Chapter Six – Flavonoid Glycosides
About: This article is published in Studies in Inorganic Chemistry.The article was published on 1989-12-31. It has received 67 citations till now.
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TL;DR: In this article, 10 phenolic compounds were isolated from a butanol fraction of sage extracts and their structures were determined by spectral methods (NMR, MS, IR). Among them, a novel compound, 4-hydroxyacetophenone-4-O-β-d-apiofuranosyl-(1→6)-O- β-dglucopyranoside, was identified.
Abstract: Ten phenolic compounds were isolated from a butanol fraction of sage extracts. Their structures were determined by spectral methods (NMR, MS, IR). Among them, a novel compound, 4-hydroxyacetophenone-4-O-β-d-apiofuranosyl-(1→6)-O-β-d-glucopyranoside, was identified. Two test systems, DPPH free radical scavenging activity and radical cation ABTS•+ scavenging activity, were used to evaluate their antioxidant activity. The most active compounds were found to be rosmarinic acid and luteolin-7-O-β-glucopyranoside. Keywords: Sage; Salvia officinalis; phenolic compounds; antioxidant activity
643 citations
TL;DR: Eight extracts, methanol extracts of Acacia nilotica, Boswellia carterii, Embelia schimperi, Quercus infectoria, Trachyspermum ammi and water extracts of Piper cubeba, Q. infectoria and Syzygium aromaticum were the most active.
Abstract: One hundred fifty-two methanol and water extracts of different parts of 71 plants commonly used in Sudanese traditional medicine were screened for their inhibitory effects on hepatitis C virus (HCV) protease (PR) using in vitro assay methods. Thirty-four extracts showed significant inhibitory activity (>/=60% inhibition at 100 microg/mL). Of these, eight extracts, methanol extracts of Acacia nilotica, Boswellia carterii, Embelia schimperi, Quercus infectoria, Trachyspermum ammi and water extracts of Piper cubeba, Q. infectoria and Syzygium aromaticum, were the most active (>/=90% inhibition at 100 microg/mL). From the E. schimperi extract, two benzoquinones, embelin (I) and 5-O-methylembelin (II), were isolated and found as potent HCV-PR inhibitors with IC(50) values of 21 and 46 microM, respectively. Inhibitory activities of derivatives of I against HCV-PR as well as their effects on other serine proteases were also investigated.
295 citations
TL;DR: A new depside, jaboticabin, together with 17 known compounds were isolated from the fruit of jaboticaba and significantly inhibited chemokine interleukin (IL)-8 production before and after cigarette smoke treatment of cells.
Abstract: A new depside, jaboticabin (1), together with 17 known compounds were isolated from the fruit of jaboticaba (Myrciaria cauliflora). The structure of 1 was elucidated by spectroscopic data interpretation. Known compounds were identified by comparison of their spectroscopic data with literature values or by comparison to authentic standards. Compound 1 and the related depside 2-O-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxyphenylacetic acid (2) significantly inhibited chemokine interleukin (IL)-8 production before and after cigarette smoke treatment of cells. Compound 1 was cytotoxic in the HT29 colon cancer cell line (IC50 = 65 microM), and 2 was active against HCT116 colon cancer cells (IC50 = 30 microM). Compounds 1 and 2 also exhibited antiradical activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay (IC50 = 51.4 and 61.8 microM, respectively). Two anthocyanins, cyanidin 3-glucoside (3) and delphinidin 3-glucoside (4), also showed good activity in these assays.
145 citations
TL;DR: Given the wide availability and underutilization of C. folliculata, this forage may provide a source of bioactive compounds useful for nutraceutical purposes, and this is the first reported phytochemical investigation of the plant.
Abstract: Plants of the Carex genus (Family: Cyperaceae) have attracted recent attention as potential food additives because they contain high levels of bioactive polyphenols commonly found in plant foods. Seven compounds, which included two resveratrol oligomers and five flavonoids, were isolated from seeds of Carex folliculata L. (northern long sedge), a forage prevalent in the northern United States. The compounds were identified by 1H and 13C nuclear magnetic resonance and mass spectrometry data. The resveratrol oligomers were pallidol (1), a resveratrol dimer reported to be present in levels equivalent to those of resveratrol in red wine, and kobophenol A (2), a resveratrol tetramer with a unique 2,3,4,5-tetraaryltetrahydrofuran skeleton. The flavonoids were isoorientin (3), luteolin (4), quercetin (5), 3-O-methylquercetin (6), and rutin (7). Compounds were evaluated for antioxidant activity in the diphenylpicrylhydrazyl (DPPH) radical scavenging assay; cytotoxicity activity against human colon (HCT116, HT29) ...
