Two new N-acetyldopamine tetrapolymers from periostracum Cicadae.

Two new N-acetyldopamine tetrapolymers, cicadamide A (1) and cicadamide B (2), were isolated from periostracum Cicadae, and their structures were elucidated as 3-acetylamino-7-(3″-acetylamino-7″-(N-acetyl-2‴-aminoethyl)-1″,4″-benzodioxan-2″-yl)-2-(2'-(3″″,4″″-dihydroxyphenyl)-3'-acetylamino-1',4'-benzodioxan-7'-yl)-1,4-benzodioxane (1) and 3-acetylamino-7-(3″-acetylamino-6″-(N-acetyl-2‴-aminoethyl)-1″,4″-benzodioxan-2″-yl)-2-(2'-(3″″,4″″-dihydroxyphenyl)-3'-acetylamino-1',4'-benzodioxan-7'-yl)-1,4-benzodioxane (2), by the combined analysis of 1D NMR and 2D NMR, and mass spectrometry. Pharmacological investigation on two compounds obtained in this study showed that part of them had anti-inflammatory activities.