Search results for "glycoside"
showing 10 items of 296 documents
Steroidal saponins from the fruits of Solanum torvum
2013
Abstract Seven steroidal glycosides have been isolated from the fruits of Solanum torvum Swartz. Their structures were established by 2D NMR spectroscopic techniques ( 1 H, 1 H-COSY, TOCSY, NOESY, HSQC, and HMBC) and mass spectrometry as (25 S )-26-(β- d -glucopyranosyloxy)-3-oxo-5α-furost-20(22)-en-6α-yl- O -β- d -xylopyranoside ( 1 ), (25 S )-26-(β- d -glucopyranosyloxy)-3-oxo-22α-methoxy-5α-furostan-6α-yl -O -β- d -xylopyranoside ( 2 ), (25 S )-26-(β- d -glucopyranosyloxy)-3β-hydroxy-22α-methoxy-5α-furostan-6α-yl- O -α- l -rhamnopyranosyl-(1 → 3)-β- d -glucopyranoside ( 3 ), (25 S )-3β-hydroxy-5α-spirostan-6α-yl- O -β- d -xylopyranoside ( 4 ), (25 S )-3-oxo-5α-spirostan-6α-yl- O -β- d -x…
Two new biologically active triterpene saponins from Acanthophyllum squarrosum.
2000
Two novel triterpenoid saponins (1 and 2) have been isolated from the roots of Acanthophyllum squarrosum. The structures were established mainly by a combination of 2D NMR techniques as 3-O-beta-D-galactopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-be ta-D-glucuronopyranosylgypsogenin-28-O-beta-D-xylopyranosyl-(1-->3 )-b eta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->4)-[alpha-L- rhamnopyranosyl-(1-->3)]-beta-D-fucopyranoside (1) and 3-O-beta-D-glucopyranosylgypsogenin-28-O-alpha-L-rhamnopyranosyl-( 1-- >2)-alpha-L-arabinopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->6 )]- beta-D-glucopyranoside (2). Compound 1 showed a moderate concentration-dependent immunomodulatory effect …
Dynamics of the biosynthesis of methylursubin in plant cells employing in vivo 13CNMR without labelling.
1995
Abstract In vivo NMR experiments with a digital 600 MHz instrument, exploiting the natural abundance of 13C, allowed us for the first time to follow the biosynthesis of the newly detected glycoside, methylursubin ( 4- methoxyphenyl -O-β- d -primeveroside ), from 4-methoxyphenol through the intermediate methylarbutin in cell suspensions of the Indian medical plant, Rauwolfia serpentina. The metabolic dynamics indicate that, within 48 hr, 4-methoxyphenol is almost completely converted into the primeveroside, methylursubin. Because of the higher sensitivity at 150.9 MHz compared to that at 100.6 MHz, measuring times could be reduced to 1.5 hr. This allows detailed monitoring of the conversion …
New prenylhydroquinone glycosides from Phagnalon rupestre.
2001
Three new hydroquinone glycosides were isolated from the MeOH extract of the aerial parts of Phagnalon rupestre. Their structures were elucidated as 1-O-beta-glucopyranosyl-1,4-dihydroxy-2-(3',3'-dimethylallyl)benzene (1), 1-O-beta-glucopyranosyl-1,4-dihydroxy-2-(3'-hydroxymethyl-3'-methylallyl)benzene (2), and 1-O-(4' '-O-caffeoyl)-beta-glucopyranosyl-1,4-dihydroxy-2-(3',3'-dimethylallyl)benzene (3) by spectroscopic methods.
Triterpene Saponins from Cyclamen persicum
2010
A new triterpene saponin 3- O-β-D-glucopyranosyl-(1→4)-α-L-arabinopyranosyl-16α-hydroxy-13β,28-epoxy-oleanan-30-al (1), along with four known triterpene glycosides (2-5) were isolated from Cyclamen persicum. Their structures were characterized by a combination of 1D- and 2D-NMR (1H-1H COSY, TOCSY, NOESY, HSQC, and HMBC) and MS spectrocopic data. The cytotoxicity of compounds 2 and 4 was evaluated using two human colon cancer cell lines HT-29 and HCT 116.
