Search results for "ACEA"
showing 10 items of 2814 documents
Phenylethanoid glycosides from Prostanthera melissifolia
1999
Abstract Six phenylethanoid glycosides were isolated from aerial parts of Prostanthera melissifolia, together with apigenin and ursolic acid. The glycosides were characterized by spectral methods as martynoside, isomartynoside, verbascoside, isoverbascoside, betonyoside F and isobetonyoside F, the latter being a new natural product.
Phytochemical constituents and chemosystematic significance of Pulicaria jaubertii E.Gamal-Eldin (Asteraceae)
2018
Abstract The chemical characterization of methylene chloride/methanol (1:1) extract of the air-dried whole medicinal plant, Pulicaria jaubertii E. Gamal-Eldin, led to isolation and identification of two new hydroquinone compounds; 2-(2-acetoxy propyl), 5-methyl hydroquinone (1) and 2-(2-hydroxy propyl), 5-methyl hydroquinone-4-O-β-D-glucopyranoside (2), four known flavonols (3-6) and 7 known dihydroflavonols (7-13). The structures were established depending upon comprehensive analysis of the NMR, IR and HR/EI-MS data. Herein, compounds 6, and 10-13 were isolated for the first time from this plant. The chemotaxonomic significance of the isolated flavonoids from P. jaubertii comparing with th…
The dcuD (former yhcL ) gene product of Escherichia coli as a member of the DcuC family of C4-dicarboxylate carriers: lack of evident expression
1999
The dcuD gene (formerly yhcL) of Escherichia coli shows significant sequence similarity only to the dcuC gene of E. coli, which encodes a C4-dicarboxylate carrier (DcuC) that functions during anaerobic growth. Inactivation of dcuD had no effect on the growth of E. coli under a large number of conditions and led to no detectable changes in phenotype. Translational dcuD'-'lacZ gene fusions were not significantly expressed in the presence of dicarboxylates or monocarboxylates under oxic or anoxic conditions. Other potential substrates such as amino sugar derivatives, amino acids, and alpha-aspartyl dipeptides also did not lead to expression of dcuD. Changes in medium composition, pH, ionic str…
Spirostane and cholestane glycosides from the bulbs of Allium nigrum L
2011
Abstract A phytochemical investigation of the fresh bulbs of Allium nigrum L. led to the isolation of new spirostane-type glycosides as two inseparable isomer mixtures, nigrosides A1/A2 (1a/1b) and nigrosides B1/B2 (2a/2b), two new cholestane-type glycosides, nigrosides C and D (3 and 4), together with the known compounds, 25(R,S)-5α-spirostan-2α,3β,6β-trio1-3-O-β- d -glucopyranosyl-(1 → 2)-O-[β- d -xylopyranosyl-(1 → 3)]-O-β- d -glucopyranosyl-(1 → 4)-β- d -galactopyranoside (5a/5b) and 25(R,S)-5α-spirostan-2α,3β,6β-trio1 3-O-β- d -glucopyranosyl-(1 → 2)-O-[4-O-(3S)-3-hydroxy-3-methylglutaryl-β- d -xylopyranosyl-(1 → 3)]-O-β- d -glucopyranosyl-(1 → 4)-β- d -galactopyranoside (6a/6b), isola…
Mimonoside D: a new triterpenoid saponin from Mimosa diplotricha Sauvalle (Fabaceae)
2021
A new triterpenoid saponin (Mimonoside D: 3-O-��-L-arabinopyranosyl-3��-hydroxyolean-12-en-28-oic acid 28-O-��-D-xylopyranosyl-(1���2)-��-D- glucopyranoside ester (1)) was isolated from the aerial parts of Mimosa diplotricha Sauvalle together with nine known compounds: 7,4���-dihydroxyflavone (2), kaempferol (3), lupeol (4), betulinic acid (5), ��-sitosterol (6), ��-sitosterol-3-O-��-D-glucopyranoside (7), lutein (8), 5,2���-dihydroxy-7,4���,5���-trimethoxyflavone (9) and vitexin (10). Their structures were elucidated on the basis of spectroscopic (1 D and 2 D nuclear magnetic resonance) and high-resolution mass spectrometric data as well as by comparison of their spectral data with those o…
Relationships among soil characteristics, plant macronutrients, and cardenolide accumulation in natural populations of Digitalis obscura
2005
In the present study, we have investigated relationships among several soil parameters (pH, organic matter, total carbonate, macronutrients, electrical conductivity, cation-exchange capacity) and macronutrient and cardenolide contents in leaves of wild Digitalis obscura plants. Young and mature leaves and soil samples were collected in ten different areas, corresponding to three Mediterranean bioclimatic belts (thermo-, meso-, and supramediterranean belts). Soil and leaf macronutrient (N, P, K, Ca, and Mg) contents and leaf cardenolide contents were determined. Bioclimatic conditions influenced the development of D. obscura, biomass being lowest in plant populations of the supramediterranea…
Cardenolides of Digitalis obscura: The effect of phosphate and manganese on growth and productivity of shoot-tip cultures
1997
Abstract Cardenolide composition of leaves from wild and micropropagated elite plants of Digitalis obscura (genotype T4) has been investigated and no qualitative differences were found among their major cardenolides (series A). All of the detected glycosides belong to the digitoxose-type cardenolides. Genins represented less than 2% of the overall content, while lanatoside A was the predominant cardenolide ( ca. 65%) in all samples. The cardenolide yield of micropropagated D. obscura plants depended on the age and development of the cultures, but productivity of long-term cultures (2 years) was quite similar to that of the parent plant. Changes in the concentrations of phosphate or manganes…
In vivo digestibility and nutritive value of Atriplex halimus alone and mixed with wheat straw
2002
In vivo digestibility trials were carried out using six young rams fed with Atriplex halimus biomass harvested in summer (A) and in early autumn (B), and with a mixture of mid-autumn Atriplex halimus and wheat straw (5[ratio ]1 ratio on fresh matter basis) (C). Atriplex halimus had a high protein content (139·0, 135·9 and 193·4 g/kg DM in A, B and C respectively), but was rich in sodium chloride, especially in summer (145·9 g/kg DM), limiting its use as feed. The summer forage had a higher organic matter (OM) digestibility coefficient than the autumn forage (0·663 v. 0·530) but lower digestible OM intake (16·8 v. 29·4 g/day per kg BW0·75). In autumn forage, the combination with straw did no…
Acetogenins from Annona glabra seeds
1998
Abstract From the cytotoxic ethanol extract of Annona glabra seeds, a new mono-tetrahydrofuranic (mono-THF) acetogenin, glabranin, as well as pair of 22-epimer bis-THF acetogenins, were isolated by semipreparative HPLC. Four known mono-THF acetogenins with an identical threo/trans/threo relative configuration, annonacin, annonacinone, corossolin and corossolone, were found to be potent inhibitors of complex I of the mitochondrial respiratory chain.
Ingenane and lathyrane diterpenes from the latex of Euphorbia canariensis
1997
The latex of Euphorbia canariensis yielded, in addition to five known ingenol esters, the ingenane derivatives ingenol 3-angelate 5,20-diacetate and 5-deoxyingenol 3-angelate 20-acetate, and the lathyrane derivatives 2,3-diepiingol 7,12-diacetate 8-benzoate, 2,3-diepiingol 7,12-diacetate 8-isobutyrate and 2-epiingol 3,7,12-triacetate 8-benzoate. The structures were established with the aid of spectroscopic methods, mainly NMR, and molecular mechanics calculations. They were also supported by the results of some chemical transformations.