Synthesis and biological evaluation of quinic acid derivatives as anti-inflammatory agents
作者:Kui Zeng、Karin Emmons Thompson、Charles R. Yates、Duane D. Miller
DOI:10.1016/j.bmcl.2009.07.096
日期:2009.9
Quinic acid (QA) esters found in hot water extracts of Uncaria tomentosa (a.k.a. cat's claw) exert anti-inflammatory activity through mechanisms involving inhibition of the pro-inflammatory transcription factor nuclear factor kappa B (NF-kappa B). Herein, we describe the synthesis and biological testing of novel QA derivatives. Inhibition of NF-kappa B was assessed using A549 (Type 11 alveolar epithelial-like) cells that stably express a secreted alkaline phosphatase (SEAP) reporter driven by an NF-kappa B response element. A549-NF-kappa B cells were stimulated with TNF-alpha (10 ng/mL) in the presence or absence of QA derivative for 18 hours followed by measurement of SEAP activity. Amide substitution at the carboxylic acid position yielded potent inhibitors of NF-kappa B. A variety of modifications to the amide substitution were tolerated with the N-propyl amide derivative being the most potent. Further examination of the SAR demonstrated that acetylation of the hydroxyl groups reduced NF-kappa B inhibitory activity. QA amide derivatives lacked anti-oxidant activity and were found to be neither anti-proliferative nor cytotoxic at concentrations up to 100 mu M. In conclusion, we have discovered a novel series of non-toxic QA amides that potently inhibit NF-kappa B, despite their lack of anti-oxidant activity. Mechanistic studies and pre-clinical efficacy studies in various inflammatory animal models are on-going. (C) 2009 Elsevier Ltd. All rights reserved.