Chemical constituents from Piper boehmeriifolium (Miq.) Wall. ex C. DC

The chemical investigation of whole plants Piper boehmeriifolium (Miq.) Wall. ex C. DC. led to the isolation of 22 compounds, including two lignans (1-2), sixteen amide alkaloids (3-18), one diterpene (19), two monoterpenes (20-21), and one phenylpropanoid (22). Their structures were elucidated by extensive spectroscopic analyses including NMR, MS, and by comparison with the literature. Compounds 1-2, 6-7, 11-12, 14, and 17-22 were firstly isolated from P. boehmeriifolium, while compounds 2, and 19-20 were isolated from Piper genus for the first time. The chemotaxonomic significance of these isolated compounds is discussed.