Search results for "PHENOLS"
showing 10 items of 766 documents
Double and triple calix[4]arenis connected via the oxygen functions
1990
New macrocyclic molecules are described containing two or three p-tert-butylcalix[4]arene subunits connected via their oxygen atoms. These macrocycles are available by two general methods which are capable of producing assemblies with bridges of varying rigidity and length.
On the Occurrence of Caffeoyltartronic Acid and Other Phenolics in Chondrilla juncea
1993
Abstract Caffeoyltartronic acid and other eleven phenolic com pounds were identified in the MeOH extract of Chondrilla juncea: the flavonoids luteolin, luteolin-7-glucoside, luteolin-7-galactosylglucuronide and quercetin-3-galactoside; the phenolic acids protocatechuic, caffeic, chlorogenic, isochlorogenic and isoferulic and the coumarins cichoriin and aesculetin. The taxonomic im plications of these com pounds have been discussed.
Alkylation of acidic organic compounds for gas chromatographic analysis
1973
A new alkylation method is proposed. Organic solutions of fatty acids, phenols or barbituric acids are refluxed with an alkylating reagent and solid K2CO3. The reaction mixture is injected directly into the gas chromatograph. The scope of this convenient method for quantitative and qualitative analyses is considerable as different classes of alkylating agents can be used.
Prediction of the genetic variety of Spanish extra virgin olive oils using fatty acid and phenolic compound profiles established by direct infusion m…
2007
Abstract The genetic varieties of Spanish extra virgin olive oils (Arbequina, Hojiblanca and Picual) were predicted by direct infusion of the samples in the electrospray ionization source of a mass spectrometer, followed by linear discriminant analysis of the spectral data. The samples were 1:50 diluted (v/v) with an 85:15 propanol/methanol (v/v) mixture containing 40 mM KOH and infused. The abundances of the [M–H] − peaks of the free fatty acids (7 peaks) and 28 phenolic compounds (20 peaks) were measured. Ratios of pairs of peak abundances were used as predictors in the construction of the linear discriminant analysis models. An excellent resolution between the three genetic varieties was…
Chemical Constituents of Urospermum picroides
1992
Seven phenolic compounds were isolated from the aerial parts of U. picroides. They were identified by UV spectra, TLC and HPLC-DAD as luteolin, luteolin-7-glucoside, quercetin, quercetin-3-galactoside, kaempferol-3-galactoside, chlorogenic and isochlorogenic acids. Other phenolics were characterized by HPLC-DAD analysis: gallic, protocatechuic, caffeic, ferulic and isoferulic acids, quercetin-3-glucoside and luteolin-4′-glucoside.
A Specific Radioimmunoassay for the Determination of Low Quantities of Indole-3-acetic Acid in Spruce Needles of Healthy and Damaged Trees
1988
Summary The aim of the present investigation was to develop a radioimmunoassay for the quantification of indole-3-acetic acid in needles of Picea abies in damaged and phenotypically healthy trees. Phenols, lipophilic substances or compounds with cross-reactivity had to be separated from the extracts in several purification steps. Measurements were carried out between May and October 1986 on trees from two spruce plantations. Marked differences were found in IAA content in needles of healthy and damaged trees. In most cases the needles of the damaged trees contain lower endogenous IAA levels. The auxin levels also depended on the age of the tree, the year of needle formation, and the vegetat…
Reaktive Metabolite cancerogener polycyclischer Kohlenwasserstoffe: Synthese und Abfangreaktion von 9-Hydroxybenzo[a]pyren-4,5-oxid
1985
Le compose du titre est prepare a partir de l'acetate-9 de benzo [a] pyrene et piege par l'ethanethiol. Mecanismes
Ruminant fat volatiles as affected by diet. A review.
2006
Volatile compounds in meat have been widely studied for their favourable or undesirable effects on meat flavour, or for their potential use in tracing the animal feeding system. To date, the chemical mechanisms causing the appearance of volatile compounds in meat have been largely understood. Several variables are involved in the accumulation of volatiles in animal tissues and among them animal diet plays a key role. The purpose of the present review is to highlight the effects of different dietary regimes (concentrate, green grass and fat-enriched diets) on the appearance of fat volatile compounds in ruminant meat. Grain-based diets induce greater accumulations in meat of branched-chain fa…
Inhibitoren der Korrosion 23 (1) - Gibt es eine Struktur- Wirkungs-Beziehung bei organischen Inhibitoren der Korrosion von Aluminium?
1978
Uber 400 organische Verbindungen wurden routinemasig darauf gepruft, ob sie die Auflosung des Aluminiums in In Salzsaure in Gegenwart von 2,5% NaCl und bei einer Konzentration von 10−2 Mol/l der zu prufenden Verbindung beeinflussen. Es wurde versucht, eine “Struktur-Wirkungs-Beziehung” zu erstellen. Eingehender diskutiert wurden folgende Verbindungsklassen: Arsenverbindungen, Phosphon- und Phosphinsauren, aromatische Aldehyde und Ketone, aromatische und aliphatische Carbonsauren, zweiwertige Phenole, Tetrazoliumsalze und formazane, Sulfoxide und aromatische Sulfonsauren, Sulfonamide und Sulfone. Bei einer Auswahl von Inhibitoren wurde die Abhangigkeit der Schutzwirkung von deren Konzentrati…
Green extraction approach for the recovery of polyphenols from Croatian olive leaves (Olea europea)
2017
Abstract Pressurized liquid extraction (PLE) is shown as an innovative green technology for the effective extraction of the various phytochemicals from food by-products, therefore the aims of this study were to evaluate the application of PLE to engineer green extracts of Croatian olive leaves ( Olea europaea , cv. Oblica) for potential industrial production (functional foods/pharmaceuticals). PLE was conducted under various cycle numbers (1, 2), temperature (60, 80, 100 °C) and static times (5, 10, 15 min). Obtained extracts were characterized in terms of: (i) total polyphenols (TP); (ii) total flavonoids (TF); hydroxycinnamic acids (HCA); and (iv) flavonols (FLA). Response surface methodo…