- ANTHRAQUINONES FROM CASSIA SOPHERA HEARTWOOD
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From the heartwood of Cassia sophera two new isomeric anthraquinones, 1,2,7-trihydroxy-6,8-dimethoxy-3-methyl- and 1,2,6-trihydroxy-7,8-dimethoxy-3-methylanthraquinone have been isolated along with 1-octadecanol and quercetin.Key Word Index - Cassia sophera; Leguminosae; heartwood; 1,2,7-trihydroxy-6,8-dimethoxy-3-methylanthraquinone; 1,2,6-trihydroxy-7,8-dimethoxy-3-methylanthraquinone.
- Malhotra, Swadesh,Misra, Krishna
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- Synthesis of high specific radioactivity [3H]emodin
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Emodin, a precursor of chrysophanol in the biosynthesis of cynodontin by Pyrenochaeta terrestris, has been tritiated with a high specific radioactivity (12.5 Ci/mmol) by hydrogenolysis of bromomethyl emodin.
- Hadj-Hamdri,Vidal-Cros,Gaudry,Sobrio,Rousseau
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- PRENYLATED BIANTHRONES AND VISMIONE FROM PSOROSPERMUM FEBRIFUGUM
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Psorospermum febrifugum; Guttiferae; geranyloxyemodin; 2-geranylemodin; vismiones D and F; bianthrones.The roots of Psorospermum febrifugum collected in Malawi contained together with the known vismione D and geranyloxyemodin four new compounds: vismione F and the three bianthrones A1, A3a and A3b.All the isolated compounds contained C- or O-geranyl substituents and showed a close biogenetic relationship.
- Botta, B.,Monache, F. Delle,Monache, G. Delle,Bettolo, G. B. Marini,Msonthi, J. D.
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- Novel metabolites from ploiarium alternifolium: A bixanthone and two anthraquinonylxanthones
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From branches of the shrub Plotarium atternifolium three novel metabolites have been isolated: a C---C′ - linked bixanthone, ploiarixanthone(1). and two anthraquinonylxanthones, euxanmodin A and B (2 and 3).
- Bennett, Graham J.,Lee, Hiok-Huang,Lowrey, Timothy K.
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- Enhancement of emodin production by medium optimization and KH2PO4 supplementation in submerged fermentation of marine-derived aspergillus favipes HN4-13
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Emodin is a widely distributed anthraquinone derivative with a variety of biological activities, one that can be efficiently produced by marine-derived fungus Aspergillus favipes HN4-13. However, its relatively low fermentation yield limits further development and pharmaceutical research work. In this study, Plaekett–Burman design and central composite design were adopted to optimize the fermentation conditions of A. favipes HN4-13. Optimal fermentation conditions in a 250-mL Erlenmeyer flask with 50 mL of medium were 59.3 g/L soluble starch, 10 g/L yeast extract paste, 30 g/L seawater salt, 1.04 g/L KH2PO4, 0.05 g/L MgSO4·7H2O, 0.01 g/L FeSO4·7H2O, seed culture 24 h, pH 5, inoculum size 18%, culture temperature 32?C, and shaking at 160 rpm/min for 7 days. The production of emodin could achieve 132.40 ± 3.09 mg/L, with no significant difference from the predicted value (132.47 mg/L). Furthermore, KH2PO4 supplementation strategy was employed to regulate the mycelial morphology, upregulate the transcriptional level of biosynthesis gene cluster, and enhance emodin production (185.56 ± 4.39 mg/L).
