Lignan bis-glucosides from Galium sinaicum (original) (raw)
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Journal of natural products, 2017
Four new colchicinoids were isolated from the seeds of Gloriosa superba together with the known compounds colchicoside (4) and 3-de-O-methylcolchicine-3-O-β-d-glucopyranosyl-(1→4)-3-O-β-d-glucopyranoside (6), by means of conventional column chromatography and LC-DAD-SPE-NMR. The new compounds were identified as N-deacetyl-N-formyl-3-de-O-methylcolchicine-3-O-β-d-glucopyranoside (1), 3-de-O-methylcolchicine-3-O-β-d-glucopyranosyl-(1→6)-3-O-β-d-glucopyranoside (2), N-deacetyl-N-formyl-3-de-O-methylcolchicine-3-O-β-d-glucopyranosyl-(1→6)-3-O-β-d-glucopyranoside (3), and 3-de-O-methylcolchicine-3-O-β-d-glucopyranosyl-(1→3)-3-O-β-d-glucopyranoside (5). The structure elucidation was performed by means of NMR (COSY, HSQC, and HMBC), HRESIMS/MS, and GCMS data analysis.
New Flavonol Tetraglycosides from Astragalus caprinus
Chemical and Pharmaceutical Bulletin, 2002
Astragalus caprinus MAIRE (Fabaceae) is an endemic of North Africa, the leaves of which are used as an antihaemorrhoidal in Tunisian folk medicine. Our previous paper describing the structure of a new 3-O-tetraglycoside of kaempferol from this plant was the first phytochemical report on this species. 1) Here we report the isolation and structural elucidation of five new flavonol glycosides. Results and Discussion The methanolic extract of dried leaves from A. caprinus, once prepurified, was fractionated by repeated column and preparative thin-layer chromatography to give 1-5. Analysis of the 1 Hand 13 C-NMR spectra of compound 1 (Table 1; all assignments based on heteronuclear single quantum coherence-total correlation spectroscopy (HSQC-TOCSY) and heteronuclear multiple bond correlation (HMBC) experiments) showed the presence of one aromatic system and four sugar moieties. The 1 H-NMR resonances of two metacoupled doublets at d 6.19 and 6.38 ppm (1H, Jϭ1.9 Hz), correlated with the carbons at 99.8 and 94.7 ppm, respectively, in the HSQC spectrum, characterized the 6-and 8-protons of a flavonoid 5,7 dihydroxy A-ring. 2) Ring B was assigned as a 1,4-substituted benzene ring (d H 8.07, d, 2H, Jϭ8.8 Hz; 6.89, d, 2H, Jϭ8.8 Hz) from a HMBC experiment. Thus, the aglycone of 1 was identified as 3,5,7,4Ј-tetrahydroxyflavone (kaempferol), as suggested by its UV spectral properties. A HSQC-TOCSY experiment was performed to identify the spin systems of sugar units, starting from anomeric protons at d 5.57 (d, Jϭ7.8 Hz), 5.22 (s), 4.52 (s) and 4.32 (d, Jϭ7.4 Hz); on the basis of the chemical shifts, multiplicity of the signals and values of the coupling constants, the sugars were identified as b-galactopyranosyl (Gal), a-rhamnopyranosyls (Rha a and Rha b) and b-xylopyranosyl (Xyl). 3) The common D-configuration for Gal and Xyl, and the L-configuration for Rha were assumed according to those most often encountered among the plant glycosides. HMBC experiments showed long-range correlations between Gal H-1 (d 5.57) and Kaempferol C-3 (d 134.5), Rha a H-1/C-1 (d 5.22/102.6) and Gal C-2/H-2 (d 77.5/3.93), Rha b H-1/C-1 (d 4.52/101.8) and Gal C-6/H-6 (d 67.5/3.68), Xyl H-1/C-1 (d 4.32/106.4) and Rha b C-3/H-3 (d 82.3/3.55). Thus, compound 1 was identified as kaempferol-3-O-{[b-Dxylopyranosyl(1→3)-a-L-rhamnopyranosyl(1→6)][a-Lrhamnopyranosyl(1→2)]}-b-D-galactopyranoside. This identification was corroborated by electrospray ionization mass July 2002 Notes Chem. Pharm. Bull. 50(7) 981-984 (2002) 981
Phenylethyl Glycosides from Globularia alypum Growing in Turkey
Helvetica Chimica Acta, 2008
From the leaves of Globularia alypum, three new phenylethyl glycosides, namely galypumosides A (¼ 2-(3,4-dihydroxyphenyl)ethyl O-a-rhamnopyranosyl-(1 ! 3)-4-O-[(E)-caffeoyl]-6-O-[(E)-p-coumaroyl]-b-glucopyranoside; 1), B (¼ 2-(3,4-dihydroxyphenyl)ethyl O-a-rhamnopyranosyl-(1 ! 3)-4-O-[(E)-caffeoyl]-6-O-[(E)-feruloyl]-b-glucopyranoside; 2), and C (¼ 2-(3,4-dihydroxyphenyl)ethyl O-arhamnopyranosyl-(1 ! 3)-4-O-[(E)-caffeoyl]-6-O-menthiafoloyl-b-glucopyranoside; 3), were isolated, together with two known phenylethyl glycosides, calceolarioside A and verbascoside. Eight iridoid glucosides, catalpol, globularicisin, globularin, globularidin, globularinin, globularimin, lytanthosalin, and alpinoside, a flavon glycoside, 6-hydroxyluteolin 7-O-sophoroside, a lignan glycoside, syringaresinol 4'-O-b-glucopyranoside, and a phenylpropanoid glycoside, syringin, were also obtained and characterized. The structures of the isolates were elucidated on the basis of 1D-and 2D-NMR experiments as well as HR-MALDI-MS.
