J. Orjala et al., GIBBILIMBOLS A-D, CYTOTOXIC AND ANTIBACTERIAL ALKENYLPHENOLS FROM PIPER GIBBILIMBUM, Journal of natural products, 61(7), 1998, pp. 939-941
Fractionation of the petroleum ether extract from the leaves of Piper
gibbilimbum collected in Papua New Guinea afforded four new alkenylphe
nols, gibbilimbols A-D (1-4). The structures of the isolates were eluc
idated by spectroscopic methods, mainly 1D- and 2D-NMR spectroscopy. G
ibbilimbols A-D were found to he toxic to brine shrimp with an LC50 of
approximately 5 mu g/mL. Gibbilimbols A-D were further found to be cy
totoxic toward KB nasopharyngal carcinoma cells (ED50 7.8-2.1 mu g/mL)
. All isolates also showed antibacterial activity toward Staphylococcu
s epidermidis and Bacillus cereus.