Anthraquinones

About: Anthraquinones is a research topic. Over the lifetime, 1297 publications have been published within this topic receiving 21604 citations. The topic is also known as: anthraquinonoids.

Anti-cancer properties of anthraquinones from rhubarb.

Abstract: Rhubarb has been used as a traditional Chinese medicine since ancient times and today it is still present in various herbal preparations. In this review the toxicological and anti-neoplastic potentials of the main anthraquinones from Rhubarb, Rheum palmatum, will be highlighted. It is interesting to note that although the chemical structures of various anthraquinones in this plant are similar, their bioactivities are rather different. The most abundant anthraquinone of rhubarb, emodin, was capable of inhibiting cellular proliferation, induction of apoptosis, and prevention of metastasis. These capabilities are reported to act through tyrosine kinases, phosphoinositol 3-kinase (PI3K), protein kinase C (PKC), NF-kappa B (NF-kappaB), and mitogen-activated protein kinase (MAPK) signaling cascades. Aloe-emodin is another major component in rhubarb found to have anti-tumor properties. Its anti-proliferative property has been demonstrated to be through the p53 and its downstream p21 pathway. Our recent proteomic study also suggests that the molecular targets of these two anthraquinones are different. However, both components were found to be able to potentiate the anti-proliferation of various chemotherapeutic agents. Rhein is the other major rhubarb anthraquinone, although less well studied. This compound could effectively inhibit the uptake of glucose in tumor cells, caused changes in membrane-associated functions and led to cell death. Interestingly, all three major rhubarb anthraquinones were reported to have in vitro phototoxic. This re-evaluation of an old remedy suggests that several bioactive anthraquinones of rhubarb possess promising anti-cancer properties and could have a broad therapeutic potential.

The Site of the Inhibition of the Shikimate Pathway by Glyphosate: II. INTERFERENCE OF GLYPHOSATE WITH CHORISMATE FORMATION IN VIVO AND IN VITRO

Abstract: In the presence of the nonselective herbicide glyphosate (N-[phosphonomethyl]glycine), buckwheat (Fagopyrum esculentum Moench) hypocotyls and cultured cells of Galium mollugo L. accumulate an organic acid, which was identified as shikimate by mass-spectroscopy of its methyl ester. After growth in 0.5 millimolar glyphosate for 10 days, G. mollugo cells contained shikimate in amounts of up to 10% of their dry weight. Synthesis of chorismate-derived anthraquinones in G. mollugo was blocked by glyphosate. Chorismate and o-succinylbenzoate (an anthraquinone precursor) alleviated the inhibition. The conclusion drawn from these experiments, that glyphosate inhibits a step in the biosynthetic sequence from shikimate to chorismate, was substantiated by the finding that glyphosate is a powerful inhibitor of the conversion of shikimate to chorismate in cell-free extracts from Aerobacter aerogenes 62-1.

Anthraquinones As Pharmacological Tools and Drugs

Abstract: Anthraquinones (9,10-dioxoanthracenes) constitute an important class of natural and synthetic compounds with a wide range of applications. Besides their utilization as colorants, anthraquinone derivatives have been used since centuries for medical applications, for example, as laxatives and antimicrobial and antiinflammatory agents. Current therapeutic indications include constipation, arthritis, multiple sclerosis, and cancer. Moreover, biologically active anthraquinones derived from Reactive Blue 2 have been utilized as valuable tool compounds for biochemical and pharmacological studies. They may serve as lead structures for the development of future drugs. However, the presence of the quinone moiety in the structure of anthraquinones raises safety concerns, and anthraquinone laxatives have therefore been under critical reassessment. This review article provides an overview of the chemistry, biology, and toxicology of anthraquinones focusing on their application as drugs.

High performance liquid chromatography of anthraquinones: analysis of plant and insect extracts and dyed textiles

Abstract: Separation and quantitative determination of anthraquinones is achieved by high performance liquid chromatography in mixtures of methanol, water and formic acid on a reversed-phase stationary phase. The products are identified by retention time and, more accurately, by standard additions and UV-visible spectroscopy. This methodology has been applied to extracts of plant roots and insects, commonly used in earlier times as the source of red dyestuffs for dyeing textiles. Quantitative evaluation of the anthraquinone derivatives present in ancient red dyes was earned out after acid hydrolysis of 0·2 to 2·0mg of textile fibre. Due to the great sensitivity of the method, important minor constituents, such as kermesic acid in cochineal, can be detected.