O2 production. Experimental results reveal a change of hydrophilicity in COF−O, leading to suppressed charge recombination, diminished charge transfer resistance, and accelerated interfacial electron transfer. An apparent quantum yield as high as 10.3 % (λ=420 nm) can be achieved with H2O and O2 through oxygen reduction reaction. This is among the highest ever reported for polymer photocatalysts. This study may provide a novel avenue for optimizing photocatalytic activity and selectivity in H2O2 generation. [ABSTRACT FROM AUTHOR]

Photocatalytic synthesis of H2O2 is an advantageous and ecologically sustainable alternative to the conventional anthraquinone process. However, achieving high conversion efficiency without sacrificial agents remains a challenge. In this study, two covalent organic frameworks (COF−O and COF−C) were prepared with identical skeletal structures but with their pore walls anchored to different alkyl chains. They were used to investigate the effect of the chemical microenvironment of pores on photocatalytic H2O2 production. Experimental results reveal a change of hydrophilicity in COF−O, leading to suppressed charge recombination, diminished charge transfer resistance, and accelerated interfacial electron transfer. An apparent quantum yield as high as 10.3 % (λ=420 nm) can be achieved with H2O and O2 through oxygen reduction reaction. This is among the highest ever reported for polymer photocatalysts. This study may provide a novel avenue for optimizing photocatalytic activity and selectivity in H2O2 generation. [ABSTRACT FROM AUTHOR]

A series of bimetallic‐ionic liquid (IL) pincer catalysts Pd−M@IL were synthesized using low Pd‐loading amount (0.3 %) and adopting six kinds of ion liquids with the cation containing the imidazole ring, and then evaluated the catalytic activities toward 2‐ethylanthraquinone hydrogenation reaction with the purpose to produce H2O2. Under the reaction conditions of 60 °C, 0.30 MPa and 15 min reaction time, over the catalysts Pd−La@[BMIm]Ac/alu and Pd−La@[VBIM]Br/alu achieved high hydrogenation efficiency(9.4 g/L and 8.5 g/L) but also high selectivity toward the active anthraquinone (98.9 % and 99.6 %). Through characterizations of STEM, TPD, in‐situ XPS, etc., it illustrates that the pincer catalysts Pd−La@[BMIm]Ac/alu and Pd−La@[VBIM]Br/alu have much better dispersity than the bimetallic Pd−La/alu, these two ionic liquids of [BMIm]Ac and [VBIM]Br provide different local environment around Pd−La sites, which in turn modulate the catalytic activity of the pincer‐catalysts toward anthraquinone hydrogenation. DFT calculations disclose the unique electron transfer between ILs ([BMIm]Ac and [VBIM]Br) and Pd−La clusters and subsequent changes of energy barriers for anthraquinone hydrogenation. The work illuminates a facile strategy to design novel hydrogenation catalysts through combining the pincer microenvironment partially encapsulated by the cation and the anion of ionic liquids with the internal bimetallic sites. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) is a versatile oxidant, and its eco-friendly synthesis via visible light and air oxygen is crucial. Anthraquinone compounds were employed as homogeneous photocatalysts for alcohol oxidation, yielding H2O2 under visible light. Instead of using traditional catalyst library screening, a model based on density functional theory was proposed to structurally optimize anthraquinone photocatalysts, resulting in the discovery of a novel catalyst significantly boosting H2O2 generation (up to 621.2 mM h-1 intermittently). Continuous flow reactor design improvements can enhance chemical transformation efficiency, as demonstrated by continuous H2O2 production using 2,6-di-tert-butyl anthraquinone. When isopropanol was used as the hydrogen atom donor, H2O2 production rates reached 3950.6 mM h-1 in a 7-minute reaction, with a space--time yield of 7.90 mol (L h) -1, showcasing promising advancements in green H2O2 synthesis. [ABSTRACT FROM AUTHOR]

In recent years, there is an increasing interest in finding better and more efficient ways to detect CN− ions. Most of the anthraquinone-based probes show less fluorescence This paper presents the design and synthesis of a new anthraquinone based imine probe with good colorimetric sensing property and fluorescent turn on behavior toward CN− ion. Herein, we report a receptor with both colorimetric and fluorescent enhancement of cyanide ion in DMSO medium is synthesized. The synthesized receptor shows an immediate color change from orange to pink when cyanide is added; and it can be readily observed visually due to the presence of diverse p-conjugated systems in the receptor. These studies were confirmed by UV–Visible, PL studies, DFT, HRMS and 1H NMR titration. Moreover, this receptor shows 1:1 stoichiometry and micromolar detection limit. Further the receptor was applied to a real sample in finger millet (Eleusine Coracana) to detect the presence of cyanide ion. Moreover, the receptor is applicable toward INHIBITION, IMPLICATION logic gates with two input systems. [ABSTRACT FROM AUTHOR]

Skin cancer is threatening more and more people's health; its postoperative recurrence and wound infection are still critical challenges. Therefore, specialty wound dressings with multifunctional bioactivity are urgently desired. Emodin is a natural anthraquinone compound that has anti-cancer and anti-bacterial properties. Herein, we fabricated coaxial electrospinning nanofibers loaded with emodin to exploit a multifunctional wound dressing for skin cancer postoperative management, which encapsulated emodin in a polyvinylpyrrolidone core layer, combined with chitosan-polycaprolactone as a shell layer. The nanofibers were characterized via morphology, physicochemical nature, drug load efficiency, pH-dependent drug release profiles, and biocompatibility. Meanwhile, the anti-cancer and anti-bacterial effects were evaluated in vitro. The emodin-loaded nanofibers exhibited smooth surfaces with a relatively uniform diameter distribution and a clear shell-core structure; remarkably, emodin was evenly dispersed in the nanofibers with significantly enhanced dissolution of emodin. Furthermore, they not only display good wettability, high emodin entrapment efficiency, and biphasic release profile but also present superior biocompatibility and anti-cancer properties by increasing the levels of MDA and ROS in A-375 and HSC-1 cells via apoptosis-related pathway, and long-term anti-bacterial effects in a dose-independent manner. The findings indicate that the emodin-loaded nanofiber wound dressing can provide a potential treatment strategy for skin cancer postoperative management. [ABSTRACT FROM AUTHOR]

