- A facile synthesis of emodin derivatives, emodin carbaldehyde, citreorosein, and their 10-deoxygenated derivatives and their inhibitory activities on μ-calpain
-
A new procedure for the preparation of emodin carbaldehyde and citreorosein was described, in which, ω,ω'-dibromomethylemodin triacetate was prepared as a key intermediate by NBSmediated bromination of 1,3,8-triacetylemodin. Reduction of emodin and citreorosein with SnCl 2 in a 1:1 mixture of HOAc and HCl afforded the corresponding anthrones in 90% and 92% yield, respectively, while the corresponding 10-desoxyemodin carbaldehyde was prepared by MnO2 oxidation of 10-desoxycitreorosein. 10-Desoxycitreorosein and emodin carbaldehyde showed feasible μ-calpain inhibitory activities with IC50 values of 20.15 and 25.77 M, respectively.
- Liang, Jing Lu,Cha, Hyo Chang,Lee, Seung Ho,Son, Jong-Keun,Chang, Hyeun Wook,Eom, Ji-Eun,Kwon, Youngjoo,Jahng, Yurngdong
-
-
Read Online
- A biocatalytic approach towards the preparation of natural deoxyanthraquinones and their impact on cellular viability
-
Herein, a two-step chemoenzymatic process for the synthesis of medicinally important 3-deoxygenated anthra-9,10-quinones is developed. It involves a regio- and stereoselective reduction of hydroanthraquinones to (R)-configured dihydroanthracenones using an anthrol reductase of T. islandicus, followed by oxidation and dehydration to obtain deoxyanthraquinones in 65-80% yield. Comparison of the cell viability of normal human kidney HEK293 cells between anthraquinones and their deoxy derivatives revealed less toxicity for the latter.
- Das, Kiran,De, Arijit,Husain, Syed Masood,Maity, Biswanath,Mondal, Amit,Rajput, Anshul
-
supporting information
p. 3087 - 3090
(2022/02/21)
-
- Chemoenzymatic, biomimetic total synthesis of (-)-rugulosin B, C and rugulin analogues and their biosynthetic implications
-
Herein, we report the chemoenzymatic synthesis of a heterodimeric (-)-rugulosin B, homodimeric (-)-rugulosin C, and several rugulin analogues in three to four steps starting from anthraquinones. This work supports dimerization between variously substituted putative monomeric intermediates during the biosynthesis of naturally occurring (+)-rugulosin B and C.
- Mondal, Amit,Singh, Shailesh Kumar,Manna, Tanaya,Husain, Syed Masood
-
supporting information
p. 3337 - 3340
(2020/04/02)
-
- Chemoenzymatic reduction of citreorosein and its implications on aloe-emodin and rugulosin C (bio)synthesis
-
A chemoenzymatic reduction of citreorosein by the NADPH-dependent polyhydroxyanthracene reductase from Cochliobolus lunatus or MdpC from Aspergillus nidulans in the presence of Na2S2O4 gave access to putative biosynthetic intermediates, (R)-3,8,9,10-tetrahydroxy-6-(hydroxymethyl)-3,4-dihydroanthracene-1(2H)-one and its oxidized form, (R)-3,4-dihydrocitreorosein. Herein, we discuss the implications of these results towards the (bio)synthesis of aloe-emodin and (+)-rugulosin C in fungi.
- Mondal, Amit,Saha, Nirmal,Rajput, Anshul,Singh, Shailesh Kumar,Roy, Brindaban,Husain, Syed Masood
-
supporting information
p. 8711 - 8715
(2019/10/16)
-
- Identification and characterization of an anthrol reductase from: Talaromyces islandicus (Penicillium islandicum) WF-38-12
-
An NADPH-dependent oxidoreductase from Talaromyces islandicus WF-38-12 has been identified through genome analysis. It has been shown to catalyze a regio- and stereoselective reduction of anthrols (formed in situ by the reduction of anthraquinones in the presence of Na2S2O4) to (R)-dihydroanthracenones, with high enantiomeric excess (>99%). The implications of results on the biosynthesis of deoxygenated (bis)anthraquinones and modified (bis)anthraquinones are discussed.
