- REVISION OF THE STRUCTURE OF PRZEWALSKINONE B
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Biosynthetic considerations suggested that the recently assigned structure (1) of Przewalskinone B was incorrect.Synthetic studies support the revision of the structure of przewalskinone B to 3.
- Kelly, T. Ross,Ma, Zhenkun,Xu, Wei
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- Synthesis and biological activity evaluation of emodin quaternary ammonium salt derivatives as potential anticancer agents
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Twenty-six emodin derivatives (17 novel) which attach quaternary ammonium salt were synthesized and evaluated for their anticancer activities in vitro and in vivo. Compounds 11g + 12g and 11h + 12h had more significant antiproliferative ability against three cancer cell lines and low cytotoxicity to HELF. 11g + 12g and 11h + 12h induced AGS cell apoptosis and arrested cell cycle at the G0/G1 phase in a dose-dependent manner. Furthermore, the activities of the caspase-3, -9 enzymes were increased in the treated cells. In vivo studies revealed that compounds 11g + 12g and 11h + 12h showed significant anti-tumor activity compared with controlled group.
- Wang, Wenfeng,Bai, Zedong,Zhang, Fengsen,Wang, Conghui,Yuan, Yaofeng,Shao, Jingwei
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- Comparison of the cytotoxic activities of naturally occurring hydroxyanthraquinones and hydroxynaphthoquinones
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Seven hydroxyanthraquinone derivatives, 1-7, were isolated from the root of Rheum palmatum (Polygonaceae). Two propionated anthraquinone derivatives, 8 and 9, were synthesized. Four hydroxynaphthoquinone derivatives, 13, 14, 16 and 21, were isolated from the root of Lithospermum erythrorhizon Sieb. et Zucc. (Boraginaceae) and also three naphthoquinone derivatives, 19, 22 and 23, were isolated from the root of Macrotomia euchroma (Royle) Pauls. (Boraginaceae). The cytotoxicity of the anthraquinone and naphthoquinone derivatives on P-gp-underexpressing HCT 116 cells and P-gp-overexpressing Hep G2 cells was examined by MTT assay. Among the anthraquinone derivatives, compounds 3-5 which had OH, CH2OH and COOH substituent groups on the anthraquinone skeletons, respectively, showed potent growth inhibitory activities against both types of cancer cells (IC50 values: 5.7 ± 0.9 to 13.0 ± 0.7 μM in the case of HCT 116 cells and 5.2 ± 0.7 to 12.3 ± 0.9 μM in the case of Hep G2 cells). All hydroxynaphthoquinone derivatives isolated in this study exhibited extremely potent growth inhibitory activities against both types of cancer cells (IC50 values: 0.3 ± 0.09 to 0.46 ± 1.0 μM in the case of HCT 116 cells and 0.22 ± 0.03 to 0.59 ± 0.06 μM in the case of Hep G2 cells) as well as shikonin 10 (IC50 values: 0.32 ± 0.02 μM in the case of HCT 116 cells and 0.24 ± 0.03 μM in the case of Hep G2 cells).
- Cui, Xing-Ri,Tsukada, Maiko,Suzuki, Nao,Shimamura, Takeshi,Gao, Li,Koyanagi, Jyunichi,Komada, Fusao,Saito, Setsuo
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- PHYSCION-8-O-GENTIOBIOSIDE FROM RHAMNUS VIRGATA
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A new anthraquinone diglucoside isolated from rhamnus virgata has been shown to be physcion-8-O-b-gentiobioside on the basis of spectral and othe evidence.Key words: Rhamnus virgata; Rhamnaceae; physcion; physcion-8-O-gentiobioside; anthraquinone.
- Kalidhar, S. B.,Sharma, Pushpa
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- 4-AMINOPHYSCION, AN ANTHRAQUINONE DERIVATIVE FROM DERMOCYBE (AGARICALES)
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The anthraquinones physcion, erythroglaucin and 4-aminophyscion (4-amino-1,8-dihydroxy-6-methoxy-3-methyl-9,10-anthraquinone) have been isolated from the fungal species Dermocybe canaria Horak (ined.). 4-Aminophyscion is reported for the first time as a natural product and represents the first fungal anthraquinone with an amino group. - Key Word Index: Dermocybe; Cortinariaceae; anthraquinones; erythroglaucin; physcion; 4-aminophyscion (4-amino-1,8-dihydroxy-6-methoxy-3-methyl-9,10-anthraquinone).
- Keller, Gerwin,Steglich, Wolfgang
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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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- Modulation of ROS production in photodynamic therapy using a pH controlled photoinduced electron transfer (PET) based sensitiser
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A new sensitiser (4) for use in photodynamic therapy (PDT) has been developed to enable control of ROS production as a function of pH. This pH dependent PDT behaviour was tested in HeLa cells and in SCID mice bearing human xenograft pancreatic cancer (BxPC-3) tumours.