To date, there are no real physiological mechanisms for iron excretion in eukaryote, and no physiological "actuator" that can control all the three fundamental biologic processes of absorption, storage, and excretion. Here, we observed that the accumulation of anthraquinones by Thermomyces dupontii under cold stress can achieve this process. Through mutation analysis, we found that mutant ΔAn deficiency in anthraquinones accumulated ferrous and total free iron due to adopting a rare lifestyle with no endocytosis but accumulation of membrane‐derived vesicles. Anthraquinone complement indicated that the vesicles in ΔAn could coat the extrinsic anthraquinone‐induced granules to prevent contact with the fungal interiors. Detailed chemical investigation on ΔAn led to characterization of a rare oxygen‐free ergosterene with unstable nature in air as the major membrane steroid in ΔAn, suggesting hypoxia inner in ΔAn cells, consistent with dramatically low oxygen‐consuming rates in ΔAn. A series of physiological and metabolic analyses indicated anthraquinones were involved in exporting ferrous and promoting formation of oxygen‐containing metabolites, including ergosterols for endocytosis and iron chelators for iron storage. Moreover, we found that both the anticancer agent mitoxantrone with well‐known‐cardiotoxicity side effect and the major terpenoid‐derived polycyclic aromatics from Danshen for treating cardiovascular disease showed potent ferrous transporting capabilities in human cancer cells. Our findings provide a novel insight into the underlying mechanisms of polycyclic aromatics in nature and pharmacology, and offer a new strategy for developing potential therapeutics and agents for membrane transport, iron homestasis, and anticold. [ABSTRACT FROM AUTHOR]

To combine the activity characteristics of 18β‐glycyrrhetinic acid (18β‐GA) and anthraquinone compounds (rhein and emodin), reduce toxicity, and explore the structure–activity relationship (SAR) of anthraquinones, 18β‐GA‐anthraquinone ester compounds were synthesized by one‐step organic synthesis. The products were separated and purified by HPLC and characterized by NMR and EI‐MS. It was finally determined as di‐18β‐GA‐3‐rhein ester (1, New), GA dimer (2, known), 18β‐GA‐3‐emodin ester (3, known), and di‐18β‐GA‐1‐emodin ester (4, new). The MIC of three reactants and four products against Escherichia coli and Staphylococcus aureus were detected in vitro. Its developmental toxicity and cardiotoxicity were assessed using zebrafish embryos. The experimental results showed that rhein had the best antibacterial activity against Staphylococcus aureus with MIC50 of 2.4 mM, and it was speculated that –COOH, –OH, and intramolecular hydrogen bonds in anthraquinone compounds would enhance the antibacterial effect, while the presence of‐CH3 might weaken the antibacterial activity. Product 1 increased the hatching rate and survival rate of zebrafish embryos and reduced the malformation rate and cardiomyocyte apoptosis. This experiment lays the foundation for further studying the SAR of anthraquinones and providing new drug candidates. [ABSTRACT FROM AUTHOR]

Melanosis coli occurs with the administration of stimulant laxatives for the relief of constipation. However, the duration of macroscopic improvement of melanosis coli after discontinuation of anthracene laxatives is not well understood. We describe the case of an 81-year-old female diagnosed with melanosis coli via colonoscopy who had been taking senna laxatives for 5 years. Seven months after cessation of senna laxatives, colonoscopy showed no melanosis coli in the colon. This impressive report describes the observation of melanosis coli with colonoscopy; 7 months after the withdrawal of senna stimulant laxatives, melanosis coli resolved. [ABSTRACT FROM AUTHOR]

[Display omitted] Disulfide bonds, especially unsymmetric disulfide bonds, have important applications in bioactivity and drug molecules, but the synthesis of unsymmetric disulfide bonds remains challenging due to efficiency and selectivity issues. Herein, this work utilizes anthraquinone (AQ) and cyclictriphosphonononitrile through a nucleophilic substitution reaction to synthesize an organic polymer (ANTH-AMI) that incorporates an ortho -polyquinone (o -polyquinone) redox center. The anthraquinone molecule functions as a redox center, capable of accepting photoinduced electrons and subsequently transferring them to initiate an electron-coupled hydrogenation reaction (AQ to AQH). Moreover, the proximity of the o -polyquinone redox sites facilitates the catalysis of unsymmetric disulfide bond formation. Consequently, the ANTH-AMI photocatalysts demonstrate exceptional yields (up to 82 %), substrate versatility, cycling stability, and scalable preparation in promoting unsymmetric coupling reactions of thiol. This work offers a solution for designing organic polymer photocatalysts with adjacent multiple redox centers for cross-coupling reactions. [ABSTRACT FROM AUTHOR]

