β-Boswellic acid, acetyl-β-boswellic acid, acetyl-11-keto-β-boswellic adid & 11-keto-β-boswellic acid, four pentacyclic triterpene acids from the resin of Boswellia serrata - Pardhy ,R.S,.; Bhattacharyya ,S.C.. (Roxb. Ind. J. Chem., 1978)