Anthrasesamones from roots of Sesamum indicum

Three anthraquinones, named anthrasesamones A, B and C, were isolated from the roots of Sesamum indicum, and their respective structures were determined to be 1-hydroxy-2-(4-methylpent-3-enyl)anthraquinone, 1,4-dihydroxy-2-(4-methylpent-3-enyl)anthraquinone and 2-chloro-1,4-dihydroxy-3-(4-methylpent-3-enyl)anthraquinone on the basis of spectroscopic evidence. Two known anthraquinones were also isolated for the first time from S. indicum roots and characterized as 2-(4-methylpent-3-enyl)anthraquinone and (E)-2-(4-methylpenta-1,3-dienyl)anthraquinone. Anthrasesamone C is a rare chlorinated anthraquinone in higher plants.     

Isolation and photoisomerization of a new anthraquinone from hairy root cultures of Sesamum indicum

An unstable anthraquinone was isolated from hairy root cultures of Sesamum indicum after preventing light throughout all experimental procedures. The structure of the (Z)-isomer of a previously isolated anthraquinone was determined to be 2-[(Z)-4-methylpenta-1,3-dien-1-yl]anthraquinone by spectroscopic methods. This compound was readily isomerized to the known (E)-isomer under light.     

Anthrasesamone F from the Seeds of Black Sesamum indicum

A new anthraquinone derivative, named anthrasesamone F, was isolated from the seeds of Sesamum indicum. Its structure was determined to be (Z)-6,7-dihydroxy-2-(6-hydroxy-4-methyl-3-pentenyl)anthraquinone on the basis of spectroscopic evidence.     

Biosynthesis of anthraquinone derivatives in a Sesamum indicum hairy root culture

In order to investigate the intermediacy of 2-(4-methylpent-3-en-1-yl)anthraquinone (MPAQ), a possible intermediate for the biosynthesis of anthraquinone derivatives in sesame (Sesamum indicum), ²H-labeled MPAQ was administered to a hairy root culture of S. indicum. Efficient conversion of fed MPAQ to 2-[(Z)-4-methylpenta-1,3-dien-1-yl]anthraquinone ((Z)-MPDEAQ) was observed. Furthermore, administration experiment with ²H-labeled 2-geranyl-1,4-naphthohydroquinone, another possible intermediate, showed that it was converted to MPAQ and (Z)-MPDEAQ. The results clearly demonstrated that these substrates are the actual precursors for the production of (Z)-MPDEAQ. In contrast, neither MPAQ nor 2-geranyl-1,4-naphthohydroquinone was converted to anthrasesamone B and 2,3-epoxyanthrasesamone B, other anthraquinone derivatives in the hairy roots, suggesting that these substrates may not be the common precursors in the biosynthesis of anthraquinone derivatives.     

Anthrasesamones D and E from Sesamum indicum roots

Two anthraquinone derivatives, named anthrasesamones D and E, were isolated from the roots of Sesamum indicum. Their respective structures were determined to be 1,2,4-trihydroxy-3-(4-methylpent-3-enyl)anthraquinone and 1,2-dihydroxy-3-(4-methylpent-3-enyl)anthraquinone on the basis of spectroscopic evidence.     

Isolation and Photoisomerization of a New Anthraquinone from Hairy Root Cultures of Sesamum indicum

An unstable anthraquinone was isolated from hairy root cultures of Sesamum indicum after preventing light throughout all experimental procedures. The structure of the (Z)-isomer of a previously isolated anthraquinone was determined to be 2-[(Z)-4-methylpenta-1,3-dien-1-yl]anthraquinone by spectroscopic methods. This compound was readily isomerized to the known (E)-isomer under light.     

Anthrasesamones D and E from Sesamum indicum Roots

Two anthraquinone derivatives, named anthrasesamones D and E, were isolated from the roots of Sesamum indicum. Their respective structures were determined to be 1,2,4-trihydroxy-3-(4-methylpent-3-enyl)anthraquinone and 1,2-dihydroxy-3-(4-methylpent-3-enyl)anthraquinone on the basis of spectroscopic evidence.     