- Qiu, Xiaohan,Gong, Lizhi,Xin, Xiujuan,An, Faliang
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- Inhibition of human carbonyl reducing enzymes by plant anthrone and anthraquinone derivatives
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Members of the aldo-keto reductase and short-chain dehydrogenase/reductase enzyme superfamilies catalyze the conversion of a wide range of substrates, including carbohydrates, lipids, and steroids. These enzymes also participate in the transformation of xenobiotics, inactivation of the cytostatics doxo- and daunorubicin, and play a role in the development of cancer. Therefore, inhibitors of such enzymes may improve therapeutic outcomes. Plant-derived compounds such as anthraquinones have been used for medicinal purposes for several centuries. In the current study, the inhibitory potential of selected anthrone and anthraquinone derivatives (from plants) was tested on six recombinant human carbonyl reducing enzymes (AKR1B1, AKR1B10, AKR1C3, AKR7A2, AKR7A3, CBR1) isolated from an Escherichia coli expression system. Overall, the least inhibition was observed with the anthrone derivative aloin, while IC50 values obtained with the anthraquinone derivatives (frangula emodin, aloe emodin, frangulin A, and frangulin B) and the aldo-keto reductase AKR1B10 were in the low micromolar range (3.5–16.6 μM). AKR1B1 inhibition was significantly weaker in comparison with AKR1B10 inhibition (IC50 values > 50 μM). The strongest inhibition was observed with the short-chain dehydrogenase/reductase CBR1. AKR7A2, AKR7A3, and AKR1C3 were not, or less inhibited by inhibitor concentrations of up to 50 μM. Analysis of the kinetic data suggests noncompetitive or uncompetitive inhibition mechanisms. The new inhibitors described here may serve as lead structures for the development of future drugs.
- Adomako-Bonsu, Amma G.,Maser, Edmund,Thiele, Solveig,Westermann, Magdalena,?i?ek, Serhat Sezai,Martin, Hans-J?rg
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- Intertwined Biosynthesis of Skyrin and Rugulosin A Underlies the Formation of Cage-Structured Bisanthraquinones
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Skyrin and rugulosin A are bioactive bisanthraquinones found in many fungi, with the former suggested as a precursor of hypericin (a diversely bioactive phytochemical) and the latter characterized by its distinct cage-like structure. However, their biosynthetic pathways remain mysterious, although they have been characterized for over six decades. Here, we present the rug gene cluster that governs simultaneously the biosynthesis of skyrin and rugulosin A in Talaromyces sp. YE3016, a fungal endophyte residing in Aconitum carmichaeli. A combination of genome sequencing, gene inactivation, heterologous expression, and biotransformation tests allowed the identification of the gene function, biosynthetic precursor, and enzymatic sets involved in their molecular architecture constructions. In particular, skyrin was demonstrated to form from the 5,5′-dimerization of emodin radicals catalyzed by RugG, a cytochrome P450 monooxygenase evidenced to be potentially applicable for the (chemo)enzymatic synthesis of dimeric polyphenols. The fungal aldo-keto reductase RugH was shown to be capable of hijacking the closest skyrin precursor (CSP) immediately after the emodin radical coupling, catalyzing the ketone reduction of CSP to inactivate its tautomerization into skyrin and thus allowing for the spontaneous intramolecular Michael addition to cyclize the ketone-reduced form of CSP into rugulosin A, a representative of diverse cage-structured bisanthraquinones. Collectively, the work updates our understanding of bisanthraquinone biosynthesis and paves the way for synthetic biology accesses to skyrin, rugulosin A, and their siblings.
- Bai, Wei,Ding, Chun Xia,Han, Yun Bin,Liang, Jie,Tan, Ren Xiang,Wu, Shao-Hua
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supporting information
p. 14218 - 14226
(2021/09/13)
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- Synthesis of (-)-Flavoskyrins by Catalyst-Free Oxidation of (R)-Configured Dihydroanthracenones in Aqueous Media and Its (Bio)synthetic Implications
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A catalyst-free method for the synthesis of dimeric (-)-flavoskyrins has been developed. It involves the autoxidation of chemoenzymatically synthesized (R)-configured dihydroanthracenones in the presence of molecular oxygen in buffer of pH 6.0 followed by spontaneous [4 + 2] cycloaddition in stereocontrolled exo-anti fashion to form (-)-flavoskyrins. The method is applied to obtain several homo- A s well as heterodimerized flavoskyrins (nine examples) in 27-72% yield and implies the involvement of a similar pathway in the (bio)synthesis of modified bisanthraquinones and their analogues.
- Mondal, Amit,De, Arijit,Husain, Syed Masood
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supporting information
p. 8511 - 8515
(2020/11/12)
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- Synthesis and antibacterial activity of emodin and its derivatives against methicillin-resistant Staphylococcus aureus
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Synthesis of the antibacterial emodin was improved using Friedel-Crafts acylation as a key step leading to 37% overall yield. In addition, 21 analogues were synthesized by structural modification of the hydroxyl and methyl groups, as well as the aromatic ring of emodin. Antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and cytotoxicity against noncancerous Vero cells were evaluated. A structure-activity relationship (SAR) study indicated that the hydroxyl groups and the methyl group in the emodin skeleton were crucial for anti-MRSA activity. Furthermore, the presence of an iodine atom or ethylamino group on the aromatic ring enhanced the anti-MRSA activity with higher selectivity indices, while derivatives containing bromine, chlorine atoms or quaternary ammonium salt were as active as emodin. The quaternary ammonium group on the aromatic ring also led to non-cytotoxicity against Vero cells.
