Unique Coordination Mode of Potassium Ions to Glycyrrhizin:X-ray Crystal Structure of Glycyrrhizin Dipotassium Salt (2009) 【2009】 Yasuko In, Masaru Uchida, Masamichi Watanabe, Norio Aimi, and Toshimasa IshidaOsaka University of Pharmaceutical Sciences, Tokiwa Phytochemical Co., Ltd, Chiba UniversityChemistry Letters Vol.38, No.11