Abstract Background The search for new bioactive natural compounds with anticancer activity is still of great importance. Even though their potential for diagnostics and treatment of cancer has already been proved, the availability is still limited. Hypericin, a naphthodianthrone isolated essentially from plant source Hypericum perforatum L. along with other related anthraquinones and bisanthraquinones belongs to this group of compounds. Although it has been proven that hypericin is synthesized by the polyketide pathway in plants, none of the candidate genes coding for key enzymes has been experimentally validated yet. Despite the rare occurrence of anthraquinones in plants, their presence in microorganisms, including endophytic fungi, is quite common. Unlike plants, several biosynthetic genes grouped into clusters (BGCs) in fungal endophytes have already been characterized. Results The aim of this work was to predict, identify and characterize the anthraquinone BGCs in de novo assembled and functionally annotated genomes of selected endophytic fungal isolates (Fusarium oxysporum, Plectosphaerella cucumerina, Scedosporium apiospermum, Diaporthe eres, Canariomyces subthermophilus) obtained from different tissues of Hypericum spp. The number of predicted type I polyketide synthase (PKS) BGCs in the studied genomes varied. The non-reducing type I PKS lacking thioesterase domain and adjacent discrete gene encoding protein with product release function were identified only in the genomes of C. subthermophilus and D. eres. A candidate bisanthraquinone BGC was predicted in C. subthermophilus genome and comprised genes coding the enzymes that catalyze formation of the basic anthraquinone skeleton (PKS, metallo-beta-lactamase, decarboxylase, anthrone oxygenase), putative dimerization enzyme (cytochrome P450 monooxygenase), other tailoring enzymes (oxidoreductase, dehydrogenase/reductase), and non-catalytic proteins (fungal transcription factor, transporter protein). Conclusions The results provide an insight into genetic background of anthraquinone biosynthesis in Hypericum-borne endophytes. The predicted bisanthraquinone gene cluster represents a basis for functional validation of the candidate biosynthetic genes in a simple eukaryotic system as a prospective biotechnological alternative for production of hypericin and related bioactive anthraquinones.

Bipolar‐type electrode materials are capable of improving the specific power and reducing the manufacturing costs for rechargeable symmetric batteries, while their development is plagued by the lack of reliable and affordable bipolar‐type materials. Here, a bipolar‐type indanthrene (IDT) with synergetic coupling effects of two redox centers of p‐type dihydrophenazines and n‐type anthraquinone in a single molecule is proposed to construct a symmetric battery. Due to the mutually affecting of n‐type and p‐type redox couples, the conjugated "p–n fusion" in the IDT material facilitates mutual electron cloud donation and withdrawal between two redox centers, thus a considerable output voltage of 0.62 V is realized in symmetric aqueous battery. Benefiting from its enriched redox centers and extended π‐conjugated structure, the symmetric battery also delivers a specific capacity of 139 mAh g−1 at 0.1 A g−1 and a long cycling stability with a capacity retention of 79% after 600 cycles at 2 A g−1. Comprehensive ex‐situ characterizations paired with density functional theroy calculations reveal both reversible HSO4− and H+ uptake/removal behavior during charging/discharging process. Additionally, a symmetric cell with quasi‐solid electrolyte is established, which exhibits superior practical application capability with a capacity retention of 78% at 2 A g−1 over 1000 cycles. [ABSTRACT FROM AUTHOR]

Antibiotics resistance is a clear threat to the future of current tuberculosis treatments like rifampicin, prompting the need for new treatment options in this field. While plants can offer a plethora of chemical diversity in their constitutive natural products to tackle this issue, finding potentially bioactive compounds in them has not always proven to be that simple. Classical bioactivity-guided fractionation approaches are still trendy, but they bear significant shortfalls, like their time-consuming nature as well as the everincreasing risk of isolating known bioactive compounds. In this regard, we have developed an alternative method to the latter approach that allows for natural derivatives of a known bioactive scaffold to be efficiently targeted and isolated within a large library of plant extracts. Hence our approach allows for the anticipation of bioactive structure independently of preliminary bioassays. By relying on the chemical diversity of a set of 1,600 plant extracts analyzed by HRMS/MS, we were able to isolate and characterize several minor derivatives of a previously reported bioactive aza-anthraquinone compound from Cananga brandisiana, selected within the plant set. Assessment of bioactivity on these derivatives (especially onychine, with an IC50 value of 39 μM in infection) confirmed their expected activity on Mycobacterium marinum in our antiinfective assay. This proof-of-concept study has established an original path towards bioactive compounds isolation, with the advantage of potentially highlighting minor bioactive compounds, whose activity may not even be detectable at the extract level. [ABSTRACT FROM AUTHOR]

Traditional textile dyeing processes usually require large quantities of water and energy and generate wastewater that can be harmful to the environment. Dyeing in supercritical carbon dioxide (sc‐CO2) media is promising in textile coloration due especially to it providing a waterless process and eliminating the need for an energy intensive drying step. The natural anthraquinone emodin showed promising results for dyeing different fibres through sc‐CO2 process. However, emodin is mutagenic. The aim of this study was to develop non‐mutagenic derivatives of emodin that can be applied to textiles using sc‐CO2. Emodin structure was modified incorporating acryloyl groups, which are considered suitable for decreasing potential for DNA intercalation, and thus mutagenicity. The presence of acryloyl groups would also enable atmospheric plasma induced bonding with fibres. Molecular modelling studies showed that emodin derivatives became less planar with increasing number of attached acryloyl groups, making intercalation unlikely. The derivatives produced were tested to assess mutagenicity in vitro (Salmonella/microsome assay, TA1537, 10% S9) and in vivo (micronucleus test in hemocytes of aquatic crustacean). We found that emodin can be derivatised using acryloyl chlorides to give mono‐ and di‐acrylate esters suitable for dyeing polyester fibres in sc‐CO2. However, the new dyes presented mutagenicity for both in vitro and in vivo. Although the derivatives provided greenish‐yellow alternatives to emodin for dyeing synthetic fibres, they do not appear to be viable alternatives from the point of view of preserving human and environmental health. Plasma bonding studies are underway. [ABSTRACT FROM AUTHOR]