蒽醌衍生物结构及其对小麦白粉病菌生物活性的关系研究

蒽醌衍生物是植物产生的一类次生代谢产物,对植物病原真菌具有明显的活性。为明确蒽醌衍生物结构与其生物活性之间的关系,以小麦白粉病菌为研究对象,测定了蒽醌及16种蒽醌衍生物对该病菌的活性。结果表明,蒽醌衍生物对小麦白粉病菌的活性明显大于葸醌的活性;甲氧基的位置与活性关系密切,6位是决定活性的关键,活性顺序为5、6位〉1、6位〉6位〉8位。     

The transformation and toxicity of anthraquinone dyes during thermophilic (55 degrees C) and mesophilic (30 degrees C) anaerobic treatments

We studied in batch assays the transformation and toxicity of anthraquinone dyes during incubations with anaerobic granular sludge under mesophilic (30 degrees C) and thermophilic (55 degrees C) conditions. Additionally, the electron shuttling capacity of the redox mediator anthraquinone-2-sulfonic acid (AQS) and subsequent increase on decolourisation rates was investigated on anthraquinone dyes. Compared with incubations at 30 degrees C, serum bottles at 55 degrees C presented distinctly higher decolourisation rates not only with an industrial wastewater containing anthraquinone dyes, but also with model compounds. Compared with batch assays at 30 degrees C, the first-order rate constant "k" of the Reactive Blue 5 (RB5) was enhanced 11-fold and 6-fold for bottles at 55 degrees C supplemented and free of AQS, respectively. However, the anthraquinone dye Reactive Blue 19 (RB19) demonstrated a very strong toxic effect on volatile fatty acids (VFA) degradation and methanogenesis at both 30 degrees C and 55 degrees C. The apparent inhibitory concentrations of RB19 exerting 50% reduction in methanogenic activity (IC50-value) were 55 mg l(-1) at 30 degrees C and 45 mg l(-1) at 55 degrees C. Further experiments at both temperatures revealed that RB19 was mainly toxic to methanogens, because the glucose oxidizers including acetogens, propionate-forming, butyrate-forming and ethanol-forming microorganisms were not affected by the dye toxicity.     

Anthraquinones from Hedyotis capitellata

Four new furanoanthraquinones, 2-hydroxymethyl-3,4-[2'-(1-hydroxy-1-methylethyl)-dihydrofurano]-8-hydroxyanthraquinone, 2-hydroxymethyl-3,4-[1'-hydroxy-2'-(1-hydroxy-1-methylethyl)-dihydrofurano]-8-hydroxyanthraquinone, 2-hydroxymethyl-3,4-[2'-1-hydroxy-1-methylethyl)-dihydrofurano]anthraquinone and 2-methyl-3,4-[2'-(1-hydroxy-1-methylethyl)-dihydrofurano] anthraquinone or capitellataquinone A-D and four known anthraquinones, rubiadin, anthragallol 2-methyl ether, alizarin 1-methyl ether and digiferruginol, together with scopoletin were isolated from the stems of Hedyotis capitellata Wall (Rubiaceae). Lucidin-3-O-beta-glucoside was isolated from the roots of the plant. Characterization of the new compounds was carried out by extensive NMR studies using FGCOSY, FGHMQC, FGHMBC and DEPT-135 in addition to other spectroscopic methods.     

Sequence-specific DNA damage induced by carcinogenic danthron and anthraquinone in the presence of Cu(II), cytochrome P450 reductase and NADPH

The mechanism of metal-mediated DNA damage by carcinogenic danthron (1,8-dihydroxyanthraquinone) and anthraquinone was investigated by the DNA sequencing technique using ³²P-labeled human DNA fragments obtained from the human c-Ha-ras-1 proto-oncogene and the p53 tumor suppressor gene. Danthron caused DNA damage particularly at guanines in the 5′-GG-3′, 5-GGGG-3′, 5′-GGGGG-3′ sequences (damaged bases are underlined) in the presence of Cu(II), cytochrome P450 reductase and the NADPH-generating system. The DNA damage was inhibited by catalase and bathocuproine, suggesting the involvement of H₂O₂ and Cu(I). The formation of 8-oxo-7,8-dihydro-2′-deoxyguanosine increased with increasing concentration of danthron. On the other hand, carcinogenic anthraquinone induced less oxidative DNA damage than danthron. Electron spin resonance study showed that the semiquinone radical could beproduced by P450 reductase plus NADPH-mediated reduction of danthron, while little signal was observed with anthraquinone. These results suggest that danthron is much more likely to be reduced by P450 reductase and generate reactive oxygen species through the redox cycle, leading to more extensive Cu(II)-mediated DNA damage than anthraquinone. In the case of anthraquinone, its hydroxylated metabolites with similar reactivity to danthron may participate in DNA damage in vivo. We conclude that oxidative DNA damage by danthron and anthraquinone seems to be relevant for the expression of their carcinogenicity.     

