Pleonotoquinones, Cytotoxic Oxepinenaphthoquinones from Pleonotoma jasminifolia .
Leandro T AnselmoThalisson A de SouzaThiago A M BritoEldrinei Gomes PeresFelipe M A da SilvaValdenizia R SilvaLuciano de S SantosMilena B P SoaresDaniel Pereira BezerraEmmanoel Vilaça CostaVictor M SipoloniLívia Soman de Medeiros MedeirosMarcelo S da SilvaJosean Fechine TavaresWaldireny R GomesHector Henrique Ferreira KoolenPublished in: Journal of natural products (2024)
Two unusual naphthoquinones, named here as pleonotoquinones A ( 1 ) and B ( 2 ), were isolated along with two known anthraquinones ( 3 and 4 ) via chromatographic separations of an ethyl acetate extract of the roots of Pleonotoma jasminifolia . Compounds 1 and 2 are the first examples of quinones bearing a 2-methyloxepine moiety. The compounds were isolated with the aid of mass spectrometry and molecular networking, and their structures were resolved using 1D and 2D NMR and HRESIMS data. The isolated compounds were evaluated for their antiproliferative activity against human cancer cell lines, and compounds 1 and 2 displayed cytotoxicity against human colon cancer HCT116 cells (IC 50 = 2.6 μM for compound 1 and IC 50 = 4.3 μM for compound 2 ) and human liver cancer HepG2 cells (IC 50 = 1.9 μM for compound 1 and IC 50 = 6.4 μM for compound 2 ).