New oleanane saponins in Chenopodium quinoa.

Six triterpenoid saponins were isolated from the seeds of Chenopodium quinoa (Chenopodiaceae). Their structures were as follows: phytolaccagenic acid 3-O-[alpha-L-arabinopyranosyl-(1' '-->3')-beta-D-glucuronopyranosyl]-28-O-beta-D-glucopyranoside (1); spergulagenic acid 3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl-28-O-beta-D-glucopyranoside (2); hederagenin 3-O-[beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl]-28-O-beta-D-glucopyranoside (3); phytolaccagenic acid 3-O-[beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl]-28-O-beta-D-glucopyranoside (4); hederagenin 3-O-[beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl]-28-O-beta-D-glucopyranoside (5); and spergulagenic acid 3-O-[alpha-L-arabinopyranosyl-(1' '-->3')-beta-D-glucuronopyranosyl]-28-O-beta-D-glucopyranoside (6). Saponins 5 and 6 are new. The structures were characterized on the basis of hydrolysis and spectral evidence, including IR, UV, optical rotations, 1D- and 2D-NMR (HMQC and HMBC), ESIMS, and FABMS analyses.

Studies on the constituents of Chenopodium quinoa seeds: isolation and characterization of new triterpene saponins.

Six triterpenoid saponins were isolated from the edible grain quinoa, which is seeds of Chenopodium quinoa (Chenopodiaceae). Following are their structures: phytolaccagenic acid 3-O-[alpha-L-arabinopyranosyl-(1' '-->3')-beta-D-glucuronopyranosyl]-28-O-beta-D-glucopyranoside (1); phytolaccagenic acid 3-O-[beta-D-glucopyranosyl-(1' '-->3')-alpha-L-arabinopyranosyl]-28-O-beta-D-glucopyranoside (2); phytolaccagenic acid 3-O-[beta-D-glucopyranosyl-(1' "-->3' ')-beta-D-xylopyranosyl-(1' '-->2')-beta-D-glucopyranosyl]-28-O-beta-D-glucopyranoside (3); phytolaccagenic acid 3-O-[beta-D-glucopyranosyl-(1' "-->2' ')-beta-D-glucopyranosyl-(1' '-->3')-alpha-L-arabinopyranosyl]-28-O-beta-D-glucopyranoside (4); oleanolic acid 3-O-[alpha-L-arabinopyranosyl-(1' '-->3')-beta-D-glucuronopyranosyl]-28-O-beta-D-glucopyranoside (5); and oleanolic acid 3-O-[beta-D-glucopyranosyl-(1' '-->3')-alpha-L-arabinopyranosyl]-28-O-beta-D-glucopyranoside (6). The oleanane-type saponins (5, 6) were isolated for the first time in this plant, two of the phytolaccagenane (1, 3) were new compounds and two (2, 4) were previously found in quinoa. The structures were characterized on the basis of hydrolysis and spectral evidence, including 1D- and 2-D NMR (HMQC and HMBC) and ESI-MS analyses.

Flavonoid glycosides of Barbarea vulgaris L. (Brassicaceae).

Seven flavonoid derivatives were for the first time isolated from aerial parts of an alimentary and medicinal plant of the Brassicaceae family, Barbarea vulgaris L. The products were characterized on the basis of spectroscopic NMR ((1)H, (13)C, COSY, HMQC, HMBC) and FAB-MS data. The occurrence of flavonoids in this plant is interesting for their important nutritional properties and for chemotaxonomical pourposes.

Physiological and pharmacological properties of an endogenous sodium pump inhibitor.

To investigate on Na+, K+-ATPase behavior in chronic uremia, pre and postdialysis serum from 10 chronic dialysis patients and 10 healthy subjects was pooled and subjected to reverse phase C-18 HPLC. Only one fraction, isolated from pre and postdialysis sera, eluting at 28 min (F1), was found to display significant effects on electrophysiological and transepithelial 22Na flux pattern of rabbit distal colon mucosa mounted in Ussing type chambers; indeed, serosal addition of uremic F1 to colonic mucosa resulted in a slow, but constant, decline in short-circuit current (Isc) (deltaIsc = 1.55+/-0.16 microEq h(-1) cm(-2), mean +/- S.E.M., n=12, p<0.01) and transepithelial conductance (G(T)) (from 4.50+/-0.23 to 3.71+/-0.33 mS cm(-2), p<0.01, n=12). Measurement of transepithelial 22Na fluxes in the presence of pre or postdialysis sera also showed a significant Na+ absorption rate decrease (from 1.3+/-0.22 to 0.48+/-0.30 microEq h(-1) cm(-2), mean +/- S.E.M., n=4, p<0.01), mainly due to a decrease in mucosal-to-serosal Na+ flux. By contrast, assays of peaks isolated from healthy sera did not inhibit Isc and transepithelial Na+ transport. The incubation of highly purified basolateral membranes with F1 for 1 min produced a approximately 26% inhibition of Na+, K+-ATPase. These findings are consistent with the presence of an endogenous inhibitor of sodium pump activity in uremic plasma; it is of pharmacological interest in that it may participate in the development of unpredictable responsiveness to digitalis therapy in pathophysiologic states.