- Chalothorn, Thidarat,Rukachaisirikul, Vatcharin,Phongpaichit, Souwalak,Pannara, Sakawrat,Tansakul, Chittreeya
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supporting information
(2019/08/08)
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- Anthraquinone glycosides from Cassia roxburghii and evaluation of its free radical scavenging activity
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The methanolic extract of the leaves of Cassia roxburghii DC., was investigated for its anthraquinone glycosides and antioxidant activity. Two new anthraquinone glycosides named emodin 1-O-β-d-glucopyranosyl-(1→2)- glucopyranoside (1) and aloemodin 8-O-β-
- El-Toumy, Sayed A.,El Souda, Sahar S.,Mohamed, Tahia K.,Brouard, Inaki,Bermejo, Jame
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- Biosynthesis of Actinorhodin and Related Antibiotics: Discovery of Alternative Routes for Quinone Formation Encoded in the act Gene Cluster
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All known benzoisochromanequinone (BIQ) biosynthetic gene clusters carry a set of genes encoding a two-component monooxygenase homologous to the ActVA-ORF5/ActVB system for actinorhodin biosynthesis in Streptomyces coelicolor A3(2). Here, we conducted molecular genetic and biochemical studies of this enzyme system. Inactivation of actVA-ORF5 yielded a shunt product, actinoperylone (ACPL), apparently derived from 6-deoxy-dihydrokalafungin. Similarly, deletion of actVB resulted in accumulation of ACPL, indicating a critical role for the monooxygenase system in C-6 oxygenation, a biosynthetic step common to all BIQ biosyntheses. Furthermore, in vitro, we showed a quinone-forming activity of the ActVA-ORF5/ActVB system in addition to that of a known C-6 monooxygenase, ActVA-ORF6, by using emodinanthrone as a model substrate. Our results demonstrate that the act gene cluster encodes two alternative routes for quinone formation by C-6 oxygenation in BIQ biosynthesis.
- Okamoto, Susumu,Taguchi, Takaaki,Ochi, Kozo,Ichinose, Koji
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experimental part
p. 226 - 236
(2010/06/20)
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- An expedient and efficient synthesis of naturally occurring hydroxy substituted anthraquinones
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A general method for the synthesis of naturally occurring anthraquinones in high yield via Diels-Alder reaction is reported.
- Khan,Blessing,Schmidt
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p. 255 - 257
(2007/10/02)
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- Method for dyeing keratinous fibres using a monohydroxyindole or dihydroxyindole and a non-oxidizing aromatic carbonyl derivative and dyeing agent
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The present invention relates to a method for dyeing keratinous fibers, characterized in that the following are applied to the fibers: a) a composition (A) containing, in a medium appropriate for dyeing, at least one monohydroxyindole or dihydroxyindole, this application being preceded or followed by the application of b) a composition (B) containing, in a medium appropriate for dyeing, at least one aromatic carbonyl derivative chosen from hydroxyacetophenones, hydroxybenzophenones, 2-hydroxy-1,4-benzoquinones, hydroxy-1,4-naphthoquinones,amino-1,4-naphthoquinones,hydroxy-9,10-anthraquinones and amino-9,10-anthraquinones. It also relates to the dyeing agents for carrying it out.
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- Novel anthraquinone inhibitors of human leukocyte elastase and cathepsin G
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A large series of variously substituted anthraquinones has been synthesized and assayed for inhibitory capacity against human leukocyte elastase (HLE) and cathepsin G (CatG), two serine proteinases implicated in diseases characterized by the abnormal degradation of connective tissue, such as pulmonary emphysema and rheumatoid arthritis. It was found that 2-alkyl- 1,8-dihydroxyanthraquinone analogues are competitive inhibitors of HLE with IC50 values ranging from 4 to 10 μM, and also inhibit CatG with IC50 values ranging from 25 to 55 μM. Consequently, analogues containing the 2- alkyl-1-hydroxy-8-methoxyanthraquinone substitution pattern inhibit HLE to the same magnitude as for the compounds above, but show very little inhibition of CatG. Anthraquinones containing long, hydrophobic n-butyl carbonate moieties in the 1- and 8-positions in conjunction with a third hydrophobic substituent in the 2- or 3-position are highly selective for HLE, with K(i) values in the range of 10-7 M. All of the inhibitors described are completely reversible, with no evidence of acyl-enzyme formation detected.
