A New Ferulic Acid Ester, a New Ellagic Acid Derivative, and Other Constituents from Pachycentria formosana: Effects on Neutrophil Pro- Inflammatory Responses by Jui-Ying Cho a ), Tzong-Huei Lee* a ), Tsong-Long Hwang b ), Sheng-Zehn Yang c ), Ih-Sheng Chen d ), Tsung-Hsien Chou d ), Ping-Jyun Sung e ), and Jih-Jung Chen* f ) a )School of Pharmacy, Taipei Medical University, Taipei 110, Taiwan b )Graduate Institute of Natural Products, Chang Gung University, Taoyuan 333, Taiwan c )Department of Forest Resource, Management and Technology, National Pingtung University of Scienceand Technology, Pingtung 912, Taiwan d )Faculty of Pharmacy, Kaohsiung Medical University, Kaohsiung 807, Taiwan e ) National Museum of Marine Biology and Aquarium, Pingtung 944, Taiwan f )Graduate Institute of Pharmaceutical Technology & Department of Pharmacy, Tajen University, Pingtung 907, Taiwan (phone: þ 886-8-7624002 (ext. 2827); fax: þ 886-8-7624002 (ext. 5121); e-mail: jjchen@mail.tajen.edu.tw) A new ferulic acid ester derivative, tetracosane-1,24-diyl di[( Z)-ferulate] (1) , and a new ellagic acid derivative, 3,4 : 3’,4’-bis(O,O-methylene)ellagic acid (2), have been isolated from leaves and twigs of Pachycentria formosana, together with eight known compounds. Their structures were determined by in- depth spectroscopic and mass-spectrometric analyses. Among the isolated compounds, oleanolic acid (6), ursolic acid acetate (7) , and 3-epibetulinic acid (9) exhibited potent inhibition ( IC 50 values  21.8 mm) of O . 2 generation by human neutrophils in response to N-formyl-l-methionyl-l-leucyl-l-phenylalanine/ cytochalasin B (fMLP/CB). In addition, oleanolic acid (6), 3-O-[( E)-feruloyl]ursolic acid (8), 3- epibetulinic acid (9), and lawsonic acid (10) also inhibited fMLP/CB-induced elastase release with IC 50 values  18.6 mm. Introduction. – Pachycentria formosana Hayata (Melastomataceae) is an endemic creeping shrub distributed in 300– 2100-m forests throughout Taiwan [1]. Various tannins [2] [3], flavonoids [4 – 6], and triterpenoids [7] [8] are widely distributed in plants of the family Melastomataceae. Many of these compounds exhibit antioxidant [2][4], anti-inflammatory [3], cytotoxic [4][7], antifungal [5], antiprotozoal [6], and antimicrobial [8] activities. In our studies of Formosan plants for in vitro anti-inflammatory activity, P. formosana was found to be an active species. Investigation on the CH 2 Cl 2 -soluble fraction of the leaves and twigs of P. formosana led to the isolation of a new ferulic acid ester, tetracosane-1,24-diyl di-[( Z)-ferulate] (1), and a new ellagic acid derivative, 3,4 : 3’,4’-bis(O,O-methylene)ellagic acid (2), along with eight known compounds. Here, we describe the structure elucidation of 1 and 2, and the inhibitory activity of the isolates on superoxide generation and elastase release by neutrophils. Results and Discussion. – Structure Elucidation. Extensive chromatographic purification of the CH 2 Cl 2 -soluble fraction of the MeOH extract of leaves and twigs of P. formosana on a silica-gel column and preparative TLC afforded two new, 1 and 2, CHEMISTRY & BIODIVERSITY – Vol. 8 (2011) 1709  2011 Verlag Helvetica Chimica Acta AG, Zürich