Open AccessPsiguajadials A–K: Unusual Psidium Meroterpenoids as Phosphodiesterase-4 Inhibitors from the Leaves of Psidium guajava
Author(s) -
GuiHua Tang,
Zhen Dong,
Yingjie Guo,
Zhongbin Cheng,
ChuJun Zhou,
Sheng Yin
Publication year - 2017
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/s41598-017-01028-4
Subject(s) - psidium , bioassay , chemistry , phosphodiesterase , phloroglucinol , stereochemistry , biology , enzyme , biochemistry , botany , organic chemistry , genetics
Bioassay-guided fractionation of the ethanolic extract of the leaves of Psidium guajava led to the isolation of 11 new Psidium meroterpenoids, psiguajadials A–K ( 1 – 11 ), along with 17 known ones ( 12 – 28 ). Their structures and absolute configurations were elucidated by spectroscopic methods and comparison of experimental and calculated ECD. Compounds 1 and 2 represent two unprecedented skeletons of 3,5-diformyl-benzyl phloroglucinol-coupled sesquiterpenoid, while 3 is the first example of Psidium meroterpenoids coupling via an oxepane ring. Putative biosynthetic pathways towards 1 and 2 are proposed. Compounds 1 – 13 and 16 – 26 exhibited moderate inhibitory activities against phosphodiesterase-4 (PDE4), a drug target for asthma and chronic obstructive pulmonary disease, with IC 50 values in the range of 1.34–7.26 μ M.