Nine alkaloids were isolated from the cold ethanol extract of Piper longum roots, of which six known compounds were identified as cepharadione B, cepharadione A, cepharanone B, aristolactam AII, norcepharadione B, and 2-hydroxy-1-methoxy-4H-dibenzo[de, g]quinoline-4,5(6H)-dione. The three new alkaloids were characterized as 10-amino-4-hydroxy-3-methoxyphenanthrene-l-carboxylic acid lactam [piperolactam A], 10-amino-4-hydroxy-2,3-dimethoxyphenanthrene-l-carboxylic acid lactam [piperolactam B] and 2-hydroxy-1-methoxy-6-methyl-4H-dibenzo[de, g]quinoline-4,5(6H)-dione [piperadione]. © 1988.