- Atchison, Jordan,Kamila, Sukanta,McEwan, Conor,Nesbitt, Heather,Davis, James,Fowley, Colin,Callan, Bridgeen,McHale, Anthony P.,Callan, John F.
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supporting information
p. 16832 - 16835
(2015/11/27)
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- In vitro formation of the anthranoid scaffold by cell-free extracts from yeast-extract-treated Cassia bicapsularis cell cultures
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The anthranoid skeleton is believed to be formed by octaketide synthase (OKS), a member of the type III polyketide synthase (PKS) superfamily. Recombinant OKSs catalyze stepwise condensation of eight acetyl units to form a linear octaketide intermediate which, however, is incorrectly folded and cyclized to give the shunt products SEK4 and SEK4b. Here we report in vitro formation of the anthranoid scaffold by cell-free extracts from yeast-extract-treated Cassia bicapsularis cell cultures. Unlike field- and in vitro-grown shoots which accumulate anthraquinones, cell cultures mainly contained tetrahydroanthracenes, formation of which was increased 2.5-fold by the addition of yeast extract. The elicitor-stimulated accumulation of tetrahydroanthracenes was preceded by an approx. 35-fold increase in OKS activity. Incubation of cell-free extracts from yeast-extract-treated cell cultures with acetyl-CoA and [2-14C]malonyl-CoA led to formation of torosachrysone (tetrahydroanthracene) and emodin anthrone, beside two yet unidentified products. No product formation occurred in the absence of acetyl-CoA as starter substrate. To confirm the identities of the enzymatic products, cell-free extracts were incubated with acetyl-CoA and [U- 13C3]malonyl-CoA and 13C incorporation was analyzed by ESI-MS/MS. Detection of anthranoid biosynthesis in cell-free extracts indicates in vitro cooperation of OKS with a yet unidentified factor or enzyme for octaketide cyclization.
- Abdel-Rahman, Iman A.M.,Beuerle, Till,Ernst, Ludger,Abdel-Baky, Afaf M.,Desoky, Ezz El-Din K.,Ahmed, Amany S.,Beerhues, Ludger
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- Characterization of emodin metabolites in Raji cells by LC-APCI-MS/MS
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A rapid, simple, and sensitive liquid chromatography-atmospheric pressure chemical ionization tandem mass spectrometry (LC-APCI-MS/MS) method was developed for the identification and quantification of emodin metabolites in Raji cells, using aloe-emodin as an internal standard. Analyses were performed on an LC system employing a Cosmosil 5C18 AR-II column and a stepwise gradient elution with methanol-20 mM ammonium formate at a flow rate of 1.0 mL/min operating in the negative ion mode. As a result, the starting material emodin and its five metabolites were detected by analyzing extracts of Raji cells that had been cultivated in the presence of emodin. The identification of the metabolites and elucidation of their structures were performed by comparing their retention times and spectral patterns with those of synthetic samples. In addition to the major metabolite 8-O-methylemodin, four other metabolites were assigned as ω-hydroxyemodin, 3-O-methyl-ω-hydroxyemodin, 3-O-methylemodin (physcion), and chrysophanol.
- Koyama, Junko,Takeuchi, Atsuko,Morita, Izumi,Nishino, Yu,Shimizu, Maki,Inoue, Munetaka,Kobayashi, Norihiro
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experimental part
p. 7493 - 7499
(2011/02/23)
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- A new anthraquinone glycoside from the roots of plumbago zeylanica
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Isolation of a new anthraquinone, 1-hydroxy-3-methyl-6-methoxyanthraquinone-8-O-β-D-xylopyrano side 1 along with naphthoquinones, droserone 2 and zeylanone 3 is reported from roots of the Plumbago zeylanica. Structures of the compounds have been elucidated by spectroscopic and chemical studies.
- Gupta,Siddiqui,Singh
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p. 796 - 798
(2007/10/03)
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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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- ANNOQUINONE-A, AN ANTIMICROBIAL AND CYTOTOXIC PRINCIPLE FROM ANNONA MONTANA
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A new naturally occuring phenanthrene-1,4-quinone, annoquinone-A, along with parietin (physcion) and β-sitostenone were isolated from the stem bark of Annona montana.The structure of annoquinone-A was elucidated by spectral methods and synthesis.Annoquinone-A demonstrated potent antimicrobial activity against Bacillus subtilis and Micrococcus luteus as well as cytotoxicity in the KB (ED50=0.16 μg/ml) tissue culture assay. β-Sitostenone also showed significant cytotoxicity.Key Word Index - Annona montana; Annonaceae; phenanthrene-1,4-quinone; annoquinone-A; anthraquinone; antibacterial activity; cytotoxicity.
