Antibacterial Activity of Isolates from Piper longum and Taxus baccata

This study describes the antibacterial activity of the pure isolates from Piper longum (L.) (black pepper) and Taxus baccata (L.) (Yew). Three isolates of black pepper were active against Gram-positive bacteria and moderately active against Gram-negative bacteria. Each isolate was highly active against at least one particular species of bacteria; piperlonguminine (1) against Bacillus subtilis, piperine (2) against Staphylococcus aureus, and pellitorine (3) against Bacillus sphaericus. 3-(3'-4'-5'-Trimethoxyphenyl) propionicacid (4) did not show any antibacterial activity. The isolate (--)-rhododendrol (5) of Taxus baccata (L.) inhibited Salmonella typhimurium and Pseudomonas syringae, while 4-(4'-hydroxyphenyl)-butan-2-one (6) and 4-(4'-hydroxyphenyl)-trans-but-3-en-2-one (7) inhibited Pseudomonas syringae and Bacillus sphaericus. It is therefore evident that all the isolates of Piper longum had antibacterial activity except 3-(3'-4'-5'-trimethoxyphenyl) propionicacid (4), whereas isolates of T. baccata showed moderate activity.