Results 201 to 210 of about 21,254 (224)
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1988
Publisher Summary This chapter discusses anthraquinones and the quantitative aspects of its occurrence. Anthraquinones (AQs) are derived from anthracenes and have two keto groups. AQs occur in oxidized and reduced form as well as in a free or a combined state.
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Publisher Summary This chapter discusses anthraquinones and the quantitative aspects of its occurrence. Anthraquinones (AQs) are derived from anthracenes and have two keto groups. AQs occur in oxidized and reduced form as well as in a free or a combined state.
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Anthraquinones in the Rubiaceae
1986This review has been written in order to update the literature on anthraquinones occurring in the Rubiaceae. Since appearance of the excellent book on naturally-occurring quinones by R.H. Thomson (120) in 1971 about 50 new anthraquinones have been isolated from members of the Rubiaceae. Also several new methods have been used for structure analysis and
R. Wijnsma, Robert Verpoorte
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ChemInform Abstract: ANTHRAQUINONES. VIII. NOTE ON THE OXIDATION OF (HYDROXYMETHYL)ANTHRAQUINONES
Chemischer Informationsdienst, 1977AbstractMnOz‐ Oxidation der Alkohole (I) gibt die Aldehyde (II).
G. Sigmund, Karl Bredereck, H. Kimmich
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Chemotaxonomy of anthraquinones in Rumex
Phytochemistry, 1972Abstract The distribution of anthraquinones (aglycones, O-glycosides and C-glycosides) in all parts of the plant of 19 representative species of Rumex has been studied. All species contained emodin, chrysophanol and physcion and in addition some contained aloe-emodin (side chain oxidized to the alcohol) and others rhein or rhein-like substances (side
F.J. El-Muhtadi, J.W. Fairbairn
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Stereochemical Studies on Pre-Anthraquinones and Dimeric Anthraquinone Pigments
1988Labelling studies have shown that the biosynthesis of emodin (6) and related anthraquinone pigments in fungi and higher plants occurs via the acetate/malonate pathway (ref. 1). Details of the early steps in this biosynthesis, however, remain unknown.
Wolfgang Steglich +4 more
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ChemInform Abstract: The Anthraquinones of Heterodermia obscurata.
ChemInform, 1995AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Peter A. Cohen, G.H.Neil Towers
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A new synthesis of anthraquinones
Journal of the Chemical Society, Chemical Communications, 1988AbstractThe dimethoxyphenyloxazoline (I) is coupled with the benzylmagnesium chloride (II) to give the diphenylmethane (III).
Teresa M. Nicoletti +2 more
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Chemotaxonomic survey of anthraquinones and pre-anthraquinones in roots of Aloe species
Biochemical Systematics and Ecology, 1995Abstract Root samples from 172 species of Aloe were surveyed by TLC and HPLC for the presence of anthraquinones and pre-anthraquinones. With the exception of the three species of the series Serrulatae , 1,8-Dihydroxyanthraquinones (chrysophanol and asphodelin) were detected in all the species sampled.
Van Wyk, Ben-Erik +2 more
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Acetylenic derivatives of anthraquinone
Bulletin of the Academy of Sciences of the USSR Division of Chemical Science, 1981AbstractWie im Formelschema angegeben werden die Ethinylanthracene (II), (IV), (VI), (VIII) und (IX) hergestellt, die sich mit Chromtrioxid in Essigsäure zu den entsprechenden Anthrachinonen (X) bzw. (XI) oxidieren lassen.
Mark S. Shvartsberg +2 more
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Journal of Physical Organic Chemistry, 1992
AbstractDewar‐anthraquinone (1a) and 1,2,3‐tri‐tert‐butyl‐5,8‐Dewar‐anthraquinone (1b) were synthesized. Thermodynamic parameters for their cycloreversion to the corresponding anthraquinones indicate that thermal population of the excited states of the products via non‐adiabatic valence isomerization is energetically feasible. On thermolysis of 1b, the
Zen-ichi Yoshida +2 more
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AbstractDewar‐anthraquinone (1a) and 1,2,3‐tri‐tert‐butyl‐5,8‐Dewar‐anthraquinone (1b) were synthesized. Thermodynamic parameters for their cycloreversion to the corresponding anthraquinones indicate that thermal population of the excited states of the products via non‐adiabatic valence isomerization is energetically feasible. On thermolysis of 1b, the
Zen-ichi Yoshida +2 more
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