大黄蒽醌衍生物对酪氨酸酶的抑制作用

大黄素对酪氨酸酶有显著的竞争性抑制作用,K_i值为1.51×10~(-4)mol,50％抑制的药物浓度为36.6μg/ml;大黄酸的抑制作用较弱,芦荟大黄素几乎无抑制作用。氯化铜(3.3×10~(-7)mol/L)、半胱氨酸(3.3×10~(-7)mol/L)和牛血清白蛋白(1.0mg/ml)对大黄素抑制酪氨酸酶有较强的拮抗作用,恢复率分别为60.0％、45.7％和61.1％。大黄素能与牛血清白蛋白非特异性结合形成复合物,引起吸收光谱红移55毫微米。大黄蒽醌衍生物对酪氨酸酶的抑制作用可能是大黄抗黑色素瘤的作用机制之一。     

中低压制备色谱制备茜草蒽醌成分的研究

建立新的中低压制备色谱技术,分离纯化茜草蒽醌单体.先采用高压液相色谱技术分析所分离产物的纯度,再用核兹共振谱、红外、质谱分析确证单体的化学结构.结果表明:用中低压色谱分离茜草的乙醇提取物而得到的4个单体,其纯度分别为99.87％、99.56％、99.42％、98.21％,结构鉴定为从石油醚萃取物中分离得到的单体为大叶茜...     

Identification of Anthraquinone-Degrading Bacteria in Soil Contaminated with Polycyclic Aromatic Hydrocarbons

Quinones and other oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs) are toxic and/or genotoxic compounds observed to be cocontaminants at PAH-contaminated sites, but their formation and fate in contaminated environmental systems have not been well studied. Anthracene-9,10-dione (anthraquinone) has been found in most PAH-contaminated soils and sediments that have been analyzed for oxy-PAHs. However, little is known about the biodegradation of oxy-PAHs, and no bacterial isolates have been described that are capable of growing on or degrading anthraquinone. PAH-degrading Mycobacterium spp. are the only organisms that have been investigated to date for metabolism of a PAH quinone, 4,5-pyrenequinone. We utilized DNA-based stable-isotope probing (SIP) with [U-¹³C]anthraquinone to identify bacteria associated with anthraquinone degradation in PAH-contaminated soil from a former manufactured-gas plant site both before and after treatment in a laboratory-scale bioreactor. SIP with [U-¹³C]anthracene was also performed to assess whether bacteria capable of growing on anthracene are the same as those identified to grow on anthraquinone. Organisms closely related to Sphingomonas were the most predominant among the organisms associated with anthraquinone degradation in bioreactor-treated soil, while organisms in the genus Phenylobacterium comprised the majority of anthraquinone degraders in the untreated soil. Bacteria associated with anthracene degradation differed from those responsible for anthraquinone degradation. These results suggest that Sphingomonas and Phenylobacterium species are associated with anthraquinone degradation and that anthracene-degrading organisms may not possess mechanisms to grow on anthraquinone.     

Effect of chitosan elicitation and media components on the production of anthraquinone colorants in madder (Rubia akane Nakai) cell culture

To increase the production of anthraquinone colorants in madder (Rubia akane Nakai) cell culture, the effects of elicitation on the colorant production were investigated. Chitosan was the best biotic elicitor among nine plant derived and microbial derived polysaccharides. When elicited with 25 mg/L chitosan, the total production was increased approximately two times in a seven-day culture as compared to that in the unelicited cells. Anthraquinone production was increased in proportion to the contact period up to day 3. Maximum anthraquinone colorants were obtained with 3-day treatment of chitosan. During chitosan elicitation, the total production was increased 1.3 times in MS medium containing galactose as compared to that containing sucrose. The degree of deacetylation in chitosan and the use of growth regulator or addition of precursor did not affect the production of anthraquinone colorants. When madder cells were elicited at optimum condition, anthraquinone concentration and specific anthraquinone content increased 1.3 times (0.69 g/L) and 2.2 times (0.32 g/g DCW), respectively.     

Microbial metabolism of 1-aminoanthracene by Beauveria bassiana

The carcinogen and mutagen, 1-aminoanthracene, was efficiently metabolized by the fungal strain Beauveria bassiana ATCC 7159 to yield three new metabolites identified as 1-acetamido-5-[(4′-O-methyl-β-d-glucopyranosyl)oxy]anthracene, 1-acetamido-8-[(4′-O-methyl-β-d-glucopyranosyl)oxy]anthraquinone, and 1-acetamido-6-[(4′-O-methyl-β-d-glucopyranosyl)oxy]anthraquinone, together with 1-acetamidoanthracene and 1-acetamidoanthraquinone. Formation of these metabolites suggests that the metabolic pathways of 1-aminoanthracene in B. bassiana ATCC 7159 involve acetylation, oxidation, hydroxylation, and O-methylglucosylation.     

