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RESEARCH PRODUCT

Triterpene Saponins from Four Species of the Polygalaceae Family

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description

Twelve triterpene saponins were isolated by successive MPLC over silica gel from four species of Polygalaceae: From Polygala ruwenzoriensis, five new saponins 1–5 of which 1–4 as two pairs of (E)/(Z)-isomers, together with the four known compounds tenuifoline, (E)- and (Z)-senegasaponin b, (E)- and (Z)-senegin II, and polygalasaponin XXVIII, from the genus Carpolobia, one new saponin 6 from C. alba and the known arilloside (11) from C. lutea, and another new triterpene glycoside 7 from Polygala arenaria. Their structures were established mainly by 600-MHz 2D-NMR techniques (1H,1H-COSY, TOCSY, NOESY, HSQC, HMBC) as 3-O-(β-D-glucopyranosyl)presenegenin 28-{O-α-L-arabinopyranosyl-(1  4)-O-β-D-xylopyranosyl-(1  4)-O-α-L-rhamnopyranosyl-(1  2)-4-O-[(E)-4-methoxycinnamoyl]-β-D-fucopyranosyl} ester (1) and its (Z)-isomer 2, 3-O-(β-D-glucopyranosyl)presenegenin 28-{O-α-L-arabinopyranosyl-(1  4)-O-β-D-xylopyranosyl-(1  4)-O-α-L-rhamnopyranosyl-(1  2)-4-O-[(E)-3,4-dimethoxycinnamoyl]-β-D-fucopyranosyl} ester (3) and its (Z)-isomer 4, 3-O-(β-D-glucopyranosyl)presenegenin 28-[O-β-D-galactopyranosyl-(1  4)-O-β-D-xylopyranosyl-(1  4)-O-α-L-rhamnopyranosyl-(1  2)-β-D-fucopyranosyl] ester (5), 3-O-(β-D-glucopyranosyl)presenegenin 28-{O-α-L-arabinopyranosyl-(1  3)-O-[β-D-galactopyranosyl-(1  4)]-O-β-D-xylopyranosyl-(1  4)-O-α-L-rhamnopyranosyl-(1  2)-O-[β-D-apiofuranosyl-(1  3)]-4-O-acetyl-β-D-fucopyranosyl} ester (6), and 3-O-(β-D-glucopyranosyl)presenegenin 28-{O-β-D-galactopyranosyl-(1  4)-O-[β-D-glucopyranosyl-(1  3)]-O-β-D-xylopyranosyl-(1  4)-O-α-L-rhamnopyranosyl-(1  2)-β-D-fucopyranosyl} ester (7) (presenegenin = (2β,3β,4α)-2,3,27-trihydroxyolean-12-ene-23,28-dioic acid).