np7b00606_si_006.cif (349.99 kB)

Rearranged Phloroglucinol-Monoterpenoid Adducts from Callistemon rigidus

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posted on 20.12.2017 by Jia-Qing Cao, Hai-Yan Tian, Man-Mei Li, Wei Zhang, Ying Wang, Lei Wang, Wen-Cai Ye
Callisretones A (1) and B (2), two rearranged phloroglucinol-monoterpenoid adducts featuring an unprecedented isopropylcyclopenta­[b]­benzofuran backbone, together with their postulated biosynthetic precursors (39), were isolated from Callistemon rigidus. The previously assigned absolute configurations of viminalins H (7), L (8), and N (9) 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, 1 and 2 showed inhibitory effects on nitric oxide production with IC50 values of 15.3 ± 1.0 and 17.7 ± 1.1 μM, respectively.