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An extract from the knotwood of Populus tremula (quaking aspen) was studied by HPLC, NMR spectroscopy, and mass spectrometry in order to identify new sources of natural compounds as promising basis for the development of medicinal agents. The following compounds were detected and characterized in the extract: 6-O-(α-l-rhamnopyranosyl)-β-d-glucopyranosyl E-3-(4-hydroxyphenyl)acrylate, 6-O-(α-l-rhamnopyranosyl)-β-d-glucopyranosyl Z-3-(4-hydroxyphenyl)acrylate, trans-3-(4-hydroxyphenyl)acrylic acid, 7-O-(β-d-glucopyranosyl)naringenin, dihydrokaempferol, and naringenin. [ABSTRACT FROM AUTHOR]

An extract from the knotwood of Abies sibirica (Siberian fir) was studied by HPLC, NMR spectroscopy, and mass spectrometry with the goal to identify new sources of phytoestrogens, which are promising medicinal agents, and to obtain new representatives of natural compounds of the indicated group. The following compounds were found in the extract and identified: 2-(4-hydroxy-3-methoxyphenyl)-3-hydroxymethyl-4-[1-hydroxy-1-(4-hydroxy-3-methoxy-phenyl)methyl]tetrahydrofuran (1), 5′-(7-hydroxymatairesinyl)-5″-(7‴-hydroxymatairesinol) (2), 2,3-bis(4-hydroxy-3-methoxybenzyl)butane-1,4-diol (3, (−)-secoisolariciresinol), and 3-(4-hydroxy-3-methoxybenzyl)-5-(4-hydroxy-3-methoxyphenyl)-4-(hydroxymethyl)dihydro-furan-2(3H)-one (4). Compound 2 was previously unknown. [ABSTRACT FROM AUTHOR]

According to HPLC, NMR spectroscopy, and mass spectrometry, the extracts of the knotwood of Salix capreal. contain catechin (1), 7-O-(β-d-glucopyranosyl)dihydrokaempferol (2), 7-O-(β-d-glucopyranosyl)dihydrokaempferol-4′-O-methyl ether (3), 7-O-(β-d-glucopyranosyl)naringenin (prunin) (4), naringenin (5), and dihydrokaempferide (6). Compound 3 was not described previously. [ABSTRACT FROM AUTHOR]

Electrospray ionization (ESI) high resolution mass spectra of positively charged ions (the first and the second order) of protonated molecules of isomeric β-(1→6)-linked cyclic tetrasaccharides of the Glcp2GlcpN2 composition were recorded and interpret. It was shown that the second-order mass spectra of these compounds have some differences reflecting the mutual positions of the glucopyranose and glucosamine residues. The most significant qualitative differences were observed for MS/MS spectra of doubly protonated, doubly charged molecules. [ABSTRACT FROM AUTHOR]

Chemical composition of the extract from the Pinus roxburghii Sarg. knotwood was studied for the first time. The extracts were obtained by ultrasound assisted sequential extraction of knotwood with hexane, acetone—water (95 : 5, v/v), and water. According to GC-MS analysis, hexane extract was dominated by monoterpenoids amounting to 53.57% and sesquiterpenoids (41.05%). Components of the acetone—water (95 : 5, v/v) extract were isolated, purified by HPLC, and identified by NMR spectroscopy and mass spectrometry as 2,3-bis(4-hydroxy-3-methoxybenzyl)butan-1,4-diol, 3-hydroxy-3,4-bis(4-hydroxy-3-methoxybenzyl)dihydrofuran-2(3H)-one and 3,4-bis(4-hydroxy-3-methoxybenzyl)dihydrofuran-2(3H)-one. These compounds demonstrated notable antioxidant capacity determined using the amperometric method. [ABSTRACT FROM AUTHOR]

The composition of the extract from the Dalbergia Sissoo Linn. knot wood was studied. Components obtained by extraction with 95% aqueous acetone were isolated, purified by HPLC, and identified by NMR spectroscopy and mass spectrometry as 7,6,3',5'-trihydroxyflavanone (1), 7,3',4'-trihydroxy-6-methoxyflavanone (2), 7,3',5'-trihydroxyflavanone (3), 6-hydroxy-7-methoxy-4-phenyl-2H-chromen-2-one (dalbergin) (4), 2-methoxy-5-(1-phenylallyl)cyclohexa-2,5-diene-1,4-dione (dalbegione) (5), and 2,4-dimethoxy-5-(1-phenylallyl)phenol (dalbergiphenol) (6). In the extract from the Dalbergia Sissoo Linn. wood knots, compounds 1–3 were found for the first time. The isolated compounds demonstrated notable antioxidant ability determined by using the amperometric method. [ABSTRACT FROM AUTHOR]

Positive and negative ion high-resolution electrospray ionization mass spectra (MS and MS2) of cyclooligo-β-(1→6)-D-glucosamines and cyclooligo-β-(1→6)-N-acetyl-D-glucosamines were acquired and interpret. It was shown that the cleavages of glycosidic bonds are the main processes in the decay of protonated and metallated molecules. In addition, elimination of the water molecules (and ammonia for cyclooligo-β-(1→6)-D-glucosamines) was observed along with other processes including the unknown skeletal rearrangement. A primary fragmentation of the negatively charged ions (deprotonated molecules) differed from that of the positively charged ones. [ABSTRACT FROM AUTHOR]