10.1021/acs.jnatprod.7b00606.s006 Jia-Qing Cao Jia-Qing Cao Hai-Yan Tian Hai-Yan Tian Man-Mei Li Man-Mei Li Wei Zhang Wei Zhang Ying Wang Ying Wang Lei Wang Lei Wang Wen-Cai Ye Wen-Cai Ye Rearranged Phloroglucinol-Monoterpenoid Adducts from <i>Callistemon rigidus</i> American Chemical Society 2017 biosynthetic precursors isopropylcyclopenta Callistemon rigidus Callisretones biosynthetic pathway viminalins H phloroglucinol-monoterpenoid adducts nitric oxide production X-ray diffraction data 17.7 benzofuran IC 50 values 1.0 Rearranged Phloroglucinol-Monoterpenoid Adducts terpenoid motif rearrangement Callistemon rigidus 15.3 configuration 1.1 callisretone 2017-12-20 18:05:26 Dataset https://acs.figshare.com/articles/dataset/Rearranged_Phloroglucinol-Monoterpenoid_Adducts_from_i_Callistemon_rigidus_i_/5723239 Callisretones A (<b>1</b>) and B (<b>2</b>), two rearranged phloroglucinol-monoterpenoid adducts featuring an unprecedented isopropylcyclopenta­[<i>b</i>]­benzofuran backbone, together with their postulated biosynthetic precursors (<b>3</b>–<b>9</b>), were isolated from <i>Callistemon rigidus</i>. The previously assigned absolute configurations of viminalins H (<b>7</b>), L (<b>8</b>), and N (<b>9</b>) were revised and unequivocally established by X-ray diffraction data. A putative biosynthetic pathway toward callisretones A and B involving the rearrangement of the terpenoid motif is proposed. In addition, <b>1</b> and <b>2</b> showed inhibitory effects on nitric oxide production with IC<sub>50</sub> values of 15.3 ± 1.0 and 17.7 ± 1.1 μM, respectively.