Piqueria trinervia monoterpenes

Pioneering plants of disturbed habitats often produce active monoterpenes. (+ )-Pulegone (29) was four times, and (-1-)- and ( —)-camphor two times more toxic to seeds and seedlings of Raphanus sativus (Brassicaceae) than HCN (Asplund, 1968). The Mexican plant Piqueria trinervia (As-teraceae) produced monoterpene diols, piquerol A (82) and B (83), that strongly inhibited root and stem growth of competing plants at 50-200 ppm. 

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