Cinnamtannin B-1 is an A-type proanthocyanidin contained in several plant species such as Laurus nobilis L., Vaccinium vitis-idaea, Parameria laevigata, Cinnamomum zeylanicum and Lindera umbellata. Cinnamtannin B-1 is a potent antioxidant and protective agent against oxidative stress and apoptosis in human platelets. Cinnamtannin B-1 is a Cox-2 (cyclooxygenase-2) inhibitor.