The Eleutherine bulbosa bulb has been reported as a potent antioxidant in food. This work aims to extract the E. bulbosa bulb for use as an antioxidative agent in cosmetics. Water, 95% ethanol (EtOH), and propylene glycol (PG), which are normally used in cosmetic formulation, were employed as green and sustainable extraction solvents. EtOH and PG displayed better candidacy to extract active components from E. bulbosa bulbs than using water, and the mixture of EtOH and PG (EtOH/PG) resulted in the extract with higher bioactive compounds and biological activities compared with using EtOH or PG. The total phenolic content of the EtOH/PG extract was 87.60 ± 2.00 mgGAE/mL which was about an 18–23% increase from when using single EtOH or PG (70.91 ± 2.30, 74.05 ± 0.67 mgGAE/mL). UHPLC-ESI-QTOF-MS/MS analysis showed that the E. bulbosa bulb extracted in EtOH/PG was composed of naphthalenes, naphthoquinones, anthraquinones, myricetin, quercetin, epicatechin, catechin, epigallocatechin, and their derivatives. The ethanolic crude extract exhibited anti-elastase and anti-collagenase activity with the IC50 of 7.76 ± 0.35 and 0.53 ± 0.23 mg/mL, respectively, and was non-cytotoxic to human dermal fibroblast cells at 0.0001–1 mg/mL. The emulsion cream containing 2%(w/w) E. bulbosa bulb concentrated extract was found cosmetically stable after a one-month stability test under 4 °C, ambient temperature (30–35 °C), 45 °C, fluorescent light, and daylight. However, exposure to sunlight during daytime caused changes in the emulsion's color with ΔE* of 3.85 ± 0.08, and at 45 °C caused the 12% decrease in DPPH activity of emulsion. The finding of this work heightens the antioxidative and safety potentials of the E. bulbosa bulb in cosmetic preparations. [ABSTRACT FROM AUTHOR]

Doum palm and turmeric are traditional medicinal plants with a rich history of use. This study investigated the phytochemical composition, proximate analysis, and GC-MS characterization of doum palm and turmeric blends at different ratios (100%, 80:20%, 60:40%, and 50:50%) using ethanol and warm-water extracts. Phytochemical screening revealed the presence of various bioactive compounds, including alkaloids, anthraquinones, flavonoids, glycosides, saponins, tannins, terpenoids, and phenols, in the blends at ratios of 80:20%, 60:40%, and 50:50%. Alkaloids were absent in the 100% doum palm sample. Proximate analysis showed significant variations in moisture, ash, fat, and protein content among the samples. GC-MS characterization identified at most 30 phytochemical compounds in sample A and more additional 9 bioactive compounds in samples B, C and D, including two new compounds, eucalyptol and carotol, found in the doum palm-turmeric blends. These compounds have been known to possess various antioxidant and therapeutic potential. The findings suggest that doum palm and turmeric blends have improved potential health benefits due to their high content of phytochemical compounds and balanced proximate composition. Further research is warranted to determine the most effective doum palm to turmeric ratio (Optimal Blending Ratios) for specific health applications. This includes identifying the blend ratios that maximize the therapeutic benefits for particular conditions or diseases. [ABSTRACT FROM AUTHOR]

This study presents findings that suggest it is possible to fine‐tune and enhance the optical properties of anthraquinone (AQ) and its photocatalytic performance in the degradation of rhodamine B (RhB) at the molecular level through varying its keleton substituents. Specifically, the electron‐withdrawing substituent demonstrates a more pronounced improvement effect compared to the electron‐donating substituent. Out of the several compounds, 2‐carboxyanthraquinone (AQ−COOH) exhibits the highest photocatalytic activity. This is due to its ionization in water, generating H+ ions that enhance the destruction of RhB through photodegradation. After 30 min of exposure to visible light, the degradation rate of RhB reaches an impressive 99.9 %. It is noteworthy that a hydrochloric acid solution with a concentration of 0.5 mmol ⋅ L−1 has a considerable promoting impact on the photodegradation of RhB catalyzed by AQ−COOH, and that the total degradation of RhB can be accomplished in 15 min. In addition, AQ−COOH also has good applicability for the degradation of tetracycline, methylene blue, and methyl orange. As a recyclable solid catalyst, the catalytic activity of AQ−COOH remained mostly unchanged after being used five times. Additionally, AQ−COOH did not undergo degradation when exposed to visible light, indicating its excellent stability in the process of catalyzing RhB degradation. According to quenching experiments and EPR spectrum characterizations, the photo‐generated active species oxygen vacancies (h+), photogenerated electrons (e−), superoxide free radicals (O2⋅−), singlet oxygen (1O2) and hydroxyl radical (•OH) are involved in the hypothesized photo‐catalytic degradation mechanism. [ABSTRACT FROM AUTHOR]

