ChemInform Abstract: SYLVONE, A NEW FURANOID LIGNAN OF PIPER SYLVATICUM

New Cytotoxic Cyclobutanoid Amides, a New Furanoid Lignan and Anti-Platelet Aggregation Constituents fromPiper arborescens

“…The UV absorptions were similar to those of sylvone [10] and suggested the presence of a 2,3,4-trisubstituted furanoid lignan skeleton [11]. Compound 4 possessed a hydroxy group (IR: n = 3444 cm ±1 ) and a conjugated carbonyl group (IR: n = 1670 cm ±1 ; 13 C-NMR: d = 198.5).…”

“…Compound 4 possessed a hydroxy group (IR: n = 3444 cm ±1 ) and a conjugated carbonyl group (IR: n = 1670 cm ±1 ; 13 C-NMR: d = 198.5). The 1 H-NMR spectrum of 4 resembled that of sylvone [10], except that 4 had a 2-(3,4,5-trimethoxyphenyl) group in place of the 2-(3,4-trimethoxyphenyl) group in sylvone. The relative stereochemistry of H-2, H-3 was determined as cis-orientation by the smaller coupling constant (J = 6.0 Hz), as in sylvone [10], and further confirmed by the NOESY correlation between H-2 and H-3 (Fig.…”

Lignans

“…Furthermore, neolignans of different carbon-skeletons (e.g. 10,11,12) clearly belong to different biogenetic types and it would be misleading indeed to consider them in the At this stage, the inclusion of the C 6 -Crdimers in their putative biogenetic class is much more important than a decision concerning the lignan/neolignan controversy. All three are clearly derived from identical propenylphenol (ISa) plus allylphenol (ISb) precursors, and occur together in the same or in related plant species.…”