Untitled

Malikov, V. M.; Yuldashev, M. P.

doi:10.1023/a:1021638411150

Cited by 104 publications

(45 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The peak at m/z 271.1 [M-H] + from positive ESI-MS exhibited the presence of a flavone skeleton (She et al, 2009). The UV maxima (λ max ) (MeOH) were at 267 nm (Band II) and 337 nm (Band I), characteristics of a flavone skeleton (Malikov and Yuldashev, 2002). An FTIR spectrum (KBr) (Fig.…”

Section: Resultsmentioning

confidence: 99%

Apigenin-7-O-β-d-glycoside isolation from the highly copper-tolerant plant Elsholtzia splendens

Peng

Zhang

2016

J. Zhejiang Univ. Sci. B

View full text Add to dashboard Cite

Elsholtzia splendens (Lamiaceae) is a copper-tolerant plant species growing on copper deposits in the south of China. Chromatographic separation of n-BuOH extracts from the flowering aerial biomass afforded apigenin-7-O-β-D-glycoside, using macroporous resin, Sephadex™ LH-20 gel, polyamide resin as well as preparative highperformance liquid chromatography (P-HPLC) columns. Chemical structure was elucidated using HPLC/ESI-MS (electrospray ionization-mass spectrometry), Fourier transform infrared (FTIR), and 1 D-and 2 D-nuclear magnetic resonance (NMR). Apigenin-7-O-β-D-glycoside could be the post-harvesting product from E. splendens biomass.

show abstract

Section: Resultsmentioning

confidence: 99%

Apigenin-7-O-β-d-glycoside isolation from the highly copper-tolerant plant Elsholtzia splendens

Peng

Zhang

2016

J. Zhejiang Univ. Sci. B

View full text Add to dashboard Cite

show abstract

“…Analysis of NMR spectra of total fractions of extract 4 demonstrates that in all the cases, quercetin (3,5,7,3'4'-pentahydroxyflavone [13]) was the main aglycone of the flavonoid complex. (Table 1) contained the bulk of tannins and anthocyanins.…”

Section: Resultsmentioning

confidence: 99%

“…Individual flavonoids (figure, I -IX ) were isolated by column chromatography of extract 3 on silica gel KSK (Meaton, Russia; 0-140 µ m) using a chloroform-ethanol (100 : 1 to 5 : 1) elution system. Structures of the compounds were determined from spectral data of individual substances by comparing with the spectra of known flavonoids [13]. The data were processed statistically by conventional methods [14].…”

Section: Effects Of Natural and Artificial Defoliation On The Contentmentioning

confidence: 99%

Effects of natural and artificial defoliation on the content and composition of extractive substances in birch leaves

Shul

Bakhvalov

Petrova

et al. 2005

Appl Biochem Microbiol

View full text Add to dashboard Cite

The changes inflicted on plants (within the same population) by herbivorous insects are among the vital aspects of population dynamics [1,2] as well as of evolution [3] of the plant-insect-parasite system. Analysis of the literature data demonstrates that good quality of a forest stand and foliage as well as the content of protective substances in leaves are interconnected and allow the number of phyllophages and their parasites to be predicted with a high probability [2,4,5]. Defoliation of plants enhances their resistance to insects, resulting in a decrease in the viability of phyllophages and an increase in their sensitivity to pathogens [3,4,[6][7][8].In this process, secondary metabolites are thought important, as they provide active protection of plants from insects and under certain physiological conditions, may be preserved by plants and produced in larger quantities. The plant chemical compounds responsible for resistance to insects are manifold (terpenoids, various phenolic compounds, and condensed tannins) [1, 6-8], making development of general analytical methods for their quantitative determination rather difficult. However, study of the component composition of extractive substances as well as determination and isolation of the compounds produced by plants in response to defoliation stress is topical and important, in particular, for solving a number of ecological problems.The goal of this work was to develop an efficient analytical method and use it for studying the composition and concentration dynamics of extractive substances in leaves upon defoliation of the European white birch ( Betula pendula Roth.)-the main feeding tree for the major birch forest pest in Western Siberia, the gypsy moth ( Lymantria dispar L.). MATERIALS AND METHODSPreparation of material. European white birch ( Betula pendula Roth.) leaves were collected in natural birch woods during the mass reproduction of gypsy moths (Novosibirsk oblast, Russia). Samples Xp1 were produced by extraction of the leaves collected 30 days after artificial defoliation with loss of 75% of the foliage; samples Xp2 , by extraction of the leaves collected 1 year after artificial defoliation from the same trees. The extractive substances Xp3 were obtained from the leaves of the trees with 75% of the foliage depredated during the previous 2 years. The leaves with normal foliage were used as a control ( Xc ). Extractive substances were isolated upon drying the leaves at room temperature.Isolation of extractive substances. Air-dried ground leaves (40 g) were extracted with ether 3 × 150 ml) in the dark (20 ° C) for 2 days. The extracts were pooled, washed with water, and dried with magnesium sulfate;Abstract -Qualitative and quantitative compositions of extracts of birch ( Betula pendula Roth.) leaves after natural and artificial defoliation were studied. Composition of the fraction of total lipids was determined. Overall, 11 fatty acids were identified. Differences between the fatty acid compositions of total lipids in the trees subjected to defoliati...