A new biologically active acylated triterpene saponin from Silene fortunei.
1998
A new acylated triterpene-saponin (1), together with a mixture of the known jenisseensosides C and D, has been isolated from the roots of Silene fortunei. The structure of the new compound was established by chemical means and spectroscopic methods as 3-O-[beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl]-28 -O- [[alpha-L-arabinopyranosyl-(1-->2)-alpha-L-arabinopyranosyl- (1-->3)-b eta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)]-[beta-D- glucopyranosyl-(1-->3)]-4-O-acetyl-beta-D-fucopyranosyl]quillaic acid. This saponin showed a significant enhancement of granulocyte phagocytosis in vitro.
Glycosidic juvenogens: derivatives bearing alpha,beta-unsaturated ester functionalities.
2007
Abstract A series of the protected alkyl glycosides 5a / 5b – 12a / 12b was synthesized from the parent isomeric alcohols (insect juvenile hormone bioanalogs; juvenoids), 4-[4′-(2″-hydroxycyclohexyl)methylphenoxy]-3-methyl-but-2-enoic acid ethyl ester ( 1a / 1b – 4a / 4b ; racemic structures) and ( 1a – 4a ; enantiopure structures). Cadmium carbonate was used as a promoter of this Koenigs–Knorr reaction, and the products were obtained in 82–92% yields. Deprotection of the carbohydrate functionality of 5a / 5b – 12a / 12b was carefully performed using ethanolysis in the presence of zinc acetate, due to the presence of another ester functionality in the aglycone part of the molecule of protec…
Three new acylated triterpene saponins from Acanthophyllum squarrosum.
2001
Three new triterpenoid saponins, 1-3, were isolated from the roots of Acanthophyllum squarrosum. Their structures were established mainly by 2D NMR techniques as 3-O-beta-D-galactopyranosyl-(1--2)-[beta-D-xylopyranosyl-(1--3)]-beta-D-glucuronopyranosyl-gypsogenin-28-O-beta-D-xylopyranosyl-(1--3)-beta-D-xylopyranosyl-(1--4)-beta-D-xylopyranosyl-(1--4)-3-O-acetyl-alpha-L-rhamnopyranosyl-(1--2)-3,4-di-O-acetyl-beta-D-fucopyranoside (1), 3-O-beta-D-galactopyranosyl-(1--2)-[beta-D-xylopyranosyl-(1--3)]-beta-D-glucuronopyranosyl-gypsogenin-28-O-beta-D-xylopyranosyl-(1--4)-alpha-L-rhamnopyranosyl-(1--2)-[5-O-acetyl-alpha-L-arabinofuranosyl-(1--3)]-4-O-acetyl-beta-D-fucopyranoside (2), and 3-O-beta…
Glucuronide triterpene saponins from Bersama engleriana
2006
Five 3-O-glucuronide triterpene saponins (1-5) were isolated from the stem bark of Bersama engleriana Gurke along with two known saponins, polyscias saponin C and aralia saponin 15, and one major C-glycoside xanthone, mangiferin. The structures of the saponins were established mainly by means of spectroscopic methods (one- and two-dimensional NMR spectroscopy as well as FAB-, HRESI-mass spectrometry) as 3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-glucuronopyranosyl]-28-O-[beta-D-glucopyranosyl]-betulinic acid (1), 3-O-[beta-D-glucopyranosyl-(1-->2)-[beta-D-galactopyranosyl-(1-->3)]-beta-D-glucuronopyranosyl]-oleanolic acid (2), 3-O-[beta-D-glucopyranosyl-(1-->3)-beta-D-glucuronopyranosyl]-28-…
Triterpene Saponins from Tupidanthus calyptratus
2001
Five new bisdesmosidic saponins (1--5) were isolated from the aerial parts of Tupidanthus calyptratus. Their structures were determined by (1)H--(1)H correlation spectroscopy (COSY, TOCSY, ROESY) and (1)H--(13)C correlation (HSQC, HMBC) NMR experiments, FABMS, and chemical data.