Background: Rubia cordifolia L. a spiky perennial climber of Rubiaceae family, is a rich reservoir of anthraquinone containing compounds purpurin and alizarin. It emerges as a versatile powerhouse possessing diverse pharmacological properties which includes antibacterial, antitumor, antioxidant, antiplatelet, potent blood purifier, diuretic, anti-stress, neuroprotective, anti-mutagenic, anticancer, anti-inflammatory, antidepressant, antidiabetic and vasodilation. Thereby it offers a holistic approach for disease prevention through its pharmacological properties. Objectives: However due to lack of standardization for R. cordifolia roots and its derived marketed herbal products, its quality control remains a daunting task. The present study aims to develop a simple, novel, reliable and specific HPTLC method for quantifying purpurin and alizarin in R. cordifolia roots as well as in its marketed preparations. Materials and Methods: The separation and quantification of purpurin and alizarin has been carried out on HPTLC plates pre-coated with Silica gel 60 F254 as stationary phase and toluene, ethyl acetate, glacial acetic acid (6:3.5:0.5; v/v/v) as mobile phase. Determination and quantification were performed by densitometric scanning at 254 nm. Results: The developed method gave compact spots at Rf 0.57±0.007 for purpurin and 0.73±0.008 for alizarin. The method was validated as per International Council for Harmonization Q2(R1) guidelines for specificity, precision, robustness, accuracy and recovery. Linearity range for purpurin and alizarin was 100-2000 ng/spot, which showed good regression coefficient for purpurin and alizarin; R²=0.9967 and R²=0.9941 at 254 nm respectively. The LOD and LOQ for validated marker compounds purpurin and alizarin at 254 nm were found as 23.87±0.52, 71.61±0.84 ng/spot and 18.36±0.72, 55.08±0.26 ng/spot respectively. The content of purpurin and alizarin in R. cordifolia plant extract was found as 17.960±0.658, 34.645±1.153 µg/mg, marketed preparation A, contains 21.741±0.746 and 6.824±0.485 µg/mg while marketed preparation B, contains 18.289±1.014 and 3.031±0.234 µg/mg of the sample. Conclusion: The developed method was found to be simple, precise, accurate, economical and convenient for rapid screening of bioactive marker purpurin and alizarin present in methanolic extracts of R. cordifolia roots and its marketed preparations. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) is a mild, environmentally friendly, and versatile oxidizer. The current main production process, the anthraquinone method, has high energy consumption and pollution. However, the photocatalytic production of H2O2 is considered to be a green and sustainable process. In this paper, the research progress of photocatalytic production of H2O2 was reviewed. Firstly, the basic principle of photocatalytic production of H2O2 and the three production pathways, namely, oxygen reduction, water oxidation, and dual-channel were introduced. Then, advanced photocatalysts for H2O2 production were introduced with emphasis. From the reactants and products, several new reaction systems and improvement strategies were introduced, including the construction of a spontaneous system without a sacrifice agent, a gas–liquid–solid three-phase system, and inhibition of H2O2 decomposition. The in-situ applications of photocatalytic H2O2 production in the environmental field, including in-situ disinfection and in-situ degradation of pollutants are discussed. Finally, the research progress and future research directions in this field are summarized and prospected. [ABSTRACT FROM AUTHOR]

Anthraquinones constitute an important class of compounds with wide applications. The solubility of derivatives at 298.15 K was discussed in ethanol–water solution and at atmospheric pressure, the solubility of 1-amino-4-hydroxy-9,10-anthraquinone (AHAQ) in binary solvents (ethanol–water combinations) was determined. Colour strength and fastening properties depend upon the kind and position of a hydrophobic group connected to the phenoxy ring of Anthraquinone moiety. There is a continuing interest in the creation of novel anthraquinone derivatives with biological activities since they have demonstrated potential for treating multiple sclerosis. For this purpose, by utilizing voltammetric and absorption studies, interactions of various derivatives with calf thymus DNA (ct-DNA) and the cationic surfactant cetyltrimethylammoniumbromide (CTAB) were examined. Here prominent Hydrophobic interaction and electron transfer resulting in binding to CTAB micelles were observed. The polarity index of the media was assessed and associated with the electrochemical parameters. The medicinal behaviour of Anthraquinone derivatives was a result of electron transfer reactions with DNA. UV–Visible and fluorescence properties were due to the transitions between n* and π* orbitals. Large absorption band with low dichroic ratio was characteristic of various derivatives of Anthraquinone. Presence of –NH group proves various derivatives remarkable calorimetric and anionic sensors. [ABSTRACT FROM AUTHOR]

Background Cassia (Family: Fabaceae) species are a large group of flowering plants rich in bioactive anthraquinone and flavonoids used in botanical supplements and nutraceuticals. Objective A simple and reliable high-performance liquid chromatography-photodiode array (HPLC-PDA) method was developed and validated for separating and quantifying 13 anthraquinone and flavonoids. These compounds were further confirmed using an LC-based electrospray ionization mass spectrometry (ESI-MS/MS) method in the leaves and flowers of selected Cassia species. A simple and rapid HPTLC method was developed for chemical fingerprint analysis of all Cassia species. Method All 13 compounds were chromatographically separated on a Zorbax TC18 (4.6 × 250, 5 μm particle size) analytical column, and 0.1% formic acid and acetonitrile as elution solvents at a flow rate of 0.8 mL/min with detection at 259 nm. For HPTLC fingerprinting, the mobile phase compositions of toluene, ethyl acetate, and formic acid (5.5:4.2:0.6, v/v/v) were optimized to separate and identify all compounds using silica gel 60F254 aluminum plates. Results The validation data for the developed HPLC-PDA method for 13 compounds showed good linearity (r2 >0.99) with a sensitive LOD (0.082–1.969 μg/mL), LOQ (0.250–5.967 μg/mL), and excellent recoveries (85.22–100.32%). The quantification results were found to be precise and accurate (<5.0% and relative error), -0.77–0.44 with ESI-MS/MS confirmation in the Cassia samples. The novel HPTLC method was excellent separation for 13 compounds, with Rf values ranging between 0.12 and 0.61. Conclusions The developed HPLC-PDA method was simple and precise and could separate and quantify anthraquinones and flavonoids along with confirmation, using a novel LC-based ESI-MS/MS. The HPTLC method was found to be simple and precise, with excellent separation capabilities for these compounds. Highlights This novel multiplatform approach successfully identified and quantified 13 compounds simultaneously using an integration of data strategy in seven medicinally important Cassia species' leaves and flowers. [ABSTRACT FROM AUTHOR]