- Zembower,Kam,Powers,Zalkow
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p. 1597 - 1605
(2007/10/02)
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- A Convenient Synthesis of Isotopically Labelled Anthraquinones, Chrysophanol, Islandicin, and Emodin. Incorporation of Chrysophanol into Tajixanthone in Aspergillus variecolor
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Cycloaddition reactions of labelled 6-methoxy-3-methyl-2-pyrone (1) with naphthoquinones provide the common fungal anthraquinones, chrysophanol (2), islandicin (3), and emodin (4) suitably labelled for biosynthetic studies, as demonstrated by synthesis and incorporation of chrysophanol into the xanthone metabolite, tajixanthone (17) in Aspergillus variecolor.
- Ahmed, Salman A.,Bardshiri, Esfandiar,Simpson, Thomas J.
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p. 883 - 884
(2007/10/02)
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- 3-GERANYLOXY-6-METHYL-1,8-DIHYDROXYANTHRAQUINONE AND VISMIONES C, D AND E FROM PSOROSPERMUM FEBRIFUGUM
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Tree new vismiones and 3-geranyloxy-6-methyl-1,8-dihydroxyanthraquinone were isolated from the berries of Psorospermum febrifugum together with the known chrysophanic acid, 2-isoprenylemodin and ferruginin B.Their structures were established through chemical and spectral means.The occurrence of prenylated anthracenes only in Vismieae suggests their use as systematic markers for the tribe.Key Word - Psorospermum febrifugum; Guttiferae; Vismieae; prenylated anthracenes; 3-geranyloxy-6-methyl-1,8-dihydroxyanthraquinone; vismiones C, D and E.
- Botta, B.,Monache, F. Delle,Monache, G. Delle,Bettolo, G. B. Marini,Oguakwa, J. U.
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p. 539 - 542
(2007/10/02)
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- ANTHRAQUINONES IN VENTILAGO SPECIES
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Eleven anthraquinones have been isolated from the root bark of Ventilago calyculata of which xanthorin-5-methyl ether and 2-hydroxyislandicin are new natural products.Eight anthraquinones have been isolated from the root bark of V. maderaspatana.Key Word Index - Ventilago calyculata; Ventilago maderaspatana; Rhamnaceae; anthraquinones.
- Rao, B. Kesava,Hanumaiah, T.,Rao, C. P.,Rao, G. S. R.,Rao, K. V. J.,Thomson, Ronald H.
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p. 2583 - 2586
(2007/10/02)
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- SYNTHETISCHE ANTHRACYCLINONE XVI SYNTHESE HYDROXYLIERTER ANTHRACHINONE DURCH REGIOSELEKTIVE DIELS-ALDER-REAKTION
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Naturally occuring quinones such as 7-methyljuglone, chrysophanol, emodin, helminthosporin, phomarin and physcion were prepared via Diels-Alder reaction and PCC-oxidation of the allylic alcohols obtained from the adducts.
- Krohn, Karsten
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p. 3557 - 3560
(2007/10/02)
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- Chemistry of Quinones. Part 6. The Selective Hydrolysis of α-Acetoxyanthraquinones and Related Compounds by Trifluoroacetic Acid Containing Small Amounts of Water
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Acetoxy- or benzoyloxy-substituents adjacent to the carbonyl groups of anthraquinone, 1,4-naphthoquinone, naphthacene-5,12-quinone, benzophenone, and methyl benzoate are selectively converted into hydroxy-groups by treatment with trifluoroacetic acid containing small amounts of water.In the absence of water a reversible acidolysis occurs.Water reacts with the acylating agent, thus preventing the reverse reaction.Evidence is presented that the hydrolyses are of the AAC1 type.
- Harrison, Charles R.,Hodge, Philip,Khan, Naeem
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p. 1592 - 1594
(2007/10/02)
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