- Wu, Tian-Shung,Jong, Ting-Ting,Tien, Hsien-Ju,Kuoh, Chang-Sheng,Furukawa, Hiroshi,Lee, Kuo-Hsiung
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p. 1623 - 1626
(2007/10/02)
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- REACTIONS OF KETENE ACETALS 16. THE REGIOSPECIFIC SYNTHESIS OF PARTIALLY METHYLATED PURPURINS
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Two novel vinylketene acetals, 1,4-dimethoxy-1,3-bistrimethylsiloxybutadiene and 1,3,4-trimethoxy-1-trimethylsiloxybutadiene have been prepared in view of their eventual application to the synthesis of the antitumor antibiotic bikaverin.Use of the former in the elaboration of anthraquinones has shown that structures proposed for two natural products, purpurin 1-methyl ether and 8-hydroxypurpurin 1-methyl ether are in fact those of anthragallol derivatives.The second diene has afforded confirmation of the nature of xanthorin 5-methyl ether as well as of a degradation product of bostrycin.A substitution pattern claimed for another natural product, 5-hydroxyanthragallol 2,5-dimethyl ether, is also incorrect.
- Simoneau, Bruno,Brassard, Paul
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p. 3767 - 3774
(2007/10/02)
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- ANTHRAQUINONES FROM THE GENUS CORTINARIUS
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The anthraquinones 6-methylxanthopurpurin-3-methyl ether, xanthorin, and 1,4-dihydroxy-2-methoxy-7-methyl-9,10-anthraquinone (austrocortitnin) have been isolated from fruit bodies of a red Australian toadstool belonging to the genus Cortinarius; austrocortinin is reported for the first time as a natural product. Key Word Index - Cortinarius; Dermocybe; basidiomycete; anthraquinones.
- Archard, Michelle A.,Gill, Melvyn,Strauch, Richard J.
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p. 2755 - 2758
(2007/10/02)
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- AN ANTHRAQUINONE GLYCOSIDE FROM RHAMNUS PALLASII
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A new anthraquinone glycoside, together with α-sorinin, has been isolated from the bark of Rhamnus pallasii and its structure elucidated as physcion-8-O-β-primeveroside.Key Word Index -- Rhamnus pallasii; Rhamnaceae; α-sorinin; anthraquinone glycoside; physcion-8-O-β-primeveroside; 1,8-dihydroxy-3-methyl-6-methoxy-anthraquinone-8-O-β-primeveroside.
- Coskun, Maksut,Tanker, Nevin,Sakushima, Akiyo,Kitagawa, Shizuka,Nishibe, Sansei
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p. 1485 - 1488
(2007/10/02)
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- Torosachrysone and physcion gentiobiosides from the seeds of Cassia torosa
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Torosachrysone 8-β-D-gentiobioside (1) and physcion 8-β-D-gentiobioside (2) were isolated along with protocatechuic acid from the unripe and ripe seeds of Cassia torosa CAVANILLES, respectively. The structure of 1 was established on the basis of chemical and spectroscopic findings. In addition, the 13C nuclear magnetic resonance spectra of torosachrysone and related compounds are discussed.
- Kitanaka,Takido
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p. 3436 - 3440
(2007/10/02)
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- REACTIONS OF KETENE ACETALS-14; THE USE OF SIMPLE MIXED VINYLKETENE ACETALS IN THE ANNULATION OF QUINONES
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α,β- and β,γ-unsaturated esters can be converted by strong base and chlorotrimethylsilane to the corresponding mixed vinylketene acetals which are shown to be particularly useful and generally applicable reagents for the regiospecific annulation of halogenoquinones.The reaction proceeds readily with a variety of substrates including benzoquinones.
- Savard, Jacques,Brassard, Paul
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p. 3455 - 3464
(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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- DIMERIC HYDROANTHRACENES FROM THE UNRIPE SEEDS OF CASSIA TOROSA
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From the unripe seeds of Cassia torosa three new dimeric hydroanthracene derivatives were isolated along with stigmasterol, sitosterol, campesterol, physcion-9-anthrone, torosachyrsone and the phlegmacins A2 and B2.The structures of the new derivatives were established as physcion-10,10'-bianthrone, anhydrophlegmacin B2 and torosanin , respectively.Key Word Index - Cassia torosa; Leguminosae; physcion-9-anthrone; physcion-10,10'-bianthrone; phlegmacin; anhydrophlegmacin B2; torosanin; hydroanthracene; phytosterols.
- Kitanaka, Susumu,Takido, Michio
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p. 2103 - 2106
(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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