Stabilizing effect of propionic acid derivative of anthraquinone--polyamine conjugate incorporated into α-β chimeric oligonucleotides on the alternate-stranded triple helix

Two types of anthraquinone conjugates were synthesized as non-nucleosidic oligonucleotide components. These include an anthraquinone derivative conjugated with 2,2-bis(hydroxymethyl)propionic acid and an anthraquinone--polyamine derivative conjugated with 2,2-bis(hydroxymethyl)propionic acid. The conjugates were successfully incorporated into the "linking-region" of the α-β chimeric oligonucleotides via phosphoramidite method as non-nucleosidic backbone units. The resultant novel α-β chimeric oligonucleotides possessed two diastereomers that were generated by the introduction of the anthraquinone conjugate with a stereogenic carbon atom. The isomers were successfully separated by a reversed-phase HPLC. UV-melting experiments revealed that both stereoisomers formed a substantially stable alternate-strand triple helix, irrespective of the stereochemistry of the incorporated non-nucleosidic backbone unit. However, the enhancing effect on thermal stability depended on the length of the alkyl linker connecting anthraquinone moiety and the propionic acid moiety. The sequence discrimination ability of the chimeric oligonucleotides toward mismatch target duplex was also examined. The T(m) values of the triplexes containing the mismatch target were substantially lower than the T(m) values of those containing the full-match target. The thermodynamic parameters (ΔH°, ΔS°, and ΔG°) required for the dissociation of the triplexes into the third strand and target duplex were also measured.     

Sequence-specific DNA damage induced by carcinogenic danthron and anthraquinone in the presence of Cu(II), cytochrome P450 reductase and NADPH

The mechanism of metal-mediated DNA damage by carcinogenic danthron (1,8-dihydroxyanthraquinone) and anthraquinone was investigated by the DNA sequencing technique using ³²P-labeled human DNA fragments obtained from the human c-Ha-ras-1 proto-oncogene and the p53 tumor suppressor gene. Danthron caused DNA damage particularly at guanines in the 5'-GG-3', 5-GGGG-3', 5'-GGGGG-3' sequences (damaged bases are underlined) in the presence of Cu(II), cytochrome P450 reductase and the NADPH-generating system. The DNA damage was inhibited by catalase and bathocuproine, suggesting the involvement of H₂O₂ and Cu(I). The formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine increased with increasing concentration of danthron. On the other hand, carcinogenic anthraquinone induced less oxidative DNA damage than danthron. Electron spin resonance study showed that the semiquinone radical could beproduced by P450 reductase plus NADPH-mediated reduction of danthron, while little signal was observed with anthraquinone. These results suggest that danthron is much more likely to be reduced by P450 reductase and generate reactive oxygen species through the redox cycle, leading to more extensive Cu(II)-mediated DNA damage than anthraquinone. In the case of anthraquinone, its hydroxylated metabolites with similar reactivity to danthron may participate in DNA damage in vivo. We conclude that oxidative DNA damage by danthron and anthraquinone seems to be relevant for the expression of their carcinogenicity.     

Purification and some properties of five anthraquinone specific glucosyltransferases from Cinchona succirubra cell suspension culture

Five anthraquinone-specific glucosyltransferases were partially purified from Cinchona succirubra cell suspension culture by fractional precipitation with ammonium sulphate, gel filtration and chromatofocusing on a fast protein liquid chromatography system. Five, distinct glucosylating activities were resolved with apparent pI values of 5.3, 4.8, 4.5, 4.3 and 4.1. They accepted emodin, anthrapurpurin, quinizarin, 2,6-dihydroxy anthraquinone and 1,8- dihydroxy anthraquinone as the best substrates, respectively. These enzymes exhibited similar characteristics as to pH optimum (pH 7) in histidine/HCl buffer, M, 50 000, had no cation requirement and were inhibited by various SH-group reagents. The K_m value of the respective anthraquinones for either of the five enzymes was 10 μM. The physiological role of these novel enzymes is discussed in relation to the biosynthesis of anthraquinone glucosides in this tissue.     

Sennidin stimulates glucose incorporation in rat adipocytes

A novel small molecule compound which exerts insulin mimetic is desirable. Dozens of natural products that have quinone, naphthoquinone, or anthraquinone structure, were tested by a glucose incorporation assay. We found that sennidin A, anthraquinone derivative, stimulated glucose incorporation to near level of maximal insulin-stimulated and sennidin B, a stereoisomer of sennidin A, also stimulated, but the activity of sennidin B was lower than sennidin A. Sennidin A-stimulated glucose incorporation was completely inhibited by wortmannin. Sennidin A did not induce tyrosine phosphorylation of insulin receptor (IR) and insulin receptor substrate-1 (IRS-1), but induced phosphorylation of Akt and glucose transporter 4 (GLUT4) translocation. Our results suggest that in rat adipocytes, sennidin A stimulates glucose incorporation in the phosphatidylinositol 3-kinase (PI3K)- and Akt-dependent, but in the IR/IRS1-independent manner.