Caldensinic acid, a prenylated benzoic acid from Piper caldense

The CH2Cl2 and MeOH extracts from leaves of Piper caldense were subjected to chromatographic separation procedures to afford the new prenylated benzoic acid, caldensinic acid (3-[(2'E,6'E,10'E)-11'-carboxy-3',7',15'-trimethylhexadeca-2',6',10',14'-tetraenyl]-4,5-dihydroxybenzoic acid) whose structure was determined by spectral analysis, mainly NMR (H-1, C-13, HSQC, HMBC) and ESI-MS. The natural compound and derivatives displayed antifungal activity against the phytopathogenic fungi Cladosporium cladosporioides and C. sphaerospermum by direct bioautography. (C) 2009 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.