RESUMO
Objective: To study the chemical constituents from Leonurus japonicus Injection. Methods: The constituents were purified by macroporus resin, silica gel, Sephadex LH-20, and recrystallization. The structures were identified by spectroscopic methods and spectroscopic analysis. Results: Fifteen compounds were isolated from L. japonicus Injection, including four amino acids and their derivatives such as N-isobutyl valine (1), valine (2), alanine (3), L-pyroglutamic acid methyl ester (4), nine alkaloids: stachydrine (5), choline (6), trigonelline (7), uracil (8), 5-methyluracil (9), 2', 3'-O-isopropylidene uridine (10), 3-hydroxypyridine (11), 5-hydroxyl-2-hydroxymethylpyridine (12), and 2-methyl-3-hydroxypyridine (13); and two furoic acids such as furan-2- carboxylic acid (14) and 5-hydroxymethyl-2-furancarboxyic acid (15). Conclusion: In addition to compounds 5 and 8, the others are isolated from the plants of Leonurus Linn. for the first time. Among them, compound 1 is a natural product. Its NMR data, undoubtedly assigned by 2D-NMR, have been reported for the first time.