title: 3-Ishwarone, a rare ishwarane sesquiterpene from Peperomia scandens Ruiz & Pavon: structural elucidation through a joint experimental and theoretical study.
abstract: 3-Ishwarone, (1), a sesquiterpene with a rare ishwarane skeleton, was isolated from Peperomia scandens Ruiz & Pavon (Piperaceae). Its structure was unambiguously determined by 1D- and 2D-NMR and infrared analyses, as well as by comparative theoretical studies which involved calculations of 13C-NMR chemical shifts, using the Density Functional Theory (DFT) with the mPW1PW91 hybrid functional and Pople's 6-31G(d) basis set, and of vibrational frequencies, using the B3LYP hybrid functional and triple ζ Dunning's correlation consistent basis set (cc-pVTZ), of (1) and three of its possible diastereomers, compounds 2-4.
authors.affiliation: Núcleo de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil. mbamorim@nppn.ufrj.br.
authors.forename: Fernando M dos S
authors.initials: FM
authors.lastname: Junior
authors.forename: Leosvaldo S M
authors.initials: LS
authors.lastname: Velozo
authors.forename: Erika M
authors.initials: EM
authors.lastname: de Carvalho
authors.forename: André M
authors.initials: AM
authors.lastname: Marques
authors.forename: Ricardo M
authors.initials: RM
authors.lastname: Borges
authors.forename: Ana Paula F
authors.initials: AP
authors.lastname: Trindade
authors.forename: Maria Isabel S
authors.initials: MI
authors.lastname: dos Santos
authors.forename: Ana Carolina F
authors.initials: AC
authors.lastname: de Albuquerque
authors.forename: Fabio L P
authors.initials: FL
authors.lastname: Costa
authors.forename: Maria Auxiliadora C
authors.initials: MA
authors.lastname: Kaplan
authors.forename: Mauro B
authors.initials: MB
authors.lastname: de Amorim
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D036941:Peperomia / Q000737:chemistry*; D012717:Sesquiterpenes / Q000737:chemistry*
chemical_list: D012717:Sesquiterpenes