- Singh, Shailesh Kumar,Mondal, Amit,Saha, Nirmal,Husain, Syed Masood
-
supporting information
p. 6594 - 6599
(2019/12/26)
-
- Synthesis and antibacterial activity of emodin and its derivatives against methicillin-resistant Staphylococcus aureus
-
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
-
supporting information
(2019/08/08)
-
- Chemical Reactivity of Emodin and Its Oxidative Metabolites to Thiols
-
Polygonum multiflorum is an herbal medicine widely employed in China. Hepatotoxicity of the herbal medicine has been well documented, but the mechanisms of the toxicity remain unknown. Emodin (EM) is a major constituent of the herb and has been reported to be hepatotoxic. The main purpose of this study was to define the metabolic pathways of EM in order to characterize the potential reactive intermediates. EM was incubated with rat liver microsomes or human liver microsomes, followed by LC-MS/MS analysis to investigate the in vitro and in vivo metabolism of EM. As a result, three monohydroxylation metabolites (M1-M3) were detected after exposure to EM: -hydroxyemodin, 2-hydroxyemodin, and 5-hydroxyemodin. Urinary M1 and M2 were detected in rats administered EM. Three mercapturic acids (M4-M6) were found in microsomal incubations containing EM, NADPH, and N-acetylcysteine. It appears that M4 originated from parent compound EM, and M5 and M6 originated from M1 and M2, respectively. Two biliary EM-derived GSH conjugates were found in EM-treated rats. One arose from direct adduction of EM with GSH, and the other was derived from M1. Cytochrome P450's 1A2, 2C19, and 3A4 were the predominant P450 enzymes to oxidize EM. The findings helped us to understand the mechanisms of EM-induced hepatotoxicity.
- Qin, Boyang,Xu, Yang,Chen, Jiaming,Huang, Wenlin,Peng, Ying,Zheng, Jiang
-
p. 2114 - 2124
(2016/12/26)
-
- Characterization of emodin metabolites in Raji cells by LC-APCI-MS/MS
-
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
-
scheme or table
p. 7493 - 7499
(2011/02/23)
-
- Synthesis and properties of ionophore conjugated hypericin derivatives
-
Two types of derivatives substituted with ionophoric residues at the ω,ω′-methyl groups of hypericin were synthesized. On the one hand, an open chain triethylene glycol derivative did not form stable complexes with alkali metal ions. Embedded as its deter
- Altmann, Robert,Falk, Heinz,Gruber, Hermann J.
-
p. 235 - 244
(2007/10/03)
-
- An expedient and efficient synthesis of naturally occurring hydroxy substituted anthraquinones
-
A general method for the synthesis of naturally occurring anthraquinones in high yield via Diels-Alder reaction is reported.
- Khan,Blessing,Schmidt
-
p. 255 - 257
(2007/10/02)
-
- The Chemical Structure and the Mutagenicity of Emodin Metabolites
-
Emodin (1,3,8-trihydroxy-6-methyl-9,10-anthraquinone) is a natural occuring anthraquinone formed in rhubarb and fungal metabolites.Emodin was transformed into 6 major metabolites by rat hepatic microsomes.The metabolites were identified as 2-hydroxyemodin, 4-hydroxyemodin, 5-hydroxyemodin, 7-hydroxyemodin, ω-hydroxyemodin, and emodic acid by comparison with the synthetic compounds using thin-layer chromatography.It was clear that 2-hydroxyemodin is a proximate mutagen as a synthetic compound by the Salmonella assay.Other metabolites, such as 5-hydroxyemodin and ω-hydroxyemodin, became active after metabolic activation, but 4-hydroxyemodin and emodic acid were inactive either in the presence or in the absence of the metabolic activation system.
- Morooka, Nobuhisa,Nakano, Sonoko,Itoi, Noriko,Ueno, Yoshio
-
p. 1247 - 1252
(2007/10/02)
-
- Synthesis of Emodine Aldehyde
-
By chromium trioxide oxidation and subsequent acid hydrolysis triacetyl emodine (3) was transferred to the aldehyde 9 in a two-step synthesis.In a more favourable sequence 3 was reacted to the bromomethyl derivative 4 and this solvolyzed to the citreoroseine derivative 5.A second NBS reaction gave 8 which after acid hydrolysis led to emodine aldehyde (9).This five-step process proceeded without chromatographic separation in 27percent overall yield. - Key words: Emodine, Citreoroseine, 3-Formyl-1,6,8-trihydroxyanthraquinone, 1H NMR Spectra
- Thiem, Joachim,Wessel, Hans-Peter
-
p. 422 - 425
(2007/10/02)
-
- Chemische Studien ueber natuerliche Anthrachinone. II. Synthese von Citreoroseine, Fallacinol und Fallacinal
-
The meltingpoint and infrared spectrum of synthesized 1,6,8-trihydroxy-3-hydroxymethylanthraquinone (II) were identical with those of citreoroseine (I) .Synthesis of 1,3-diacetoxy-3-bromomethyl-6-methoxyanthraquinone (VIII) was established.And fallacinal (V) could be prepared by oxidation of fallacinol (IV).Keywords - Penicillium citreo-roseum DIERCKX; Xanthoria fallax (HEPP.) ARN.; citreorosein; fallacinol; fallacinal; 3-formyl-1,6,8-trihydroxyanthraquinone
- Hirose, Yoshio,Suehiro, Yoshihisa,Furukawa, Yumiko,Murakami, Takao
-
p. 4186 - 4188
(2007/10/02)
-
