guineensine and piperine

The insecticidal activity of Piper nigrum fruit-derived piperidine alkaloid (piperine) and N-isobutylamide alkaloids (pellitorine, guineensine, pipercide and retrofractamide A) against female adults of Culex pipiens pallens and Aedes aegypti was examined. On the basis of 24-h LD(50) values, the compound most toxic to female C. pipiens pallens was pellitorine (0.4 µg/♀) followed by guineensine (1.9 µg/♀), retrofractamide A (2.4 µg/♀) and pipercide (3.2 µg/♀). LD(50) value of chlorpyrifos was 0.03 µg/♀. Against female A. aegypti, the insecticidal activity was more pronounced in pellitorine (0.17 µg/♀) than in retrofractamide A (1.5 µg/♀), guineensine (1.7 µg/♀), and pipercide (2.0 µg/♀). LD(50) value of chlorpyrifos was 0.0014 µg/♀.

Topics: Aedes; Alkaloids; Alkenes; Amides; Animals; Benzodioxoles; Culex; Fatty Acids, Unsaturated; Female; Heterocyclic Compounds, 2-Ring; Insecticides; Male; Piper nigrum; Piperidines; Polyunsaturated Alkamides

The methanolic extract from the fruit of Piper chaba (Piperaceae) was found to have a hepatoprotective effect on D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced liver injury in mice. From the ethyl acetate-soluble fraction, a new amide constituent named piperchabamide E together with twenty known amide constituents (e.g., piperine, piperchabamides A-D, and piperanine) and two aromatic constituents were isolated as the hepatoprotective constituents. With regard to structure-activity relationships, the amide moiety and the 1,9-decadiene structure between the benzene ring and amide moiety were suggested to be important for strong inhibition of D-GalN/tumor necrosis factor-alpha (TNF-alpha)-induced death of hepatocytes. Furthermore, a principal amide constituent, piperine, dose-dependently inhibited increase in serum GPT and GOT levels at doses of 2.5-10 mg/kg (p.o.) in D-GalN/LPS-treated mice, and this inhibitory effect was suggested to depend on the reduced sensitivity of hepatocytes to TNF-alpha.

Topics: Alanine Transaminase; Alkaloids; Amides; Animals; Aspartate Aminotransferases; Benzodioxoles; Cell Death; Chromatography, High Pressure Liquid; Fruit; Galactosamine; Hepatocytes; Lipopolysaccharides; Liver; Liver Diseases; Male; Mice; Mice, Mutant Strains; Molecular Structure; Piperaceae; Piperidines; Plant Extracts; Polyunsaturated Alkamides; Structure-Activity Relationship; Tumor Necrosis Factor-alpha