rimary forest covers about 75% of Papua New Guinea. Every year about 200,000 ha are cleared for commercial operations, including logging, plantations, and subsistence agriculture. The latter mainly takes the form of shifting cultivation. In many parts of the humid lowlands, secondary fallow vegetation is dominated by the shrub Piper aduncum L (see color plate 20). It is not known exactly when a...

Chemical composition and antibacterial activity of Piper lenticellosum C.D.C essential oil collected in EcuadorMaría Eugenia Rondón, Judith Velasco, Xavier Cornejo, Janeth Fernández, Vladimir Morocho

ÐThe essential oils from Piper capense, P. nigrum, P. guineense and P. umbellatum from S. Tome e Prõ ncipe were investigated for the ®rst time. They were analysed by GC, GC-mass spectrometry and C NMR. Monoterpene hydrocarbons were the main group of constituents in three of the samples (P. capense, P. nigrum and P. umbellatum), whereas for the other species (P. guineense) phenylpropanoid deri...

The antioxidant properties and effect of essential oil of black pepper (Piper guineense) seeds on α -amylase, α -glucosidase (key enzymes linked to type-2 diabetes), and angiotensin-I converting enzyme (ACE) (key enzyme linked to hypertension) were assessed. The essential oil was obtained by hydrodistillation and dried with anhydrous Na2SO4, and the phenolic content, radical [1,1-diphenyl-2 pic...