neo-Clerodane diterpenes from Ajuga ciliata and their inhibitory activities on LPS-induced NO production

Two new neo-clerodane diterpenes, (12S)-6 alpha-acetoxy-4 alpha, 18-epoxy-12-hydroxy-19-tigloyloxy-neo-clerod-13-en-15,16-olide (1) and 6 alpha,18-diacetoxy-4 alpha-hydroxy-19-tigloyloxy-neo-clerod-13-en-15,16-olide (2), along with three known analogs (3-5) have been isolated from the whole plants of Ajuga ciliata Bunge. Their structures were elucidated on the basis of spectroscopic data analyses (IR, ESI-MS, HR-ESI-MS, HMQC, HMBC, COSY, and NOESY). The inhibitory activities on LPS-induced NO production of these diterpenes were evaluated and compounds 1 and 5 showed inhibitory effects. (C) 2012 Phytochemical Society of Europe. Published by Elsevier B. V. All rights reserved.