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  • 11
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 706 (1967), S. 187-197 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aus dem Extrakt der Myrobalanen wurden die 1.3.6-Trigalloyl-β-glucose und die 1.2.3.4.6-Pentagalloyl-β-glucose isoliert. Die beiden Verbindungen waren zwar als Abbauprodukte von anderen Gerbstoffen bekannt, aber nicht selbst in der Natur gefunden worden. Aus ihrer Menge wurde geschlossen, daß damit über 2/3 der Myrobalanengerbstoffe aufgeklärt sind. Die 1.3.6-Trigalloyl-glucose ist kein Abbauprodukt der Pentagalloyl-glucose, sondern ein selbständiger Gerbstoff. Die beiden neu in den Myrobalanen aufgefundenen Oligogalloyl-glucosen können als Schlüsselsubstanzen für die Entstehung der Chebulinsäure (1), Chebulagsäure (2), des Terchebins (4) und des Corilagins (6) aufgefaßt werden.
    Additional Material: 3 Ill.
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    European food research and technology 171 (1980), S. 193-199 
    ISSN: 1438-2385
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Description / Table of Contents: Zusammenfassung In fast allen gebräuchlichen Gewürzen wurden die aus ihren natürlich vorkommenden Verbindungen freigesetzten Hydroxizimtsäuren und Hydroxibenzoesäuren qualitativ und quantitativ bestimmt. In tropischen Gewürzen wurden Hydroxibenzoesäuren und Hydroxizimtsäuren in etwa gleichen Größenordnungen gefunden, meist zwischen 10 und 200 mg/kg pro Substanz. In den einheimischen, meist grünen Gewürzkrätern dominiert der Hydroxizimtsäuregehalt.Apiaceae (Umbelliferen),Lamiaceae (Labiaten) undAsteraceae (Compositen) wiesen Kaffeesäure in Konzentrationen von 0,1 bis über 2% in der Trockensubstanz auf. In Anis und weißem Senf wurden 0,1%p-Hydroxibenzoesäure gefunden.
    Notes: Summary Hydroxycinnamic and hydroxybenzoic acids were determined qualitatively and quantitatively in nearly all common spices, after release from their naturally occurring derivatives. In tropical spices, hydroxybenzoic and hydroxycinnamic acids were found at the same concentration level, mostly between 10 and 200 ppm per compound. In the green spice-herbs, which generally grow in this region, the content of hydroxycinnamic acids dominates.Apiaceae (Umbelliferae), Lamiaceae (Labiatae), andAsteraceae (Compositae) showed contents of caffeic acid in the range of 0.1 to more than 2% in dried samples. In anisseed and white mustard seed 0.1 % p-hydroxybenzoic acid was found.
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    European food research and technology 171 (1980), S. 278-280 
    ISSN: 1438-2385
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Description / Table of Contents: Zusammenfassung Catechine [vor allem (-)-Epicatechin] und Proanthocyanidine wurden nur in Lorbeerblättern und -früchten, Zimt, Sternanis, Muskatnull, Piment und Wacholder aufgefunden. Alle anderen Gewürze enthielten weder Catechine noch Proanthocyanidine.
    Notes: Summary Catechins [especially (-)-epicatechin] and proanthocyanidins are found only in bay leaves and fruits, cinnamom, star anise, nutmeg, allspice, and juniper. All the other spices contained neither catechins nor proanthocyanidins.
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    European food research and technology 172 (1981), S. 253-256 
    ISSN: 1438-2385
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Description / Table of Contents: Zusammenfassung Verschiedene Senfsaaten (Sinapis alba, Brassica nigra, Brassica juncea) wurden auf den natürlichen Gehalt von p-Hydroxibenzoesäure-Derivaten untersucht. InSinapis alba wurde mittels Hydrolyse p-Hydroxibenzoesäure in der Größenordnung von 1 g/kg freigesetzt. Diese Phenolcarbonsäure wird hauptsächlich aus p-Hydroxibenzylglucosinolat und in kleineren Mengen aus Kämpferolglykosiden, aus einer Bindung an die Pflanzenmatrix und wahrscheinlich aus einem Glucoseester freigesetzt.
    Notes: Summary Various mustard seeds (Sinapis alba, Brassica nigra, Brassica juncea) were examined as to their natural contents of p-hydroxybenzoic acid derivatives. InSinapis alba p-hydroxybenzoic acid was found after hydrolysis in the range of 1 g/kg. This phenolic acid arises chiefly from p-hydroxybenzyl glucosinolate and to a lesser extent from kaempferol glycosides, a bound form on the plant matrix, and probably a glucose ester.
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  • 15
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1,6-Anhydrofuranoses, X. A Simple Synthesis for 1,6-Anhydro-3-deoxy-α-D-xylo-hexofuranoseTreatment of 1,6-anhydro-2,3,5-tri-O-tosyl-α-D-galactofuranose (1) with KOH in dioxane/water gives by way of cis-elimination 1,6-anhydro-3deoxy-5-O-tosyl-α-D-threo-hexofuranos-2-ulose (2) in good yield, which tends to dimerize easily in an aldol type reaction to 3. NaBH4 reduces 2 stereoselectively to 4a Removal of the tosyl group giving the title compound 4c is accomplished by sodium amalgam.
