Three new cyclobutanoid amides with trans-trans-trans configurations, piperarborenine C, piperarborenine D and piperarborenine E, and a new furanoid lignan, (+)-arborone, together with twelve known compounds, were isolated from the stems of Piper arborescens. The structures of these new compounds were determined by means of spectral analyses. Piperarborenine C, (+)-diayangambin, piplartine, piperolactam B, piperolactam C, aristolactam BIII, goniothalactam, and methyl trans-3,4,5-trimethoxycinnamate possessed anti-platelet aggregation activity in vitro. Among them, piplartine showed the most potent anti-platelet aggregation activity induced by collagen and showed an IC50 value of 21.5 μM. Piperarborenines A - E, piperarborenine, aristololactam BIII and goniothalactam showed significant cytotoxic activity (IC50 values < 4 μg/mL) against P-388, HT-29 and A549 cell lines in vitro.
14 September 2012 in Journal of Agricultural and Food Chemistry
Further study on the chloroform-soluble portion of the root bark of Zanthoxylum schinifolium led to the isolation of eight new coumarins: methylschinilenol (1), hydroxyepoxycollinin I (2), 8-methoxyanisocoumarin H (3), hydroxyschininallylol (4), hydroxyepoxycollinin II (5), schinitrienin (6), schininallylone (7), and isoschinilenol (8), along with twenty-six known compounds including fourteen coumarins, and nine alkaloids. The structural elucidation was determined by spectroscopic data. Among the isolates, terpenyl-coumarins and furoquinolines were the active constituents with antiplatelet aggregation in vitro and collinin (10) showed significant anti-HBC DNA replication activity.
A new tetrahydroprotoberberine N-oxide alkaloid, (-)-cis-isocorypalmine N-oxide (1), together with two known compounds, 6-methoxydihydrosanguinarine (2) and norjuziphine (3), were isolated in continuing studies of the entire Formosan Corydalis tashiroi plant. The structures of these three compounds were determined through spectral analyses. In addition, compounds 1, 2, 3 and the seven alkaloids previously reported: (-)-cis-corydalmine N-oxide, (-)-trans-corydalmine N-oxide, (-)-trans-isocorypalmine N-oxide, scoulerine, protopine, oxysanguinarine and corydalmine, were found to possess anti-platelet aggregation activity.