Various parts of
Piper obliquum Ruíz & Pavon yielded the new alkenylphenols obliquol A (
1) and obliquol B (
2), the new 4-chromanone
3 together with the known compounds
4 and
5. A synthesis of obliquol B (
2) was developed in order to confirm its structure and to provide sufficient amounts for biological testing. Compounds
1 and
2 have antibacterial activity comparable to that of ampicillin,
2 in addition possesses potent anti-NF-κB activity by targeting early events in the TNF
-induced NF-κB inflammatory pathway, which may explain the effects reported for the traditional use of the plant.