106 citations
TL;DR: Based on the occurrence of internal monosaccharide residue loss and the relative abundances of Y-type ions formed by fragmentation at glycosidic bonds, four pairs of isomeric flavonoid O-diglycosides can be unambiguously differentiated.
Abstract: Tandem mass spectrometric methods have been evaluated for the characterisation of the type and the differentiation of the interglycosidic linkage of isomeric flavonoid O-diglycosides. Based on the occurrence of internal monosaccharide residue loss and the relative abundances of Y-type ions formed by fragmentation at glycosidic bonds, four pairs of isomeric flavonoid O-diglycosides can be unambiguously differentiated. The different techniques used, i.e. linked scanning at constant B/E without collisional activation and low-energy collision-induced dissociation using methane or helium as collision gas, have been shown to be useful for distinguishing the two most common (1, 2- and 1, 6-) interglycosidic linkages, e.g. flavonoid O-neohesperidosides and O-rutinosides.
102 citations
References
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01 Jan 1982TL;DR: In this paper, carbon-13 NMR Spectroscopy of Flavonoids was used for isolation techniques for the extraction of Flavone and Flavonol Glycosides, respectively.
Abstract: 1 Isolation Techniques for Flavonoids.- 2 Carbon-13 NMR Spectroscopy of Flavonoids.- 3 Anthocyanins.- 4 Flavones and Flavonols.- 5 Flavone and Flavonol Glycosides.- 6 The Minor Flavonoids.- 7 Proanthocyanidins.- 8 C-Glycosylflavonoids.- 9 Biflavonoids.- 10 Isoflavonoids.- 11 Biosynthesis.- 12 Mammalian Metabolism of Flavonoids.- Plant Species Index.
1,586 citations
TL;DR: An overview of the 13 Carbon-Nuclear magnetic resonance (13 C-NMR) spectroscopy of monosaccharides can be found in this paper, where an almost complete collection of 13 C- NMR chemical shifts of polysaccharides, their methyl glycosides, and acetates is presented.
Abstract: Publisher Summary This chapter provides an overview of the 13 Carbon-nuclear magnetic resonance ( 13 C-NMR) spectroscopy of monosaccharides. The 13 C-NMR spectroscopy has become increasingly important as a tool for the characterization and structural elucidation of sugars and their derivatives. Although 13 C-NMR is closely related to 1 H-NMR spectroscopy, especially when both types of spectra are recorded with Fourier-transform instruments, the two techniques are sufficiently different to be valuable complements to each other. In many cases, in particular when dealing with complex molecules such as polysaccharides, the amount of information obtainable from 1 H-NMR spectra is limited as compared to that revealed by 13 C- NMR spectra. This chapter provides an almost complete collection of 13 C- NMR chemical shifts of monosaccharides, their methyl glycosides, and acetates, along with the examples of shift data for as many different types of monosaccharide derivative as possible. It also provides details on sampling techniques and assignment techniques, and discusses the identity of monosaccharides, their structure determination, and conformational analysis .
1,273 citations
TL;DR: In this article, 13 C NMR spectra for a variety of flavonoid glycosidcs are presented and analyzed, and evidence is presented which demonstrates that 13 C nMR spectroscopy is a valuable technique for distinguishing the sites of methylation, glycosylation and acylation in glycoiides.
858 citations
TL;DR: In this article, the direct coupling constants between the anomeric carbon atoms and protons {1J[13C-H(1)]} were found to be ca. 160 in the β-anomers and ca. 170 Hz in the α-anomer; the difference of ca. 10 Hz between pairs of anomers was found in almost all cases.
Abstract: Proton decoupled and undecoupled 13C n.m.r. spectra have been measured on a number of hexopyranoses. The direct coupling constants between the anomeric carbon atoms and protons {1J[13C–H(1)]} were found to be ca. 160 in the β-anomers and ca. 170 Hz in the α-anomers; the difference of ca. 10 Hz between pairs of anomers was found in almost all cases. Chemical shifts and 1J(13CH) values of the other carbon atoms in the pyranose rings were also measured.
728 citations
TL;DR: The 13 C NMR chemical shifts of 130 naturally occurring steroidal sapogenins and saponin derivatives published up to 1983 are listed and a number of methods for signal assignment are explained as discussed by the authors.
549 citations