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  • 16
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    ISSN: 0009-2940
    Keywords: [2.2]Metacyclophanes ; Chromium complexes ; Chirality (helicity, planar chirality) ; Clathrates ; Configuration, absolute ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Regioselective Complexation of [2.2]Metacyclophanes with TriamminetricarbonylchromiumThe new [2.2]phanes 12, 13, 15, and 17 have been prepared. For the preparation of the known phane 16 a new route has been developed which leads to better yields and includes an interesting reduction with Raney nickel of the naphthalene ring of 15 to a tetrahydronaphthalene ring (→17). The phanes react regioselectively with triamminetricarbonylchromium, which results exclusively in the complexation of the sterically less hindered benzene ring. The bis(tricarbonylchromium) complexes of 18 and 17 were available in good yields, when two equivalents of the precursor of the tricarbonylchromium group were used. 18a was lithiated at -78°C, and the lithiated complexes were trapped with either chlorotrimethylsilane or ethyl chloroformate to yield 4- and 5-substituted products in a ratio of 4:5. Ten X-ray structures, including those of six transition metal π complexes, which were investigated and compared under the aspect of steric interactions between the tricarbonylchromium group and the substituent at the arene ring, are discussed. Interestingly, the tricarbonylchromium group shows no noticable effect on the boat-like deformation of the benzene ring in [2.2]metacyclophanes. A new definition of the “angles of helicity” in helical [2.2]phanes is introduced.
    Additional Material: 6 Tab.
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  • 17
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    ISSN: 0009-2940
    Keywords: Chirality ; Chromium complexes ; Helicity ; Configuration (absolute) ; [2.2]Metacyclophanes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tricarbonylchromium Complexes of Chiral [2.2]Metacyclophanes: Syntheses, Structures, and Chiroptical PropertiesHPLC-baseline separations of three racemic cyclophanes 3, 4, and 6 on cellulose tris(3,5-dimethylphenyl)carbamate led to their enantiomers with high optical purity. Complexation of (-)-3 and (+)-3 with triamminetricarbonylchromium yielded chiral Cr(CO)3 complexes (-)-(S)P-(3S)M-3a and (+)-(R)P-(3R)M-3a stereoselectively. Derivatisation of the complexes by lithiation and reaction with electrophiles gave new substituted chiral Cr(CO)3 complexes of [2.2]metacyclophanes regio-selectively. X-ray structure analyses of one chiral chromium complex (-)-(R)P-(5S)M-14a and three chiral chromium-free ligands (-)-(S)P-3, (-)-(S)P-4, and (-)-(S)P-6 led to the assignment of the absolute configurations of all chiral compounds discussed here. The influences of substituents on the chiroptical properties are investigated. The helicity of [2.2]metacyclophanes is discussed. For the first time X-ray structure analyses were performed of a bis-Cr(CO)3 complex (9a) as well as of the first chromium complex 10a of a heteraphane. Dethioketalisation of (-)-(S)P-3 with NBS gave (-)-(S)P-18, the absolute chirality of which has been known, under retention of configuration.
    Additional Material: 17 Ill.
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  • 18
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,6-Anhydrofuranoses, IX. Selective Monotosylation of 1,6-Anhydro-α-D-galactofuranose. Synthesis and Structure Determination of 1,6: 3,5-Dianhydro-α-D-gulofuranoseReaction of 1,6-anhydro-α-D-galactofuranose (1a) with 1.7 mol ρ-toluenesulfonyl chloride gives a mixture of all possible tosylates, the 3-0-derivative 1f with than 40% isolated yield predominating. Cyclization of 1f yields 1,6:3,5-dianhydro-α-D-gulofuranose (2a) with 2,5,7-trioxatricyclo[4.2.1.03.8]nonane skeleton. the structure of it being determined by X-ray crystallography and discussed in comparison to the equally determind structure of 1,6-anhydro-α-L-gulofuranose (3a).
    Notes: Umsetzung von 1,6-Anhydro-α-D-galactofuranose (1a) mit 1.7 mol ρ-Toluolsulfonylchlorid liefert ein Gemisch aller denkbaren Tosylate, in dem das 3-0-Derivat 1fmit über 40% isolierter Ausbeute überwiegt. Dieses läßt sich zur 1,6:3,5-Dianhydro-α-D-gulofuranose (2a) mit 2,5,7-Trioxatricyclo[4.2.1.03.8] nonan-Gerüst cyclisieren, deren Struktur wie die der 1,6-Anhydro-α-L-gulofuranose (3a) durch Röntgenstrukturanalyse bestimmt und diskutiert wird.
    Additional Material: 2 Ill.
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  • 19
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die Wurzeln von Gaillardia- und Helenium-Arten enthalten in relativ großer Menge viele schwer trennbare Ester, die durch ihre Spektren und Abbaureaktionen als mehr oder weniger stark abgewandelte Derivate des Thymols (1, 2, 7, 8, 11, 12, 14, 15, 16, 17) erkannt wurden.
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  • 20
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    ISSN: 0009-2940
    Keywords: [2.2]Metacyclophanes ; Chromium tricarbonyl complexes ; Chirality, helical, planar ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Regioselective Substitution of [2.2]Metacyclophanes via Chromium Tricarbonyl ComplexesThe [2.2]metacyclophanes 6, 8, and 9 are regioselectively complexed with triammintricarbonylchromium. The complexes are lithiated with nBuLi/TMEDA at -78°C, and the resulting aryllithium complexes are trapped with electrophiles to give new phanes exhibiting substitution patterns, which are not or more difficult available by other routes. Complex 6a gives 5-substitution almost exclusively, while the chiral complex 8a is substituted in positions 5 and 4 in a ratio of 3:1. Steric effects, caused by the large dithiane group, seem to play a role in both complexation and derivatisation of these substrates. An X-ray crystal structure analysis of the chromium tricarbonyl phane complex 11 is performed.
    Additional Material: 3 Ill.
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