show abstract

“…The study of flavonoids is becoming increasingly interesting because of the important role that they play in the metabolism of plants and animals and their high and diversified biological activity [2]. Chrysin (5,7-dihydroxyflavone) is one of the most common flavonoids, has been isolated from various plant families [3,4], and possesses, like its derivatives, a broad spectrum of biological activity. Thus, chrysin exhibits anticancer [5,6], antioxidant [7, 8], anti-inflammatory [9, 10], vasodilating [11, 12], immunomodulating [13, 14], antibacterial [15, 16], antifungal [16], antiprotozal [17], neuroprotective [18], hypotensive [19], and anti-allergy [20] activity.…”

mentioning

confidence: 99%

Synthesis of amino-acid derivatives of chrysin

et al. 2008

View full text Add to dashboard Cite

Various conjugates of amino acids with chrysin in which the amino acid was bonded through the C-or N-terminus to the flavone were prepared using peptide chemistry methods (symmetric anhydrides and activated esters).Flavonoids are the most widely distributed compounds of natural origin. They can be found in practically all plant species. At present, flavonoids comprise about 6500 natural compounds [1]. The study of flavonoids is becoming increasingly interesting because of the important role that they play in the metabolism of plants and animals and their high and diversified biological activity [2]. Chrysin (5,7-dihydroxyflavone) is one of the most common flavonoids, has been isolated from various plant families [3,4], and possesses, like its derivatives, a broad spectrum of biological activity. Thus, chrysin exhibits anticancer [5,6], antioxidant [7, 8], anti-inflammatory [9, 10], vasodilating [11, 12], immunomodulating [13, 14], antibacterial [15, 16], antifungal [16], antiprotozal [17], neuroprotective [18], hypotensive [19], and anti-allergy [20] activity. Chrysin derivatives possess hypoglycemic [21], anticancer [22-25], anti-inflammatory [26, 27], and antibacterial [15] action.Considering the importance to the metabolism of all animals of amino acids and their derivatives, our goal was to synthesize chrysin derivatives with pharmacophores containing amino acids.The amino-acid derivatives of chrysin were synthesized via two modification pathways. The first was based on formation of the ester of N-protected amino acid and phenolic compounds. The most suitable and convenient method for synthesizing 7-O-amino-acid chromone derivatives is the reaction of 7-hydroxychromones and symmetric anhydrides of N-substituted amino acids because the reaction proceeds under mild conditions and is not complicated by side reactions [28]. It has been used successfully to synthesize similar types of compounds [29,30].The hydroxyls of 5,7-dihydroxychromones have different reactivities because of the different influence of electrondonors, steric factors, and intramolecular H-bonds. Therefore, the 7-hydroxyl of the chromone system is acylated exclusively under mild conditions [31,32].Symmetric anhydrides of N-protected amino acids were prepared by reaction of dicyclohexylcarbodiimide (DCC) with two equivalents of the corresponding N-protected amino acid in anhydrous dioxane at 0°C. The amines of the amino acids were blocked with t-butyloxycarbonyl (Boc), benzyloxycarbonyl (Cbz), and p-toluenesulfonic acid (Tos). Chrysin was acylated by the resulting amino-acid anhydrides at 0°C in anhydrous dioxane in the presence of catalytic amounts of 4-dimethylaminopyridine (DMAP) to produce N-protected 7-O-aminoacyl-5-hydroxy-2-phenylchromen-4-ones 2-20. The products contained glycine (2, 8), L-alanine (3, 9), L-valine (4, 10), L-leucine (5, 11), L-isoleucine (6, 12), L-methionine (13), L-phenylalanine (7, 14), β-alanine (15, 17, 19), and 6-aminohexanoic acid (16, 18, 20).The selective acylation of the chromone 7-hydroxyl was confirmed by PMR ...

show abstract

Untitled

Cited by 104 publications

References 0 publications

Apigenin-7-O-β-d-glycoside isolation from the highly copper-tolerant plant Elsholtzia splendens

Apigenin-7-O-β-d-glycoside isolation from the highly copper-tolerant plant Elsholtzia splendens

Effects of natural and artificial defoliation on the content and composition of extractive substances in birch leaves

Synthesis of amino-acid derivatives of chrysin

Contact Info

Product

Resources

About