Background: Wound healing represents a complex clinical challenge, necessitating the selection of appropriate wound dressings to facilitate an efficient healing process. This study aims to explore an effective approach to enhance wound healing by investigating the therapeutic potential of a nanocellulose-based anthraquinone derived from marine fungi. Forty male Wistar rats were divided into five groups, including a control group and various four treatment groups. The wound healing process was assessed by measuring the wound area at different time points. Results: The results showed promising outcomes in terms of wound healing progression. The group treated with anthraquinone and nanocellulose demonstrated the most favorable results, with normal epidermal architecture, marked hyperkeratosis, and minimal dermal edema. This study provides comprehensive evidence supporting the efficacy of this novel alternative therapy through histopathological and immunohistochemical analyses conducted on a rat model. Conclusion: By addressing the limitations associated with conventional wound dressings, our research contributes to the development of innovative strategies for optimizing wound healing outcomes. The findings presented herein underscore the potential of nanocellulose-based anthraquinone as a promising therapeutic option for promoting skin wound healing. Further investigations are warranted to elucidate the underlying mechanisms and establish the clinical viability of this alternative therapy. [ABSTRACT FROM AUTHOR]

Two metal‐ and acid‐free anthracene (AN) and anthraquinone (AQ)‐based photocatalysts (HCP‐AQ‐2Ph and HCP‐AN‐2Ph) are synthesized and used for the effective acetalization of glycerol to obtain selectively solketal, an added‐value compound with several industrial applications and high demand as an oxygenated additive of fuels. HCP‐AQ‐2Ph and HCP‐AN‐2Ph are prepared by a Friedel–Crafts coupling reaction between the AQ or AN and biphenyl (2Ph) as comonomer which leads to the formation of high thermally stable hyper‐crosslinked porous networks with specific surface areas of 295 and 596 m2 g−1, respectively. Initial tests suggest that HCP‐AN‐2Ph is a less efficient catalyst compared to HCP‐AQ‐2Ph. However, subsequent runs indicate that during the first trial, the AN units are oxidized, resulting in a catalyst (HCP‐AN(OX)‐2Ph) just as effective as the AQ‐based one. The quantitative and selective conversion of glycerol into solketal is achieved in just 3 h using a 4 wt% catalyst and maintaining this catalytic performance for at least 5 cycles. In addition, the process can be scaled allowing the obtaining of solketal with high purity on a gram scale. These results place these catalysts among the most effective for the selective production of solketal from glycerol compared to previously reported metal‐ or acid‐catalyzed reaction. [ABSTRACT FROM AUTHOR]

Introduction: Sicklepod [Cassia obtusifolia L. syn Senna obtusifolia (L.) H.S. Irwin & Barneby, Fabaceae] sprouts are promising ingredients with health‐promoting benefits. Notwithstanding, the pharmacologically active compounds in sicklepod sprouts have not been studied or analysed in detail. Objective: This study aimed to isolate and structurally identify phytochemicals showing α‐glucosidase inhibitory activity in sicklepod sprouts and simultaneously quantify the compounds in the sprouts to determine the optimal cultivation method and germination time to maximise active compounds. Method: A simultaneous high‐performance liquid chromatography‐ultraviolet (HPLC‐UV) method with high sensitivity and accuracy was developed and used to analyse time‐dependent changes in anthraquinone content during sicklepod germination. Results: Thirteen anthraquinones were isolated and identified, of which six—chrysoobtusin, emodin, 1‐O‐methyl‐2‐methoxychrysophanol, 7‐O‐methylobtusin, chrysophanol, and physcion—showed moderate α‐glucosidase inhibitory activity. The maximum content of anthraquinones in a sprout was observed on Day 5 under both light and dark conditions. Conclusion: The findings of this study revealed that sicklepod sprouts which are promising functional food materials contain a variety of anthraquinones. In this study, the functional characterization and simultaneous HPLC analysis of 13 anthraquinones in sicklepod (Cassia obtusifolia L.) sprouts. The phytochemical investigation revealed that sicklepod sprouts produced various free anthraquinones, which exhibited α‐glucosidase inhibitory activity. Interestingly, the anthraquinone content increased during sprouting. Hypothetically, because hydrolase in the seeds was activated during sprouting and anthraquinone glycosides were changed to free anthraquinones with α‐glucosidase inhibitory activity, the activity of the sprouts was stronger than that of the seeds. [ABSTRACT FROM AUTHOR]

Chemotherapy resistance in cancer is an essential factor leading to high mortality rates. Tumor multidrug resistance arises as a result of the autophagy process. Our previous study found that compound 1-nitro-2 acyl anthraquinone-leucine (C2) exhibited excellent anti-colorectal cancer (CRC) activity involving autophagy and apoptosis-related proteins, whereas its underlying mechanism remains unclear. A notable aspect of this study is how C2 overcomes the multidrug susceptibility of HCT116/L-OHP, a colon cancer cell line that is resistant to both in vitro and in vivo oxaliplatin (trans-/-diaminocyclohexane oxalatoplatinum; L-OHP). In a xenograft tumor mouse model, we discovered that the mixture of C2 and L-OHP reversed the resistance of HCT116/L-OHP cells to L-OHP and inhibited tumor growth; furthermore, C2 down-regulated the gene expression levels of P-gp and BCRP and decreased P-gp's drug efflux activity. It is important to note that while C2 re-sensitized the HCT116/L-OHP cells to L-OHP for apoptosis, it also triggered a protective autophagic pathway. The expression levels of cleaved caspase-3 and Beclin 1 steadily rose. Expression of PI3K, phosphorylated AKT, and mTOR were decreased, while p53 increased. We demonstrated that the anthraquinone derivative C2 acts as an L-OHP sensitizer and reverses resistance to L-OHP in HCT116/L-OHP cells. It suggests that C2 can induce autophagy in HCT116/L-OHP cells by mediating p53 and the PI3K/AKT/mTOR signaling pathway. [ABSTRACT FROM AUTHOR]

