Triterpene saponins from Calendula arvensis

From the aerial parts of Calendula arvensis a new triterpene saponin arvensoside C (1) was isolated together with four known triterpene saponins. The aglycon moieties had the oleanane skeleton for all of them. Three known flavonol glycosides, isorhamnetin 3-O-β -D-glucopyranoside, quercetin 3-O-β -D-glucopyranoside and quercetin 3-O-β -D-galactopyranoside were also obtained and characterized. Their structures were elucidated by 1D and 2D NMR experiments including 1D-TOCSY, DQF-COSY, HOHAHA, HSQC and HMBC spectroscopy as well as HRESIMS analysis

Flavonoids and isoflavonoids from Gynerium sagittatum

Four flavonoids namely (2R,3R)-2,3-trans-7,4 '-dimethoxydihydroflavonol, (2R,3S,4S)-2,3-trans-3,4-cis-7,4'-dimethoxy-3,4-flavandiol, 6-hydroxy-7,4 '-dimethoxyflavone, 6,7,4 '-trimethoxyflavone, along with the known isoflavonoids ferreirin, dihydrocajanin, dalbergioidin, dihydrobiochanin A and biochanin A and other I I known compounds were isolated from the roots of Gynerium sagittatum. The structural characterization of these compounds was carried out via one- and two-dimensional NMR experiments in combination with ESI-MS. Finally a quantitative analysis of the isoflavones of the methanolic extract was performed by LC-ESI-MS. The high quantity of isoflavonoids found in G. sagittatum makes this plant a good natural source of isoflavonoids. (c) 2007 Elsevier Ltd. All rights reserved