Two New Triterpenes from the Surface Layer of Poria cocos by Chun-Hua Yang a ) b ), Shi-Fang Zhang c ), Wen-Ying Liu b ) d ), Zun-Jian Zhang a ) b ), and Jing-Han Liu* c ) a ) Center of Instrumental Analysis, China Pharmaceutical University, Nanjing 210009, P. R. China b ) Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, China Pharmaceutical University, Nanjing 210009, P.R. China c ) Department of Phytochemistry, China Pharmaceutical University, Nanjing 210009, P. R. China (phone: þ 86-25-8327-1328; fax: þ 86-25-8327-1328; e-mail: liujinghan512@hotmail.com) d ) Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing 210009, P. R. China Two new triterpenes, poricoic acid AE (1) and poricoic acid CE (2), were isolated from the surface layer of the mushroom Poria cocos (Schw.) Wolf, together with four known triterpenes, 3-O- acetyldehydroeburicoic acid, 3-oxolanosta-7,9(11),24(31)-trien-21-oic acid, dehydrotrametenolic acid, and poricoic acid A. The structures of the two new triterpenes were elucidated as 16a-hydroxy-3,4-seco- lanosta-4(28),7,9(11),24(31)-tetraene-3,21-dioic acid-3-ethyl ester (1) and 3,4-secolanosta- 4(28),7,9(11),24(31)-tetraene-3,21-dioic acid-3-ethyl ester (2) mainly on the basis of HR-ESI-MS, EI- MS, and 2D-NMR analyses. Introduction. – The surface layer of Poria cocos (Schw.)W olf, known as Fu-Ling- Pi in Chinese folklore, was recorded in the Pharmacopoeia of P. R. China and used in many famous traditional Chinese prescriptions [1]. Modern phytochemical and pharmacological investigations showed that major active components such as triterpenoids [2] and polysaccharides [3] separated from this fungi had anti- inflammatory [4], antineoplasmic [5], and antiproliferative activities [6]. In this study, we report the isolation and structure determination of six triterpenes from the surface layer of P. cocos . Among them, 1 and 2 were new compounds. Their structures were elucidated on the basis of spectroscopic methods, especially EI-MS and Helvetica Chimica Acta – Vol. 92 (2009) 660  2009 Verlag Helvetica Chimica Acta AG, Zürich