Pigments such as anthraquinones (AQs) and melanins are antioxidants, protectants, or virulence factors. AQs from the entomopathogenic bacterium Photorhabdus laumondii are produced by a modular type II polyketide synthase system. A key enzyme involved in AQ biosynthesis is PlAntI, which catalyzes the hydrolysis of the bicyclic‐intermediate‐loaded acyl carrier protein, polyketide trimming, and assembly of the aromatic AQ scaffold. Here, multiple crystal structures of PlAntI in various conformations and with bound substrate surrogates or inhibitors are reported. Structure‐based mutagenesis and activity assays provide experimental insights into the three sequential reaction steps to yield the natural product AQ‐256. For comparison, a series of ligand‐complex structures of two functionally related hydrolases involved in the biosynthesis of 1,8‐dihydroxynaphthalene‐melanin in pathogenic fungi is determined. These data provide fundamental insights into the mechanism of polyketide trimming that shapes pigments in pro‐ and eukaryotes. [ABSTRACT FROM AUTHOR]

A DFT and TDDFT study has been carried out on monomeric anthraquinones Emodin and Dermocybin (Em, Derm) recently proposed as natural antibacterial photosensitizers able to act also against gram‐negative microbes. The computational study has been performed considering the relative amount of neutral and ionic forms of each compound in water, with the variation of pH. The occurrence of both Type I and Type II photoreactions has been explored computing the absorption properties of each species, the spin‐orbit coupling constants (SOC), the vertical ionization potentials and the vertical electron affinities. The most plausible deactivation channels leading to the population of excited triplet states have been proposed. Our data indicate Emodin as more active than Dermocybin in antimicrobial photodynamic therapy throughout the Type II mechanism. Our data support a dual TypeI/II activity of the monomeric anthraquinones Emodin and Dermccybin in water, in all the considered protonation states. [ABSTRACT FROM AUTHOR]

Anthraquinone is one of the organic molecules that can potentially replace metal‐based electrodes due to its fast and reversible redox reaction as well as the abundance in nature. Here, we reported the redox activity of anthraquinone on N‐doped porous carbon electrodes derived from chemical activation of tea leaves with potassium carbonate. Electrochemical behavior was evaluated by cyclic voltammetry and galvanostatic charge/discharge in sulfuric acid, with X‐ray photoelectron spectroscopy providing insights into the surface chemistry of the electrodes. Anthraquinone on the composite electrode was able to achieve 97 % of its theoretical storage capacity. We found that nitrogen‐containing functional groups, especially graphitic and pyrrolic groups, had a major impact on the enhanced redox activity of anthraquinone. [ABSTRACT FROM AUTHOR]

Background: The search for new bioactive natural compounds with anticancer activity is still of great importance. Even though their potential for diagnostics and treatment of cancer has already been proved, the availability is still limited. Hypericin, a naphthodianthrone isolated essentially from plant source Hypericum perforatum L. along with other related anthraquinones and bisanthraquinones belongs to this group of compounds. Although it has been proven that hypericin is synthesized by the polyketide pathway in plants, none of the candidate genes coding for key enzymes has been experimentally validated yet. Despite the rare occurrence of anthraquinones in plants, their presence in microorganisms, including endophytic fungi, is quite common. Unlike plants, several biosynthetic genes grouped into clusters (BGCs) in fungal endophytes have already been characterized. Results: The aim of this work was to predict, identify and characterize the anthraquinone BGCs in de novo assembled and functionally annotated genomes of selected endophytic fungal isolates (Fusarium oxysporum, Plectosphaerella cucumerina, Scedosporium apiospermum, Diaporthe eres, Canariomyces subthermophilus) obtained from different tissues of Hypericum spp. The number of predicted type I polyketide synthase (PKS) BGCs in the studied genomes varied. The non-reducing type I PKS lacking thioesterase domain and adjacent discrete gene encoding protein with product release function were identified only in the genomes of C. subthermophilus and D. eres. A candidate bisanthraquinone BGC was predicted in C. subthermophilus genome and comprised genes coding the enzymes that catalyze formation of the basic anthraquinone skeleton (PKS, metallo-beta-lactamase, decarboxylase, anthrone oxygenase), putative dimerization enzyme (cytochrome P450 monooxygenase), other tailoring enzymes (oxidoreductase, dehydrogenase/reductase), and non-catalytic proteins (fungal transcription factor, transporter protein). Conclusions: The results provide an insight into genetic background of anthraquinone biosynthesis in Hypericum-borne endophytes. The predicted bisanthraquinone gene cluster represents a basis for functional validation of the candidate biosynthetic genes in a simple eukaryotic system as a prospective biotechnological alternative for production of hypericin and related bioactive anthraquinones. [ABSTRACT FROM AUTHOR]

A photocatalyzed oxidation of functionalized cyclobutanones to access γ‐lactones has been performed in acetonitrile at room temperature, using anthraquinone derivatives as catalysts in the presence of TFA. The best reaction results were obtained by using 3 mol % of 9,10‐anthraquinone as a catalyst under 370 nm irradiation in an O2 environment. The scope and the limitations of this reaction have been investigated using both 2‐ and 3‐substituted cyclobutanones, as well as enantiopure ketones, to obtain full preservation of their stereochemical identity after the oxidation. The process furnishes in most cases the desired compounds with high purity after catalyst removal by simple filtration, and reducing the production of solvents waste. [ABSTRACT FROM AUTHOR]

