Acetyl-11-keto-β-boswellic acid (AKBA): structure requirements for binding and 5-lipoxygenase inhibitory activity. - Sailer ,E-R,.; Subramanian ,L.R,.; Rall ,B,.; Hoernlein ,R.F,.; Ammon ,H.PT,.; Safayhi ,H.. (Br. J. Pharmacol., 1996)