Assignment of 1 H and 13 C NMR data for iridoid glycoside derivatives
Magnetic Resonance in Chemistry
Adansonia digitata commonly known as "Baobab" is found mainly in Africa. [1] The products of baobab such as bark, leaves, fruits, and seeds served as a source of food and medicine for the livelihood of many African populations. [2,3] In our continuing search for pharmacological and structurally interesting substances from the trunk buck of baobab, [4,5] three new iridoid glycoside derivatives (1-3), together with one known compound, have been isolated. The complete proton and carbon assignments of these compounds were accomplished by the use of a series of 1D and 2D nuclear magnetic resonance (NMR) experiments including 1 H-1 H COSY, HSQC, HMBC, and ROESY experiments. Compounds 1-3 (Figure 1), bearing a butoxy group in the molecule, were confirmed to be the artifacts of verminoside derivative generated during the n-butnol partition process according to the UHPLC-DAD-HRMS n .
Holzforschung, 2014
Twelve monolignol (coniferyl alcohol, sinapyl alcohol and p-coumaryl alcohol) β-glycosides (β-glucosides, β-galactosides, β-xylosides and β-mannosides) were synthesised to obtain fundamental NMR data for the analysis of phenyl glycoside type lignin-carbohydrate complexes (LCCs). That is, the 1,2-trans glycosides (the β-glucosides, β-galactosides and β-xylosides) and the 1,2-cis glycosides (the β-mannosides) were synthesized by means of Koenig-Knorr glycosylation and β-selective Mitsunobu glycosylation strategies, respectively. In addition, dihydromonolignol and p-hydroxybenzaldehyde derivative β-glycosides were also prepared from the corresponding monolignol glycosides and their intermediates, respectively. The correlation observed for the C1β-H1β bonds of the sugar moieties in the HSQC spectra of the all β-glycosides varied and were in the range of δ C/δ H 96–104/4.7–5.4 ppm. Especially, it was found that the correlations derived from the C1β-H1β bonds of the guaiacyl and p-hydroxy...
Two new diacetylene glycosides: bhutkesoside A and B from the roots of Ligusticopsis wallichiana
2015
Two new diacetylene glycosides: bhutkesoside A (<b>1</b>) and B (<b>2</b>), along with 10 known compounds, i.e. falcarindiol (<b>3</b>), chlorogenic acid (<b>4</b>), 5-<i>O</i>-<i>p</i>-coumaroyl-quinic acid (<b>5</b>), 3,5-di-<i>O</i>-caffeoyl-quinic acid (<b>6</b>), 4-hydroxy-7-methoxy-phenylethanol (<b>7</b>), ferulic acid (<b>8</b>), dehydrodiconiferyl alcohol-4-<i>O</i>-<i>β</i>-d-glucopyranoside (<b>9</b>), 5,7-dihydroxy-2-methylchromone-7-<i>O</i>-rutinoside (<b>10</b>), schumanniofioside B (<b>11</b>) and marmesinin (<b>12</b>) were isolated from the roots of <i>Ligusticopsis wallichiana</i> (DC) Pimenov & Kljuykov (Apiaceae), commonly known as 'Bhutkesh' in Nepal. The structures were determined on the basis of spectroscopic data. Compounds &l...