Celamonols A–D, four triterpenoid and catechin conjugates with immunosuppressive activities from the stems of Celastrus monospermus

Abstract

Celamonols A–D (1–4), featuring an unusual pattern of conjunction between a 24,29-dinorfriedelane-type triterpenoid and a catechin, were isolated from the stems of Celastrus monospermus. Their structures were elucidated by extensive spectroscopic analyses, modified Mosher's method, and ECD calculations. Compounds 1 and 4 exhibited moderate activities against the proliferation of B lymphocytes with IC₅₀ values of 1.46 and 1.35 μM, respectively.