The Apocynaceae is a known plant family that is rich in alkaloid, and many of its species were reported to have medicinal significance. An endemic plant from the Philippines, Alyxia linearis Markgr. -- which has not yet been investigated for its phytochemistry nor bioactivity -- is reported here. This study aims to characterize the phytochemical compounds and evaluate the antimicrobial, cytotoxic, and genotoxic activities of A. linearis. The hexane, dichloromethane, and methanol extracts from the roots, twigs, and leaves were subjected to different tests. The antimicrobial activity of the phytoconstituents was investigated against four bacteria (S. aureus, P. aeruginosa, E. faecalis, and E. coli) and two fungi (Penicillum sp. and A. niger). The antimicrobial analysis showed that among the nine extracts, only two extracts exhibited a partial inhibitory activity against those Gram-positive bacteria used, and only one extract exhibited a fungicidal activity. ATD inhibited the growth of both S. aureus and E. faecalis, whereas ARM inhibited only the growth of E. faecalis. Among the nine extracts, only ARD inhibited Penicillum growth. The genotoxicity of the extracts was tested using Allium cepa assay. The semipolar and polar extracts of A. linearis were all genotoxic except 1 ppm ALM. Cytotoxicity of the ALD extract was evaluated using an MTT assay on human dermal fibroblasts neonatal (HDFn). The assessment of cytotoxicity of ALD against HDFn showed an IC50 below 12.5 µg/mL as compared to the IC50 of the doxorubicin, which is 2.89 µg/mL. This indicates that the ALD extract is moderately cytotoxic as compared with doxorubicin. The phytochemical constituents of the A. linearis extracts were classified mainly as phenols, flavonoids, steroids, and triterpenes -- with a slight occurrence of coumarins, anthraquinones, and anthrones. [ABSTRACT FROM AUTHOR]

Biocolourants could be a sustainable option for dyes that require fossil-based chemicals in their synthesis. We studied the in vitro toxicity of anthraquinone aglycone extract obtained from Cortinarius sanguineus fungus and compared it to the toxicity of its two main components, emodin and previously studied dermocybin. Cell viability, cytotoxicity, and oxidative stress responses in HepG2 liver and THP-1 immune cell lines were studied along with skin sensitisation. In addition, genotoxicity was studied with comet assay in HepG2 cells. Cellular viability was determined by MTT, propidium iodide, and lactate dehydrogenase assays, which showed that the highest doses of both the aglycone extract and emodin affected the viability. However, the effect did not occur in all of the used assays. Notably, after both exposures, a dose-dependent increase in oxidative stress factors was observed in both cell lines as measured by MitoSOX and dihydroethidium assays. C. sanguineus extract was not genotoxic in the comet assay. Importantly, both emodin and the extract activated the skin sensitisation pathway in the KeratinoSens assay, suggesting that they can induce allergy in humans. As emodin has shown cytotoxic and skin-sensitising effects, it is possible that the adverse effects caused by the extract are also mediated by it since it is the main component present in the fungus. [ABSTRACT FROM AUTHOR]

Fungal anthraquinones dermocybin and dermorubin are attractive alternatives for synthetic dyes but their metabolism is largely unknown. We conducted a qualitative in vitro study to identify their metabolism using human liver microsomes and cytosol, as well as recombinant human cytochrome P450 (CYP), UDP‐glucuronosyltransferase (UGT) and sulfotransferase (SULT) enzymes. Additionally, liver microsomal and cytosolic fractions from rat, mouse and pig were used. Following incubations of the biocolourants with the enzymes in the presence of nicotinamide adenine dinucleotide phosphate, UDP‐glucuronic acid, 3′‐phosphoadenosine‐5′‐phosphosulfate (PAPS) or S‐adenosyl methionine (SAM) to enable CYP oxidation, glucuronidation, sulfonation or methylation, we observed several oxidation and conjugation metabolites for dermocybin but none for dermorubin. Human CYP1A1, 1A2, 1B1, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 3A4 and 3A7 catalysed dermocybin oxidation. The formation of dermocybin glucuronides was catalysed by human UGT1A1, 1A3, 1A7, 1A8, 1A9, 1A10 and 2B15. Human SULT1B1, 1C2 and 2A1 sulfonated dermocybin. Dermocybin oxidation was faster than conjugation in human liver microsomes. Species differences were seen in dermocybin glucuronidation between human, rat, mouse and pig. In conclusion, many CYP and conjugation enzymes metabolized dermocybin, whereas dermorubin was not metabolized in human liver fractions in vitro. The results indicate that dermocybin would be metabolized in humans in vivo. [ABSTRACT FROM AUTHOR]

Enhancing the cycling efficiency and controlling lithium dendrite growth through a stable and heterogeneous lithium‐electrolyte interface are crucial steps for the practical application of lithium metal batteries. In this study, a carbon network composed of graphdiyne modified with redox‐active anthraquinone units (AN‐GDY) is developed to optimize the performance of the battery separator (PE film) also lithium anode. The AN‐GDY films are integrated with the conventional commercial battery separator (PE film) to create a double‐separator system, aimed at enhancing the interior characteristics of the battery. Electrochemical tests confirme that lithium symmetric batteries with AN‐GDY/PE double‐separator system can deliver high areal capacities of 1, 2, and 5 mAh cm−2 and ultra‐high current densities of 1, 2, and 5 mA cm−2 stable Li plating/stripping for over 800 h. Furthermore, lithium batteries employing AN‐GDY as the lithium anode preserve a capacity of 100 mAh g−1 and exhibite a Coulombic efficiency exceeding 98% after 5000 cycles, even at a high current rate of 500 mA g−1. [ABSTRACT FROM AUTHOR]